Hi: This series tries to fix various issues of vhost: - Patch 1 adds a missing write barrier between used idx updating and logging. - Patch 2-3 brings back the protection of device IOTLB through vq mutex, this fixes possible use after free in device IOTLB entries. - Patch 4 fixes the diry page logging when device IOTLB is enabled. We should done through GPA instead of GIOVA, this was done through logging through iovec and traversing GPA->HPA list for the GPA. Please consider them for -stable. Thanks Jason Wang (4): vhost: make sure used idx is seen before log in vhost_add_used_n() vhost_net: rework on the lock ordering for busy polling Revert "net: vhost: lock the vqs one by one" vhost: log dirty page correctly drivers/vhost/net.c | 21 +++++++-- drivers/vhost/vhost.c | 101 ++++++++++++++++++++++++++++++++++-------- drivers/vhost/vhost.h | 3 +- 3 files changed, 102 insertions(+), 23 deletions(-) -- 2.17.1
Jason Wang
2018-Dec-10 09:44 UTC
[PATCH net 1/4] vhost: make sure used idx is seen before log in vhost_add_used_n()
We miss a write barrier that guarantees used idx is updated and seen
before log. This will let userspace sync and copy used ring before
used idx is update. Fix this by adding a barrier before log_write().
Fixes: 8dd014adfea6f ("vhost-net: mergeable buffers support")
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/vhost/vhost.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 6b98d8e3a5bf..5915f240275a 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -2220,6 +2220,8 @@ int vhost_add_used_n(struct vhost_virtqueue *vq, struct
vring_used_elem *heads,
return -EFAULT;
}
if (unlikely(vq->log_used)) {
+ /* Make sure used idx is seen before log. */
+ smp_wmb();
/* Log used index update. */
log_write(vq->log_base,
vq->log_addr + offsetof(struct vring_used, idx),
--
2.17.1
Jason Wang
2018-Dec-10 09:44 UTC
[PATCH net 2/4] vhost_net: rework on the lock ordering for busy polling
When we try to do rx busy polling in tx path in commit 441abde4cd84
("net: vhost: add rx busy polling in tx path"), we lock rx vq mutex
after tx vq mutex is held. This may lead deadlock so we try to lock vq
one by one in commit 78139c94dc8c ("net: vhost: lock the vqs one by
one"). With this commit, we avoid the deadlock with the assumption
that handle_rx() and handle_tx() run in a same process. But this
commit remove the protection for IOTLB updating which requires the
mutex of each vq to be held.
To solve this issue, the first step is to have a exact same lock
ordering for vhost_net. This is done through:
- For handle_rx(), if busy polling is enabled, lock tx vq immediately.
- For handle_tx(), always lock rx vq before tx vq, and unlock it if
busy polling is not enabled.
- Remove the tricky locking codes in busy polling.
With this, we can have a exact same lock ordering for vhost_net, this
allows us to safely revert commit 78139c94dc8c ("net: vhost: lock the
vqs one by one") in next patch.
The patch will add two more atomic operations on the tx path during
each round of handle_tx(). 1 byte TCP_RR does not notice such
overhead.
Fixes: commit 78139c94dc8c ("net: vhost: lock the vqs one by one")
Cc: Tonghao Zhang <xiangxia.m.yue at gmail.com>
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/vhost/net.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index ab11b2bee273..5f272ab4d5b4 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -513,7 +513,6 @@ static void vhost_net_busy_poll(struct vhost_net *net,
struct socket *sock;
struct vhost_virtqueue *vq = poll_rx ? tvq : rvq;
- mutex_lock_nested(&vq->mutex, poll_rx ? VHOST_NET_VQ_TX:
VHOST_NET_VQ_RX);
vhost_disable_notify(&net->dev, vq);
sock = rvq->private_data;
@@ -543,8 +542,6 @@ static void vhost_net_busy_poll(struct vhost_net *net,
vhost_net_busy_poll_try_queue(net, vq);
else if (!poll_rx) /* On tx here, sock has no rx data. */
vhost_enable_notify(&net->dev, rvq);
-
- mutex_unlock(&vq->mutex);
}
static int vhost_net_tx_get_vq_desc(struct vhost_net *net,
@@ -913,10 +910,16 @@ static void handle_tx_zerocopy(struct vhost_net *net,
struct socket *sock)
static void handle_tx(struct vhost_net *net)
{
struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
