Hi all: This is an updated version of kernel support for vDPA device. Various changes were made based on the feedback since last verion. One major change is to drop the sysfs API and leave the management interface for future development, and introudce the incremental DMA bus operations. Please see changelog for more information. The work on vhost, IFCVF (intel VF driver for vDPA) and qemu is ongoing. Please provide feedback. Thanks Change from V1: - drop sysfs API, leave the management interface to future development (Michael) - introduce incremental DMA ops (dma_map/dma_unmap) (Michael) - introduce dma_device and use it instead of parent device for doing IOMMU or DMA from bus driver (Michael, Jason, Ling Shan, Tiwei) - accept parent device and dma device when register vdpa device - coding style and compile fixes (Randy) - using vdpa_xxx instead of xxx_vdpa (Jason) - ove vDPA accessors to header and make it static inline (Jason) - split vdp_register_device() into two helpers vdpa_init_device() and vdpa_register_device() which allows intermediate step to be done (Jason) - warn on invalidate queue state when fail to creating virtqueue (Jason) - make to_virtio_vdpa_device() static (Jason) - use kmalloc/kfree instead of devres for virtio vdpa device (Jason) - avoid using cast in vdpa bus function (Jason) - introduce module_vdpa_driver and fix module refcnt (Jason) - fix returning freed address in vdapsim coherent DMA addr allocation (Dan) - various other fixes and tweaks V1: https://lkml.org/lkml/2020/1/16/353 Jason Wang (5): vhost: factor out IOTLB vringh: IOTLB support vDPA: introduce vDPA bus virtio: introduce a vDPA based transport vdpasim: vDPA device simulator MAINTAINERS | 2 + drivers/vhost/Kconfig | 7 + drivers/vhost/Kconfig.vringh | 1 + drivers/vhost/Makefile | 2 + drivers/vhost/net.c | 2 +- drivers/vhost/vhost.c | 221 ++++------- drivers/vhost/vhost.h | 36 +- drivers/vhost/vhost_iotlb.c | 171 +++++++++ drivers/vhost/vringh.c | 421 ++++++++++++++++++-- drivers/virtio/Kconfig | 15 + drivers/virtio/Makefile | 2 + drivers/virtio/vdpa/Kconfig | 26 ++ drivers/virtio/vdpa/Makefile | 3 + drivers/virtio/vdpa/vdpa.c | 160 ++++++++ drivers/virtio/vdpa/vdpa_sim.c | 678 +++++++++++++++++++++++++++++++++ drivers/virtio/virtio_vdpa.c | 392 +++++++++++++++++++ include/linux/vdpa.h | 233 +++++++++++ include/linux/vhost_iotlb.h | 45 +++ include/linux/vringh.h | 36 ++ 19 files changed, 2249 insertions(+), 204 deletions(-) create mode 100644 drivers/vhost/vhost_iotlb.c create mode 100644 drivers/virtio/vdpa/Kconfig create mode 100644 drivers/virtio/vdpa/Makefile create mode 100644 drivers/virtio/vdpa/vdpa.c create mode 100644 drivers/virtio/vdpa/vdpa_sim.c create mode 100644 drivers/virtio/virtio_vdpa.c create mode 100644 include/linux/vdpa.h create mode 100644 include/linux/vhost_iotlb.h -- 2.19.1
This patch factors out IOTLB into a dedicated module in order to be
reused by other modules like vringh. User may choose to enable the
automatic retiring by specifying VHOST_IOTLB_FLAG_RETIRE flag to fit
for the case of vhost device IOTLB implementation.
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
MAINTAINERS | 1 +
drivers/vhost/Kconfig | 7 ++
drivers/vhost/Makefile | 2 +
drivers/vhost/net.c | 2 +-
drivers/vhost/vhost.c | 221 +++++++++++-------------------------
drivers/vhost/vhost.h | 36 ++----
drivers/vhost/vhost_iotlb.c | 171 ++++++++++++++++++++++++++++
include/linux/vhost_iotlb.h | 45 ++++++++
8 files changed, 304 insertions(+), 181 deletions(-)
create mode 100644 drivers/vhost/vhost_iotlb.c
create mode 100644 include/linux/vhost_iotlb.h
diff --git a/MAINTAINERS b/MAINTAINERS
index 2549f10eb0b1..d4bda9c900fa 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -17607,6 +17607,7 @@ T: git
git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git
S: Maintained
F: drivers/vhost/
F: include/uapi/linux/vhost.h
+F: include/linux/vhost_iotlb.h
VIRTIO INPUT DRIVER
M: Gerd Hoffmann <kraxel at redhat.com>
diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig
index 3d03ccbd1adc..eef634ff9a6e 100644
--- a/drivers/vhost/Kconfig
+++ b/drivers/vhost/Kconfig
@@ -36,6 +36,7 @@ config VHOST_VSOCK
config VHOST
tristate
+ select VHOST_IOTLB
---help---
This option is selected by any driver which needs to access
the core of vhost.
@@ -54,3 +55,9 @@ config VHOST_CROSS_ENDIAN_LEGACY
adds some overhead, it is disabled by default.
If unsure, say "N".
+
+config VHOST_IOTLB
+ tristate
+ default m
+ help
+ Generic IOTLB implementation for vhost and vringh.
diff --git a/drivers/vhost/Makefile b/drivers/vhost/Makefile
index 6c6df24f770c..df99756fbb26 100644
--- a/drivers/vhost/Makefile
+++ b/drivers/vhost/Makefile
@@ -11,3 +11,5 @@ vhost_vsock-y := vsock.o
obj-$(CONFIG_VHOST_RING) += vringh.o
obj-$(CONFIG_VHOST) += vhost.o
+
+obj-$(CONFIG_VHOST_IOTLB) += vhost_iotlb.o
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index e158159671fa..e4a20d7a2921 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -1594,7 +1594,7 @@ static long vhost_net_reset_owner(struct vhost_net *n)
struct socket *tx_sock = NULL;
struct socket *rx_sock = NULL;
long err;
- struct vhost_umem *umem;
+ struct vhost_iotlb *umem;
mutex_lock(&n->dev.mutex);
err = vhost_dev_check_owner(&n->dev);
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index f44340b41494..9059b95cac83 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -50,10 +50,6 @@ enum {
#define vhost_used_event(vq) ((__virtio16 __user
*)&vq->avail->ring[vq->num])
#define vhost_avail_event(vq) ((__virtio16 __user
*)&vq->used->ring[vq->num])
-INTERVAL_TREE_DEFINE(struct vhost_umem_node,
- rb, __u64, __subtree_last,
- START, LAST, static inline, vhost_umem_interval_tree);
-
#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
static void vhost_disable_cross_endian(struct vhost_virtqueue *vq)
{
@@ -581,21 +577,25 @@ long vhost_dev_set_owner(struct vhost_dev *dev)
}
EXPORT_SYMBOL_GPL(vhost_dev_set_owner);
-struct vhost_umem *vhost_dev_reset_owner_prepare(void)
+static struct vhost_iotlb *iotlb_alloc(void)
+{
+ return vhost_iotlb_alloc(max_iotlb_entries,
+ VHOST_IOTLB_FLAG_RETIRE);
+}
+
+struct vhost_iotlb *vhost_dev_reset_owner_prepare(void)
{
- return kvzalloc(sizeof(struct vhost_umem), GFP_KERNEL);
+ return iotlb_alloc();
}
EXPORT_SYMBOL_GPL(vhost_dev_reset_owner_prepare);
/* Caller should have device mutex */
-void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_umem *umem)
+void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_iotlb *umem)
{
int i;
vhost_dev_cleanup(dev);
- /* Restore memory to default empty mapping. */
- INIT_LIST_HEAD(&umem->umem_list);
dev->umem = umem;
/* We don't need VQ locks below since vhost_dev_cleanup makes sure
* VQs aren't running.
@@ -618,28 +618,6 @@ void vhost_dev_stop(struct vhost_dev *dev)
}
EXPORT_SYMBOL_GPL(vhost_dev_stop);
-static void vhost_umem_free(struct vhost_umem *umem,
- struct vhost_umem_node *node)
-{
- vhost_umem_interval_tree_remove(node, &umem->umem_tree);
- list_del(&node->link);
- kfree(node);
- umem->numem--;
-}
-
-static void vhost_umem_clean(struct vhost_umem *umem)
-{
- struct vhost_umem_node *node, *tmp;
-
- if (!umem)
- return;
-
- list_for_each_entry_safe(node, tmp, &umem->umem_list, link)
- vhost_umem_free(umem, node);
-
- kvfree(umem);
-}
-
static void vhost_clear_msg(struct vhost_dev *dev)
{
struct vhost_msg_node *node, *n;
@@ -677,9 +655,9 @@ void vhost_dev_cleanup(struct vhost_dev *dev)
eventfd_ctx_put(dev->log_ctx);
dev->log_ctx = NULL;
/* No one will access memory at this point */
- vhost_umem_clean(dev->umem);
+ vhost_iotlb_free(dev->umem);
dev->umem = NULL;
- vhost_umem_clean(dev->iotlb);
+ vhost_iotlb_free(dev->iotlb);
dev->iotlb = NULL;
vhost_clear_msg(dev);
wake_up_interruptible_poll(&dev->wait, EPOLLIN | EPOLLRDNORM);
@@ -715,27 +693,26 @@ static bool vhost_overflow(u64 uaddr, u64 size)
}
/* Caller should have vq mutex and device mutex. */
-static bool vq_memory_access_ok(void __user *log_base, struct vhost_umem *umem,
+static bool vq_memory_access_ok(void __user *log_base, struct vhost_iotlb
*umem,
int log_all)
{
- struct vhost_umem_node *node;
+ struct vhost_iotlb_map *map;
if (!umem)
return false;
- list_for_each_entry(node, &umem->umem_list, link) {
- unsigned long a = node->userspace_addr;
+ list_for_each_entry(map, &umem->list, link) {
+ unsigned long a = map->addr;
- if (vhost_overflow(node->userspace_addr, node->size))
+ if (vhost_overflow(map->addr, map->size))
return false;
- if (!access_ok((void __user *)a,
- node->size))
+ if (!access_ok((void __user *)a, map->size))
return false;
else if (log_all && !log_access_ok(log_base,
- node->start,
- node->size))
+ map->start,
+ map->size))
return false;
}
return true;
@@ -745,17 +722,17 @@ static inline void __user *vhost_vq_meta_fetch(struct
vhost_virtqueue *vq,
u64 addr, unsigned int size,
int type)
{
- const struct vhost_umem_node *node = vq->meta_iotlb[type];
+ const struct vhost_iotlb_map *map = vq->meta_iotlb[type];
- if (!node)
+ if (!map)
return NULL;
- return (void *)(uintptr_t)(node->userspace_addr + addr - node->start);
+ return (void *)(uintptr_t)(map->addr + addr - map->start);
}
/* Can we switch to this memory table? */
/* Caller should have device mutex but not vq mutex */
-static bool memory_access_ok(struct vhost_dev *d, struct vhost_umem *umem,
+static bool memory_access_ok(struct vhost_dev *d, struct vhost_iotlb *umem,
int log_all)
{
int i;
@@ -1020,47 +997,6 @@ static inline int vhost_get_desc(struct vhost_virtqueue
*vq,
return vhost_copy_from_user(vq, desc, vq->desc + idx, sizeof(*desc));
}
-static int vhost_new_umem_range(struct vhost_umem *umem,
- u64 start, u64 size, u64 end,
- u64 userspace_addr, int perm)
-{
- struct vhost_umem_node *tmp, *node;
-
- if (!size)
- return -EFAULT;
-
- node = kmalloc(sizeof(*node), GFP_ATOMIC);
- if (!node)
- return -ENOMEM;
-
- if (umem->numem == max_iotlb_entries) {
- tmp = list_first_entry(&umem->umem_list, typeof(*tmp), link);
- vhost_umem_free(umem, tmp);
- }
-
- node->start = start;
- node->size = size;
- node->last = end;
- node->userspace_addr = userspace_addr;
- node->perm = perm;
- INIT_LIST_HEAD(&node->link);
- list_add_tail(&node->link, &umem->umem_list);
- vhost_umem_interval_tree_insert(node, &umem->umem_tree);
- umem->numem++;
-
- return 0;
-}
-
-static void vhost_del_umem_range(struct vhost_umem *umem,
- u64 start, u64 end)
-{
- struct vhost_umem_node *node;
-
- while ((node = vhost_umem_interval_tree_iter_first(&umem->umem_tree,
- start, end)))
- vhost_umem_free(umem, node);
-}
-
static void vhost_iotlb_notify_vq(struct vhost_dev *d,
struct vhost_iotlb_msg *msg)
{
@@ -1117,9 +1053,9 @@ static int vhost_process_iotlb_msg(struct vhost_dev *dev,
break;
}
vhost_vq_meta_reset(dev);
- if (vhost_new_umem_range(dev->iotlb, msg->iova, msg->size,
- msg->iova + msg->size - 1,
- msg->uaddr, msg->perm)) {
+ if (vhost_iotlb_add_range(dev->iotlb, msg->iova,
+ msg->iova + msg->size - 1,
+ msg->uaddr, msg->perm)) {
ret = -ENOMEM;
break;
}
@@ -1131,8 +1067,8 @@ static int vhost_process_iotlb_msg(struct vhost_dev *dev,
break;
}
vhost_vq_meta_reset(dev);
- vhost_del_umem_range(dev->iotlb, msg->iova,
- msg->iova + msg->size - 1);
+ vhost_iotlb_del_range(dev->iotlb, msg->iova,
+ msg->iova + msg->size - 1);
break;
default:
ret = -EINVAL;
@@ -1311,44 +1247,42 @@ static bool vq_access_ok(struct vhost_virtqueue *vq,
unsigned int num,
}
static void vhost_vq_meta_update(struct vhost_virtqueue *vq,
- const struct vhost_umem_node *node,
+ const struct vhost_iotlb_map *map,
int type)
{
int access = (type == VHOST_ADDR_USED) ?
VHOST_ACCESS_WO : VHOST_ACCESS_RO;
- if (likely(node->perm & access))
- vq->meta_iotlb[type] = node;
+ if (likely(map->perm & access))
+ vq->meta_iotlb[type] = map;
}
static bool iotlb_access_ok(struct vhost_virtqueue *vq,
int access, u64 addr, u64 len, int type)
{
- const struct vhost_umem_node *node;
- struct vhost_umem *umem = vq->iotlb;
+ const struct vhost_iotlb_map *map;
+ struct vhost_iotlb *umem = vq->iotlb;
u64 s = 0, size, orig_addr = addr, last = addr + len - 1;
if (vhost_vq_meta_fetch(vq, addr, len, type))
return true;
while (len > s) {
- node = vhost_umem_interval_tree_iter_first(&umem->umem_tree,
- addr,
- last);
- if (node == NULL || node->start > addr) {
+ map = vhost_iotlb_itree_first(umem, addr, last);
+ if (map == NULL || map->start > addr) {
vhost_iotlb_miss(vq, addr, access);
return false;
- } else if (!(node->perm & access)) {
+ } else if (!(map->perm & access)) {
/* Report the possible access violation by
* request another translation from userspace.
*/
return false;
}
- size = node->size - addr + node->start;
+ size = map->size - addr + map->start;
if (orig_addr == addr && size >= len)
- vhost_vq_meta_update(vq, node, type);
+ vhost_vq_meta_update(vq, map, type);
s += size;
addr += size;
@@ -1364,12 +1298,12 @@ int vq_meta_prefetch(struct vhost_virtqueue *vq)
if (!vq->iotlb)
return 1;
- return iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->desc,
+ return iotlb_access_ok(vq, VHOST_MAP_RO, (u64)(uintptr_t)vq->desc,
vhost_get_desc_size(vq, num), VHOST_ADDR_DESC) &&
- iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->avail,
+ iotlb_access_ok(vq, VHOST_MAP_RO, (u64)(uintptr_t)vq->avail,
vhost_get_avail_size(vq, num),
VHOST_ADDR_AVAIL) &&
- iotlb_access_ok(vq, VHOST_ACCESS_WO, (u64)(uintptr_t)vq->used,
+ iotlb_access_ok(vq, VHOST_MAP_WO, (u64)(uintptr_t)vq->used,
vhost_get_used_size(vq, num), VHOST_ADDR_USED);
}
EXPORT_SYMBOL_GPL(vq_meta_prefetch);
@@ -1408,25 +1342,11 @@ bool vhost_vq_access_ok(struct vhost_virtqueue *vq)
}
EXPORT_SYMBOL_GPL(vhost_vq_access_ok);
-static struct vhost_umem *vhost_umem_alloc(void)
-{
- struct vhost_umem *umem = kvzalloc(sizeof(*umem), GFP_KERNEL);
-
- if (!umem)
- return NULL;
-
- umem->umem_tree = RB_ROOT_CACHED;
- umem->numem = 0;
- INIT_LIST_HEAD(&umem->umem_list);
-
- return umem;
-}
-
static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user
*m)
{
struct vhost_memory mem, *newmem;
struct vhost_memory_region *region;
- struct vhost_umem *newumem, *oldumem;
+ struct vhost_iotlb *newumem, *oldumem;
unsigned long size = offsetof(struct vhost_memory, regions);
int i;
@@ -1448,7 +1368,7 @@ static long vhost_set_memory(struct vhost_dev *d, struct
vhost_memory __user *m)
return -EFAULT;
}
- newumem = vhost_umem_alloc();
+ newumem = iotlb_alloc();
if (!newumem) {
kvfree(newmem);
return -ENOMEM;
@@ -1457,13 +1377,12 @@ static long vhost_set_memory(struct vhost_dev *d, struct
vhost_memory __user *m)
for (region = newmem->regions;
region < newmem->regions + mem.nregions;
region++) {
- if (vhost_new_umem_range(newumem,
- region->guest_phys_addr,
- region->memory_size,
- region->guest_phys_addr +
- region->memory_size - 1,
- region->userspace_addr,
- VHOST_ACCESS_RW))
+ if (vhost_iotlb_add_range(newumem,
+ region->guest_phys_addr,
+ region->guest_phys_addr +
+ region->memory_size - 1,
+ region->userspace_addr,
+ VHOST_MAP_RW))
goto err;
}
@@ -1481,11 +1400,11 @@ static long vhost_set_memory(struct vhost_dev *d, struct
vhost_memory __user *m)
}
kvfree(newmem);
- vhost_umem_clean(oldumem);
+ vhost_iotlb_free(oldumem);
return 0;
err:
- vhost_umem_clean(newumem);
+ vhost_iotlb_free(newumem);
kvfree(newmem);
return -EFAULT;
}
@@ -1726,10 +1645,10 @@ EXPORT_SYMBOL_GPL(vhost_vring_ioctl);
int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled)
{
- struct vhost_umem *niotlb, *oiotlb;
+ struct vhost_iotlb *niotlb, *oiotlb;
int i;
- niotlb = vhost_umem_alloc();
+ niotlb = iotlb_alloc();
if (!niotlb)
return -ENOMEM;
@@ -1745,7 +1664,7 @@ int vhost_init_device_iotlb(struct vhost_dev *d, bool
enabled)
mutex_unlock(&vq->mutex);
}
- vhost_umem_clean(oiotlb);
+ vhost_iotlb_free(oiotlb);
return 0;
}
@@ -1875,8 +1794,8 @@ static int log_write(void __user *log_base,
static int log_write_hva(struct vhost_virtqueue *vq, u64 hva, u64 len)
{
- struct vhost_umem *umem = vq->umem;
- struct vhost_umem_node *u;
+ struct vhost_iotlb *umem = vq->umem;
+ struct vhost_iotlb_map *u;
u64 start, end, l, min;
int r;
bool hit = false;
@@ -1886,16 +1805,15 @@ static int log_write_hva(struct vhost_virtqueue *vq, u64
hva, u64 len)
/* More than one GPAs can be mapped into a single HVA. So
* iterate all possible umems here to be safe.
