Based on Rusty's patches.
Coding style and funny jokes are his.
Bugs and a star wars reference (should be easy to spot) are mine.
Untested, but useful as basis for beginning the qemu work.
TODO:
= simplify probing: use a common probe function, probe with modern driver
first, if that fails - probe with legacy driver.
BUGS: ATM legacy driver can win and drive a transitional device
Until this is fixed, to test, disable transitional mode in device
More ideas (optional):
= allow disabling legacy driver
= support shared IRQ for config, read ISR
= allocate VQ ring in chunks, good for large rings
= use less meory for small VQ ring in chunks, good for large rings
General TODOs:
= add config generation support
= move alloc_virtqueue_pages to virtio core, reuse in e.g. ccw
Michael S Tsirkin (1):
pci: add pci_iomap_range
Michael S. Tsirkin (2):
virtio_pci: add VIRTIO_PCI_NO_LEGACY
virtio_pci: modern driver
Rusty Russell (2):
virtio-pci: define layout for virtio 1.0
virtio_pci: macros for PCI layout offsets.
drivers/virtio/virtio_pci_common.h | 23 +-
include/asm-generic/pci_iomap.h | 5 +
include/uapi/linux/virtio_pci.h | 106 ++++++-
drivers/virtio/virtio_pci_modern.c | 621 +++++++++++++++++++++++++++++++++++++
lib/pci_iomap.c | 46 ++-
drivers/virtio/Makefile | 2 +-
6 files changed, 788 insertions(+), 15 deletions(-)
create mode 100644 drivers/virtio/virtio_pci_modern.c
--
MST
Michael S. Tsirkin
2014-Dec-11 19:37 UTC
[PATCH RFC 1/5] virtio_pci: add VIRTIO_PCI_NO_LEGACY
Add macro to disable all legacy register defines. Helpful to make sure legacy macros don't leak through into modern code. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- include/uapi/linux/virtio_pci.h | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h index e5ec1ca..35b552c 100644 --- a/include/uapi/linux/virtio_pci.h +++ b/include/uapi/linux/virtio_pci.h @@ -41,6 +41,8 @@ #include <linux/virtio_config.h> +#ifndef VIRTIO_PCI_NO_LEGACY + /* A 32-bit r/o bitmask of the features supported by the host */ #define VIRTIO_PCI_HOST_FEATURES 0 @@ -67,16 +69,11 @@ * a read-and-acknowledge. */ #define VIRTIO_PCI_ISR 19 -/* The bit of the ISR which indicates a device configuration change. */ -#define VIRTIO_PCI_ISR_CONFIG 0x2 - /* MSI-X registers: only enabled if MSI-X is enabled. */ /* A 16-bit vector for configuration changes. */ #define VIRTIO_MSI_CONFIG_VECTOR 20 /* A 16-bit vector for selected queue notifications. */ #define VIRTIO_MSI_QUEUE_VECTOR 22 -/* Vector value used to disable MSI for queue */ -#define VIRTIO_MSI_NO_VECTOR 0xffff /* The remaining space is defined by each driver as the per-driver * configuration space */ @@ -94,4 +91,12 @@ /* The alignment to use between consumer and producer parts of vring. * x86 pagesize again. */ #define VIRTIO_PCI_VRING_ALIGN 4096 + +#endif /* VIRTIO_PCI_NO_LEGACY */ + +/* The bit of the ISR which indicates a device configuration change. */ +#define VIRTIO_PCI_ISR_CONFIG 0x2 +/* Vector value used to disable MSI for queue */ +#define VIRTIO_MSI_NO_VECTOR 0xffff + #endif -- MST
Michael S. Tsirkin
2014-Dec-11 19:37 UTC
[PATCH RFC 2/5] virtio-pci: define layout for virtio 1.0
From: Rusty Russell <rusty at rustcorp.com.au>
Based on patches by Michael S. Tsirkin <mst at redhat.com>, but I found it
hard to follow so changed to use structures which are more
self-documenting.
Signed-off-by: Rusty Russell <rusty at rustcorp.com.au>
Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
---
include/uapi/linux/virtio_pci.h | 62 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 62 insertions(+)
diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h
index 35b552c..8423764 100644
--- a/include/uapi/linux/virtio_pci.h
+++ b/include/uapi/linux/virtio_pci.h
@@ -99,4 +99,66 @@
/* Vector value used to disable MSI for queue */
#define VIRTIO_MSI_NO_VECTOR 0xffff
+#ifndef VIRTIO_PCI_NO_MODERN
+
+/* IDs for different capabilities. Must all exist. */
+
+/* Common configuration */
+#define VIRTIO_PCI_CAP_COMMON_CFG 1
+/* Notifications */
+#define VIRTIO_PCI_CAP_NOTIFY_CFG 2
+/* ISR access */
+#define VIRTIO_PCI_CAP_ISR_CFG 3
+/* Device specific confiuration */
+#define VIRTIO_PCI_CAP_DEVICE_CFG 4
+
+/* This is the PCI capability header: */
+struct virtio_pci_cap {
+ __u8 cap_vndr; /* Generic PCI field: PCI_CAP_ID_VNDR */
+ __u8 cap_next; /* Generic PCI field: next ptr. */
+ __u8 cap_len; /* Generic PCI field: capability length */
+ __u8 type_and_bar; /* Upper 3 bits: bar.