+ struct vhost_net_virtqueue *nvq_rx = &net->vqs[VHOST_NET_VQ_RX];
struct vhost_virtqueue *vq = &nvq->vq;
+ struct vhost_virtqueue *vq_rx = &nvq_rx->vq;
struct socket *sock;
+ mutex_lock_nested(&vq_rx->mutex, VHOST_NET_VQ_RX);
mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_TX);
+ if (!vq->busyloop_timeout)
+ mutex_unlock(&vq_rx->mutex);
+
sock = vq->private_data;
if (!sock)
goto out;
@@ -933,6 +936,8 @@ static void handle_tx(struct vhost_net *net)
handle_tx_copy(net, sock);
out:
+ if (vq->busyloop_timeout)
+ mutex_unlock(&vq_rx->mutex);
mutex_unlock(&vq->mutex);
}
@@ -1060,7 +1065,9 @@ static int get_rx_bufs(struct vhost_virtqueue *vq,
static void handle_rx(struct vhost_net *net)
{
struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_RX];
+ struct vhost_net_virtqueue *nvq_tx = &net->vqs[VHOST_NET_VQ_TX];
struct vhost_virtqueue *vq = &nvq->vq;
+ struct vhost_virtqueue *vq_tx = &nvq_tx->vq;
unsigned uninitialized_var(in), log;
struct vhost_log *vq_log;
struct msghdr msg = {
@@ -1086,6 +1093,9 @@ static void handle_rx(struct vhost_net *net)
int recv_pkts = 0;
mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_RX);
+ if (vq->busyloop_timeout)
+ mutex_lock_nested(&vq_tx->mutex, VHOST_NET_VQ_TX);
+
sock = vq->private_data;
if (!sock)
goto out;
@@ -1200,6 +1210,8 @@ static void handle_rx(struct vhost_net *net)
out:
vhost_net_signal_used(nvq);
mutex_unlock(&vq->mutex);
+ if (vq->busyloop_timeout)
+ mutex_unlock(&vq_tx->mutex);
}
static void handle_tx_kick(struct vhost_work *work)
--
2.17.1
Jason Wang
2018-Dec-10 09:44 UTC
[PATCH net 3/4] Revert "net: vhost: lock the vqs one by one"
This reverts commit 78139c94dc8c96a478e67dab3bee84dc6eccb5fd. We don't
protect device IOTLB with vq mutex, which will lead e.g use after free
for device IOTLB entries. And since we've exact the same lock order
with the help of previous patch, it's safe to revert it without having
deadlock.
Fixes: commit 78139c94dc8c ("net: vhost: lock the vqs one by one")
Cc: Tonghao Zhang <xiangxia.m.yue at gmail.com>
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/vhost/vhost.c | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 5915f240275a..55e5aa662ad5 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -295,11 +295,8 @@ static void vhost_vq_meta_reset(struct vhost_dev *d)
{
int i;
- for (i = 0; i < d->nvqs; ++i) {
- mutex_lock(&d->vqs[i]->mutex);
+ for (i = 0; i < d->nvqs; ++i)
__vhost_vq_meta_reset(d->vqs[i]);
- mutex_unlock(&d->vqs[i]->mutex);
- }
}
static void vhost_vq_reset(struct vhost_dev *dev,
@@ -895,6 +892,20 @@ static inline void __user *__vhost_get_user(struct
vhost_virtqueue *vq,
#define vhost_get_used(vq, x, ptr) \
vhost_get_user(vq, x, ptr, VHOST_ADDR_USED)
+static void vhost_dev_lock_vqs(struct vhost_dev *d)
+{
+ int i = 0;
+ for (i = 0; i < d->nvqs; ++i)
+ mutex_lock_nested(&d->vqs[i]->mutex, i);
+}
+
+static void vhost_dev_unlock_vqs(struct vhost_dev *d)
+{
+ int i = 0;
+ for (i = 0; i < d->nvqs; ++i)
+ mutex_unlock(&d->vqs[i]->mutex);
+}
+
static int vhost_new_umem_range(struct vhost_umem *umem,
u64 start, u64 size, u64 end,
u64 userspace_addr, int perm)
@@ -976,6 +987,7 @@ static int vhost_process_iotlb_msg(struct vhost_dev *dev,
int ret = 0;
mutex_lock(&dev->mutex);
+ vhost_dev_lock_vqs(dev);
switch (msg->type) {
case VHOST_IOTLB_UPDATE:
if (!dev->iotlb) {
@@ -1009,6 +1021,7 @@ static int vhost_process_iotlb_msg(struct vhost_dev *dev,
break;
}
+ vhost_dev_unlock_vqs(dev);
mutex_unlock(&dev->mutex);
return ret;
--
2.17.1
Vhost dirty page logging API is designed to sync through GPA. But we
try to log GIOVA when device IOTLB is enabled. This is wrong and may
lead to missing data after migration.
To solve this issue, when logging with device IOTLB enabled, we will:
1) reuse the device IOTLB translation result of GIOVA->HVA mapping to
get HVA, for writable descriptor, get HVA through iovec. For used
ring update, translate its GIOVA to HVA
2) traverse the GPA->HVA mapping to get the possible GPA and log
through GPA. Pay attention this reverse mapping is not guaranteed
to be unique, so we should log each possible GPA in this case.
This fix the failure of scp to guest during migration. In -next, we
will probably support passing GIOVA->GPA instead of GIOVA->HVA.