*/
- list_for_each_entry(u, &umem->umem_list, link) {
- if (u->userspace_addr > hva - 1 + len ||
- u->userspace_addr - 1 + u->size < hva)
+ list_for_each_entry(u, &umem->list, link) {
+ if (u->addr > hva - 1 + len ||
+ u->addr - 1 + u->size < hva)
continue;
- start = max(u->userspace_addr, hva);
- end = min(u->userspace_addr - 1 + u->size,
- hva - 1 + len);
+ start = max(u->addr, hva);
+ end = min(u->addr - 1 + u->size, hva - 1 + len);
l = end - start + 1;
r = log_write(vq->log_base,
- u->start + start - u->userspace_addr,
+ u->start + start - u->addr,
l);
if (r < 0)
return r;
@@ -2046,9 +1964,9 @@ EXPORT_SYMBOL_GPL(vhost_vq_init_access);
static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len,
struct iovec iov[], int iov_size, int access)
{
- const struct vhost_umem_node *node;
+ const struct vhost_iotlb_map *map;
struct vhost_dev *dev = vq->dev;
- struct vhost_umem *umem = dev->iotlb ? dev->iotlb : dev->umem;
+ struct vhost_iotlb *umem = dev->iotlb ? dev->iotlb : dev->umem;
struct iovec *_iov;
u64 s = 0;
int ret = 0;
@@ -2060,25 +1978,24 @@ static int translate_desc(struct vhost_virtqueue *vq,
u64 addr, u32 len,
break;
}
- node = vhost_umem_interval_tree_iter_first(&umem->umem_tree,
- addr, addr + len - 1);
- if (node == NULL || node->start > addr) {
+ map = vhost_iotlb_itree_first(umem, addr, addr + len - 1);
+ if (map == NULL || map->start > addr) {
if (umem != dev->iotlb) {
ret = -EFAULT;
break;
}
ret = -EAGAIN;
break;
- } else if (!(node->perm & access)) {
+ } else if (!(map->perm & access)) {
ret = -EPERM;
break;
}
_iov = iov + ret;
- size = node->size - addr + node->start;
+ size = map->size - addr + map->start;
_iov->iov_len = min((u64)len - s, size);
_iov->iov_base = (void __user *)(unsigned long)
- (node->userspace_addr + addr - node->start);
+ (map->addr + addr - map->start);
s += size;
addr += size;
++ret;
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index a123fd70847e..b99c6ffb6be1 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -12,6 +12,7 @@
#include <linux/virtio_config.h>
#include <linux/virtio_ring.h>
#include <linux/atomic.h>
+#include <linux/vhost_iotlb.h>
struct vhost_work;
typedef void (*vhost_work_fn_t)(struct vhost_work *work);
@@ -52,27 +53,6 @@ struct vhost_log {
u64 len;
};
-#define START(node) ((node)->start)
-#define LAST(node) ((node)->last)
-
-struct vhost_umem_node {
- struct rb_node rb;
- struct list_head link;
- __u64 start;
- __u64 last;
- __u64 size;
- __u64 userspace_addr;
- __u32 perm;
- __u32 flags_padding;
- __u64 __subtree_last;
-};
-
-struct vhost_umem {
- struct rb_root_cached umem_tree;
- struct list_head umem_list;
- int numem;
-};
-
enum vhost_uaddr_type {
VHOST_ADDR_DESC = 0,
VHOST_ADDR_AVAIL = 1,
@@ -90,7 +70,7 @@ struct vhost_virtqueue {
struct vring_desc __user *desc;
struct vring_avail __user *avail;
struct vring_used __user *used;
- const struct vhost_umem_node *meta_iotlb[VHOST_NUM_ADDRS];
+ const struct vhost_iotlb_map *meta_iotlb[VHOST_NUM_ADDRS];
struct file *kick;
struct eventfd_ctx *call_ctx;
struct eventfd_ctx *error_ctx;
@@ -128,8 +108,8 @@ struct vhost_virtqueue {
struct iovec *indirect;
struct vring_used_elem *heads;
/* Protected by virtqueue mutex. */
- struct vhost_umem *umem;
- struct vhost_umem *iotlb;
+ struct vhost_iotlb *umem;
+ struct vhost_iotlb *iotlb;
void *private_data;
u64 acked_features;
u64 acked_backend_features;
@@ -164,8 +144,8 @@ struct vhost_dev {
struct eventfd_ctx *log_ctx;
struct llist_head work_list;
struct task_struct *worker;
- struct vhost_umem *umem;
- struct vhost_umem *iotlb;
+ struct vhost_iotlb *umem;
+ struct vhost_iotlb *iotlb;
spinlock_t iotlb_lock;
struct list_head read_list;
struct list_head pending_list;
@@ -182,8 +162,8 @@ void vhost_dev_init(struct vhost_dev *, struct
vhost_virtqueue **vqs,
long vhost_dev_set_owner(struct vhost_dev *dev);
bool vhost_dev_has_owner(struct vhost_dev *dev);
long vhost_dev_check_owner(struct vhost_dev *);
-struct vhost_umem *vhost_dev_reset_owner_prepare(void);
-void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_umem *);
+struct vhost_iotlb *vhost_dev_reset_owner_prepare(void);
+void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_iotlb *iotlb);
void vhost_dev_cleanup(struct vhost_dev *);
void vhost_dev_stop(struct vhost_dev *);
long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user
*argp);
diff --git a/drivers/vhost/vhost_iotlb.c b/drivers/vhost/vhost_iotlb.c
new file mode 100644
index 000000000000..e08710f1690c
--- /dev/null
+++ b/drivers/vhost/vhost_iotlb.c
@@ -0,0 +1,171 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2020 Red Hat, Inc.
+ * Author: Jason Wang <jasowang at redhat.com>
+ *
+ * IOTLB implementation for vhost.
+ */
+#include <linux/slab.h>
+#include <linux/vhost_iotlb.h>
+#include <linux/module.h>
+
+#define MOD_VERSION "0.1"
+#define MOD_DESC "VHOST IOTLB"
+#define MOD_AUTHOR "Jason Wang <jasowang at redhat.com>"
+#define MOD_LICENSE "GPL v2"
+
+#define START(map) ((map)->start)
+#define LAST(map) ((map)->last)
+
+INTERVAL_TREE_DEFINE(struct vhost_iotlb_map,
+ rb, __u64, __subtree_last,
+ START, LAST, static inline, vhost_iotlb_itree);
+
+static void iotlb_map_free(struct vhost_iotlb *iotlb,
+ struct vhost_iotlb_map *map)
+{
+ vhost_iotlb_itree_remove(map, &iotlb->root);
+ list_del(&map->link);
+ kfree(map);
+ iotlb->nmaps--;
+}
+
+/**
+ * vhost_iotlb_add_range - add a new range to vhost IOTLB
+ * @iotlb: the IOTLB
+ * @start: start of the IOVA range
+ * @last: last of IOVA range
+ * @addr: the address that is mapped to @start
+ * @perm: access permission of this range
+ *
+ * Returns an error last is smaller than start or memory allocation
+ * fails
+ */
+int vhost_iotlb_add_range(struct vhost_iotlb *iotlb,
+ u64 start, u64 last,
+ u64 addr, unsigned int perm)
+{
+ struct vhost_iotlb_map *map;
+
+ if (last < start)
+ return -EFAULT;
+
+ if (iotlb->limit &&
+ iotlb->nmaps == iotlb->limit &&
+ iotlb->flags & VHOST_IOTLB_FLAG_RETIRE) {
+ map = list_first_entry(&iotlb->list, typeof(*map), link);
+ iotlb_map_free(iotlb, map);
+ }
+
+ map = kmalloc(sizeof(*map), GFP_ATOMIC);
+ if (!map)
+ return -ENOMEM;
+
+ map->start = start;
+ map->size = last - start + 1;
+ map->last = last;
+ map->addr = addr;
+ map->perm = perm;
+
+ iotlb->nmaps++;
+ vhost_iotlb_itree_insert(map, &iotlb->root);
+
+ INIT_LIST_HEAD(&map->link);
+ list_add_tail(&map->link, &iotlb->list);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vhost_iotlb_add_range);
+
+/**
+ * vring_iotlb_del_range - delete overlapped ranges from vhost IOTLB
+ * @iotlb: the IOTLB
+ * @start: start of the IOVA range
+ * @last: last of IOVA range
+ */
+void vhost_iotlb_del_range(struct vhost_iotlb *iotlb, u64 start, u64 last)
+{
+ struct vhost_iotlb_map *map;
+
+ while ((map = vhost_iotlb_itree_iter_first(&iotlb->root,
+ start, last)))
+ iotlb_map_free(iotlb, map);
+}
+EXPORT_SYMBOL_GPL(vhost_iotlb_del_range);
+
+/**
+ * vhost_iotlb_alloc - add a new vhost IOTLB
+ * @limit: maximum number of IOTLB entries
+ * @flags: VHOST_IOTLB_FLAG_XXX
+ *
+ * Returns an error is memory allocation fails
+ */
+struct vhost_iotlb *vhost_iotlb_alloc(unsigned int limit, unsigned int flags)
+{
+ struct vhost_iotlb *iotlb = kzalloc(sizeof(*iotlb), GFP_KERNEL);
+
+ if (!iotlb)
+ return NULL;
+
+ iotlb->root = RB_ROOT_CACHED;
+ iotlb->limit = limit;
+ iotlb->nmaps = 0;
+ iotlb->flags = flags;
+ INIT_LIST_HEAD(&iotlb->list);
+
+ return iotlb;
+}
+EXPORT_SYMBOL_GPL(vhost_iotlb_alloc);
+
+/**
+ * vhost_iotlb_reset - reset vhost IOTLB (free all IOTLB entries)
+ * @iotlb: the IOTLB to be reset
+ */
+void vhost_iotlb_reset(struct vhost_iotlb *iotlb)
+{
+ vhost_iotlb_del_range(iotlb, 0ULL, 0ULL - 1);
+}
+EXPORT_SYMBOL_GPL(vhost_iotlb_reset);
+
+/**
+ * vhost_iotlb_free - reset and free vhost IOTLB
+ * @iotlb: the IOTLB to be freed
+ */
+void vhost_iotlb_free(struct vhost_iotlb *iotlb)
+{
+ if (iotlb) {
+ vhost_iotlb_reset(iotlb);
+ kfree(iotlb);
+ }
+}
+EXPORT_SYMBOL_GPL(vhost_iotlb_free);
+
+/**
+ * vhost_iotlb_itree_first - return the first overlapped range
+ * @iotlb: the IOTLB
+ * @start: start of IOVA range
+ * @end: end of IOVA range
+ */
+struct vhost_iotlb_map *
+vhost_iotlb_itree_first(struct vhost_iotlb *iotlb, u64 start, u64 last)
+{
+ return vhost_iotlb_itree_iter_first(&iotlb->root, start, last);
+}
+EXPORT_SYMBOL_GPL(vhost_iotlb_itree_first);
+
+/**
+ * vhost_iotlb_itree_first - return the next overlapped range
+ * @iotlb: the IOTLB
+ * @start: start of IOVA range
+ * @end: end of IOVA range
+ */
+struct vhost_iotlb_map *
+vhost_iotlb_itree_next(struct vhost_iotlb_map *map, u64 start, u64 last)
+{
+ return vhost_iotlb_itree_iter_next(map, start, last);
+}
+EXPORT_SYMBOL_GPL(vhost_iotlb_itree_next);
+
+MODULE_VERSION(MOD_VERSION);
+MODULE_DESCRIPTION(MOD_DESC);
+MODULE_AUTHOR(MOD_AUTHOR);
+MODULE_LICENSE(MOD_LICENSE);
diff --git a/include/linux/vhost_iotlb.h b/include/linux/vhost_iotlb.h
new file mode 100644
index 000000000000..a44c61f5627b
--- /dev/null
+++ b/include/linux/vhost_iotlb.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_VHOST_IOTLB_H
+#define _LINUX_VHOST_IOTLB_H
+
+#include <linux/interval_tree_generic.h>
+
+struct vhost_iotlb_map {
+ struct rb_node rb;
+ struct list_head link;
+ u64 start;
+ u64 last;
+ u64 size;
+ u64 addr;
+#define VHOST_MAP_RO 0x1
+#define VHOST_MAP_WO 0x2
+#define VHOST_MAP_RW 0x3
+ u32 perm;
+ u32 flags_padding;
+ u64 __subtree_last;
+};
+
+#define VHOST_IOTLB_FLAG_RETIRE 0x1
+
+struct vhost_iotlb {
+ struct rb_root_cached root;
+ struct list_head list;
+ unsigned int limit;
+ unsigned int nmaps;
+ unsigned int flags;
+};
+
+int vhost_iotlb_add_range(struct vhost_iotlb *iotlb, u64 start, u64 last,
+ u64 addr, unsigned int perm);
+void vhost_iotlb_del_range(struct vhost_iotlb *iotlb, u64 start, u64 last);
+
+struct vhost_iotlb *vhost_iotlb_alloc(unsigned int limit, unsigned int flags);
+void vhost_iotlb_free(struct vhost_iotlb *iotlb);
+void vhost_iotlb_reset(struct vhost_iotlb *iotlb);
+
+struct vhost_iotlb_map *
+vhost_iotlb_itree_first(struct vhost_iotlb *iotlb, u64 start, u64 last);
+struct vhost_iotlb_map *
+vhost_iotlb_itree_next(struct vhost_iotlb_map *map, u64 start, u64 last);
+
+#endif
--
2.19.1
This patch implements the third memory accessor for vringh besides
current kernel and userspace accessors. This idea is to allow vringh
to do the address translation through an IOTLB which is implemented
via vhost_map interval tree. Users should setup and IOVA to PA mapping
in this IOTLB.
This allows us to:
- Using vringh to access virtqueues with vIOMMU
- Using vringh to implement software vDPA devices
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/vhost/Kconfig.vringh | 1 +
drivers/vhost/vringh.c | 421 +++++++++++++++++++++++++++++++++--
include/linux/vringh.h | 36 +++
3 files changed, 435 insertions(+), 23 deletions(-)
diff --git a/drivers/vhost/Kconfig.vringh b/drivers/vhost/Kconfig.vringh
index c1fe36a9b8d4..a8d4dd0cb06e 100644
--- a/drivers/vhost/Kconfig.vringh
+++ b/drivers/vhost/Kconfig.vringh
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
config VHOST_RING
tristate
+ select VHOST_IOTLB
---help---
This option is selected by any driver which needs to access
the host side of a virtio ring.
diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
index a0a2d74967ef..ee0491f579ac 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -13,6 +13,9 @@
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/export.h>
+#include <linux/bvec.h>
+#include <linux/highmem.h>
+#include <linux/vhost_iotlb.h>
#include <uapi/linux/virtio_config.h>
static __printf(1,2) __cold void vringh_bad(const char *fmt, ...)
