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[Qemu-stable] [PULL 2/7] virtio: update MemoryRegionCaches when guest ne
From: |
Michael S. Tsirkin |
Subject: |
[Qemu-stable] [PULL 2/7] virtio: update MemoryRegionCaches when guest negotiates features |
Date: |
Fri, 7 Sep 2018 17:51:21 -0400 |
From: Paolo Bonzini <address@hidden>
Because the cache is sized to include the rings and the event indices,
negotiating the VIRTIO_RING_F_EVENT_IDX feature will result in the size
of the cache changing. And because MemoryRegionCache accesses are
range-checked, if we skip this we end up with an assertion failure.
This happens with OpenBSD 6.3.
Reported-by: Fam Zheng <address@hidden>
Fixes: 97cd965c070152bc626c7507df9fb356bbe1cd81
Cc: address@hidden
Signed-off-by: Paolo Bonzini <address@hidden>
Tested-by: Fam Zheng <address@hidden>
Reviewed-by: Michael S. Tsirkin <address@hidden>
Signed-off-by: Michael S. Tsirkin <address@hidden>
---
hw/virtio/virtio.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index d4e4d98b59..f6a588ab57 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -2006,14 +2006,25 @@ static int virtio_set_features_nocheck(VirtIODevice
*vdev, uint64_t val)
int virtio_set_features(VirtIODevice *vdev, uint64_t val)
{
- /*
+ int ret;
+ /*
* The driver must not attempt to set features after feature negotiation
* has finished.
*/
if (vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) {
return -EINVAL;
}
- return virtio_set_features_nocheck(vdev, val);
+ ret = virtio_set_features_nocheck(vdev, val);
+ if (!ret && virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
+ /* VIRTIO_RING_F_EVENT_IDX changes the size of the caches. */
+ int i;
+ for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
+ if (vdev->vq[i].vring.num != 0) {
+ virtio_init_region_cache(vdev, i);
+ }
+ }
+ }
+ return ret;
}
int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id)
--
MST
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