Fixes: 6b1e6cc7855b ("vhost: new device IOTLB API")
Reported-by: Jintack Lim <jintack at cs.columbia.edu>
Cc: Jintack Lim <jintack at cs.columbia.edu>
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/vhost/net.c | 3 +-
drivers/vhost/vhost.c | 78 +++++++++++++++++++++++++++++++++++--------
drivers/vhost/vhost.h | 3 +-
3 files changed, 68 insertions(+), 16 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 5f272ab4d5b4..754ca22efb43 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -1196,7 +1196,8 @@ static void handle_rx(struct vhost_net *net)
if (nvq->done_idx > VHOST_NET_BATCH)
vhost_net_signal_used(nvq);
if (unlikely(vq_log))
- vhost_log_write(vq, vq_log, log, vhost_len);
+ vhost_log_write(vq, vq_log, log, vhost_len,
+ vq->iov, in);
total_len += vhost_len;
if (unlikely(vhost_exceeds_weight(++recv_pkts, total_len))) {
vhost_poll_queue(&vq->poll);
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 55e5aa662ad5..8ab279720a2b 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1733,11 +1733,66 @@ static int log_write(void __user *log_base,
return r;
}
+static int log_write_hva(struct vhost_virtqueue *vq, u64 hva, u64 len)
+{
+ struct vhost_umem *umem = vq->umem;
+ struct vhost_umem_node *u;
+ u64 gpa;
+ int r;
+ bool hit = false;
+
+ list_for_each_entry(u, &umem->umem_list, link) {
+ if (u->userspace_addr < hva &&
+ u->userspace_addr + u->size >+ hva + len) {
+ gpa = u->start + hva - u->userspace_addr;
+ r = log_write(vq->log_base, gpa, len);
+ if (r < 0)
+ return r;
+ hit = true;
+ }
+ }
+
+ /* No reverse mapping, should be a bug */
+ WARN_ON(!hit);
+ return 0;
+}
+
+static void log_used(struct vhost_virtqueue *vq, u64 used_offset, u64 len)
+{
+ struct iovec iov[64];
+ int i, ret;
+
+ if (!vq->iotlb) {
+ log_write(vq->log_base, vq->log_addr + used_offset, len);
+ return;
+ }
+
+ ret = translate_desc(vq, (u64)vq->used + used_offset, len, iov, 64,
+ VHOST_ACCESS_WO);
+ WARN_ON(ret < 0);
+
+ for (i = 0; i < ret; i++) {
+ ret = log_write_hva(vq, (u64)iov[i].iov_base, iov[i].iov_len);
+ WARN_ON(ret);
+ }
+}
+
int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
- unsigned int log_num, u64 len)
+ unsigned int log_num, u64 len, struct iovec *iov, int count)
{
int i, r;
+ if (vq->iotlb) {
+ for (i = 0; i < count; i++) {
+ r = log_write_hva(vq, (u64)iov[i].iov_base,
+ iov[i].iov_len);
+ if (r < 0)
+ return r;
+ }
+ return 0;
+ }
+
/* Make sure data written is seen before log. */
smp_wmb();
for (i = 0; i < log_num; ++i) {
@@ -1769,9 +1824,8 @@ static int vhost_update_used_flags(struct vhost_virtqueue
*vq)
smp_wmb();
/* Log used flag write. */
used = &vq->used->flags;
- log_write(vq->log_base, vq->log_addr +
- (used - (void __user *)vq->used),
- sizeof vq->used->flags);
+ log_used(vq, (used - (void __user *)vq->used),
+ sizeof vq->used->flags);
if (vq->log_ctx)
eventfd_signal(vq->log_ctx, 1);
}
@@ -1789,9 +1843,8 @@ static int vhost_update_avail_event(struct vhost_virtqueue
*vq, u16 avail_event)
smp_wmb();
/* Log avail event write */
used = vhost_avail_event(vq);
- log_write(vq->log_base, vq->log_addr +
- (used - (void __user *)vq->used),
- sizeof *vhost_avail_event(vq));
+ log_used(vq, (used - (void __user *)vq->used),
+ sizeof *vhost_avail_event(vq));
if (vq->log_ctx)
eventfd_signal(vq->log_ctx, 1);
}
@@ -2191,10 +2244,8 @@ static int __vhost_add_used_n(struct vhost_virtqueue *vq,
/* Make sure data is seen before log. */
smp_wmb();
/* Log used ring entry write. */
- log_write(vq->log_base,
- vq->log_addr +
- ((void __user *)used - (void __user *)vq->used),
- count * sizeof *used);
+ log_used(vq, ((void __user *)used - (void __user *)vq->used),
+ count * sizeof *used);
}
old = vq->last_used_idx;
new = (vq->last_used_idx += count);
@@ -2236,9 +2287,8 @@ int vhost_add_used_n(struct vhost_virtqueue *vq, struct
vring_used_elem *heads,
/* Make sure used idx is seen before log. */
smp_wmb();
/* Log used index update. */
- log_write(vq->log_base,
- vq->log_addr + offsetof(struct vring_used, idx),
- sizeof vq->used->idx);
+ log_used(vq, offsetof(struct vring_used, idx),
+ sizeof vq->used->idx);
if (vq->log_ctx)
eventfd_signal(vq->log_ctx, 1);
}
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 466ef7542291..1b675dad5e05 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -205,7 +205,8 @@ bool vhost_vq_avail_empty(struct vhost_dev *, struct
vhost_virtqueue *);
bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
- unsigned int log_num, u64 len);
+ unsigned int log_num, u64 len,