@@ -71,9 +74,11 @@ static inline int __vringh_get_head(const struct vringh *vrh,
}
/* Copy some bytes to/from the iovec. Returns num copied. */
-static inline ssize_t vringh_iov_xfer(struct vringh_kiov *iov,
+static inline ssize_t vringh_iov_xfer(struct vringh *vrh,
+ struct vringh_kiov *iov,
void *ptr, size_t len,
- int (*xfer)(void *addr, void *ptr,
+ int (*xfer)(const struct vringh *vrh,
+ void *addr, void *ptr,
size_t len))
{
int err, done = 0;
@@ -82,7 +87,7 @@ static inline ssize_t vringh_iov_xfer(struct vringh_kiov *iov,
size_t partlen;
partlen = min(iov->iov[iov->i].iov_len, len);
- err = xfer(iov->iov[iov->i].iov_base, ptr, partlen);
+ err = xfer(vrh, iov->iov[iov->i].iov_base, ptr, partlen);
if (err)
return err;
done += partlen;
@@ -96,6 +101,7 @@ static inline ssize_t vringh_iov_xfer(struct vringh_kiov
*iov,
/* Fix up old iov element then increment. */
iov->iov[iov->i].iov_len = iov->consumed;
iov->iov[iov->i].iov_base -= iov->consumed;
+
iov->consumed = 0;
iov->i++;
@@ -227,7 +233,8 @@ static int slow_copy(struct vringh *vrh, void *dst, const
void *src,
u64 addr,
struct vringh_range *r),
struct vringh_range *range,
- int (*copy)(void *dst, const void *src, size_t len))
+ int (*copy)(const struct vringh *vrh,
+ void *dst, const void *src, size_t len))
{
size_t part, len = sizeof(struct vring_desc);
@@ -241,7 +248,7 @@ static int slow_copy(struct vringh *vrh, void *dst, const
void *src,
if (!rcheck(vrh, addr, &part, range, getrange))
return -EINVAL;
- err = copy(dst, src, part);
+ err = copy(vrh, dst, src, part);
if (err)
return err;
@@ -262,7 +269,8 @@ __vringh_iov(struct vringh *vrh, u16 i,
struct vringh_range *)),
bool (*getrange)(struct vringh *, u64, struct vringh_range *),
gfp_t gfp,
- int (*copy)(void *dst, const void *src, size_t len))
+ int (*copy)(const struct vringh *vrh,
+ void *dst, const void *src, size_t len))
{
int err, count = 0, up_next, desc_max;
struct vring_desc desc, *descs;
@@ -291,7 +299,7 @@ __vringh_iov(struct vringh *vrh, u16 i,
err = slow_copy(vrh, &desc, &descs[i], rcheck, getrange,
&slowrange, copy);
else
- err = copy(&desc, &descs[i], sizeof(desc));
+ err = copy(vrh, &desc, &descs[i], sizeof(desc));
if (unlikely(err))
goto fail;
@@ -404,7 +412,8 @@ static inline int __vringh_complete(struct vringh *vrh,
unsigned int num_used,
int (*putu16)(const struct vringh *vrh,
__virtio16 *p, u16 val),
- int (*putused)(struct vring_used_elem *dst,
+ int (*putused)(const struct vringh *vrh,
+ struct vring_used_elem *dst,
const struct vring_used_elem
*src, unsigned num))
{
@@ -420,12 +429,12 @@ static inline int __vringh_complete(struct vringh *vrh,
/* Compiler knows num_used == 1 sometimes, hence extra check */
if (num_used > 1 && unlikely(off + num_used >=
vrh->vring.num)) {
u16 part = vrh->vring.num - off;
- err = putused(&used_ring->ring[off], used, part);
+ err = putused(vrh, &used_ring->ring[off], used, part);
if (!err)
- err = putused(&used_ring->ring[0], used + part,
+ err = putused(vrh, &used_ring->ring[0], used + part,
num_used - part);
} else
- err = putused(&used_ring->ring[off], used, num_used);
+ err = putused(vrh, &used_ring->ring[off], used, num_used);
if (err) {
vringh_bad("Failed to write %u used entries %u at %p",
@@ -564,13 +573,15 @@ static inline int putu16_user(const struct vringh *vrh,
__virtio16 *p, u16 val)
return put_user(v, (__force __virtio16 __user *)p);
}
-static inline int copydesc_user(void *dst, const void *src, size_t len)
+static inline int copydesc_user(const struct vringh *vrh,
+ void *dst, const void *src, size_t len)
{
return copy_from_user(dst, (__force void __user *)src, len) ?
-EFAULT : 0;
}
-static inline int putused_user(struct vring_used_elem *dst,
+static inline int putused_user(const struct vringh *vrh,
+ struct vring_used_elem *dst,
const struct vring_used_elem *src,
unsigned int num)
{
@@ -578,13 +589,15 @@ static inline int putused_user(struct vring_used_elem
*dst,
sizeof(*dst) * num) ? -EFAULT : 0;
}
-static inline int xfer_from_user(void *src, void *dst, size_t len)
+static inline int xfer_from_user(const struct vringh *vrh, void *src,
+ void *dst, size_t len)
{
return copy_from_user(dst, (__force void __user *)src, len) ?
-EFAULT : 0;
}
-static inline int xfer_to_user(void *dst, void *src, size_t len)
+static inline int xfer_to_user(const struct vringh *vrh,
+ void *dst, void *src, size_t len)
{
return copy_to_user((__force void __user *)dst, src, len) ?
-EFAULT : 0;
@@ -706,7 +719,7 @@ EXPORT_SYMBOL(vringh_getdesc_user);
*/
ssize_t vringh_iov_pull_user(struct vringh_iov *riov, void *dst, size_t len)
{
- return vringh_iov_xfer((struct vringh_kiov *)riov,
+ return vringh_iov_xfer(NULL, (struct vringh_kiov *)riov,
dst, len, xfer_from_user);
}
EXPORT_SYMBOL(vringh_iov_pull_user);
@@ -722,7 +735,7 @@ EXPORT_SYMBOL(vringh_iov_pull_user);
ssize_t vringh_iov_push_user(struct vringh_iov *wiov,
const void *src, size_t len)
{
- return vringh_iov_xfer((struct vringh_kiov *)wiov,
+ return vringh_iov_xfer(NULL, (struct vringh_kiov *)wiov,
(void *)src, len, xfer_to_user);
}
EXPORT_SYMBOL(vringh_iov_push_user);
@@ -832,13 +845,15 @@ static inline int putu16_kern(const struct vringh *vrh,
__virtio16 *p, u16 val)
return 0;
}
-static inline int copydesc_kern(void *dst, const void *src, size_t len)
+static inline int copydesc_kern(const struct vringh *vrh,
+ void *dst, const void *src, size_t len)
{
memcpy(dst, src, len);
return 0;
}
-static inline int putused_kern(struct vring_used_elem *dst,
+static inline int putused_kern(const struct vringh *vrh,
+ struct vring_used_elem *dst,
const struct vring_used_elem *src,
unsigned int num)
{
@@ -846,13 +861,15 @@ static inline int putused_kern(struct vring_used_elem
*dst,
return 0;
}
-static inline int xfer_kern(void *src, void *dst, size_t len)
+static inline int xfer_kern(const struct vringh *vrh, void *src,
+ void *dst, size_t len)
{
memcpy(dst, src, len);
return 0;
}
-static inline int kern_xfer(void *dst, void *src, size_t len)
+static inline int kern_xfer(const struct vringh *vrh, void *dst,
+ void *src, size_t len)
{
memcpy(dst, src, len);
return 0;
@@ -949,7 +966,7 @@ EXPORT_SYMBOL(vringh_getdesc_kern);
*/
ssize_t vringh_iov_pull_kern(struct vringh_kiov *riov, void *dst, size_t len)
{
- return vringh_iov_xfer(riov, dst, len, xfer_kern);
+ return vringh_iov_xfer(NULL, riov, dst, len, xfer_kern);
}
EXPORT_SYMBOL(vringh_iov_pull_kern);
@@ -964,7 +981,7 @@ EXPORT_SYMBOL(vringh_iov_pull_kern);
ssize_t vringh_iov_push_kern(struct vringh_kiov *wiov,
const void *src, size_t len)
{
- return vringh_iov_xfer(wiov, (void *)src, len, kern_xfer);
+ return vringh_iov_xfer(NULL, wiov, (void *)src, len, kern_xfer);
}
EXPORT_SYMBOL(vringh_iov_push_kern);
@@ -1042,4 +1059,362 @@ int vringh_need_notify_kern(struct vringh *vrh)
}
EXPORT_SYMBOL(vringh_need_notify_kern);
+static int iotlb_translate(const struct vringh *vrh,
+ u64 addr, u64 len, struct bio_vec iov[],
+ int iov_size, u32 perm)
+{
+ struct vhost_iotlb_map *map;
+ struct vhost_iotlb *iotlb = vrh->iotlb;
+ int ret = 0;
+ u64 s = 0;
+
+ while (len > s) {
+ u64 size, pa, pfn;
+
+ if (unlikely(ret >= iov_size)) {
+ ret = -ENOBUFS;
+ break;
+ }
+
+ map = vhost_iotlb_itree_first(iotlb, addr,
+ addr + len - 1);
+ if (!map || map->start > addr) {
+ ret = -EINVAL;
+ break;
+ } else if (!(map->perm & perm)) {
+ ret = -EPERM;
+ break;
+ }
+
+ size = map->size - addr + map->start;
+ pa = map->addr + addr - map->start;
+ pfn = pa >> PAGE_SHIFT;
+ iov[ret].bv_page = pfn_to_page(pfn);
+ iov[ret].bv_len = min(len - s, size);
+ iov[ret].bv_offset = pa & (PAGE_SIZE - 1);
+ s += size;
+ addr += size;
+ ++ret;
+ }
+
+ return ret;
+}
+
+static inline int copy_from_iotlb(const struct vringh *vrh, void *dst,
+ void *src, size_t len)
+{
+ struct iov_iter iter;
+ struct bio_vec iov[16];
+ int ret;
+
+ ret = iotlb_translate(vrh, (u64)(uintptr_t)src,
+ len, iov, 16, VHOST_MAP_RO);
+ if (ret < 0)
+ return ret;
+
+ iov_iter_bvec(&iter, READ, iov, ret, len);
+
+ ret = copy_from_iter(dst, len, &iter);
+
+ return ret;
+}
+
+static inline int copy_to_iotlb(const struct vringh *vrh, void *dst,
+ void *src, size_t len)
+{
+ struct iov_iter iter;
+ struct bio_vec iov[16];
+ int ret;
+
+ ret = iotlb_translate(vrh, (u64)(uintptr_t)dst,
+ len, iov, 16, VHOST_MAP_WO);
+ if (ret < 0)
+ return ret;
+
+ iov_iter_bvec(&iter, WRITE, iov, ret, len);
+
+ return copy_to_iter(src, len, &iter);
+}
+
+static inline int getu16_iotlb(const struct vringh *vrh,
+ u16 *val, const __virtio16 *p)
+{
+ struct bio_vec iov;
+ void *kaddr, *from;
+ int ret;
+
+ /* Atomic read is needed for getu16 */
+ ret = iotlb_translate(vrh, (u64)(uintptr_t)p, sizeof(*p),
+ &iov, 1, VHOST_MAP_RO);
+ if (ret < 0)
+ return ret;
+
+ kaddr = kmap_atomic(iov.bv_page);
+ from = kaddr + iov.bv_offset;
+ *val = vringh16_to_cpu(vrh, READ_ONCE(*(__virtio16 *)from));
+ kunmap_atomic(kaddr);
+
+ return 0;
+}
+
+static inline int putu16_iotlb(const struct vringh *vrh,
+ __virtio16 *p, u16 val)
+{
+ struct bio_vec iov;
+ void *kaddr, *to;
+ int ret;
+
+ /* Atomic write is needed for putu16 */
+ ret = iotlb_translate(vrh, (u64)(uintptr_t)p, sizeof(*p),
+ &iov, 1, VHOST_MAP_WO);
+ if (ret < 0)
+ return ret;
+
+ kaddr = kmap_atomic(iov.bv_page);
+ to = kaddr + iov.bv_offset;
+ WRITE_ONCE(*(__virtio16 *)to, cpu_to_vringh16(vrh, val));
+ kunmap_atomic(kaddr);
+
+ return 0;
+}
+
+static inline int copydesc_iotlb(const struct vringh *vrh,
+ void *dst, const void *src, size_t len)
+{
+ int ret;
+
+ ret = copy_from_iotlb(vrh, dst, (void *)src, len);
+ if (ret != len)
+ return -EFAULT;
+
+ return 0;
+}
+
+static inline int xfer_from_iotlb(const struct vringh *vrh, void *src,
+ void *dst, size_t len)
+{
+ int ret;
+
+ ret = copy_from_iotlb(vrh, dst, src, len);
+ if (ret != len)
+ return -EFAULT;
+
+ return 0;
+}
+
+static inline int xfer_to_iotlb(const struct vringh *vrh,
+ void *dst, void *src, size_t len)
+{
+ int ret;
+
+ ret = copy_to_iotlb(vrh, dst, src, len);
+ if (ret != len)
+ return -EFAULT;
+
+ return 0;
+}
+
+static inline int putused_iotlb(const struct vringh *vrh,
+ struct vring_used_elem *dst,
+ const struct vring_used_elem *src,
+ unsigned int num)
+{
+ int size = num * sizeof(*dst);
+ int ret;
+
+ ret = copy_to_iotlb(vrh, dst, (void *)src, num * sizeof(*dst));
+ if (ret != size)
+ return -EFAULT;
+
+ return 0;
+}
+
+/**
+ * vringh_init_iotlb - initialize a vringh for a ring with IOTLB.
+ * @vrh: the vringh to initialize.
+ * @features: the feature bits for this ring.
+ * @num: the number of elements.
+ * @weak_barriers: true if we only need memory barriers, not I/O.
+ * @desc: the userpace descriptor pointer.
+ * @avail: the userpace avail pointer.
+ * @used: the userpace used pointer.
+ *
+ * Returns an error if num is invalid.
+ */
+int vringh_init_iotlb(struct vringh *vrh, u64 features,
+ unsigned int num, bool weak_barriers,
+ struct vring_desc *desc,
+ struct vring_avail *avail,
+ struct vring_used *used)
+{
+ return vringh_init_kern(vrh, features, num, weak_barriers,
+ desc, avail, used);
+}
+EXPORT_SYMBOL(vringh_init_iotlb);
+
+/**
+ * vringh_set_iotlb - initialize a vringh for a ring with IOTLB.
+ * @vrh: the vring
+ * @iotlb: iotlb associated with this vring
+ */
+void vringh_set_iotlb(struct vringh *vrh, struct vhost_iotlb *iotlb)
+{
+ vrh->iotlb = iotlb;
+}
+EXPORT_SYMBOL(vringh_set_iotlb);
+
+/**
+ * vringh_getdesc_iotlb - get next available descriptor from ring with
+ * IOTLB.
+ * @vrh: the kernelspace vring.
+ * @riov: where to put the readable descriptors (or NULL)
+ * @wiov: where to put the writable descriptors (or NULL)
+ * @head: head index we received, for passing to vringh_complete_iotlb().
+ * @gfp: flags for allocating larger riov/wiov.
+ *
+ * Returns 0 if there was no descriptor, 1 if there was, or -errno.
+ *
+ * Note that on error return, you can tell the difference between an
+ * invalid ring and a single invalid descriptor: in the former case,
+ * *head will be vrh->vring.num. You may be able to ignore an invalid
+ * descriptor, but there's not much you can do with an invalid ring.
+ *
+ * Note that you may need to clean up riov and wiov, even on error!
+ */
+int vringh_getdesc_iotlb(struct vringh *vrh,
+ struct vringh_kiov *riov,
+ struct vringh_kiov *wiov,
+ u16 *head,
+ gfp_t gfp)
+{
+ int err;
+
+ err = __vringh_get_head(vrh, getu16_iotlb, &vrh->last_avail_idx);
+ if (err < 0)
+ return err;
+
+ /* Empty... */
+ if (err == vrh->vring.num)
+ return 0;
+
+ *head = err;
+ err = __vringh_iov(vrh, *head, riov, wiov, no_range_check, NULL,
+ gfp, copydesc_iotlb);
+ if (err)
+ return err;
+
+ return 1;
+}
+EXPORT_SYMBOL(vringh_getdesc_iotlb);
+
+/**
+ * vringh_iov_pull_iotlb - copy bytes from vring_iov.
+ * @vrh: the vring.
+ * @riov: the riov as passed to vringh_getdesc_iotlb() (updated as we consume)
+ * @dst: the place to copy.
+ * @len: the maximum length to copy.
+ *
+ * Returns the bytes copied <= len or a negative errno.
+ */
+ssize_t vringh_iov_pull_iotlb(struct vringh *vrh,
+ struct vringh_kiov *riov,
+ void *dst, size_t len)
+{
+ return vringh_iov_xfer(vrh, riov, dst, len, xfer_from_iotlb);
+}
+EXPORT_SYMBOL(vringh_iov_pull_iotlb);
+
+/**
+ * vringh_iov_push_iotlb - copy bytes into vring_iov.
+ * @vrh: the vring.
+ * @wiov: the wiov as passed to vringh_getdesc_iotlb() (updated as we consume)
+ * @dst: the place to copy.
+ * @len: the maximum length to copy.
+ *
+ * Returns the bytes copied <= len or a negative errno.
+ */
+ssize_t vringh_iov_push_iotlb(struct vringh *vrh,
+ struct vringh_kiov *wiov,
+ const void *src, size_t len)
+{
+ return vringh_iov_xfer(vrh, wiov, (void *)src, len, xfer_to_iotlb);
+}
+EXPORT_SYMBOL(vringh_iov_push_iotlb);
+
+/**
+ * vringh_abandon_iotlb - we've decided not to handle the descriptor(s).
+ * @vrh: the vring.
+ * @num: the number of descriptors to put back (ie. num
+ * vringh_get_iotlb() to undo).
+ *
+ * The next vringh_get_iotlb() will return the old descriptor(s) again.
+ */
+void vringh_abandon_iotlb(struct vringh *vrh, unsigned int num)
+{
+ /* We only update vring_avail_event(vr) when we want to be notified,
+ * so we haven't changed that yet.
+ */
+ vrh->last_avail_idx -= num;
+}
+EXPORT_SYMBOL(vringh_abandon_iotlb);
+
+/**
+ * vringh_complete_iotlb - we've finished with descriptor, publish it.