+ * Lower 3 is VIRTIO_PCI_CAP_*_CFG. */
+ __le32 offset; /* Offset within bar. */
+ __le32 length; /* Length. */
+};
+
+#define VIRTIO_PCI_CAP_BAR_SHIFT 5
+#define VIRTIO_PCI_CAP_BAR_MASK 0x7
+#define VIRTIO_PCI_CAP_TYPE_SHIFT 0
+#define VIRTIO_PCI_CAP_TYPE_MASK 0x7
+
+struct virtio_pci_notify_cap {
+ struct virtio_pci_cap cap;
+ __le32 notify_off_multiplier; /* Multiplier for queue_notify_off. */
+};
+
+/* Fields in VIRTIO_PCI_CAP_COMMON_CFG: */
+struct virtio_pci_common_cfg {
+ /* About the whole device. */
+ __le32 device_feature_select; /* read-write */
+ __le32 device_feature; /* read-only */
+ __le32 guest_feature_select; /* read-write */
+ __le32 guest_feature; /* read-write */
+ __le16 msix_config; /* read-write */
+ __le16 num_queues; /* read-only */
+ __u8 device_status; /* read-write */
+ __u8 unused1;
+
+ /* About a specific virtqueue. */
+ __le16 queue_select; /* read-write */
+ __le16 queue_size; /* read-write, power of 2. */
+ __le16 queue_msix_vector; /* read-write */
+ __le16 queue_enable; /* read-write */
+ __le16 queue_notify_off; /* read-only */
+ __le32 queue_desc_lo; /* read-write */
+ __le32 queue_desc_hi; /* read-write */
+ __le32 queue_avail_lo; /* read-write */
+ __le32 queue_avail_hi; /* read-write */
+ __le32 queue_used_lo; /* read-write */
+ __le32 queue_used_hi; /* read-write */
+};
+
+#endif /* VIRTIO_PCI_NO_MODERN */
+
#endif
--
MST
From: Michael S Tsirkin <mst at redhat.com>
Virtio drivers should map the part of the range they need, not necessarily
all of it. They also need non-cacheable mapping even for
prefetchable BARs.
Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
Signed-off-by: Rusty Russell <rusty at rustcorp.com.au>
---
include/asm-generic/pci_iomap.h | 5 +++++
lib/pci_iomap.c | 46 +++++++++++++++++++++++++++++++++++------
2 files changed, 45 insertions(+), 6 deletions(-)
diff --git a/include/asm-generic/pci_iomap.h b/include/asm-generic/pci_iomap.h
index ce37349..8777331 100644
--- a/include/asm-generic/pci_iomap.h
+++ b/include/asm-generic/pci_iomap.h
@@ -15,6 +15,11 @@ struct pci_dev;
#ifdef CONFIG_PCI
/* Create a virtual mapping cookie for a PCI BAR (memory or IO) */
extern void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long
max);
+extern void __iomem *pci_iomap_range(struct pci_dev *dev, int bar,
+ unsigned offset,
+ unsigned long minlen,
+ unsigned long maxlen,
+ bool force_nocache);
/* Create a virtual mapping cookie for a port on a given PCI device.
* Do not call this directly, it exists to make it easier for architectures
* to override */
diff --git a/lib/pci_iomap.c b/lib/pci_iomap.c
index 0d83ea8..1ac4def 100644
--- a/lib/pci_iomap.c
+++ b/lib/pci_iomap.c
@@ -10,33 +10,47 @@
#ifdef CONFIG_PCI
/**
- * pci_iomap - create a virtual mapping cookie for a PCI BAR
+ * pci_iomap_range - create a virtual mapping cookie for a PCI BAR
* @dev: PCI device that owns the BAR
* @bar: BAR number
- * @maxlen: length of the memory to map
+ * @offset: map memory at the given offset in BAR
+ * @minlen: min length of the memory to map
+ * @maxlen: max length of the memory to map
*
* Using this function you will get a __iomem address to your device BAR.
* You can access it using ioread*() and iowrite*(). These functions hide
* the details if this is a MMIO or PIO address space and will just do what
* you expect from them in the correct way.
*
+ * @minlen specifies the minimum length to map. We check that BAR is
+ * large enough.
* @maxlen specifies the maximum length to map. If you want to get access to
- * the complete BAR without checking for its length first, pass %0 here.
+ * the complete BAR from offset to the end, pass %0 here.
+ * @force_nocache makes the mapping noncacheable even if the BAR
+ * is prefetcheable. It has no effect otherwise.