+ struct iovec *iov, int count);
int vq_iotlb_prefetch(struct vhost_virtqueue *vq);
struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type);
--
2.17.1
Hi Jason,
I love your patch! Perhaps something to improve:
[auto build test WARNING on net/master]
url:
https://github.com/0day-ci/linux/commits/Jason-Wang/Fix-various-issue-of-vhost/20181210-223236
config: i386-randconfig-x072-201849 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
# save the attached .config to linux build tree
make ARCH=i386
All warnings (new ones prefixed by >>):
drivers//vhost/vhost.c: In function
'log_used':>> drivers//vhost/vhost.c:1771:27: warning: cast from pointer to integer
of different size [-Wpointer-to-int-cast]
ret = translate_desc(vq, (u64)vq->used + used_offset, len, iov, 64,
^
drivers//vhost/vhost.c:1776:27: warning: cast from pointer to integer of
different size [-Wpointer-to-int-cast]
ret = log_write_hva(vq, (u64)iov[i].iov_base, iov[i].iov_len);
^
drivers//vhost/vhost.c: In function 'vhost_log_write':
drivers//vhost/vhost.c:1788:26: warning: cast from pointer to integer of
different size [-Wpointer-to-int-cast]
r = log_write_hva(vq, (u64)iov[i].iov_base,
^
Cyclomatic Complexity 5 include/linux/compiler.h:__read_once_size
Cyclomatic Complexity 5 include/linux/compiler.h:__write_once_size
Cyclomatic Complexity 1
arch/x86/include/asm/barrier.h:array_index_mask_nospec
Cyclomatic Complexity 1 include/linux/kasan-checks.h:kasan_check_read
Cyclomatic Complexity 1 include/linux/kasan-checks.h:kasan_check_write
Cyclomatic Complexity 2 arch/x86/include/asm/bitops.h:set_bit
Cyclomatic Complexity 2 arch/x86/include/asm/bitops.h:clear_bit
Cyclomatic Complexity 1 arch/x86/include/asm/bitops.h:test_and_set_bit
Cyclomatic Complexity 1 arch/x86/include/asm/bitops.h:constant_test_bit
Cyclomatic Complexity 1 arch/x86/include/asm/bitops.h:variable_test_bit
Cyclomatic Complexity 1 arch/x86/include/asm/bitops.h:fls
Cyclomatic Complexity 1 include/linux/log2.h:__ilog2_u32
Cyclomatic Complexity 1 include/linux/list.h:INIT_LIST_HEAD
Cyclomatic Complexity 1 include/linux/list.h:__list_del
Cyclomatic Complexity 1 include/linux/list.h:list_empty
Cyclomatic Complexity 1 arch/x86/include/asm/current.h:get_current
Cyclomatic Complexity 3 include/linux/string.h:memset
Cyclomatic Complexity 5 include/linux/string.h:memcpy
Cyclomatic Complexity 1 include/asm-generic/getorder.h:__get_order
Cyclomatic Complexity 1
arch/x86/include/asm/atomic.h:arch_atomic_dec_and_test
Cyclomatic Complexity 1
include/asm-generic/atomic-instrumented.h:atomic_dec_and_test
Cyclomatic Complexity 1 include/linux/err.h:PTR_ERR
Cyclomatic Complexity 1 include/linux/thread_info.h:set_ti_thread_flag
Cyclomatic Complexity 1 include/linux/thread_info.h:check_object_size
Cyclomatic Complexity 5 include/linux/thread_info.h:check_copy_size
Cyclomatic Complexity 1 arch/x86/include/asm/preempt.h:preempt_count
Cyclomatic Complexity 1 include/linux/spinlock.h:spinlock_check
Cyclomatic Complexity 1 include/linux/spinlock.h:spin_lock
Cyclomatic Complexity 1 include/linux/spinlock.h:spin_unlock
Cyclomatic Complexity 1 include/linux/wait.h:init_waitqueue_func_entry
Cyclomatic Complexity 1 include/linux/llist.h:init_llist_head
Cyclomatic Complexity 1 include/linux/llist.h:llist_empty
Cyclomatic Complexity 1 include/linux/llist.h:llist_del_all
Cyclomatic Complexity 1 include/linux/rbtree.h:rb_link_node
Cyclomatic Complexity 3 include/linux/overflow.h:__ab_c_size
Cyclomatic Complexity 1 include/linux/page_ref.h:page_ref_dec_and_test
Cyclomatic Complexity 1 include/linux/sched.h:task_thread_info
Cyclomatic Complexity 1 include/linux/sched.h:need_resched
Cyclomatic Complexity 1 include/linux/mm.h:put_page_testzero
Cyclomatic Complexity 1 include/linux/mm.h:put_devmap_managed_page
Cyclomatic Complexity 1 include/uapi/linux/virtio_ring.h:vring_need_event
Cyclomatic Complexity 1
include/linux/virtio_byteorder.h:virtio_legacy_is_little_endian
Cyclomatic Complexity 2 include/linux/uio.h:copy_to_iter
Cyclomatic Complexity 2 include/linux/uio.h:copy_from_iter
Cyclomatic Complexity 2 include/linux/uio.h:copy_from_iter_full
Cyclomatic Complexity 1 include/linux/uio.h:iov_iter_count
Cyclomatic Complexity 1 include/linux/slab.h:kmalloc_type
Cyclomatic Complexity 28 include/linux/slab.h:kmalloc_index
Cyclomatic Complexity 67 include/linux/slab.h:kmalloc_large
Cyclomatic Complexity 4 include/linux/slab.h:kmalloc
Cyclomatic Complexity 1 arch/x86/include/asm/smap.h:clac