+ * @vrh: the vring.
+ * @head: the head as filled in by vringh_getdesc_iotlb.
+ * @len: the length of data we have written.
+ *
+ * You should check vringh_need_notify_iotlb() after one or more calls
+ * to this function.
+ */
+int vringh_complete_iotlb(struct vringh *vrh, u16 head, u32 len)
+{
+ struct vring_used_elem used;
+
+ used.id = cpu_to_vringh32(vrh, head);
+ used.len = cpu_to_vringh32(vrh, len);
+
+ return __vringh_complete(vrh, &used, 1, putu16_iotlb, putused_iotlb);
+}
+EXPORT_SYMBOL(vringh_complete_iotlb);
+
+/**
+ * vringh_notify_enable_iotlb - we want to know if something changes.
+ * @vrh: the vring.
+ *
+ * This always enables notifications, but returns false if there are
+ * now more buffers available in the vring.
+ */
+bool vringh_notify_enable_iotlb(struct vringh *vrh)
+{
+ return __vringh_notify_enable(vrh, getu16_iotlb, putu16_iotlb);
+}
+EXPORT_SYMBOL(vringh_notify_enable_iotlb);
+
+/**
+ * vringh_notify_disable_iotlb - don't tell us if something changes.
+ * @vrh: the vring.
+ *
+ * This is our normal running state: we disable and then only enable when
+ * we're going to sleep.
+ */
+void vringh_notify_disable_iotlb(struct vringh *vrh)
+{
+ __vringh_notify_disable(vrh, putu16_iotlb);
+}
+EXPORT_SYMBOL(vringh_notify_disable_iotlb);
+
+/**
+ * vringh_need_notify_iotlb - must we tell the other side about used buffers?
+ * @vrh: the vring we've called vringh_complete_iotlb() on.
+ *
+ * Returns -errno or 0 if we don't need to tell the other side, 1 if we do.
+ */
+int vringh_need_notify_iotlb(struct vringh *vrh)
+{
+ return __vringh_need_notify(vrh, getu16_iotlb);
+}
+EXPORT_SYMBOL(vringh_need_notify_iotlb);
+
+
MODULE_LICENSE("GPL");
diff --git a/include/linux/vringh.h b/include/linux/vringh.h
index d237087eb257..bd0503ca6f8f 100644
--- a/include/linux/vringh.h
+++ b/include/linux/vringh.h
@@ -14,6 +14,8 @@
#include <linux/virtio_byteorder.h>
#include <linux/uio.h>
#include <linux/slab.h>
+#include <linux/dma-direction.h>
+#include <linux/vhost_iotlb.h>
#include <asm/barrier.h>
/* virtio_ring with information needed for host access. */
@@ -39,6 +41,9 @@ struct vringh {
/* The vring (note: it may contain user pointers!) */
struct vring vring;
+ /* IOTLB for this vring */
+ struct vhost_iotlb *iotlb;
+
/* The function to call to notify the guest about added buffers */
void (*notify)(struct vringh *);
};
@@ -248,4 +253,35 @@ static inline __virtio64 cpu_to_vringh64(const struct
vringh *vrh, u64 val)
{
return __cpu_to_virtio64(vringh_is_little_endian(vrh), val);
}
+
+void vringh_set_iotlb(struct vringh *vrh, struct vhost_iotlb *iotlb);
+
+int vringh_init_iotlb(struct vringh *vrh, u64 features,
+ unsigned int num, bool weak_barriers,
+ struct vring_desc *desc,
+ struct vring_avail *avail,
+ struct vring_used *used);
+
+int vringh_getdesc_iotlb(struct vringh *vrh,
+ struct vringh_kiov *riov,
+ struct vringh_kiov *wiov,
+ u16 *head,
+ gfp_t gfp);
+
+ssize_t vringh_iov_pull_iotlb(struct vringh *vrh,
+ struct vringh_kiov *riov,
+ void *dst, size_t len);
+ssize_t vringh_iov_push_iotlb(struct vringh *vrh,
+ struct vringh_kiov *wiov,
+ const void *src, size_t len);
+
+void vringh_abandon_iotlb(struct vringh *vrh, unsigned int num);
+
+int vringh_complete_iotlb(struct vringh *vrh, u16 head, u32 len);
+
+bool vringh_notify_enable_iotlb(struct vringh *vrh);
+void vringh_notify_disable_iotlb(struct vringh *vrh);
+
+int vringh_need_notify_iotlb(struct vringh *vrh);
+
#endif /* _LINUX_VRINGH_H */
--
2.19.1
vDPA device is a device that uses a datapath which complies with the virtio specifications with vendor specific control path. vDPA devices can be both physically located on the hardware or emulated by software. vDPA hardware devices are usually implemented through PCIE with the following types: - PF (Physical Function) - A single Physical Function - VF (Virtual Function) - Device that supports single root I/O virtualization (SR-IOV). Its Virtual Function (VF) represents a virtualized instance of the device that can be assigned to different partitions - ADI (Assignable Device Interface) and its equivalents - With technologies such as Intel Scalable IOV, a virtual device (VDEV) composed by host OS utilizing one or more ADIs. Or its equivalent like SF (Sub function) from Mellanox.>From a driver's perspective, depends on how and where the DMAtranslation is done, vDPA devices are split into two types: - Platform specific DMA translation - From the driver's perspective, the device can be used on a platform where device access to data in memory is limited and/or translated. An example is a PCIE vDPA whose DMA request was tagged via a bus (e.g PCIE) specific way. DMA translation and protection are done at PCIE bus IOMMU level. - Device specific DMA translation - The device implements DMA isolation and protection through its own logic. An example is a vDPA device which uses on-chip IOMMU. To hide the differences and complexity of the above types for a vDPA device/IOMMU options and in order to present a generic virtio device to the upper layer, a device agnostic framework is required. This patch introduces a software vDPA bus which abstracts the common attributes of vDPA device, vDPA bus driver and the communication method (vdpa_config_ops) between the vDPA device abstraction and the vDPA bus driver: With the abstraction of vDPA bus and vDPA bus operations, the difference and complexity of the under layer hardware is hidden from upper layer. The vDPA bus drivers on top can use a unified vdpa_config_ops to control different types of vDPA device. Signed-off-by: Jason Wang <jasowang at redhat.com> --- MAINTAINERS | 1 + drivers/virtio/Kconfig | 2 + drivers/virtio/Makefile | 1 + drivers/virtio/vdpa/Kconfig | 9 ++ drivers/virtio/vdpa/Makefile | 2 + drivers/virtio/vdpa/vdpa.c | 160 ++++++++++++++++++++++++ include/linux/vdpa.h | 233 +++++++++++++++++++++++++++++++++++ 7 files changed, 408 insertions(+) create mode 100644 drivers/virtio/vdpa/Kconfig create mode 100644 drivers/virtio/vdpa/Makefile create mode 100644 drivers/virtio/vdpa/vdpa.c create mode 100644 include/linux/vdpa.h diff --git a/MAINTAINERS b/MAINTAINERS index d4bda9c900fa..578d2a581e3b 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -17540,6 +17540,7 @@ F: tools/virtio/ F: drivers/net/virtio_net.c F: drivers/block/virtio_blk.c F: include/linux/virtio*.h +F: include/linux/vdpa.h F: include/uapi/linux/virtio_*.h F: drivers/crypto/virtio/ F: mm/balloon_compaction.c diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig index 078615cf2afc..9c4fdb64d9ac 100644 --- a/drivers/virtio/Kconfig +++ b/drivers/virtio/Kconfig @@ -96,3 +96,5 @@ config VIRTIO_MMIO_CMDLINE_DEVICES If unsure, say 'N'. endif # VIRTIO_MENU + +source "drivers/virtio/vdpa/Kconfig" diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile index 3a2b5c5dcf46..fdf5eacd0d0a 100644 --- a/drivers/virtio/Makefile +++ b/drivers/virtio/Makefile @@ -6,3 +6,4 @@ virtio_pci-y := virtio_pci_modern.o virtio_pci_common.o virtio_pci-$(CONFIG_VIRTIO_PCI_LEGACY) += virtio_pci_legacy.o obj-$(CONFIG_VIRTIO_BALLOON) += virtio_balloon.o obj-$(CONFIG_VIRTIO_INPUT) += virtio_input.o +obj-$(CONFIG_VDPA) += vdpa/ diff --git a/drivers/virtio/vdpa/Kconfig b/drivers/virtio/vdpa/Kconfig new file mode 100644 index 000000000000..7a99170e6c30 --- /dev/null +++ b/drivers/virtio/vdpa/Kconfig @@ -0,0 +1,9 @@ +# SPDX-License-Identifier: GPL-2.0-only +config VDPA + tristate + default m + help + Enable this module to support vDPA device that uses a + datapath which complies with virtio specifications with + vendor specific control path. + diff --git a/drivers/virtio/vdpa/Makefile b/drivers/virtio/vdpa/Makefile new file mode 100644 index 000000000000..ee6a35e8a4fb --- /dev/null +++ b/drivers/virtio/vdpa/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_VDPA) += vdpa.o diff --git a/drivers/virtio/vdpa/vdpa.c b/drivers/virtio/vdpa/vdpa.c new file mode 100644 index 000000000000..4003d90f5df3 --- /dev/null +++ b/drivers/virtio/vdpa/vdpa.c @@ -0,0 +1,160 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * vDPA bus. + * + * Copyright (c) 2020, Red Hat. All rights reserved. + * Author: Jason Wang <jasowang at redhat.com> + * + */ + +#include <linux/module.h> +#include <linux/idr.h> +#include <linux/vdpa.h> + +static DEFINE_IDA(vdpa_index_ida); + +static int vdpa_dev_probe(struct device *d) +{ + struct vdpa_device *vdev = dev_to_vdpa(d); + struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver); + int ret = 0; + + if (drv && drv->probe) + ret = drv->probe(vdev); + + return ret; +} + +static int vdpa_dev_remove(struct device *d) +{ + struct vdpa_device *vdev = dev_to_vdpa(d); + struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver); + + if (drv && drv->remove) + drv->remove(vdev); + + return 0; +} + +static struct bus_type vdpa_bus = { + .name = "vdpa", + .probe = vdpa_dev_probe, + .remove = vdpa_dev_remove, +}; + +/** + * vdpa_init_device - initilaize a vDPA device + * This allows driver to some prepartion between after device is + * initialized but before vdpa_register_device() + * @vdev: the vdpa device to be initialized + * @parent: the paretn device + * @dma_dev: the actual device that is performing DMA + * @config: the bus operations support by this device + * + * Returns an error when parent/config/dma_dev is not set or fail to get + * ida. + */ +int vdpa_init_device(struct vdpa_device *vdev, struct device *parent, + struct device *dma_dev, + const struct vdpa_config_ops *config) +{ + int err; + + if (!parent || !dma_dev || !config) + return -EINVAL; + + err = ida_simple_get(&vdpa_index_ida, 0, 0, GFP_KERNEL); + if (err < 0) + return -EFAULT; + + vdev->dev.bus = &vdpa_bus; + vdev->dev.parent = parent; + + device_initialize(&vdev->dev); + + vdev->index = err; + vdev->dma_dev = dma_dev; + vdev->config = config; + + dev_set_name(&vdev->dev, "vdpa%u", vdev->index); + + return 0; +} +EXPORT_SYMBOL_GPL(vdpa_init_device); + +/** + * vdpa_register_device - register a vDPA device + * Callers must have a succeed call of vdpa_init_device() before. + * @vdev: the vdpa device to be registered to vDPA bus + * + * Returns an error when fail to add to vDPA bus + */ +int vdpa_register_device(struct vdpa_device *vdev) +{ + int err = device_add(&vdev->dev); + + if (err) { + put_device(&vdev->dev); + ida_simple_remove(&vdpa_index_ida, vdev->index); + } + + return err; +} +EXPORT_SYMBOL_GPL(vdpa_register_device); + +/** + * vdpa_unregister_device - unregister a vDPA device + * @vdev: the vdpa device to be unregisted from vDPA bus + */ +void vdpa_unregister_device(struct vdpa_device *vdev) +{ + int index = vdev->index; + + device_unregister(&vdev->dev); + ida_simple_remove(&vdpa_index_ida, index); +} +EXPORT_SYMBOL_GPL(vdpa_unregister_device); + +/** + * __vdpa_register_driver - register a vDPA device driver + * @drv: the vdpa device driver to be registered + * @owner: module owner of the driver + * + * Returns an err when fail to do the registration + */ +int __vdpa_register_driver(struct vdpa_driver *drv, struct module *owner) +{ + drv->driver.bus = &vdpa_bus; + drv->driver.owner = owner; + + return driver_register(&drv->driver); +} +EXPORT_SYMBOL_GPL(__vdpa_register_driver); + +/** + * vdpa_unregister_driver - unregister a vDPA device driver + * @drv: the vdpa device driver to be unregistered + */ +void vdpa_unregister_driver(struct vdpa_driver *drv) +{ + driver_unregister(&drv->driver); +} +EXPORT_SYMBOL_GPL(vdpa_unregister_driver); + +static int vdpa_init(void) +{ + if (bus_register(&vdpa_bus) != 0) + panic("virtio bus registration failed"); + return 0; +} + +static void __exit vdpa_exit(void) +{ + bus_unregister(&vdpa_bus); + ida_destroy(&vdpa_index_ida); +} +core_initcall(vdpa_init); +module_exit(vdpa_exit); + +MODULE_AUTHOR("Jason Wang <jasowang at redhat.com>"); +MODULE_LICENSE("GPL v2"); diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h new file mode 100644 index 000000000000..52543a862801 --- /dev/null +++ b/include/linux/vdpa.h @@ -0,0 +1,233 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_VDPA_H +#define _LINUX_VDPA_H + +#include <linux/device.h> +#include <linux/interrupt.h> +#include <linux/vhost_iotlb.h> + +/** + * vDPA callback definition. + * @callback: interrupt callback function + * @private: the data passed to the callback function + */ +struct vdpa_callback { + irqreturn_t (*callback)(void *data); + void *private; +}; + +/** + * vDPA device - representation of a vDPA device + * @dev: underlying device + * @dma_dev: the actual device that is performing DMA + * @config: the configuration ops for this device. + * @index: device index + */ +struct vdpa_device { + struct device dev; + struct device *dma_dev; + const struct vdpa_config_ops *config; + int index; +}; + +/** + * vDPA_config_ops - operations for configuring a vDPA device. + * Note: vDPA device drivers are required to implement all of the + * operations unless it is mentioned to be optional in the following + * list. + * + * @set_vq_address: Set the address of virtqueue + * @vdev: vdpa device + * @idx: virtqueue index + * @desc_area: address of desc area + * @driver_area: address of driver area + * @device_area: address of device area + * Returns integer: success (0) or error (< 0) + * @set_vq_num: Set the size of virtqueue + * @vdev: vdpa device + * @idx: virtqueue index + * @num: the size of virtqueue + * @kick_vq: Kick the virtqueue + * @vdev: vdpa device + * @idx: virtqueue index + * @set_vq_cb: Set the interrupt callback function for + * a virtqueue + * @vdev: vdpa device + * @idx: virtqueue index + * @cb: virtio-vdev interrupt callback structure + * @set_vq_ready: Set ready status for a virtqueue + * @vdev: vdpa device + * @idx: virtqueue index + * @ready: ready (true) not ready(false) + * @get_vq_ready: Get ready status for a virtqueue + * @vdev: vdpa device + * @idx: virtqueue index + * Returns boolean: ready (true) or not (false) + * @set_vq_state: Set the state for a virtqueue + * @vdev: vdpa device + * @idx: virtqueue index + * @state: virtqueue state (last_avail_idx) + * Returns integer: success (0) or error (< 0) + * @get_vq_state: Get the state for a virtqueue + * @vdev: vdpa device + * @idx: virtqueue index + * Returns virtqueue state (last_avail_idx) + * @get_vq_align: Get the virtqueue align requirement + * for the device + * @vdev: vdpa device + * Returns virtqueue algin requirement + * @get_features: Get virtio features supported by the device + * @vdev: vdpa device + * Returns the virtio features support by the + * device + * @set_features: Set virtio features supported by the driver + * @vdev: vdpa device + * @features: feature support by the driver + * Returns integer: success (0) or error (< 0) + * @set_config_cb: Set the config interrupt callback + * @vdev: vdpa device + * @cb: virtio-vdev interrupt callback structure + * @get_vq_num_max: Get the max size of virtqueue + * @vdev: vdpa device + * Returns u16: max size of virtqueue + * @get_device_id: Get virtio device id + * @vdev: vdpa device + * Returns u32: virtio device id + * @get_vendor_id: Get id for the vendor that provides this device + * @vdev: vdpa device + * Returns u32: virtio vendor id + * @get_status: Get the device status + * @vdev: vdpa device + * Returns u8: virtio device status + * @set_status: Set the device status + * @vdev: vdpa device + * @status: virtio device status + * @get_config: Read from device specific configuration space + * @vdev: vdpa device + * @offset: offset from the beginning of + * configuration space + * @buf: buffer used to read to + * @len: the length to read from + * configuration space + * @set_config: Write to device specific configuration space + * @vdev: vdpa device + * @offset: offset from the beginning of + * configuration space + * @buf: buffer used to write from + * @len: the length to write to + * configuration space + * @get_generation: Get device config generation (optional) + * @vdev: vdpa device + * Returns u32: device generation + * @set_map: Set device memory mapping (optional) + * and only needed for device that using + * device specific DMA translation + * (on-chip IOMMU) + * @vdev: vdpa device + * @iotlb: vhost memory mapping to be + * used by the vDPA + * Returns integer: success (0) or error (< 0) + * @dma_map: Map an area of PA to IOVA + * @vdev: vdpa device + * @iova: iova to be mapped + * @size: size of the area + * @pa: physical address for the map + * @perm: device access permission (VHOST_MAP_XX) + * Returns integer: success (0) or error (< 0) + * @dma_unmap: Unmap an area of IOVA + * @vdev: vdpa device + * @iova: iova to be unmapped + * @size: size of the area + * Returns integer: success (0) or error (< 0) + */ +struct vdpa_config_ops { + /* Virtqueue ops */ + int (*set_vq_address)(struct vdpa_device *vdev, + u16 idx, u64 desc_area, u64 driver_area, + u64 device_area); + void (*set_vq_num)(struct vdpa_device *vdev, u16 idx, u32 num); + void (*kick_vq)(struct vdpa_device *vdev, u16 idx); + void (*set_vq_cb)(struct vdpa_device *vdev, u16 idx, + struct vdpa_callback *cb); + void (*set_vq_ready)(struct vdpa_device *vdev, u16 idx, bool ready); + bool (*get_vq_ready)(struct vdpa_device *vdev, u16 idx); + int (*set_vq_state)(struct vdpa_device *vdev, u16 idx, u64 state); + u64 (*get_vq_state)(struct vdpa_device *vdev, u16 idx); + + /* Device ops */ + u16 (*get_vq_align)(struct vdpa_device *vdev); + u64 (*get_features)(struct vdpa_device *vdev); + int (*set_features)(struct vdpa_device *vdev, u64 features); + void (*set_config_cb)(struct vdpa_device *vdev, + struct vdpa_callback *cb); + u16 (*get_vq_num_max)(struct vdpa_device *vdev); + u32 (*get_device_id)(struct vdpa_device *vdev); + u32 (*get_vendor_id)(struct vdpa_device *vdev); + u8 (*get_status)(struct vdpa_device *vdev); + void (*set_status)(struct vdpa_device *vdev, u8 status); + void (*get_config)(struct vdpa_device *vdev, unsigned int offset, + void *buf, unsigned int len); + void (*set_config)(struct vdpa_device *vdev, unsigned int offset, + const void *buf, unsigned int len); + u32 (*get_generation)(struct vdpa_device *vdev); + + /* DMA ops */ + int (*set_map)(struct vdpa_device *vdev, struct vhost_iotlb *iotlb); + int (*dma_map)(struct vdpa_device *vdev, u64 iova, u64 size, + u64 pa, u32 perm); + int (*dma_unmap)(struct vdpa_device *vdev, u64 iova, u64 size); +}; + +int vdpa_init_device(struct vdpa_device *vdev, + struct device *parent, + struct device *dma_dev, + const struct vdpa_config_ops *config); +int vdpa_register_device(struct vdpa_device *vdev); +void vdpa_unregister_device(struct vdpa_device *vdev); + +/** + * vdpa_driver - operations for a vDPA driver + * @driver: underlying device driver + * @probe: the function to call when a device is found. Returns 0 or -errno. + * @remove: the function to call when a device is removed. + */ +struct vdpa_driver { + struct device_driver driver; + int (*probe)(struct vdpa_device *vdev); + void (*remove)(struct vdpa_device *vdev); +}; + +#define vdpa_register_driver(drv) \ + __vdpa_register_driver(drv, THIS_MODULE) +int __vdpa_register_driver(struct vdpa_driver *drv, struct module *owner); +void vdpa_unregister_driver(struct vdpa_driver *drv); + +#define module_vdpa_driver(__vdpa_driver) \ + module_driver(__vdpa_driver, vdpa_register_driver, \ + vdpa_unregister_driver) + +static inline struct vdpa_driver *drv_to_vdpa(struct device_driver *driver) +{ + return container_of(driver, struct vdpa_driver, driver); +} + +static inline struct vdpa_device *dev_to_vdpa(struct device *_dev) +{ + return container_of(_dev, struct vdpa_device, dev); +} + +static inline void *vdpa_get_drvdata(const struct vdpa_device *vdev) +{ + return dev_get_drvdata(&vdev->dev); +} + +static inline void vdpa_set_drvdata(struct vdpa_device *vdev, void *data) +{ + dev_set_drvdata(&vdev->dev, data); +} + +static inline struct device *vdpa_get_dma_dev(struct vdpa_device *vdev) +{ + return vdev->dma_dev; +} +#endif /* _LINUX_VDPA_H */ -- 2.19.1
This patch introduces a vDPA transport for virtio. This is used to
use kernel virtio driver to drive the mediated device that is capable
of populating virtqueue directly.