* */
-void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
+void __iomem *pci_iomap_range(struct pci_dev *dev, int bar,
+ unsigned offset,
+ unsigned long minlen,
+ unsigned long maxlen,
+ bool force_nocache)
{
resource_size_t start = pci_resource_start(dev, bar);
resource_size_t len = pci_resource_len(dev, bar);
unsigned long flags = pci_resource_flags(dev, bar);
- if (!len || !start)
+ if (len <= offset || !start)
+ return NULL;
+ len -= offset;
+ start += offset;
+ if (len < minlen)
return NULL;
if (maxlen && len > maxlen)
len = maxlen;
if (flags & IORESOURCE_IO)
return __pci_ioport_map(dev, start, len);
if (flags & IORESOURCE_MEM) {
- if (flags & IORESOURCE_CACHEABLE)
+ if (!force_nocache && (flags & IORESOURCE_CACHEABLE))
return ioremap(start, len);
return ioremap_nocache(start, len);
}
@@ -44,5 +58,25 @@ void __iomem *pci_iomap(struct pci_dev *dev, int bar,
unsigned long maxlen)
return NULL;
}
+/**
+ * pci_iomap - create a virtual mapping cookie for a PCI BAR
+ * @dev: PCI device that owns the BAR
+ * @bar: BAR number
+ * @maxlen: length of the memory to map
+ *
+ * Using this function you will get a __iomem address to your device BAR.
+ * You can access it using ioread*() and iowrite*(). These functions hide
+ * the details if this is a MMIO or PIO address space and will just do what
+ * you expect from them in the correct way.
+ *
+ * @maxlen specifies the maximum length to map. If you want to get access to
+ * the complete BAR without checking for its length first, pass %0 here.
+ * */
+void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
+{
+ return pci_iomap_range(dev, bar, 0, 0, maxlen, false);
+}
+
EXPORT_SYMBOL(pci_iomap);
+EXPORT_SYMBOL(pci_iomap_range);
#endif /* CONFIG_PCI */
--
MST
It compiles! Must be perfect.
Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
---
drivers/virtio/virtio_pci_common.h | 23 +-
include/uapi/linux/virtio_pci.h | 29 ++
drivers/virtio/virtio_pci_modern.c | 560 +++++++++++++++++++++++++++++++++++++
drivers/virtio/Makefile | 2 +-
4 files changed, 610 insertions(+), 4 deletions(-)
create mode 100644 drivers/virtio/virtio_pci_modern.c
diff --git a/drivers/virtio/virtio_pci_common.h
b/drivers/virtio/virtio_pci_common.h
index 38d99ad..1567531 100644
--- a/drivers/virtio/virtio_pci_common.h
+++ b/drivers/virtio/virtio_pci_common.h
@@ -53,12 +53,29 @@ struct virtio_pci_device {
struct virtio_device vdev;
struct pci_dev *pci_dev;
+ /* In legacy mode, these two point to within ->legacy. */
+ /* Where to read and clear interrupt */
+ u8 __iomem *isr;
+
+ /* Modern only fields */
+ /* The IO mapping for the PCI config space (non-legacy mode) */
+ struct virtio_pci_common_cfg __iomem *common;
+ /* Device-specific data (non-legacy mode) */
+ void __iomem *device;
+ /* Base of vq notifications (non-legacy mode). */
+ void __iomem *notify_base;
+
+ /* So we can sanity-check accesses. */
+ size_t notify_len;
+ size_t device_len;
+
+ /* Multiply queue_notify_off by this value. (non-legacy mode). */
+ u32 notify_offset_multiplier;
+
+ /* Legacy only field */
/* the IO mapping for the PCI config space */
void __iomem *ioaddr;
- /* the IO mapping for ISR operation */
- void __iomem *isr;
-
/* a list of queues so we can dispatch IRQs */
spinlock_t lock;
struct list_head virtqueues;
diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h
index 8423764..601c66b 100644
--- a/include/uapi/linux/virtio_pci.h
+++ b/include/uapi/linux/virtio_pci.h
@@ -159,6 +159,35 @@ struct virtio_pci_common_cfg {
__le32 queue_used_hi; /* read-write */
};
+/* Macro versions of offsets for the Old Timers! */
+#define VIRTIO_PCI_CAP_VNDR 0
+#define VIRTIO_PCI_CAP_NEXT 1
+#define VIRTIO_PCI_CAP_LEN 2
+#define VIRTIO_PCI_CAP_TYPE_AND_BAR 3
+#define VIRTIO_PCI_CAP_OFFSET 4
+#define VIRTIO_PCI_CAP_LENGTH 8
+
+#define VIRTIO_PCI_NOTIFY_CAP_MULT 12
+
+#define VIRTIO_PCI_COMMON_DFSELECT 0
+#define VIRTIO_PCI_COMMON_DF 4
+#define VIRTIO_PCI_COMMON_GFSELECT 8
+#define VIRTIO_PCI_COMMON_GF 12
+#define VIRTIO_PCI_COMMON_MSIX 16
+#define VIRTIO_PCI_COMMON_NUMQ 18
+#define VIRTIO_PCI_COMMON_STATUS 20
+#define VIRTIO_PCI_COMMON_Q_SELECT 22
+#define VIRTIO_PCI_COMMON_Q_SIZE 24
+#define VIRTIO_PCI_COMMON_Q_MSIX 26
+#define VIRTIO_PCI_COMMON_Q_ENABLE 28
+#define VIRTIO_PCI_COMMON_Q_NOFF 30
+#define VIRTIO_PCI_COMMON_Q_DESCLO 32
+#define VIRTIO_PCI_COMMON_Q_DESCHI 36
+#define VIRTIO_PCI_COMMON_Q_AVAILLO 40
+#define VIRTIO_PCI_COMMON_Q_AVAILHI 44
+#define VIRTIO_PCI_COMMON_Q_USEDLO 48
+#define VIRTIO_PCI_COMMON_Q_USEDHI 52
+
#endif /* VIRTIO_PCI_NO_MODERN */
#endif
diff --git a/drivers/virtio/virtio_pci_modern.c
b/drivers/virtio/virtio_pci_modern.c
new file mode 100644
index 0000000..e6e65e1
--- /dev/null
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -0,0 +1,560 @@
+/*
+ * Virtio PCI driver - legacy device support
+ *
+ * This module allows virtio devices to be used over a virtual PCI device.