Cyclomatic Complexity 1 arch/x86/include/asm/smap.h:stac
Cyclomatic Complexity 1 arch/x86/include/asm/uaccess.h:set_fs
Cyclomatic Complexity 1 arch/x86/include/asm/uaccess_32.h:raw_copy_to_user
Cyclomatic Complexity 5 arch/x86/include/asm/uaccess_32.h:raw_copy_from_user
Cyclomatic Complexity 1 include/linux/uaccess.h:__copy_from_user
Cyclomatic Complexity 1 include/linux/uaccess.h:__copy_to_user
Cyclomatic Complexity 2 include/linux/uaccess.h:copy_from_user
Cyclomatic Complexity 2 include/linux/uaccess.h:copy_to_user
Cyclomatic Complexity 4 include/linux/poll.h:poll_wait
Cyclomatic Complexity 1 include/linux/poll.h:init_poll_funcptr
Cyclomatic Complexity 1 include/linux/rbtree_augmented.h:rb_set_parent
Cyclomatic Complexity 1 include/linux/rbtree_augmented.h:rb_set_parent_color
Cyclomatic Complexity 3 include/linux/rbtree_augmented.h:__rb_change_child
Cyclomatic Complexity 11
include/linux/rbtree_augmented.h:__rb_erase_augmented
Cyclomatic Complexity 2
include/linux/rbtree_augmented.h:rb_erase_augmented_cached
Cyclomatic Complexity 1 drivers//vhost/vhost.h:vhost_has_feature
Cyclomatic Complexity 1 drivers//vhost/vhost.h:vhost_backend_has_feature
Cyclomatic Complexity 1 drivers//vhost/vhost.h:vhost_is_little_endian
Cyclomatic Complexity 5
drivers//vhost/vhost.c:vhost_umem_interval_tree_compute_subtree_last
Cyclomatic Complexity 3
drivers//vhost/vhost.c:vhost_umem_interval_tree_augment_propagate
Cyclomatic Complexity 1
drivers//vhost/vhost.c:vhost_umem_interval_tree_augment_copy
Cyclomatic Complexity 1
drivers//vhost/vhost.c:vhost_umem_interval_tree_augment_rotate
Cyclomatic Complexity 1
drivers//vhost/vhost.c:vhost_umem_interval_tree_remove
Cyclomatic Complexity 7
drivers//vhost/vhost.c:vhost_umem_interval_tree_subtree_search
Cyclomatic Complexity 4
drivers//vhost/vhost.c:vhost_umem_interval_tree_iter_first
Cyclomatic Complexity 1 drivers//vhost/vhost.c:vhost_disable_cross_endian
Cyclomatic Complexity 1 drivers//vhost/vhost.c:vhost_enable_cross_endian_big
Cyclomatic Complexity 1
drivers//vhost/vhost.c:vhost_enable_cross_endian_little
Cyclomatic Complexity 5 drivers//vhost/vhost.c:vhost_set_vring_endian
Cyclomatic Complexity 2 drivers//vhost/vhost.c:vhost_get_vring_endian
Cyclomatic Complexity 3 drivers//vhost/vhost.c:vhost_init_is_le
Cyclomatic Complexity 1 drivers//vhost/vhost.c:vhost_reset_is_le
Cyclomatic Complexity 1 drivers//vhost/vhost.c:vhost_work_init
Cyclomatic Complexity 1 drivers//vhost/vhost.c:vhost_poll_init
Cyclomatic Complexity 1 drivers//vhost/vhost.c:vhost_has_work
Cyclomatic Complexity 2 drivers//vhost/vhost.c:__vhost_vq_meta_reset
Cyclomatic Complexity 2 drivers//vhost/vhost.c:vhost_vq_meta_reset
Cyclomatic Complexity 1 drivers//vhost/vhost.c:vhost_vq_reset
Cyclomatic Complexity 2 drivers//vhost/vhost.c:vhost_dev_check_owner
Cyclomatic Complexity 1 drivers//vhost/vhost.c:vhost_dev_has_owner
vim +1771 drivers//vhost/vhost.c
1760
1761 static void log_used(struct vhost_virtqueue *vq, u64 used_offset, u64
len)
1762 {
1763 struct iovec iov[64];
1764 int i, ret;
1765
1766 if (!vq->iotlb) {
1767 log_write(vq->log_base, vq->log_addr + used_offset, len);
1768 return;
1769 }
1770 > 1771 ret = translate_desc(vq, (u64)vq->used + used_offset, len, iov,
64,
1772 VHOST_ACCESS_WO);
1773 WARN_ON(ret < 0);
1774
1775 for (i = 0; i < ret; i++) {
1776 ret = log_write_hva(vq, (u64)iov[i].iov_base, iov[i].iov_len);
1777 WARN_ON(ret);
1778 }
1779 }
1780
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
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From: Jason Wang <jasowang at redhat.com> Date: Mon, 10 Dec 2018 17:44:50 +0800> This series tries to fix various issues of vhost: > > - Patch 1 adds a missing write barrier between used idx updating and > logging. > - Patch 2-3 brings back the protection of device IOTLB through vq > mutex, this fixes possible use after free in device IOTLB entries. > - Patch 4 fixes the diry page logging when device IOTLB is > enabled. We should done through GPA instead of GIOVA, this was done > through logging through iovec and traversing GPA->HPA list for the > GPA. > > Please consider them for -stable.Looks like the kbuild robot found some problems. ->used is a pointer (which might be 32-bit) and you're casting it to a u64 in the translate_desc() calls of patch #4. Please make sure that you don't actually require the full domain of a u64 in these values, as obviously if vq->used is a pointer you will only get a 32-bit domain on 32-bit architectures.
