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| author | Amit Shah <amit.shah@redhat.com> | 2011-03-16 14:42:10 +0100 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2011-04-21 15:27:00 +0200 |
| commit | b3258ff1d6086bd2b9eeb556844a868ad7d49bc8 (patch) | |
| tree | 2c9dde005804227038c997a983ded7e46951ca64 /drivers/virtio | |
| parent | Merge branch 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/g... (diff) | |
| download | linux-b3258ff1d6086bd2b9eeb556844a868ad7d49bc8.tar.xz linux-b3258ff1d6086bd2b9eeb556844a868ad7d49bc8.zip | |
virtio: Decrement avail idx on buffer detach
When detaching a buffer from a vq, the avail.idx value should be
decremented as well.
This was noticed by hot-unplugging a virtio console port and then
plugging in a new one on the same number (re-using the vqs which were
just 'disowned'). qemu reported
'Guest moved used index from 0 to 256'
when any IO was attempted on the new port.
CC: stable@kernel.org
Reported-by: juzhang <juzhang@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'drivers/virtio')
| -rw-r--r-- | drivers/virtio/virtio_ring.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index cc2f73e03475..b0043fb26a4d 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -371,6 +371,7 @@ void *virtqueue_detach_unused_buf(struct virtqueue *_vq) /* detach_buf clears data, so grab it now. */ buf = vq->data[i]; detach_buf(vq, i); + vq->vring.avail->idx--; END_USE(vq); return buf; } |