+ * This can be used with QEMU based VMMs like KVM or Xen.
+ *
+ * Copyright IBM Corp. 2007
+ * Copyright Red Hat, Inc. 2014
+ *
+ * Authors:
+ * Anthony Liguori <aliguori at us.ibm.com>
+ * Rusty Russell <rusty at rustcorp.com.au>
+ * Michael S. Tsirkin <mst at redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#define VIRTIO_PCI_NO_LEGACY
+#include "virtio_pci_common.h"
+
+/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
+static const struct pci_device_id virtio_pci_id_table[] = {
+ { PCI_DEVICE(0x1af4, PCI_ANY_ID) },
+ { 0 }
+};
+
+MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
+
+static void iowrite64_twopart(u64 val, __le32 __iomem *lo, __le32 __iomem *hi)
+{
+ iowrite32((u32)val, lo);
+ iowrite32(val >> 32, hi);
+}
+
+/* virtio config->get_features() implementation */
+static u64 vp_get_features(struct virtio_device *vdev)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ u64 features;
+
+ iowrite32(0, &vp_dev->common->device_feature_select);
+ features = ioread32(&vp_dev->common->device_feature);
+ iowrite32(1, &vp_dev->common->device_feature_select);
+ features |= ((u64)ioread32(&vp_dev->common->device_feature) <<
32);
+
+ return features;
+}
+
+/* virtio config->finalize_features() implementation */
+static int vp_finalize_features(struct virtio_device *vdev)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+
+ /* Give virtio_ring a chance to accept features. */
+ vring_transport_features(vdev);
+
+ iowrite32(0, &vp_dev->common->guest_feature_select);
+ iowrite32((u32)vdev->features, &vp_dev->common->guest_feature);
+ iowrite32(1, &vp_dev->common->guest_feature_select);
+ iowrite32(vdev->features >> 32,
&vp_dev->common->guest_feature);
+
+ return 0;
+}
+
+/* virtio config->get() implementation */
+static void vp_get(struct virtio_device *vdev, unsigned offset,
+ void *buf, unsigned len)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ u8 b;
+ __le16 w;
+ __le32 l;
+
+ switch (len) {
+ case 1:
+ b = ioread8(vp_dev->device + offset);
+ memcpy(buf, &b, sizeof b);
+ break;
+ case 2:
+ w = cpu_to_le16(ioread16(vp_dev->device + offset));
+ memcpy(buf, &w, sizeof w);
+ break;
+ case 4:
+ l = cpu_to_le32(ioread32(vp_dev->device + offset));
+ memcpy(buf, &l, sizeof l);
+ break;
+ case 8:
+ l = cpu_to_le32(ioread32(vp_dev->device + offset));
+ memcpy(buf, &l, sizeof l);
+ l = cpu_to_le32(ioread32(vp_dev->device + offset + sizeof l));
+ memcpy(buf + sizeof l, &l, sizeof l);
+ break;
+ default:
+ BUG();
+ }
+}
+
+/* the config->set() implementation. it's symmetric to the
config->get()
+ * implementation */
+static void vp_set(struct virtio_device *vdev, unsigned offset,
+ const void *buf, unsigned len)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ u8 b;
+ __le16 w;
+ __le32 l;
+
+ switch (len) {
+ case 1:
+ memcpy(&b, buf, sizeof b);
+ iowrite8(b, vp_dev->device + offset);
+ break;
+ case 2:
+ memcpy(&w, buf, sizeof w);
+ iowrite16(le16_to_cpu(w), vp_dev->device + offset);
+ break;
+ case 4:
+ memcpy(&l, buf, sizeof l);
+ iowrite32(le32_to_cpu(l), vp_dev->device + offset);
+ break;
+ case 8:
+ memcpy(&l, buf, sizeof l);
+ iowrite32(le32_to_cpu(l), vp_dev->device + offset);
+ memcpy(&l, buf + sizeof l, sizeof l);
+ iowrite32(le32_to_cpu(l), vp_dev->device + offset + sizeof l);
+ break;
+ default:
+ BUG();
+ }
+}
+
+/* config->{get,set}_status() implementations */
+static u8 vp_get_status(struct virtio_device *vdev)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ return ioread8(&vp_dev->common->device_status);
+}
+
+static void vp_set_status(struct virtio_device *vdev, u8 status)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ /* We should never be setting status to 0. */
+ BUG_ON(status == 0);
+ iowrite8(status, &vp_dev->common->device_status);
+}
+
+static void vp_reset(struct virtio_device *vdev)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ /* 0 status means a reset. */
+ iowrite8(0, &vp_dev->common->device_status);
+ /* Flush out the status write, and flush in device writes,