Michael S. Tsirkin
2018-Dec-11 01:34 UTC
[PATCH net 2/4] vhost_net: rework on the lock ordering for busy polling
On Mon, Dec 10, 2018 at 05:44:52PM +0800, Jason Wang wrote:> When we try to do rx busy polling in tx path in commit 441abde4cd84 > ("net: vhost: add rx busy polling in tx path"), we lock rx vq mutex > after tx vq mutex is held. This may lead deadlock so we try to lock vq > one by one in commit 78139c94dc8c ("net: vhost: lock the vqs one by > one"). With this commit, we avoid the deadlock with the assumption > that handle_rx() and handle_tx() run in a same process. But this > commit remove the protection for IOTLB updating which requires the > mutex of each vq to be held. > > To solve this issue, the first step is to have a exact same lock > ordering for vhost_net. This is done through: > > - For handle_rx(), if busy polling is enabled, lock tx vq immediately. > - For handle_tx(), always lock rx vq before tx vq, and unlock it if > busy polling is not enabled. > - Remove the tricky locking codes in busy polling. > > With this, we can have a exact same lock ordering for vhost_net, this > allows us to safely revert commit 78139c94dc8c ("net: vhost: lock the > vqs one by one") in next patch. > > The patch will add two more atomic operations on the tx path during > each round of handle_tx(). 1 byte TCP_RR does not notice such > overhead. > > Fixes: commit 78139c94dc8c ("net: vhost: lock the vqs one by one") > Cc: Tonghao Zhang <xiangxia.m.yue at gmail.com> > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/vhost/net.c | 18 +++++++++++++++--- > 1 file changed, 15 insertions(+), 3 deletions(-) > > diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c > index ab11b2bee273..5f272ab4d5b4 100644 > --- a/drivers/vhost/net.c > +++ b/drivers/vhost/net.c > @@ -513,7 +513,6 @@ static void vhost_net_busy_poll(struct vhost_net *net, > struct socket *sock; > struct vhost_virtqueue *vq = poll_rx ? tvq : rvq; > > - mutex_lock_nested(&vq->mutex, poll_rx ? VHOST_NET_VQ_TX: VHOST_NET_VQ_RX); > vhost_disable_notify(&net->dev, vq); > sock = rvq->private_data; > > @@ -543,8 +542,6 @@ static void vhost_net_busy_poll(struct vhost_net *net, > vhost_net_busy_poll_try_queue(net, vq); > else if (!poll_rx) /* On tx here, sock has no rx data. */ > vhost_enable_notify(&net->dev, rvq); > - > - mutex_unlock(&vq->mutex); > } > > static int vhost_net_tx_get_vq_desc(struct vhost_net *net, > @@ -913,10 +910,16 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock) > static void handle_tx(struct vhost_net *net) > { > struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX]; > + struct vhost_net_virtqueue *nvq_rx = &net->vqs[VHOST_NET_VQ_RX]; > struct vhost_virtqueue *vq = &nvq->vq; > + struct vhost_virtqueue *vq_rx = &nvq_rx->vq; > struct socket *sock; > > + mutex_lock_nested(&vq_rx->mutex, VHOST_NET_VQ_RX); > mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_TX); > + if (!vq->busyloop_timeout) > + mutex_unlock(&vq_rx->mutex); > + > sock = vq->private_data; > if (!sock) > goto out; > @@ -933,6 +936,8 @@ static void handle_tx(struct vhost_net *net) > handle_tx_copy(net, sock); > > out: > + if (vq->busyloop_timeout) > + mutex_unlock(&vq_rx->mutex); > mutex_unlock(&vq->mutex); > } >So rx mutex taken on tx path now. And tx mutex is on rc path ... This is just messed up. Why can't tx polling drop rx lock before getting the tx lock and vice versa? Or if we really wanted to force everything to be locked at all times, let's just use a single mutex.> @@ -1060,7 +1065,9 @@ static int get_rx_bufs(struct vhost_virtqueue *vq, > static void handle_rx(struct vhost_net *net) > { > struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_RX]; > + struct vhost_net_virtqueue *nvq_tx = &net->vqs[VHOST_NET_VQ_TX]; > struct vhost_virtqueue *vq = &nvq->vq; > + struct vhost_virtqueue *vq_tx = &nvq_tx->vq; > unsigned uninitialized_var(in), log; > struct vhost_log *vq_log; > struct msghdr msg = { > @@ -1086,6 +1093,9 @@ static void handle_rx(struct vhost_net *net) > int recv_pkts = 0; > > mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_RX); > + if (vq->busyloop_timeout) > + mutex_lock_nested(&vq_tx->mutex, VHOST_NET_VQ_TX); > + > sock = vq->private_data; > if (!sock) > goto out; > @@ -1200,6 +1210,8 @@ static void handle_rx(struct vhost_net *net) > out: > vhost_net_signal_used(nvq); > mutex_unlock(&vq->mutex); > + if (vq->busyloop_timeout) > + mutex_unlock(&vq_tx->mutex); > } > > static void handle_tx_kick(struct vhost_work *work) > -- > 2.17.1