A new virtio-vdpa driver will be registered to the vDPA bus, when a
new virtio-vdpa device is probed, it will register the device with
vdpa based config ops. This means it is a software transport between
vDPA driver and vDPA device. The transport was implemented through
bus_ops of vDPA parent.
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/virtio/Kconfig | 13 ++
drivers/virtio/Makefile | 1 +
drivers/virtio/virtio_vdpa.c | 392 +++++++++++++++++++++++++++++++++++
3 files changed, 406 insertions(+)
create mode 100644 drivers/virtio/virtio_vdpa.c
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index 9c4fdb64d9ac..0df3676b0f4f 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -43,6 +43,19 @@ config VIRTIO_PCI_LEGACY
If unsure, say Y.
+config VIRTIO_VDPA
+ tristate "vDPA driver for virtio devices"
+ select VDPA
+ select VIRTIO
+ help
+ This driver provides support for virtio based paravirtual
+ device driver over vDPA bus. For this to be useful, you need
+ an appropriate vDPA device implementation that operates on a
+ physical device to allow the datapath of virtio to be
+ offloaded to hardware.
+
+ If unsure, say M.
+
config VIRTIO_PMEM
tristate "Support for virtio pmem driver"
depends on VIRTIO
diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
index fdf5eacd0d0a..3407ac03fe60 100644
--- a/drivers/virtio/Makefile
+++ b/drivers/virtio/Makefile
@@ -6,4 +6,5 @@ virtio_pci-y := virtio_pci_modern.o virtio_pci_common.o
virtio_pci-$(CONFIG_VIRTIO_PCI_LEGACY) += virtio_pci_legacy.o
obj-$(CONFIG_VIRTIO_BALLOON) += virtio_balloon.o
obj-$(CONFIG_VIRTIO_INPUT) += virtio_input.o
+obj-$(CONFIG_VIRTIO_VDPA) += virtio_vdpa.o
obj-$(CONFIG_VDPA) += vdpa/
diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c
new file mode 100644
index 000000000000..077796087abf
--- /dev/null
+++ b/drivers/virtio/virtio_vdpa.c
@@ -0,0 +1,392 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * VIRTIO based driver for vDPA device
+ *
+ * Copyright (c) 2020, Red Hat. All rights reserved.
+ * Author: Jason Wang <jasowang at redhat.com>
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/uuid.h>
+#include <linux/virtio.h>
+#include <linux/vdpa.h>
+#include <linux/virtio_config.h>
+#include <linux/virtio_ring.h>
+
+#define MOD_VERSION "0.1"
+#define MOD_AUTHOR "Jason Wang <jasowang at redhat.com>"
+#define MOD_DESC "vDPA bus driver for virtio devices"
+#define MOD_LICENSE "GPL v2"
+
+struct virtio_vdpa_device {
+ struct virtio_device vdev;
+ struct vdpa_device *vdpa;
+ u64 features;
+
+ /* The lock to protect virtqueue list */
+ spinlock_t lock;
+ /* List of virtio_vdpa_vq_info */
+ struct list_head virtqueues;
+};
+
+struct virtio_vdpa_vq_info {
+ /* the actual virtqueue */
+ struct virtqueue *vq;
+
+ /* the list node for the virtqueues list */
+ struct list_head node;
+};
+
+static inline struct virtio_vdpa_device *
+to_virtio_vdpa_device(struct virtio_device *dev)
+{
+ return container_of(dev, struct virtio_vdpa_device, vdev);
+}
+
+static struct vdpa_device *vd_get_vdpa(struct virtio_device *vdev)
+{
+ return to_virtio_vdpa_device(vdev)->vdpa;
+}
+
+static void virtio_vdpa_get(struct virtio_device *vdev, unsigned offset,
+ void *buf, unsigned len)
+{
+ struct vdpa_device *vdpa = vd_get_vdpa(vdev);
+ const struct vdpa_config_ops *ops = vdpa->config;
+
+ ops->get_config(vdpa, offset, buf, len);
+}
+
+static void virtio_vdpa_set(struct virtio_device *vdev, unsigned offset,
+ const void *buf, unsigned len)
+{
+ struct vdpa_device *vdpa = vd_get_vdpa(vdev);
+ const struct vdpa_config_ops *ops = vdpa->config;
+
+ ops->set_config(vdpa, offset, buf, len);
+}
+
+static u32 virtio_vdpa_generation(struct virtio_device *vdev)
+{
+ struct vdpa_device *vdpa = vd_get_vdpa(vdev);
+ const struct vdpa_config_ops *ops = vdpa->config;
+
+ if (ops->get_generation)
+ return ops->get_generation(vdpa);
+
+ return 0;
+}
+
+static u8 virtio_vdpa_get_status(struct virtio_device *vdev)
+{
+ struct vdpa_device *vdpa = vd_get_vdpa(vdev);
+ const struct vdpa_config_ops *ops = vdpa->config;
+
+ return ops->get_status(vdpa);
+}
+
+static void virtio_vdpa_set_status(struct virtio_device *vdev, u8 status)
+{
+ struct vdpa_device *vdpa = vd_get_vdpa(vdev);
+ const struct vdpa_config_ops *ops = vdpa->config;
+
+ return ops->set_status(vdpa, status);
+}
+
+static void virtio_vdpa_reset(struct virtio_device *vdev)
+{
+ struct vdpa_device *vdpa = vd_get_vdpa(vdev);
+ const struct vdpa_config_ops *ops = vdpa->config;
+
+ return ops->set_status(vdpa, 0);
+}
+
+static bool virtio_vdpa_notify(struct virtqueue *vq)
+{
+ struct vdpa_device *vdpa = vd_get_vdpa(vq->vdev);
+ const struct vdpa_config_ops *ops = vdpa->config;
+
+ ops->kick_vq(vdpa, vq->index);
+
+ return true;
+}
+
+static irqreturn_t virtio_vdpa_config_cb(void *private)
+{
+ struct virtio_vdpa_device *vd_dev = private;
+
+ virtio_config_changed(&vd_dev->vdev);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t virtio_vdpa_virtqueue_cb(void *private)
+{
+ struct virtio_vdpa_vq_info *info = private;
+
+ return vring_interrupt(0, info->vq);
+}
+
+static struct virtqueue *
+virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index,
+ void (*callback)(struct virtqueue *vq),
+ const char *name, bool ctx)
+{
+ struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev);
+ struct vdpa_device *vdpa = vd_get_vdpa(vdev);
+ const struct vdpa_config_ops *ops = vdpa->config;
+ struct virtio_vdpa_vq_info *info;
+ struct vdpa_callback cb;
+ struct virtqueue *vq;
+ u64 desc_addr, driver_addr, device_addr;
+ unsigned long flags;
+ u32 align, num;
+ int err;
+
+ if (!name)
+ return NULL;
+
+ /* Queue shouldn't already be set up. */
+ if (ops->get_vq_ready(vdpa, index))
+ return ERR_PTR(-ENOENT);
+
+ /* Allocate and fill out our active queue description */
+ info = kmalloc(sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return ERR_PTR(-ENOMEM);
+
+ num = ops->get_vq_num_max(vdpa);
+ if (num == 0) {
+ err = -ENOENT;
+ goto error_new_virtqueue;
+ }
+
+ /* Create the vring */
+ align = ops->get_vq_align(vdpa);
+ vq = vring_create_virtqueue(index, num, align, vdev,
+ true, true, ctx,
+ virtio_vdpa_notify, callback, name);
+ if (!vq) {
+ err = -ENOMEM;
+ goto error_new_virtqueue;
+ }
+
+ /* Setup virtqueue callback */
+ cb.callback = virtio_vdpa_virtqueue_cb;
+ cb.private = info;
+ ops->set_vq_cb(vdpa, index, &cb);
+ ops->set_vq_num(vdpa, index, virtqueue_get_vring_size(vq));
+
+ desc_addr = virtqueue_get_desc_addr(vq);
+ driver_addr = virtqueue_get_avail_addr(vq);
+ device_addr = virtqueue_get_used_addr(vq);
+
+ if (ops->set_vq_address(vdpa, index,
+ desc_addr, driver_addr,
+ device_addr)) {
+ err = -EINVAL;
+ goto err_vq;
+ }
+
+ ops->set_vq_ready(vdpa, index, 1);
+
+ vq->priv = info;
+ info->vq = vq;
+
+ spin_lock_irqsave(&vd_dev->lock, flags);
+ list_add(&info->node, &vd_dev->virtqueues);
+ spin_unlock_irqrestore(&vd_dev->lock, flags);
+
+ return vq;
+
+err_vq:
+ vring_del_virtqueue(vq);
+error_new_virtqueue:
+ ops->set_vq_ready(vdpa, index, 0);
+ /* VDPA driver should make sure vq is stopeed here */
+ WARN_ON(ops->get_vq_ready(vdpa, index));
+ kfree(info);
+ return ERR_PTR(err);
+}
+
+static void virtio_vdpa_del_vq(struct virtqueue *vq)
+{
+ struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vq->vdev);
+ struct vdpa_device *vdpa = vd_dev->vdpa;
+ const struct vdpa_config_ops *ops = vdpa->config;
+ struct virtio_vdpa_vq_info *info = vq->priv;
+ unsigned int index = vq->index;
+ unsigned long flags;
+
+ spin_lock_irqsave(&vd_dev->lock, flags);
+ list_del(&info->node);
+ spin_unlock_irqrestore(&vd_dev->lock, flags);
+
+ /* Select and deactivate the queue */
+ ops->set_vq_ready(vdpa, index, 0);
+ WARN_ON(ops->get_vq_ready(vdpa, index));
+
+ vring_del_virtqueue(vq);
+
+ kfree(info);
+}
+
+static void virtio_vdpa_del_vqs(struct virtio_device *vdev)
+{
+ struct virtqueue *vq, *n;
+
+ list_for_each_entry_safe(vq, n, &vdev->vqs, list)
+ virtio_vdpa_del_vq(vq);
+}
+
+static int virtio_vdpa_find_vqs(struct virtio_device *vdev, unsigned nvqs,
+ struct virtqueue *vqs[],
+ vq_callback_t *callbacks[],
+ const char * const names[],
+ const bool *ctx,
+ struct irq_affinity *desc)
+{
+ struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev);
+ struct vdpa_device *vdpa = vd_get_vdpa(vdev);
+ const struct vdpa_config_ops *ops = vdpa->config;
+ struct vdpa_callback cb;
+ int i, err, queue_idx = 0;
+
+ for (i = 0; i < nvqs; ++i) {
+ if (!names[i]) {
+ vqs[i] = NULL;
+ continue;
+ }
+
+ vqs[i] = virtio_vdpa_setup_vq(vdev, queue_idx++,
+ callbacks[i], names[i], ctx ?
+ ctx[i] : false);
+ if (IS_ERR(vqs[i])) {
+ err = PTR_ERR(vqs[i]);
+ goto err_setup_vq;
+ }
+ }
+
+ cb.callback = virtio_vdpa_config_cb;
+ cb.private = vd_dev;
+ ops->set_config_cb(vdpa, &cb);
+
+ return 0;
+
+err_setup_vq:
+ virtio_vdpa_del_vqs(vdev);
+ return err;
+}
+
+static u64 virtio_vdpa_get_features(struct virtio_device *vdev)
+{
+ struct vdpa_device *vdpa = vd_get_vdpa(vdev);
+ const struct vdpa_config_ops *ops = vdpa->config;
+
+ return ops->get_features(vdpa);
+}
+
+static int virtio_vdpa_finalize_features(struct virtio_device *vdev)
+{
+ struct vdpa_device *vdpa = vd_get_vdpa(vdev);
+ const struct vdpa_config_ops *ops = vdpa->config;
+
+ /* Give virtio_ring a chance to accept features. */
+ vring_transport_features(vdev);
+
+ return ops->set_features(vdpa, vdev->features);
+}
+
+static const char *virtio_vdpa_bus_name(struct virtio_device *vdev)
+{
+ struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev);
+ struct vdpa_device *vdpa = vd_dev->vdpa;
+
+ return dev_name(&vdpa->dev);
+}
+
+static const struct virtio_config_ops virtio_vdpa_config_ops = {
+ .get = virtio_vdpa_get,
+ .set = virtio_vdpa_set,
+ .generation = virtio_vdpa_generation,
+ .get_status = virtio_vdpa_get_status,
+ .set_status = virtio_vdpa_set_status,
+ .reset = virtio_vdpa_reset,
+ .find_vqs = virtio_vdpa_find_vqs,
+ .del_vqs = virtio_vdpa_del_vqs,
+ .get_features = virtio_vdpa_get_features,
+ .finalize_features = virtio_vdpa_finalize_features,
+ .bus_name = virtio_vdpa_bus_name,
+};
+
+static void virtio_vdpa_release_dev(struct device *_d)
+{
+ struct virtio_device *vdev + container_of(_d, struct virtio_device,
dev);
+ struct virtio_vdpa_device *vd_dev + container_of(vdev, struct
virtio_vdpa_device, vdev);
+
+ kfree(vd_dev);
+}
+
+static int virtio_vdpa_probe(struct vdpa_device *vdpa)
+{
+ const struct vdpa_config_ops *ops = vdpa->config;
+ struct virtio_vdpa_device *vd_dev;
+ int ret = -EINVAL;
+
+ vd_dev = kzalloc(sizeof(*vd_dev), GFP_KERNEL);
+ if (!vd_dev)
+ return -ENOMEM;
+
+ vd_dev->vdev.dev.parent = vdpa_get_dma_dev(vdpa);
+ vd_dev->vdev.dev.release = virtio_vdpa_release_dev;
+ vd_dev->vdev.config = &virtio_vdpa_config_ops;
+ vd_dev->vdpa = vdpa;
+ INIT_LIST_HEAD(&vd_dev->virtqueues);
+ spin_lock_init(&vd_dev->lock);
+
+ vd_dev->vdev.id.device = ops->get_device_id(vdpa);
+ if (vd_dev->vdev.id.device == 0)
+ goto err;
+
+ vd_dev->vdev.id.vendor = ops->get_vendor_id(vdpa);
+ ret = register_virtio_device(&vd_dev->vdev);
+ if (ret)
+ goto err;
+
+ vdpa_set_drvdata(vdpa, vd_dev);
+
+ return 0;
+
+err:
+ kfree(vd_dev);
+ return ret;
+}
+
+static void virtio_vdpa_remove(struct vdpa_device *vdpa)
+{
+ struct virtio_vdpa_device *vd_dev = vdpa_get_drvdata(vdpa);
+
+ unregister_virtio_device(&vd_dev->vdev);
+}
+
+static struct vdpa_driver virtio_vdpa_driver = {
+ .driver = {
+ .name = "virtio_vdpa",
+ },
+ .probe = virtio_vdpa_probe,
+ .remove = virtio_vdpa_remove,
+};
+
+module_vdpa_driver(virtio_vdpa_driver);
+
+MODULE_VERSION(MOD_VERSION);
+MODULE_LICENSE(MOD_LICENSE);
+MODULE_AUTHOR(MOD_AUTHOR);
+MODULE_DESCRIPTION(MOD_DESC);
--
2.19.1
This patch implements a software vDPA networking device. The datapath
is implemented through vringh and workqueue. The device has an on-chip
IOMMU which translates IOVA to PA. For kernel virtio drivers, vDPA
simulator driver provides dma_ops. For vhost driers, set_map() methods
of vdpa_config_ops is implemented to accept mappings from vhost.