+ * including MSI-X interrupts, if any. */
+ ioread8(&vp_dev->common->device_status);
+ /* Flush pending VQ/configuration callbacks. */
+ vp_synchronize_vectors(vdev);
+}
+
+static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
+{
+ /* Setup the vector used for configuration events */
+ iowrite16(vector, &vp_dev->common->msix_config);
+ /* Verify we had enough resources to assign the vector */
+ /* Will also flush the write out to device */
+ return ioread16(&vp_dev->common->msix_config);
+}
+
+static size_t vring_pci_size(u16 num)
+{
+ /* We only need a cacheline separation. */
+ return PAGE_ALIGN(vring_size(num, SMP_CACHE_BYTES));
+}
+
+static void *alloc_virtqueue_pages(int *num)
+{
+ void *pages;
+
+ /* TODO: allocate each queue chunk individually */
+ for (; *num && vring_pci_size(*num) > PAGE_SIZE; *num /= 2) {
+ pages = alloc_pages_exact(vring_pci_size(*num),
+ GFP_KERNEL|__GFP_ZERO|__GFP_NOWARN);
+ if (pages)
+ return pages;
+ }
+
+ if (!*num)
+ return NULL;
+
+ /* Try to get a single page. You are my only hope! */
+ return alloc_pages_exact(vring_pci_size(*num), GFP_KERNEL|__GFP_ZERO);
+}
+
+static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
+ struct virtio_pci_vq_info *info,
+ unsigned index,
+ void (*callback)(struct virtqueue *vq),
+ const char *name,
+ u16 msix_vec)
+{
+ struct virtio_pci_common_cfg __iomem *cfg = vp_dev->common;
+ struct virtqueue *vq;
+ u16 num, off;
+ int err;
+
+ if (index >= ioread16(&cfg->num_queues))
+ return ERR_PTR(-ENOENT);
+
+ /* Select the queue we're interested in */
+ iowrite16(index, &cfg->queue_select);
+
+ /* Check if queue is either not available or already active. */
+ num = ioread16(&cfg->queue_size);
+ if (!num || ioread8(&cfg->queue_enable))
+ return ERR_PTR(-ENOENT);
+
+ if (num & (num - 1)) {
+ dev_warn(&vp_dev->pci_dev->dev, "bad queue size %u",
num);
+ return ERR_PTR(-EINVAL);
+ }
+
+ /* get offset of notification word for this vq (shouldn't wrap) */
+ off = ioread16(&cfg->queue_notify_off);
+ if ((u64)off * vp_dev->notify_offset_multiplier + 2
+ > vp_dev->notify_len) {
+ dev_warn(&vp_dev->pci_dev->dev,
+ "bad notification offset %u (x %u) for queue %u > %zd",
+ off, vp_dev->notify_offset_multiplier,
+ index, vp_dev->notify_len);
+ return ERR_PTR(-EINVAL);
+ }
+
+ info->num = num;
+ info->msix_vector = msix_vec;
+
+ info->queue = alloc_virtqueue_pages(&info->num);
+ if (info->queue == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ /* create the vring */
+ vq = vring_new_virtqueue(index, info->num,
+ SMP_CACHE_BYTES, &vp_dev->vdev,
+ true, info->queue, vp_notify, callback, name);
+ if (!vq) {
+ err = -ENOMEM;
+ goto out_activate_queue;
+ }
+
+ /* activate the queue */
+ iowrite16(num, &cfg->queue_size);
+ iowrite64_twopart(virt_to_phys(info->queue),
+ &cfg->queue_desc_lo, &cfg->queue_desc_hi);
+ iowrite64_twopart(virt_to_phys(virtqueue_get_avail(vq)),
+ &cfg->queue_avail_lo, &cfg->queue_avail_hi);
+ iowrite64_twopart(virt_to_phys(virtqueue_get_avail(vq)),
+ &cfg->queue_used_lo, &cfg->queue_used_hi);
+
+
+ /* TODO: map each vq notification area individually */
+ vq->priv = (void __force *)vp_dev->notify_base +
+ off * vp_dev->notify_offset_multiplier;
+
+ if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
+ iowrite16(msix_vec, &cfg->queue_msix_vector);
+ msix_vec = ioread16(&cfg->queue_msix_vector);
+ if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
+ err = -EBUSY;
+ goto out_assign;
+ }
+ }
+
+ return vq;
+
+out_assign:
+ vring_del_virtqueue(vq);
+out_activate_queue:
+ free_pages_exact(info->queue, vring_pci_size(info->num));
+ return ERR_PTR(err);
+}
+
+static int vp_modern_find_vqs(struct virtio_device *vdev, unsigned nvqs,
+ struct virtqueue *vqs[],
+ vq_callback_t *callbacks[],
+ const char *names[])
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ struct virtqueue *vq;
+ int rc = vp_find_vqs(vdev, nvqs, vqs, callbacks, names);
+
+ if (rc)
+ return rc;
+
+ /* Select and activate all queues. Has to be done last: once we do
+ * this, there's no way to go back except reset.