On 2018/12/11 ??3:47, David Miller wrote:> From: Jason Wang <jasowang at redhat.com> > Date: Mon, 10 Dec 2018 17:44:50 +0800 > >> This series tries to fix various issues of vhost: >> >> - Patch 1 adds a missing write barrier between used idx updating and >> logging. >> - Patch 2-3 brings back the protection of device IOTLB through vq >> mutex, this fixes possible use after free in device IOTLB entries. >> - Patch 4 fixes the diry page logging when device IOTLB is >> enabled. We should done through GPA instead of GIOVA, this was done >> through logging through iovec and traversing GPA->HPA list for the >> GPA. >> >> Please consider them for -stable. > Looks like the kbuild robot found some problems. > > ->used is a pointer (which might be 32-bit) and you're casting it to > a u64 in the translate_desc() calls of patch #4. > > Please make sure that you don't actually require the full domain of > a u64 in these values, as obviously if vq->used is a pointer you will > only get a 32-bit domain on 32-bit architectures.It seems the reason is that I cast from plain void pointer directly. Let me cast it to uintptr_t first. Thanks>
Hi Jason,
I love your patch! Perhaps something to improve:
[auto build test WARNING on net/master]
url:
https://github.com/0day-ci/linux/commits/Jason-Wang/Fix-various-issue-of-vhost/20181210-223236
config: x86_64-allmodconfig (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64
All warnings (new ones prefixed by >>):
include/linux/slab.h:332:43: warning: dubious: x & !y
include/linux/slab.h:332:43: warning: dubious: x & !y
include/linux/slab.h:332:43: warning: dubious: x & !y
drivers/vhost/vhost.c:704:17: warning: incorrect type in return expression
(different address spaces)
drivers/vhost/vhost.c:704:17: expected void [noderef] <asn:1> *
drivers/vhost/vhost.c:704:17: got void *<noident>
drivers/vhost/vhost.c:704:17: warning: incorrect type in return expression
(different address spaces)
drivers/vhost/vhost.c:704:17: expected void [noderef] <asn:1> *
drivers/vhost/vhost.c:704:17: got void *<noident>
include/linux/slab.h:332:43: warning: dubious: x & !y
drivers/vhost/vhost.c:704:17: warning: incorrect type in return expression
(different address spaces)
drivers/vhost/vhost.c:704:17: expected void [noderef] <asn:1> *
drivers/vhost/vhost.c:704:17: got void
*<noident>>> drivers/vhost/vhost.c:1771:35: warning: cast removes address space
'<asn:1>' of expression
drivers/vhost/vhost.c:1776:42: warning: cast removes address space
'<asn:1>' of expression
drivers/vhost/vhost.c:1788:48: warning: cast removes address space
'<asn:1>' of expression
drivers/vhost/vhost.c:1819:13: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:1819:13: expected void *addr
drivers/vhost/vhost.c:1819:13: got restricted __virtio16 [noderef]
<asn:1> *<noident>
drivers/vhost/vhost.c:704:17: warning: incorrect type in return expression
(different address spaces)
drivers/vhost/vhost.c:704:17: expected void [noderef] <asn:1> *
drivers/vhost/vhost.c:704:17: got void *<noident>
drivers/vhost/vhost.c:851:42: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:851:42: expected void [noderef] <asn:1> *addr
drivers/vhost/vhost.c:851:42: got void *addr
drivers/vhost/vhost.c:1837:13: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:1837:13: expected void *addr
drivers/vhost/vhost.c:1837:13: got restricted __virtio16 [noderef]
[usertype] <asn:1> *<noident>
drivers/vhost/vhost.c:704:17: warning: incorrect type in return expression
(different address spaces)
drivers/vhost/vhost.c:704:17: expected void [noderef] <asn:1> *
drivers/vhost/vhost.c:704:17: got void *<noident>
drivers/vhost/vhost.c:851:42: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:851:42: expected void [noderef] <asn:1> *addr
drivers/vhost/vhost.c:851:42: got void *addr
drivers/vhost/vhost.c:1874:13: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:1874:13: expected void *addr
drivers/vhost/vhost.c:1874:13: got restricted __virtio16 [noderef]
<asn:1> *<noident>
drivers/vhost/vhost.c:704:17: warning: incorrect type in return expression
(different address spaces)
drivers/vhost/vhost.c:704:17: expected void [noderef] <asn:1> *
drivers/vhost/vhost.c:704:17: got void *<noident>
drivers/vhost/vhost.c:851:42: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:851:42: expected void [noderef] <asn:1> *addr
drivers/vhost/vhost.c:851:42: got void *addr
drivers/vhost/vhost.c:2073:21: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:2073:21: expected void *addr
drivers/vhost/vhost.c:2073:21: got restricted __virtio16 [noderef]
<asn:1> *<noident>
drivers/vhost/vhost.c:704:17: warning: incorrect type in return expression
(different address spaces)
drivers/vhost/vhost.c:704:17: expected void [noderef] <asn:1> *
drivers/vhost/vhost.c:704:17: got void *<noident>
drivers/vhost/vhost.c:851:42: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:851:42: expected void [noderef] <asn:1> *addr
drivers/vhost/vhost.c:851:42: got void *addr