Currently, vDPA device simulator will loopback TX traffic to RX. So
the main use case for the device is vDPA feature testing, prototyping
and development.
Note, there's no management API implemented, a vDPA device will be
registered once the module is probed. We need to handle this in the
future development.
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/virtio/vdpa/Kconfig | 17 +
drivers/virtio/vdpa/Makefile | 1 +
drivers/virtio/vdpa/vdpa_sim.c | 678 +++++++++++++++++++++++++++++++++
3 files changed, 696 insertions(+)
create mode 100644 drivers/virtio/vdpa/vdpa_sim.c
diff --git a/drivers/virtio/vdpa/Kconfig b/drivers/virtio/vdpa/Kconfig
index 7a99170e6c30..a7888974dda8 100644
--- a/drivers/virtio/vdpa/Kconfig
+++ b/drivers/virtio/vdpa/Kconfig
@@ -7,3 +7,20 @@ config VDPA
datapath which complies with virtio specifications with
vendor specific control path.
+menuconfig VDPA_MENU
+ bool "VDPA drivers"
+ default n
+
+if VDPA_MENU
+
+config VDPA_SIM
+ tristate "vDPA device simulator"
+ select VDPA
+ default n
+ help
+ vDPA networking device simulator which loop TX traffic back
+ to RX. This device is used for testing, prototyping and
+ development of vDPA.
+
+endif # VDPA_MENU
+
diff --git a/drivers/virtio/vdpa/Makefile b/drivers/virtio/vdpa/Makefile
index ee6a35e8a4fb..5ec0e6ae3c57 100644
--- a/drivers/virtio/vdpa/Makefile
+++ b/drivers/virtio/vdpa/Makefile
@@ -1,2 +1,3 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_VDPA) += vdpa.o
+obj-$(CONFIG_VDPA_SIM) += vdpa_sim.o
diff --git a/drivers/virtio/vdpa/vdpa_sim.c b/drivers/virtio/vdpa/vdpa_sim.c
new file mode 100644
index 000000000000..89783a2b9773
--- /dev/null
+++ b/drivers/virtio/vdpa/vdpa_sim.c
@@ -0,0 +1,678 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * VDPA networking device simulator.
+ *
+ * Copyright (c) 2020, Red Hat Inc. All rights reserved.
+ * Author: Jason Wang <jasowang at redhat.com>
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/uuid.h>
+#include <linux/iommu.h>
+#include <linux/sysfs.h>
+#include <linux/file.h>
+#include <linux/etherdevice.h>
+#include <linux/vringh.h>
+#include <linux/vdpa.h>
+#include <linux/vhost_iotlb.h>
+#include <uapi/linux/virtio_config.h>
+#include <uapi/linux/virtio_net.h>
+
+#define DRV_VERSION "0.1"
+#define DRV_AUTHOR "Jason Wang <jasowang at redhat.com>"
+#define DRV_DESC "vDPA Device Simulator"
+#define DRV_LICENSE "GPL v2"
+
+struct vdpasim_dev {
+ struct device dev;
+};
+
+struct vdpasim_dev *vdpasim_dev;
+
+struct vdpasim_virtqueue {
+ struct vringh vring;
+ struct vringh_kiov iov;
+ unsigned short head;
+ bool ready;
+ u64 desc_addr;
+ u64 device_addr;
+ u64 driver_addr;
+ u32 num;
+ void *private;
+ irqreturn_t (*cb)(void *data);
+};
+
+#define VDPASIM_QUEUE_ALIGN PAGE_SIZE
+#define VDPASIM_QUEUE_MAX 256
+#define VDPASIM_DEVICE_ID 0x1
+#define VDPASIM_VENDOR_ID 0
+#define VDPASIM_VQ_NUM 0x2
+#define VDPASIM_NAME "vdpasim-netdev"
+
+static u64 vdpasim_features = (1ULL << VIRTIO_F_ANY_LAYOUT) |
+ (1ULL << VIRTIO_F_VERSION_1) |
+ (1ULL << VIRTIO_F_IOMMU_PLATFORM);
+
+/* State of each vdpasim device */
+struct vdpasim {
+ struct vdpasim_virtqueue vqs[2];
+ struct work_struct work;
+ /* spinlock to synchronize virtqueue state */
+ spinlock_t lock;
+ struct vdpa_device vdpa;
+ struct virtio_net_config config;
+ struct vhost_iotlb *iommu;
+ void *buffer;
+ u32 status;
+ u32 generation;
+ u64 features;
+};
+
+struct vdpasim *vdpa_sim;
+
+static struct vdpasim *vdpa_to_sim(struct vdpa_device *vdpa)
+{
+ return container_of(vdpa, struct vdpasim, vdpa);
+}
+
+static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx)
+{
+ struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
+ int ret;
+
+ ret = vringh_init_iotlb(&vq->vring, vdpasim_features,
+ VDPASIM_QUEUE_MAX, false,
+ (struct vring_desc *)(uintptr_t)vq->desc_addr,
+ (struct vring_avail *)
+ (uintptr_t)vq->driver_addr,
+ (struct vring_used *)
+ (uintptr_t)vq->device_addr);
+}
+
+static void vdpasim_vq_reset(struct vdpasim_virtqueue *vq)
+{
+ vq->ready = 0;
+ vq->desc_addr = 0;
+ vq->driver_addr = 0;
+ vq->device_addr = 0;
+ vq->cb = NULL;
+ vq->private = NULL;
+ vringh_init_iotlb(&vq->vring, vdpasim_features, VDPASIM_QUEUE_MAX,
+ false, 0, 0, 0);
+}
+
+static void vdpasim_reset(struct vdpasim *vdpasim)
+{
+ int i;
+
+ for (i = 0; i < VDPASIM_VQ_NUM; i++)
+ vdpasim_vq_reset(&vdpasim->vqs[i]);
+
+ vhost_iotlb_reset(vdpasim->iommu);
+
+ vdpasim->features = 0;
+ vdpasim->status = 0;
+ ++vdpasim->generation;
+}
+
+static void vdpasim_work(struct work_struct *work)
+{
+ struct vdpasim *vdpasim = container_of(work, struct
+ vdpasim, work);
+ struct vdpasim_virtqueue *txq = &vdpasim->vqs[1];
+ struct vdpasim_virtqueue *rxq = &vdpasim->vqs[0];
+ size_t read, write, total_write;
+ int err;
+ int pkts = 0;
+
+ spin_lock(&vdpasim->lock);
+
+ if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
+ goto out;
+
+ if (!txq->ready || !rxq->ready)
+ goto out;
+
+ while (true) {
+ total_write = 0;
+ err = vringh_getdesc_iotlb(&txq->vring, &txq->iov, NULL,
+ &txq->head, GFP_ATOMIC);
+ if (err <= 0)
+ break;
+
+ err = vringh_getdesc_iotlb(&rxq->vring, NULL, &rxq->iov,
+ &rxq->head, GFP_ATOMIC);
+ if (err <= 0) {
+ vringh_complete_iotlb(&txq->vring, txq->head, 0);
+ break;
+ }
+
+ while (true) {
+ read = vringh_iov_pull_iotlb(&txq->vring, &txq->iov,
+ vdpasim->buffer,
+ PAGE_SIZE);
+ if (read <= 0)
+ break;
+
+ write = vringh_iov_push_iotlb(&rxq->vring, &rxq->iov,
+ vdpasim->buffer, read);
+ if (write <= 0)
+ break;
+
+ total_write += write;
+ }
+
+ /* Make sure data is wrote before advancing index */
+ smp_wmb();
+
+ vringh_complete_iotlb(&txq->vring, txq->head, 0);
+ vringh_complete_iotlb(&rxq->vring, rxq->head, total_write);
+
+ /* Make sure used is visible before rasing the interrupt. */
+ smp_wmb();
+
+ local_bh_disable();
+ if (txq->cb)
+ txq->cb(txq->private);
+ if (rxq->cb)
+ rxq->cb(rxq->private);
+ local_bh_enable();
+
+ if (++pkts > 4) {
+ schedule_work(&vdpasim->work);
+ goto out;
+ }
+ }
+
+out:
+ spin_unlock(&vdpasim->lock);
+}
+
+static int dir_to_perm(enum dma_data_direction dir)
+{
+ int perm = -EFAULT;
+
+ switch (dir) {
+ case DMA_FROM_DEVICE:
+ perm = VHOST_MAP_WO;
+ break;
+ case DMA_TO_DEVICE:
+ perm = VHOST_MAP_RO;
+ break;
+ case DMA_BIDIRECTIONAL:
+ perm = VHOST_MAP_RW;
+ break;
+ default:
+ break;
+ }
+
+ return perm;
+}
+
+static dma_addr_t vdpasim_map_page(struct device *dev, struct page *page,
+ unsigned long offset, size_t size,
+ enum dma_data_direction dir,
+ unsigned long attrs)
+{
+ struct vdpa_device *vdpa = dev_to_vdpa(dev);
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+ struct vhost_iotlb *iommu = vdpasim->iommu;
+ u64 pa = (page_to_pfn(page) << PAGE_SHIFT) + offset;
+ int ret, perm = dir_to_perm(dir);
+
+ if (perm < 0)
+ return DMA_MAPPING_ERROR;
+
+ /* For simplicity, use identical mapping to avoid e.g iova
+ * allocator.
+ */
+ ret = vhost_iotlb_add_range(iommu, pa, pa + size - 1,
+ pa, dir_to_perm(dir));
+ if (ret)
+ return DMA_MAPPING_ERROR;
+
+ return (dma_addr_t)(pa);
+}
+
+static void vdpasim_unmap_page(struct device *dev, dma_addr_t dma_addr,
+ size_t size, enum dma_data_direction dir,
+ unsigned long attrs)
+{
+ struct vdpa_device *vdpa = dev_to_vdpa(dev);
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+ struct vhost_iotlb *iommu = vdpasim->iommu;
+
+ vhost_iotlb_del_range(iommu, (u64)dma_addr,
+ (u64)dma_addr + size - 1);
+}
+
+static void *vdpasim_alloc_coherent(struct device *dev, size_t size,
+ dma_addr_t *dma_addr, gfp_t flag,
+ unsigned long attrs)
+{
+ struct vdpa_device *vdpa = dev_to_vdpa(dev);
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+ struct vhost_iotlb *iommu = vdpasim->iommu;
+ void *addr = kmalloc(size, flag);
+ int ret;
+
+ if (!addr)
+ *dma_addr = DMA_MAPPING_ERROR;
+ else {
+ u64 pa = virt_to_phys(addr);
+
+ ret = vhost_iotlb_add_range(iommu, (u64)pa,
+ (u64)pa + size - 1,
+ pa, VHOST_MAP_RW);
+ if (ret) {
+ *dma_addr = DMA_MAPPING_ERROR;
+ kfree(addr);
+ addr = NULL;
+ } else
+ *dma_addr = (dma_addr_t)pa;
+ }
+
+ return addr;
+}
+
+static void vdpasim_free_coherent(struct device *dev, size_t size,
+ void *vaddr, dma_addr_t dma_addr,
+ unsigned long attrs)
+{
+ struct vdpa_device *vdpa = dev_to_vdpa(dev);
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+ struct vhost_iotlb *iommu = vdpasim->iommu;
+
+ vhost_iotlb_del_range(iommu, (u64)dma_addr,
+ (u64)dma_addr + size - 1);
+ kfree(phys_to_virt((uintptr_t)dma_addr));
+}
+
+static const struct dma_map_ops vdpasim_dma_ops = {
+ .map_page = vdpasim_map_page,
+ .unmap_page = vdpasim_unmap_page,
+ .alloc = vdpasim_alloc_coherent,
+ .free = vdpasim_free_coherent,
+};
+
+static void vdpasim_release_dev(struct device *_d)
+{
+ struct vdpa_device *vdpa = dev_to_vdpa(_d);
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+
+ kfree(vdpasim->buffer);
+ kfree(vdpasim);
+}
+
+static const struct vdpa_config_ops vdpasim_net_config_ops;
+
+static struct vdpasim *vdpasim_create(void)
+{
+ struct vdpasim *vdpasim;
+ struct virtio_net_config *config;
+ struct vdpa_device *vdpa;
+ struct device *dev;
+ int ret = -ENOMEM;
+
+ vdpasim = kzalloc(sizeof(*vdpasim), GFP_KERNEL);
+ if (!vdpasim)
+ goto err_vdpa_alloc;
+
+ vdpasim->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!vdpasim->buffer)
+ goto err_buffer_alloc;
+
+ vdpasim->iommu = vhost_iotlb_alloc(2048, 0);
+ if (!vdpasim->iommu)
+ goto err_iotlb;
+
+ config = &vdpasim->config;
+ config->mtu = 1500;
+ config->status = VIRTIO_NET_S_LINK_UP;
+ eth_random_addr(config->mac);
+
+ INIT_WORK(&vdpasim->work, vdpasim_work);
+ spin_lock_init(&vdpasim->lock);
+
+ vdpa = &vdpasim->vdpa;
+ vdpa->dev.release = vdpasim_release_dev;
+
+ vringh_set_iotlb(&vdpasim->vqs[0].vring, vdpasim->iommu);
+ vringh_set_iotlb(&vdpasim->vqs[1].vring, vdpasim->iommu);
+
+ dev = &vdpa->dev;
+ dev->coherent_dma_mask = DMA_BIT_MASK(64);
+ set_dma_ops(dev, &vdpasim_dma_ops);
+
+ ret = vdpa_init_device(vdpa, &vdpasim_dev->dev, dev,
+ &vdpasim_net_config_ops);
+ if (ret)
+ goto err_init;
+
+ ret = vdpa_register_device(vdpa);
+ if (ret)
+ goto err_register;
+
+ return vdpasim;
+
+err_register:
+ put_device(&vdpa->dev);
+err_init:
+ vhost_iotlb_free(vdpasim->iommu);
+err_iotlb:
+ kfree(vdpasim->buffer);
+err_buffer_alloc:
+ kfree(vdpasim);
+err_vdpa_alloc:
+ return ERR_PTR(ret);
+}
+
+static int vdpasim_set_vq_address(struct vdpa_device *vdpa, u16 idx,
+ u64 desc_area, u64 driver_area,
+ u64 device_area)
+{
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+ struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
+
+ vq->desc_addr = desc_area;
+ vq->driver_addr = driver_area;
+ vq->device_addr = device_area;
+
+ return 0;
+}
+
+static void vdpasim_set_vq_num(struct vdpa_device *vdpa, u16 idx, u32 num)
+{
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+ struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
+
+ vq->num = num;
+}
+
+static void vdpasim_kick_vq(struct vdpa_device *vdpa, u16 idx)
+{
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+ struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
+
+ if (vq->ready)
+ schedule_work(&vdpasim->work);
+}
+
+static void vdpasim_set_vq_cb(struct vdpa_device *vdpa, u16 idx,
+ struct vdpa_callback *cb)
+{
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+ struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
+
+ vq->cb = cb->callback;
+ vq->private = cb->private;
+}
+
+static void vdpasim_set_vq_ready(struct vdpa_device *vdpa, u16 idx, bool ready)
+{
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+ struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
+
+ spin_lock(&vdpasim->lock);
+ vq->ready = ready;
+ if (vq->ready)
+ vdpasim_queue_ready(vdpasim, idx);
+ spin_unlock(&vdpasim->lock);
+}
+
+static bool vdpasim_get_vq_ready(struct vdpa_device *vdpa, u16 idx)
+{
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+ struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
+
+ return vq->ready;
+}
+
+static int vdpasim_set_vq_state(struct vdpa_device *vdpa, u16 idx, u64 state)
+{
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+ struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
+ struct vringh *vrh = &vq->vring;
+
+ spin_lock(&vdpasim->lock);
+ vrh->last_avail_idx = state;
+ spin_unlock(&vdpasim->lock);
+
+ return 0;
+}
+
+static u64 vdpasim_get_vq_state(struct vdpa_device *vdpa, u16 idx)
+{
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+ struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
+ struct vringh *vrh = &vq->vring;
+
+ return vrh->last_avail_idx;
+}
+
+static u16 vdpasim_get_vq_align(struct vdpa_device *vdpa)
+{
+ return VDPASIM_QUEUE_ALIGN;
+}
+
+static u64 vdpasim_get_features(struct vdpa_device *vdpa)
+{
+ return vdpasim_features;
+}
+
+static int vdpasim_set_features(struct vdpa_device *vdpa, u64 features)
+{
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+
+ /* DMA mapping must be done by driver */
+ if (!(features & (1ULL << VIRTIO_F_IOMMU_PLATFORM)))
+ return -EINVAL;
+
+ vdpasim->features = features & vdpasim_features;
+
+ return 0;
+}
+
+static void vdpasim_set_config_cb(struct vdpa_device *vdpa,
+ struct vdpa_callback *cb)
+{
+ /* We don't support config interrupt */
+}
+
+static u16 vdpasim_get_vq_num_max(struct vdpa_device *vdpa)
+{
+ return VDPASIM_QUEUE_MAX;
+}
+
+static u32 vdpasim_get_device_id(struct vdpa_device *vdpa)
+{
+ return VDPASIM_DEVICE_ID;
+}
+
+static u32 vdpasim_get_vendor_id(struct vdpa_device *vdpa)
+{
+ return VDPASIM_VENDOR_ID;
+}
+
+static u8 vdpasim_get_status(struct vdpa_device *vdpa)
+{
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+ u8 status;
+
+ spin_lock(&vdpasim->lock);
+ status = vdpasim->status;
+ spin_unlock(&vdpasim->lock);
+
+ return vdpasim->status;
+}
+
+static void vdpasim_set_status(struct vdpa_device *vdpa, u8 status)
+{
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+
+ spin_lock(&vdpasim->lock);
+ vdpasim->status = status;
+ if (status == 0)
+ vdpasim_reset(vdpasim);
+ spin_unlock(&vdpasim->lock);
+}
+