+ */
+ list_for_each_entry(vq, &vdev->vqs, list) {
+ iowrite16(vq->index, &vp_dev->common->queue_select);
+ iowrite8(1, &vp_dev->common->queue_enable);
+ }
+
+ return 0;
+}
+
+static void del_vq(struct virtio_pci_vq_info *info)
+{
+ struct virtqueue *vq = info->vq;
+ struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
+
+ iowrite16(vq->index, &vp_dev->common->queue_select);
+
+ if (vp_dev->msix_enabled) {
+ iowrite16(VIRTIO_MSI_NO_VECTOR,
+ &vp_dev->common->queue_msix_vector);
+ /* Flush the write out to device */
+ ioread16(&vp_dev->common->queue_msix_vector);
+ }
+
+ vring_del_virtqueue(vq);
+
+ free_pages_exact(info->queue, vring_pci_size(info->num));
+}
+
+static const struct virtio_config_ops virtio_pci_config_ops = {
+ .get = vp_get,
+ .set = vp_set,
+ .get_status = vp_get_status,
+ .set_status = vp_set_status,
+ .reset = vp_reset,
+ .find_vqs = vp_modern_find_vqs,
+ .del_vqs = vp_del_vqs,
+ .get_features = vp_get_features,
+ .finalize_features = vp_finalize_features,
+ .bus_name = vp_bus_name,
+ .set_vq_affinity = vp_set_vq_affinity,
+};
+
+/**
+ * virtio_pci_find_capability - walk capabilities to find device info.
+ * @dev: the pci device
+ * @cfg_type: the VIRTIO_PCI_CAP_* value we seek
+ * @ioresource_types: IORESOURCE_MEM and/or IORESOURCE_IO.
+ *
+ * Returns offset of the capability, or 0.
+ */
+static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type,
+ u32 ioresource_types)
+{
+ int pos;
+
+ for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
+ pos > 0;
+ pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
+ u8 type_and_bar, type, bar;
+ pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap,
+ type_and_bar),
+ &type_and_bar);
+
+ type = (type_and_bar >> VIRTIO_PCI_CAP_TYPE_SHIFT) &
+ VIRTIO_PCI_CAP_TYPE_MASK;
+ bar = (type_and_bar >> VIRTIO_PCI_CAP_BAR_SHIFT) &
+ VIRTIO_PCI_CAP_BAR_MASK;
+
+ if (type == cfg_type) {
+ if (pci_resource_flags(dev, bar) & ioresource_types)
+ return pos;
+ }
+ }
+ return 0;
+}
+
+static void __iomem *map_capability(struct pci_dev *dev, int off, size_t
minlen,
+ size_t *len)
+{
+ u8 type_and_bar, bar;
+ u32 offset, length;
+ void __iomem *p;
+
+ pci_read_config_byte(dev, off + offsetof(struct virtio_pci_cap,
+ type_and_bar),
+ &type_and_bar);
+ pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, offset),
+ &offset);
+ pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, length),
+ &length);
+
+ if (length < minlen) {
+ dev_err(&dev->dev,
+ "virtio_pci: small capability len %u (%zu expected)\n",
+ length, minlen);
+ return NULL;
+ }
+
+ if (len)
+ *len = length;
+
+ bar = (type_and_bar >> VIRTIO_PCI_CAP_BAR_SHIFT) &
+ VIRTIO_PCI_CAP_BAR_MASK;
+
+ /* We want uncachable mapping, even if bar is cachable. */
+ p = pci_iomap_range(dev, bar, offset, length, PAGE_SIZE, true);
+ if (!p)
+ dev_err(&dev->dev,
+ "virtio_pci: unable to map virtio %u@%u on bar %i\n",
+ length, offset, bar);
+ return p;
+}
+
+/* the PCI probing function */
+static int virtio_pci_probe(struct pci_dev *pci_dev,
+ const struct pci_device_id *id)
+{
+ struct virtio_pci_device *vp_dev;
+ int err, common, isr, notify, device;
+
+ /* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */
+ if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f)
+ return -ENODEV;
+
+ /* allocate our structure and fill it out */
+ vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
+ if (vp_dev == NULL)
+ return -ENOMEM;
+
+ vp_dev->vdev.dev.parent = &pci_dev->dev;
+ vp_dev->vdev.dev.release = virtio_pci_release_dev;
+ vp_dev->vdev.config = &virtio_pci_config_ops;
+ vp_dev->pci_dev = pci_dev;
+ INIT_LIST_HEAD(&vp_dev->virtqueues);
+ spin_lock_init(&vp_dev->lock);
+
+ /* check for a common config: if not, use legacy mode (bar 0). */
+ common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG,
+ IORESOURCE_IO|IORESOURCE_MEM);
+ if (!common) {
+ dev_info(&pci_dev->dev,
+ "virtio_pci: leaving for legacy driver\n");
+ return -ENODEV;
+ }
+
+ /* If common is there, these should be too... */
+ isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG,
+ IORESOURCE_IO|IORESOURCE_MEM);
+ notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG,
+ IORESOURCE_IO|IORESOURCE_MEM);
+ device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG,
+ IORESOURCE_IO|IORESOURCE_MEM);
+ if (!isr || !notify || !device) {
+ dev_err(&pci_dev->dev,
+ "virtio_pci: missing capabilities %i/%i/%i/%i\n",
+ common, isr, notify, device);
+ return -EINVAL;
+ }
+
+ /* Disable MSI/MSIX to bring device to a known good state. */
+ pci_msi_off(pci_dev);
+
+ /* enable the device */
+ err = pci_enable_device(pci_dev);
+ if (err)
+ goto out;
+
+ err = pci_request_regions(pci_dev, "virtio-pci");
+ if (err)
+ goto out_enable_device;
+
+ err = -EINVAL;
+ vp_dev->common = map_capability(pci_dev, common,
+ sizeof(struct virtio_pci_common_cfg),
+ NULL);
+ if (!vp_dev->common)
+ goto out_req_regions;
+ vp_dev->isr = map_capability(pci_dev, isr, sizeof(u8), NULL);
+ if (!vp_dev->isr)
+ goto out_map_common;
+
+ /* Read notify_off_multiplier from config space. */
+ pci_read_config_dword(pci_dev,
+ notify + offsetof(struct virtio_pci_notify_cap,
+ notify_off_multiplier),
+ &vp_dev->notify_offset_multiplier);
+ vp_dev->notify_base = map_capability(pci_dev, notify, sizeof(u8),
+ &vp_dev->notify_len);
+ if (!vp_dev->notify_len)
+ goto out_map_isr;
+ vp_dev->device = map_capability(pci_dev, device, 0,
&vp_dev->device_len);
+ if (!vp_dev->device)
+ goto out_map_notify;
+
+ pci_set_drvdata(pci_dev, vp_dev);
+ pci_set_master(pci_dev);
+
+ if (pci_dev->device < 0x1040) {
+ /* Transitional devices: use the PCI subsystem device id as
+ * virtio device id, same as legacy driver always did.
+ */
+ vp_dev->vdev.id.device = pci_dev->subsystem_device;
+ } else {
+ /* Modern devices: simply use PCI device id, but start from 0x1040. */
+ vp_dev->vdev.id.device = pci_dev->device - 0x1040;
+ }
+
+ vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
+ vp_dev->config_vector = vp_config_vector;
+ vp_dev->setup_vq = setup_vq;
+ vp_dev->del_vq = del_vq;
+
+ /* finally register the virtio device */
+ err = register_virtio_device(&vp_dev->vdev);
+ if (err)
+ goto out_set_drvdata;
+
+ return 0;
+
+out_set_drvdata:
+ pci_set_drvdata(pci_dev, NULL);
+ pci_iounmap(pci_dev, vp_dev->device);
+out_map_notify:
+ pci_iounmap(pci_dev, vp_dev->notify_base);
+out_map_isr:
+ pci_iounmap(pci_dev, vp_dev->isr);
+out_map_common:
+ pci_iounmap(pci_dev, vp_dev->common);
+out_req_regions:
+ pci_release_regions(pci_dev);
+out_enable_device:
+ pci_disable_device(pci_dev);
+out:
+ kfree(vp_dev);
+ return err;
+}
+
+static void virtio_pci_remove(struct pci_dev *pci_dev)
+{
+ struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
+
+ unregister_virtio_device(&vp_dev->vdev);
+
+ vp_del_vqs(&vp_dev->vdev);
+ pci_set_drvdata(pci_dev, NULL);
+ pci_iounmap(pci_dev, vp_dev->device);
+ pci_iounmap(pci_dev, vp_dev->notify_base);
+ pci_iounmap(pci_dev, vp_dev->isr);
+ pci_iounmap(pci_dev, vp_dev->common);
+ pci_release_regions(pci_dev);
+ pci_disable_device(pci_dev);
+ kfree(vp_dev);
+}
+
+static struct pci_driver virtio_pci_driver = {
+ .name = "virtio-pci",
+ .id_table = virtio_pci_id_table,
+ .probe = virtio_pci_probe,
+ .remove = virtio_pci_remove,
+#ifdef CONFIG_PM_SLEEP
+ .driver.pm = &virtio_pci_pm_ops,
+#endif
+};
+
+module_pci_driver(virtio_pci_driver);
diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
index bf5104b..bd230d1 100644
--- a/drivers/virtio/Makefile
+++ b/drivers/virtio/Makefile
@@ -1,5 +1,5 @@
obj-$(CONFIG_VIRTIO) += virtio.o virtio_ring.o
obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o
obj-$(CONFIG_VIRTIO_PCI) += virtio_pci.o
-virtio_pci-y := virtio_pci_legacy.o virtio_pci_common.o
+virtio_pci-y := virtio_pci_modern.o virtio_pci_legacy.o virtio_pci_common.o
obj-$(CONFIG_VIRTIO_BALLOON) += virtio_balloon.o
--
MST
Michael S. Tsirkin
2014-Dec-11 19:37 UTC
[PATCH RFC 5/5] virtio_pci: macros for PCI layout offsets.