drivers/vhost/vhost.c:2100:13: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:2100:13: expected void *addr
drivers/vhost/vhost.c:2100:13: got restricted __virtio16 [noderef]
<asn:1> *
drivers/vhost/vhost.c:704:17: warning: incorrect type in return expression
(different address spaces)
drivers/vhost/vhost.c:704:17: expected void [noderef] <asn:1> *
drivers/vhost/vhost.c:704:17: got void *<noident>
drivers/vhost/vhost.c:851:42: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:851:42: expected void [noderef] <asn:1> *addr
drivers/vhost/vhost.c:851:42: got void *addr
drivers/vhost/vhost.c:2231:21: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:2231:21: expected void *addr
drivers/vhost/vhost.c:2231:21: got restricted __virtio32 [noderef]
<asn:1> *<noident>
drivers/vhost/vhost.c:704:17: warning: incorrect type in return expression
(different address spaces)
drivers/vhost/vhost.c:704:17: expected void [noderef] <asn:1> *
drivers/vhost/vhost.c:704:17: got void *<noident>
drivers/vhost/vhost.c:851:42: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:851:42: expected void [noderef] <asn:1> *addr
drivers/vhost/vhost.c:851:42: got void *addr
drivers/vhost/vhost.c:2235:21: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:2235:21: expected void *addr
drivers/vhost/vhost.c:2235:21: got restricted __virtio32 [noderef]
<asn:1> *<noident>
drivers/vhost/vhost.c:704:17: warning: incorrect type in return expression
(different address spaces)
drivers/vhost/vhost.c:704:17: expected void [noderef] <asn:1> *
drivers/vhost/vhost.c:704:17: got void *<noident>
drivers/vhost/vhost.c:851:42: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:851:42: expected void [noderef] <asn:1> *addr
drivers/vhost/vhost.c:851:42: got void *addr
drivers/vhost/vhost.c:2281:13: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:2281:13: expected void *addr
drivers/vhost/vhost.c:2281:13: got restricted __virtio16 [noderef]
<asn:1> *<noident>
drivers/vhost/vhost.c:704:17: warning: incorrect type in return expression
(different address spaces)
drivers/vhost/vhost.c:704:17: expected void [noderef] <asn:1> *
drivers/vhost/vhost.c:704:17: got void *<noident>
drivers/vhost/vhost.c:851:42: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:851:42: expected void [noderef] <asn:1> *addr
drivers/vhost/vhost.c:851:42: got void *addr
drivers/vhost/vhost.c:2315:21: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:2315:21: expected void *addr
drivers/vhost/vhost.c:2315:21: got restricted __virtio16 [noderef]
<asn:1> *<noident>
drivers/vhost/vhost.c:704:17: warning: incorrect type in return expression
(different address spaces)
drivers/vhost/vhost.c:704:17: expected void [noderef] <asn:1> *
drivers/vhost/vhost.c:704:17: got void *<noident>
drivers/vhost/vhost.c:851:42: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:851:42: expected void [noderef] <asn:1> *addr
drivers/vhost/vhost.c:851:42: got void *addr
drivers/vhost/vhost.c:2329:13: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:2329:13: expected void *addr
drivers/vhost/vhost.c:2329:13: got restricted __virtio16 [noderef]
[usertype] <asn:1> *<noident>
drivers/vhost/vhost.c:704:17: warning: incorrect type in return expression
(different address spaces)
drivers/vhost/vhost.c:704:17: expected void [noderef] <asn:1> *
drivers/vhost/vhost.c:704:17: got void *<noident>
drivers/vhost/vhost.c:851:42: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:851:42: expected void [noderef] <asn:1> *addr
drivers/vhost/vhost.c:851:42: got void *addr
drivers/vhost/vhost.c:2374:13: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:2374:13: expected void *addr
drivers/vhost/vhost.c:2374:13: got restricted __virtio16 [noderef]
<asn:1> *<noident>
drivers/vhost/vhost.c:704:17: warning: incorrect type in return expression
(different address spaces)
drivers/vhost/vhost.c:704:17: expected void [noderef] <asn:1> *
drivers/vhost/vhost.c:704:17: got void *<noident>
drivers/vhost/vhost.c:851:42: warning: incorrect type in argument 2
(different address spaces)
drivers/vhost/vhost.c:851:42: expected void [noderef] <asn:1> *addr
vim +1771 drivers/vhost/vhost.c
1760
1761 static void log_used(struct vhost_virtqueue *vq, u64 used_offset, u64
len)
1762 {
1763 struct iovec iov[64];
1764 int i, ret;
1765
1766 if (!vq->iotlb) {
1767 log_write(vq->log_base, vq->log_addr + used_offset, len);
1768 return;
1769 }
1770 > 1771 ret = translate_desc(vq, (u64)vq->used + used_offset, len, iov,
64,
1772 VHOST_ACCESS_WO);
1773 WARN_ON(ret < 0);
1774
1775 for (i = 0; i < ret; i++) {
1776 ret = log_write_hva(vq, (u64)iov[i].iov_base, iov[i].iov_len);
1777 WARN_ON(ret);
1778 }
1779 }
1780
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
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