+static void vdpasim_get_config(struct vdpa_device *vdpa, unsigned int offset,
+ void *buf, unsigned int len)
+{
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+
+ if (offset + len < sizeof(struct virtio_net_config))
+ memcpy(buf, &vdpasim->config + offset, len);
+}
+
+static void vdpasim_set_config(struct vdpa_device *vdpa, unsigned int offset,
+ const void *buf, unsigned int len)
+{
+ /* No writable config supportted by vdpasim */
+}
+
+static u32 vdpasim_get_generation(struct vdpa_device *vdpa)
+{
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+
+ return vdpasim->generation;
+}
+
+static int vdpasim_set_map(struct vdpa_device *vdpa,
+ struct vhost_iotlb *iotlb)
+{
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+ struct vhost_iotlb_map *map;
+ u64 start = 0ULL, last = 0ULL - 1;
+ int ret;
+
+ vhost_iotlb_reset(vdpasim->iommu);
+
+ for (map = vhost_iotlb_itree_first(iotlb, start, last); map;
+ map = vhost_iotlb_itree_next(map, start, last)) {
+ ret = vhost_iotlb_add_range(vdpasim->iommu, map->start,
+ map->last, map->addr, map->perm);
+ if (ret)
+ goto err;
+ }
+ return 0;
+
+err:
+ vhost_iotlb_reset(vdpasim->iommu);
+ return ret;
+}
+
+static int vdpasim_dma_map(struct vdpa_device *vdpa, u64 iova, u64 size,
+ u64 pa, u32 perm)
+{
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+
+ return vhost_iotlb_add_range(vdpasim->iommu, iova,
+ iova + size - 1, pa, perm);
+}
+
+static int vdpasim_dma_unmap(struct vdpa_device *vdpa, u64 iova, u64 size)
+{
+ struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+
+ vhost_iotlb_del_range(vdpasim->iommu, iova, iova + size - 1);
+
+ return 0;
+}
+
+static const struct vdpa_config_ops vdpasim_net_config_ops = {
+ .set_vq_address = vdpasim_set_vq_address,
+ .set_vq_num = vdpasim_set_vq_num,
+ .kick_vq = vdpasim_kick_vq,
+ .set_vq_cb = vdpasim_set_vq_cb,
+ .set_vq_ready = vdpasim_set_vq_ready,
+ .get_vq_ready = vdpasim_get_vq_ready,
+ .set_vq_state = vdpasim_set_vq_state,
+ .get_vq_state = vdpasim_get_vq_state,
+ .get_vq_align = vdpasim_get_vq_align,
+ .get_features = vdpasim_get_features,
+ .set_features = vdpasim_set_features,
+ .set_config_cb = vdpasim_set_config_cb,
+ .get_vq_num_max = vdpasim_get_vq_num_max,
+ .get_device_id = vdpasim_get_device_id,
+ .get_vendor_id = vdpasim_get_vendor_id,
+ .get_status = vdpasim_get_status,
+ .set_status = vdpasim_set_status,
+ .get_config = vdpasim_get_config,
+ .set_config = vdpasim_set_config,
+ .get_generation = vdpasim_get_generation,
+ .set_map = vdpasim_set_map,
+ .dma_map = vdpasim_dma_map,
+ .dma_unmap = vdpasim_dma_unmap,
+};
+
+static void vdpasim_device_release(struct device *dev)
+{
+ struct vdpasim_dev *vdpasim_dev + container_of(dev, struct vdpasim_dev,
dev);
+
+ vdpasim_dev->dev.bus = NULL;
+ kfree(vdpasim_dev);
+}
+
+static int __init vdpasim_dev_init(void)
+{
+ struct device *dev;
+ int ret = 0;
+
+ vdpasim_dev = kzalloc(sizeof(*vdpasim_dev), GFP_KERNEL);
+ if (!vdpasim_dev)
+ return -ENOMEM;
+
+ dev = &vdpasim_dev->dev;
+ dev->release = vdpasim_device_release;
+ dev_set_name(dev, "%s", VDPASIM_NAME);
+
+ ret = device_register(&vdpasim_dev->dev);
+ if (ret)
+ goto err_register;
+
+ if (!vdpasim_create())
+ goto err_register;
+
+ return 0;
+
+err_register:
+ kfree(vdpasim_dev);
+ vdpasim_dev = NULL;
+ return ret;
+}
+
+static int vdpasim_device_remove_cb(struct device *dev, void *data)
+{
+ struct vdpa_device *vdpa = dev_to_vdpa(dev);
+
+ vdpa_unregister_device(vdpa);
+
+ return 0;
+}
+
+static void __exit vdpasim_dev_exit(void)
+{
+ device_for_each_child(&vdpasim_dev->dev, NULL,
+ vdpasim_device_remove_cb);
+ device_unregister(&vdpasim_dev->dev);
+}
+
+module_init(vdpasim_dev_init)
+module_exit(vdpasim_dev_exit)
+
+MODULE_VERSION(DRV_VERSION);
+MODULE_LICENSE(DRV_LICENSE);
+MODULE_AUTHOR(DRV_AUTHOR);
+MODULE_DESCRIPTION(DRV_DESC);
--
2.19.1
On Mon, Feb 10, 2020 at 11:56:08AM +0800, Jason Wang wrote:> This patch implements a software vDPA networking device. The datapath > is implemented through vringh and workqueue. The device has an on-chip > IOMMU which translates IOVA to PA. For kernel virtio drivers, vDPA > simulator driver provides dma_ops. For vhost driers, set_map() methods > of vdpa_config_ops is implemented to accept mappings from vhost. > > Currently, vDPA device simulator will loopback TX traffic to RX. So > the main use case for the device is vDPA feature testing, prototyping > and development. > > Note, there's no management API implemented, a vDPA device will be > registered once the module is probed. We need to handle this in the > future development. > > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/virtio/vdpa/Kconfig | 17 + > drivers/virtio/vdpa/Makefile | 1 + > drivers/virtio/vdpa/vdpa_sim.c | 678 +++++++++++++++++++++++++++++++++ > 3 files changed, 696 insertions(+) > create mode 100644 drivers/virtio/vdpa/vdpa_sim.c > > diff --git a/drivers/virtio/vdpa/Kconfig b/drivers/virtio/vdpa/Kconfig > index 7a99170e6c30..a7888974dda8 100644 > --- a/drivers/virtio/vdpa/Kconfig > +++ b/drivers/virtio/vdpa/Kconfig > @@ -7,3 +7,20 @@ config VDPA > datapath which complies with virtio specifications with > vendor specific control path. > > +menuconfig VDPA_MENU > + bool "VDPA drivers" > + default n > + > +if VDPA_MENU > + > +config VDPA_SIM > + tristate "vDPA device simulator" > + select VDPA > + default n > + help > + vDPA networking device simulator which loop TX traffic back > + to RX. This device is used for testing, prototyping and > + development of vDPA.So how about we make this depend on RUNTIME_TESTING_MENU?> + > +endif # VDPA_MENU > + > diff --git a/drivers/virtio/vdpa/Makefile b/drivers/virtio/vdpa/Makefile > index ee6a35e8a4fb..5ec0e6ae3c57 100644 > --- a/drivers/virtio/vdpa/Makefile > +++ b/drivers/virtio/vdpa/Makefile > @@ -1,2 +1,3 @@ > # SPDX-License-Identifier: GPL-2.0 > obj-$(CONFIG_VDPA) += vdpa.o > +obj-$(CONFIG_VDPA_SIM) += vdpa_sim.o > diff --git a/drivers/virtio/vdpa/vdpa_sim.c b/drivers/virtio/vdpa/vdpa_sim.c > new file mode 100644 > index 000000000000..89783a2b9773 > --- /dev/null > +++ b/drivers/virtio/vdpa/vdpa_sim.c > @@ -0,0 +1,678 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * VDPA networking device simulator. > + * > + * Copyright (c) 2020, Red Hat Inc. All rights reserved. > + * Author: Jason Wang <jasowang at redhat.com> > + * > + */ > + > +#include <linux/init.h> > +#include <linux/module.h> > +#include <linux/device.h> > +#include <linux/kernel.h> > +#include <linux/fs.h> > +#include <linux/poll.h> > +#include <linux/slab.h> > +#include <linux/sched.h> > +#include <linux/wait.h> > +#include <linux/uuid.h> > +#include <linux/iommu.h> > +#include <linux/sysfs.h> > +#include <linux/file.h> > +#include <linux/etherdevice.h> > +#include <linux/vringh.h> > +#include <linux/vdpa.h> > +#include <linux/vhost_iotlb.h> > +#include <uapi/linux/virtio_config.h> > +#include <uapi/linux/virtio_net.h> > + > +#define DRV_VERSION "0.1" > +#define DRV_AUTHOR "Jason Wang <jasowang at redhat.com>" > +#define DRV_DESC "vDPA Device Simulator" > +#define DRV_LICENSE "GPL v2" > + > +struct vdpasim_dev { > + struct device dev; > +}; > + > +struct vdpasim_dev *vdpasim_dev; > + > +struct vdpasim_virtqueue { > + struct vringh vring; > + struct vringh_kiov iov; > + unsigned short head; > + bool ready; > + u64 desc_addr; > + u64 device_addr; > + u64 driver_addr; > + u32 num; > + void *private; > + irqreturn_t (*cb)(void *data); > +}; > + > +#define VDPASIM_QUEUE_ALIGN PAGE_SIZE > +#define VDPASIM_QUEUE_MAX 256 > +#define VDPASIM_DEVICE_ID 0x1 > +#define VDPASIM_VENDOR_ID 0 > +#define VDPASIM_VQ_NUM 0x2 > +#define VDPASIM_NAME "vdpasim-netdev" > + > +static u64 vdpasim_features = (1ULL << VIRTIO_F_ANY_LAYOUT) | > + (1ULL << VIRTIO_F_VERSION_1) | > + (1ULL << VIRTIO_F_IOMMU_PLATFORM); > + > +/* State of each vdpasim device */ > +struct vdpasim { > + struct vdpasim_virtqueue vqs[2]; > + struct work_struct work; > + /* spinlock to synchronize virtqueue state */ > + spinlock_t lock; > + struct vdpa_device vdpa; > + struct virtio_net_config config; > + struct vhost_iotlb *iommu; > + void *buffer; > + u32 status; > + u32 generation; > + u64 features; > +}; > + > +struct vdpasim *vdpa_sim; > + > +static struct vdpasim *vdpa_to_sim(struct vdpa_device *vdpa) > +{ > + return container_of(vdpa, struct vdpasim, vdpa); > +} > + > +static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx) > +{ > + struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx]; > + int ret; > + > + ret = vringh_init_iotlb(&vq->vring, vdpasim_features, > + VDPASIM_QUEUE_MAX, false, > + (struct vring_desc *)(uintptr_t)vq->desc_addr, > + (struct vring_avail *) > + (uintptr_t)vq->driver_addr, > + (struct vring_used *) > + (uintptr_t)vq->device_addr); > +} > + > +static void vdpasim_vq_reset(struct vdpasim_virtqueue *vq) > +{ > + vq->ready = 0; > + vq->desc_addr = 0; > + vq->driver_addr = 0; > + vq->device_addr = 0; > + vq->cb = NULL; > + vq->private = NULL; > + vringh_init_iotlb(&vq->vring, vdpasim_features, VDPASIM_QUEUE_MAX, > + false, 0, 0, 0); > +} > + > +static void vdpasim_reset(struct vdpasim *vdpasim) > +{ > + int i; > + > + for (i = 0; i < VDPASIM_VQ_NUM; i++) > + vdpasim_vq_reset(&vdpasim->vqs[i]); > + > + vhost_iotlb_reset(vdpasim->iommu); > + > + vdpasim->features = 0; > + vdpasim->status = 0; > + ++vdpasim->generation; > +} > + > +static void vdpasim_work(struct work_struct *work) > +{ > + struct vdpasim *vdpasim = container_of(work, struct > + vdpasim, work); > + struct vdpasim_virtqueue *txq = &vdpasim->vqs[1]; > + struct vdpasim_virtqueue *rxq = &vdpasim->vqs[0]; > + size_t read, write, total_write; > + int err; > + int pkts = 0; > + > + spin_lock(&vdpasim->lock); > + > + if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK)) > + goto out; > + > + if (!txq->ready || !rxq->ready) > + goto out; > + > + while (true) { > + total_write = 0; > + err = vringh_getdesc_iotlb(&txq->vring, &txq->iov, NULL, > + &txq->head, GFP_ATOMIC); > + if (err <= 0) > + break; > + > + err = vringh_getdesc_iotlb(&rxq->vring, NULL, &rxq->iov, > + &rxq->head, GFP_ATOMIC); > + if (err <= 0) { > + vringh_complete_iotlb(&txq->vring, txq->head, 0); > + break; > + } > + > + while (true) { > + read = vringh_iov_pull_iotlb(&txq->vring, &txq->iov, > + vdpasim->buffer, > + PAGE_SIZE); > + if (read <= 0) > + break; > + > + write = vringh_iov_push_iotlb(&rxq->vring, &rxq->iov, > + vdpasim->buffer, read); > + if (write <= 0) > + break; > + > + total_write += write; > + } > + > + /* Make sure data is wrote before advancing index */ > + smp_wmb(); > + > + vringh_complete_iotlb(&txq->vring, txq->head, 0); > + vringh_complete_iotlb(&rxq->vring, rxq->head, total_write); > + > + /* Make sure used is visible before rasing the interrupt. */ > + smp_wmb(); > + > + local_bh_disable(); > + if (txq->cb) > + txq->cb(txq->private); > + if (rxq->cb) > + rxq->cb(rxq->private); > + local_bh_enable(); > + > + if (++pkts > 4) { > + schedule_work(&vdpasim->work); > + goto out; > + } > + } > + > +out: > + spin_unlock(&vdpasim->lock); > +} > + > +static int dir_to_perm(enum dma_data_direction dir) > +{ > + int perm = -EFAULT; > + > + switch (dir) { > + case DMA_FROM_DEVICE: > + perm = VHOST_MAP_WO; > + break; > + case DMA_TO_DEVICE: > + perm = VHOST_MAP_RO; > + break; > + case DMA_BIDIRECTIONAL: > + perm = VHOST_MAP_RW; > + break; > + default: > + break; > + } > + > + return perm; > +} > + > +static dma_addr_t vdpasim_map_page(struct device *dev, struct page *page, > + unsigned long offset, size_t size, > + enum dma_data_direction dir, > + unsigned long attrs) > +{ > + struct vdpa_device *vdpa = dev_to_vdpa(dev); > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + struct vhost_iotlb *iommu = vdpasim->iommu; > + u64 pa = (page_to_pfn(page) << PAGE_SHIFT) + offset; > + int ret, perm = dir_to_perm(dir); > + > + if (perm < 0) > + return DMA_MAPPING_ERROR; > + > + /* For simplicity, use identical mapping to avoid e.g iova > + * allocator. > + */ > + ret = vhost_iotlb_add_range(iommu, pa, pa + size - 1, > + pa, dir_to_perm(dir)); > + if (ret) > + return DMA_MAPPING_ERROR; > + > + return (dma_addr_t)(pa); > +} > + > +static void vdpasim_unmap_page(struct device *dev, dma_addr_t dma_addr, > + size_t size, enum dma_data_direction dir, > + unsigned long attrs) > +{ > + struct vdpa_device *vdpa = dev_to_vdpa(dev); > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + struct vhost_iotlb *iommu = vdpasim->iommu; > + > + vhost_iotlb_del_range(iommu, (u64)dma_addr, > + (u64)dma_addr + size - 1); > +} > + > +static void *vdpasim_alloc_coherent(struct device *dev, size_t size, > + dma_addr_t *dma_addr, gfp_t flag, > + unsigned long attrs) > +{ > + struct vdpa_device *vdpa = dev_to_vdpa(dev); > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + struct vhost_iotlb *iommu = vdpasim->iommu; > + void *addr = kmalloc(size, flag); > + int ret; > + > + if (!addr) > + *dma_addr = DMA_MAPPING_ERROR; > + else { > + u64 pa = virt_to_phys(addr); > + > + ret = vhost_iotlb_add_range(iommu, (u64)pa, > + (u64)pa + size - 1, > + pa, VHOST_MAP_RW); > + if (ret) { > + *dma_addr = DMA_MAPPING_ERROR; > + kfree(addr); > + addr = NULL; > + } else > + *dma_addr = (dma_addr_t)pa; > + } > + > + return addr; > +} > + > +static void vdpasim_free_coherent(struct device *dev, size_t size, > + void *vaddr, dma_addr_t dma_addr, > + unsigned long attrs) > +{ > + struct vdpa_device *vdpa = dev_to_vdpa(dev); > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + struct vhost_iotlb *iommu = vdpasim->iommu; > + > + vhost_iotlb_del_range(iommu, (u64)dma_addr, > + (u64)dma_addr + size - 1); > + kfree(phys_to_virt((uintptr_t)dma_addr)); > +} > + > +static const struct dma_map_ops vdpasim_dma_ops = { > + .map_page = vdpasim_map_page, > + .unmap_page = vdpasim_unmap_page, > + .alloc = vdpasim_alloc_coherent, > + .free = vdpasim_free_coherent, > +}; > + > +static void vdpasim_release_dev(struct device *_d) > +{ > + struct vdpa_device *vdpa = dev_to_vdpa(_d); > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + > + kfree(vdpasim->buffer); > + kfree(vdpasim); > +} > + > +static const struct vdpa_config_ops vdpasim_net_config_ops; > + > +static struct vdpasim *vdpasim_create(void) > +{ > + struct vdpasim *vdpasim; > + struct virtio_net_config *config; > + struct vdpa_device *vdpa; > + struct device *dev; > + int ret = -ENOMEM; > + > + vdpasim = kzalloc(sizeof(*vdpasim), GFP_KERNEL); > + if (!vdpasim) > + goto err_vdpa_alloc; > + > + vdpasim->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); > + if (!vdpasim->buffer) > + goto err_buffer_alloc; > + > + vdpasim->iommu = vhost_iotlb_alloc(2048, 0); > + if (!vdpasim->iommu) > + goto err_iotlb; > + > + config = &vdpasim->config; > + config->mtu = 1500; > + config->status = VIRTIO_NET_S_LINK_UP; > + eth_random_addr(config->mac); > + > + INIT_WORK(&vdpasim->work, vdpasim_work); > + spin_lock_init(&vdpasim->lock); > + > + vdpa = &vdpasim->vdpa; > + vdpa->dev.release = vdpasim_release_dev; > + > + vringh_set_iotlb(&vdpasim->vqs[0].vring, vdpasim->iommu); > + vringh_set_iotlb(&vdpasim->vqs[1].vring, vdpasim->iommu); > + > + dev = &vdpa->dev; > + dev->coherent_dma_mask = DMA_BIT_MASK(64); > + set_dma_ops(dev, &vdpasim_dma_ops); > + > + ret = vdpa_init_device(vdpa, &vdpasim_dev->dev, dev, > + &vdpasim_net_config_ops); > + if (ret) > + goto err_init; > + > + ret = vdpa_register_device(vdpa); > + if (ret) > + goto err_register; > + > + return vdpasim; > + > +err_register: > + put_device(&vdpa->dev); > +err_init: > + vhost_iotlb_free(vdpasim->iommu); > +err_iotlb: > + kfree(vdpasim->buffer); > +err_buffer_alloc: > + kfree(vdpasim); > +err_vdpa_alloc: > + return ERR_PTR(ret); > +} > + > +static int vdpasim_set_vq_address(struct vdpa_device *vdpa, u16 idx, > + u64 desc_area, u64 driver_area, > + u64 device_area) > +{ > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx]; > + > + vq->desc_addr = desc_area; > + vq->driver_addr = driver_area; > + vq->device_addr = device_area; > + > + return 0; > +} > + > +static void vdpasim_set_vq_num(struct vdpa_device *vdpa, u16 idx, u32 num) > +{ > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx]; > + > + vq->num = num; > +} > + > +static void vdpasim_kick_vq(struct vdpa_device *vdpa, u16 idx) > +{ > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx]; > + > + if (vq->ready) > + schedule_work(&vdpasim->work); > +} > + > +static void vdpasim_set_vq_cb(struct vdpa_device *vdpa, u16 idx, > + struct vdpa_callback *cb) > +{ > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx]; > + > + vq->cb = cb->callback; > + vq->private = cb->private; > +} > + > +static void vdpasim_set_vq_ready(struct vdpa_device *vdpa, u16 idx, bool ready) > +{ > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx]; > + > + spin_lock(&vdpasim->lock); > + vq->ready = ready; > + if (vq->ready) > + vdpasim_queue_ready(vdpasim, idx); > + spin_unlock(&vdpasim->lock); > +} > + > +static bool vdpasim_get_vq_ready(struct vdpa_device *vdpa, u16 idx) > +{ > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx]; > + > + return vq->ready; > +} > + > +static int vdpasim_set_vq_state(struct vdpa_device *vdpa, u16 idx, u64 state) > +{ > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx]; > + struct vringh *vrh = &vq->vring; > + > + spin_lock(&vdpasim->lock); > + vrh->last_avail_idx = state; > + spin_unlock(&vdpasim->lock); > + > + return 0; > +} > + > +static u64 vdpasim_get_vq_state(struct vdpa_device *vdpa, u16 idx) > +{ > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx]; > + struct vringh *vrh = &vq->vring; > + > + return vrh->last_avail_idx; > +} > + > +static u16 vdpasim_get_vq_align(struct vdpa_device *vdpa) > +{ > + return VDPASIM_QUEUE_ALIGN; > +} > + > +static u64 vdpasim_get_features(struct vdpa_device *vdpa) > +{ > + return vdpasim_features; > +} > + > +static int vdpasim_set_features(struct vdpa_device *vdpa, u64 features) > +{ > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + > + /* DMA mapping must be done by driver */ > + if (!(features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))) > + return -EINVAL; > + > + vdpasim->features = features & vdpasim_features; > + > + return 0; > +} > + > +static void vdpasim_set_config_cb(struct vdpa_device *vdpa, > + struct vdpa_callback *cb) > +{ > + /* We don't support config interrupt */ > +} > + > +static u16 vdpasim_get_vq_num_max(struct vdpa_device *vdpa) > +{ > + return VDPASIM_QUEUE_MAX; > +} > + > +static u32 vdpasim_get_device_id(struct vdpa_device *vdpa) > +{ > + return VDPASIM_DEVICE_ID; > +} > + > +static u32 vdpasim_get_vendor_id(struct vdpa_device *vdpa) > +{ > + return VDPASIM_VENDOR_ID; > +} > + > +static u8 vdpasim_get_status(struct vdpa_device *vdpa) > +{ > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + u8 status; > + > + spin_lock(&vdpasim->lock); > + status = vdpasim->status; > + spin_unlock(&vdpasim->lock); > + > + return vdpasim->status; > +} > + > +static void vdpasim_set_status(struct vdpa_device *vdpa, u8 status) > +{ > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + > + spin_lock(&vdpasim->lock); > + vdpasim->status = status; > + if (status == 0) > + vdpasim_reset(vdpasim); > + spin_unlock(&vdpasim->lock); > +} > + > +static void vdpasim_get_config(struct vdpa_device *vdpa, unsigned int offset, > + void *buf, unsigned int len) > +{ > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + > + if (offset + len < sizeof(struct virtio_net_config)) > + memcpy(buf, &vdpasim->config + offset, len); > +} > + > +static void vdpasim_set_config(struct vdpa_device *vdpa, unsigned int offset, > + const void *buf, unsigned int len) > +{ > + /* No writable config supportted by vdpasim */ > +} > + > +static u32 vdpasim_get_generation(struct vdpa_device *vdpa) > +{ > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + > + return vdpasim->generation; > +} > + > +static int vdpasim_set_map(struct vdpa_device *vdpa, > + struct vhost_iotlb *iotlb) > +{ > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + struct vhost_iotlb_map *map; > + u64 start = 0ULL, last = 0ULL - 1; > + int ret; > + > + vhost_iotlb_reset(vdpasim->iommu); > + > + for (map = vhost_iotlb_itree_first(iotlb, start, last); map; > + map = vhost_iotlb_itree_next(map, start, last)) { > + ret = vhost_iotlb_add_range(vdpasim->iommu, map->start, > + map->last, map->addr, map->perm); > + if (ret) > + goto err; > + } > + return 0; > + > +err: > + vhost_iotlb_reset(vdpasim->iommu); > + return ret; > +} > + > +static int vdpasim_dma_map(struct vdpa_device *vdpa, u64 iova, u64 size, > + u64 pa, u32 perm) > +{ > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + > + return vhost_iotlb_add_range(vdpasim->iommu, iova, > + iova + size - 1, pa, perm); > +} > + > +static int vdpasim_dma_unmap(struct vdpa_device *vdpa, u64 iova, u64 size) > +{ > + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); > + > + vhost_iotlb_del_range(vdpasim->iommu, iova, iova + size - 1); > + > + return 0; > +} > + > +static const struct vdpa_config_ops vdpasim_net_config_ops = { > + .set_vq_address = vdpasim_set_vq_address, > + .set_vq_num = vdpasim_set_vq_num, > + .kick_vq = vdpasim_kick_vq, > + .set_vq_cb = vdpasim_set_vq_cb, > + .set_vq_ready = vdpasim_set_vq_ready, > + .get_vq_ready = vdpasim_get_vq_ready, > + .set_vq_state = vdpasim_set_vq_state, > + .get_vq_state = vdpasim_get_vq_state, > + .get_vq_align = vdpasim_get_vq_align, > + .get_features = vdpasim_get_features, > + .set_features = vdpasim_set_features, > + .set_config_cb = vdpasim_set_config_cb, > + .get_vq_num_max = vdpasim_get_vq_num_max, > + .get_device_id = vdpasim_get_device_id, > + .get_vendor_id = vdpasim_get_vendor_id, > + .get_status = vdpasim_get_status, > + .set_status = vdpasim_set_status, > + .get_config = vdpasim_get_config, > + .set_config = vdpasim_set_config, > + .get_generation = vdpasim_get_generation, > + .set_map = vdpasim_set_map, > + .dma_map = vdpasim_dma_map, > + .dma_unmap = vdpasim_dma_unmap, > +}; > + > +static void vdpasim_device_release(struct device *dev) > +{ > + struct vdpasim_dev *vdpasim_dev > + container_of(dev, struct vdpasim_dev, dev); > + > + vdpasim_dev->dev.bus = NULL; > + kfree(vdpasim_dev); > +} > + > +static int __init vdpasim_dev_init(void) > +{ > + struct device *dev; > + int ret = 0; > + > + vdpasim_dev = kzalloc(sizeof(*vdpasim_dev), GFP_KERNEL); > + if (!vdpasim_dev) > + return -ENOMEM; > + > + dev = &vdpasim_dev->dev; > + dev->release = vdpasim_device_release; > + dev_set_name(dev, "%s", VDPASIM_NAME); > + > + ret = device_register(&vdpasim_dev->dev); > + if (ret) > + goto err_register; > + > + if (!vdpasim_create()) > + goto err_register; > + > + return 0; > + > +err_register: > + kfree(vdpasim_dev); > + vdpasim_dev = NULL; > + return ret; > +} > + > +static int vdpasim_device_remove_cb(struct device *dev, void *data) > +{ > + struct vdpa_device *vdpa = dev_to_vdpa(dev); > + > + vdpa_unregister_device(vdpa); > + > + return 0; > +} > + > +static void __exit vdpasim_dev_exit(void) > +{ > + device_for_each_child(&vdpasim_dev->dev, NULL, > + vdpasim_device_remove_cb); > + device_unregister(&vdpasim_dev->dev); > +} > + > +module_init(vdpasim_dev_init) > +module_exit(vdpasim_dev_exit) > + > +MODULE_VERSION(DRV_VERSION); > +MODULE_LICENSE(DRV_LICENSE); > +MODULE_AUTHOR(DRV_AUTHOR); > +MODULE_DESCRIPTION(DRV_DESC); > -- > 2.19.1
Jason Gunthorpe
2020-Feb-10 13:34 UTC
[PATCH V2 4/5] virtio: introduce a vDPA based transport
On Mon, Feb 10, 2020 at 11:56:07AM +0800, Jason Wang wrote:> This patch introduces a vDPA transport for virtio. This is used to > use kernel virtio driver to drive the mediated device that is capable > of populating virtqueue directly.Is this comment still right? Is there a mediated device still? Jason
On Mon, Feb 10, 2020 at 11:56:06AM +0800, Jason Wang wrote:> +/** > + * vdpa_register_device - register a vDPA device > + * Callers must have a succeed call of vdpa_init_device() before. > + * @vdev: the vdpa device to be registered to vDPA bus > + * > + * Returns an error when fail to add to vDPA bus > + */ > +int vdpa_register_device(struct vdpa_device *vdev) > +{ > + int err = device_add(&vdev->dev); > + > + if (err) { > + put_device(&vdev->dev); > + ida_simple_remove(&vdpa_index_ida, vdev->index); > + }This is a very dangerous construction, I've seen it lead to driver bugs. Better to require the driver to always do the put_device on error unwind The ida_simple_remove should probably be part of the class release function to make everything work right> +/** > + * vdpa_unregister_driver - unregister a vDPA device driver > + * @drv: the vdpa device driver to be unregistered > + */ > +void vdpa_unregister_driver(struct vdpa_driver *drv) > +{ > + driver_unregister(&drv->driver); > +} > +EXPORT_SYMBOL_GPL(vdpa_unregister_driver); > + > +static int vdpa_init(void) > +{ > + if (bus_register(&vdpa_bus) != 0) > + panic("virtio bus registration failed"); > + return 0; > +}Linus will tell you not to kill the kernel - return the error code and propagate it up to the module init function.> +/** > + * vDPA device - representation of a vDPA device > + * @dev: underlying device > + * @dma_dev: the actual device that is performing DMA > + * @config: the configuration ops for this device. > + * @index: device index > + */ > +struct vdpa_device { > + struct device dev; > + struct device *dma_dev; > + const struct vdpa_config_ops *config; > + int index;unsigned values shuld be unsigned int Jason
On Mon, Feb 10, 2020 at 11:56:08AM +0800, Jason Wang wrote:> + > +static struct vdpasim *vdpasim_create(void) > +{ > + struct vdpasim *vdpasim; > + struct virtio_net_config *config; > + struct vdpa_device *vdpa; > + struct device *dev; > + int ret = -ENOMEM; > + > + vdpasim = kzalloc(sizeof(*vdpasim), GFP_KERNEL); > + if (!vdpasim) > + goto err_vdpa_alloc; > + > + vdpasim->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); > + if (!vdpasim->buffer) > + goto err_buffer_alloc; > + > + vdpasim->iommu = vhost_iotlb_alloc(2048, 0); > + if (!vdpasim->iommu) > + goto err_iotlb; > + > + config = &vdpasim->config; > + config->mtu = 1500; > + config->status = VIRTIO_NET_S_LINK_UP; > + eth_random_addr(config->mac); > + > + INIT_WORK(&vdpasim->work, vdpasim_work); > + spin_lock_init(&vdpasim->lock); > + > + vdpa = &vdpasim->vdpa; > + vdpa->dev.release = vdpasim_release_dev;The driver should not provide the release function. Again the safest model is 'vdpa_alloc_device' which combines the kzalloc and the vdpa_init_device() and returns something that is error unwound with put_device() The subsystem owns the release and does the kfree and other cleanup like releasing the IDA.> + vringh_set_iotlb(&vdpasim->vqs[0].vring, vdpasim->iommu); > + vringh_set_iotlb(&vdpasim->vqs[1].vring, vdpasim->iommu); > + > + dev = &vdpa->dev; > + dev->coherent_dma_mask = DMA_BIT_MASK(64); > + set_dma_ops(dev, &vdpasim_dma_ops); > + > + ret = vdpa_init_device(vdpa, &vdpasim_dev->dev, dev, > + &vdpasim_net_config_ops); > + if (ret) > + goto err_init; > + > + ret = vdpa_register_device(vdpa); > + if (ret) > + goto err_register;See? This error unwind is now all wrong:> + > + return vdpasim; > + > +err_register: > + put_device(&vdpa->dev);Double put_device> +err_init: > + vhost_iotlb_free(vdpasim->iommu); > +err_iotlb: > + kfree(vdpasim->buffer); > +err_buffer_alloc: > + kfree(vdpasim);kfree after vdpa_init_device() is incorrect, as the put_device now does kfree via release> +static int __init vdpasim_dev_init(void) > +{ > + struct device *dev; > + int ret = 0; > + > + vdpasim_dev = kzalloc(sizeof(*vdpasim_dev), GFP_KERNEL); > + if (!vdpasim_dev) > + return -ENOMEM; > + > + dev = &vdpasim_dev->dev; > + dev->release = vdpasim_device_release; > + dev_set_name(dev, "%s", VDPASIM_NAME); > + > + ret = device_register(&vdpasim_dev->dev); > + if (ret) > + goto err_register; > + > + if (!vdpasim_create()) > + goto err_register;Wrong error unwind here too> + return 0; > + > +err_register: > + kfree(vdpasim_dev); > + vdpasim_dev = NULL; > + return ret; > +}Jason