From: Rusty Russell <rusty at rustcorp.com.au>
QEMU wants it, so why not? Trust, but verify.
Signed-off-by: Rusty Russell <rusty at rustcorp.com.au>
---
drivers/virtio/virtio_pci_modern.c | 61 ++++++++++++++++++++++++++++++++++++++
1 file changed, 61 insertions(+)
diff --git a/drivers/virtio/virtio_pci_modern.c
b/drivers/virtio/virtio_pci_modern.c
index e6e65e1..19568da 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -406,6 +406,65 @@ static void __iomem *map_capability(struct pci_dev *dev,
int off, size_t minlen,
return p;
}
+/* This is part of the ABI. Don't screw with it. */
+static inline void check_offsets(void)
+{
+ /* Note: disk space was harmed in compilation of this function. */
+ BUILD_BUG_ON(VIRTIO_PCI_CAP_VNDR !+ offsetof(struct virtio_pci_cap,
cap_vndr));
+ BUILD_BUG_ON(VIRTIO_PCI_CAP_NEXT !+ offsetof(struct virtio_pci_cap,
cap_next));
+ BUILD_BUG_ON(VIRTIO_PCI_CAP_LEN !+ offsetof(struct virtio_pci_cap,
cap_len));
+ BUILD_BUG_ON(VIRTIO_PCI_CAP_TYPE_AND_BAR !+ offsetof(struct
virtio_pci_cap, type_and_bar));
+ BUILD_BUG_ON(VIRTIO_PCI_CAP_OFFSET !+ offsetof(struct virtio_pci_cap,
offset));
+ BUILD_BUG_ON(VIRTIO_PCI_CAP_LENGTH !+ offsetof(struct virtio_pci_cap,
length));
+ BUILD_BUG_ON(VIRTIO_PCI_NOTIFY_CAP_MULT !+ offsetof(struct
virtio_pci_notify_cap,
+ notify_off_multiplier));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_DFSELECT !+ offsetof(struct
virtio_pci_common_cfg,
+ device_feature_select));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_DF !+ offsetof(struct
virtio_pci_common_cfg, device_feature));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_GFSELECT !+ offsetof(struct
virtio_pci_common_cfg,
+ guest_feature_select));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_GF !+ offsetof(struct
virtio_pci_common_cfg, guest_feature));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_MSIX !+ offsetof(struct
virtio_pci_common_cfg, msix_config));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_NUMQ !+ offsetof(struct
virtio_pci_common_cfg, num_queues));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_STATUS !+ offsetof(struct
virtio_pci_common_cfg, device_status));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SELECT !+ offsetof(struct
virtio_pci_common_cfg, queue_select));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_SIZE !+ offsetof(struct
virtio_pci_common_cfg, queue_size));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_MSIX !+ offsetof(struct
virtio_pci_common_cfg, queue_msix_vector));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_ENABLE !+ offsetof(struct
virtio_pci_common_cfg, queue_enable));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_NOFF !+ offsetof(struct
virtio_pci_common_cfg, queue_notify_off));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCLO !+ offsetof(struct
virtio_pci_common_cfg, queue_desc_lo));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_DESCHI !+ offsetof(struct
virtio_pci_common_cfg, queue_desc_hi));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILLO !+ offsetof(struct
virtio_pci_common_cfg, queue_avail_lo));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_AVAILHI !+ offsetof(struct
virtio_pci_common_cfg, queue_avail_hi));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDLO !+ offsetof(struct
virtio_pci_common_cfg, queue_used_lo));
+ BUILD_BUG_ON(VIRTIO_PCI_COMMON_Q_USEDHI !+ offsetof(struct
virtio_pci_common_cfg, queue_used_hi));
+}
+
/* the PCI probing function */
static int virtio_pci_probe(struct pci_dev *pci_dev,
const struct pci_device_id *id)
@@ -413,6 +472,8 @@ static int virtio_pci_probe(struct pci_dev *pci_dev,
struct virtio_pci_device *vp_dev;
int err, common, isr, notify, device;
+ check_offsets();
+
/* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */
if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f)
return -ENODEV;
--
MST
On Thursday 11 December 2014 21:37:34 Michael S. Tsirkin wrote:> if (flags & IORESOURCE_MEM) { > - if (flags & IORESOURCE_CACHEABLE) > + if (!force_nocache && (flags & IORESOURCE_CACHEABLE)) > return ioremap(start, len); > return ioremap_nocache(start, len); > } >ioremap is the same as ioremap_nocache, so this doesn't really make any sense. IORESOURCE_CACHEABLE is practically only set for ROM bars, which we rarely map. Arnd
Apparently Analagous Threads
- [PATCH RFC 0/5] virtio_pci: modern driver
- [PATCH RFC 0/5] virtio pci: virtio 1.0 support
- [PATCH RFC 0/5] virtio pci: virtio 1.0 support
- [PATCH v3 00/16] virtio-pci: towards virtio 1.0 guest support
- [PATCH v3 00/16] virtio-pci: towards virtio 1.0 guest support