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[Qemu-devel] [PULL 23/41] virtio: fix vq->inuse recalc after migr
From: |
Michael S. Tsirkin |
Subject: |
[Qemu-devel] [PULL 23/41] virtio: fix vq->inuse recalc after migr |
Date: |
Tue, 10 Jan 2017 07:40:18 +0200 |
From: Halil Pasic <address@hidden>
Correct recalculation of vq->inuse after migration for the corner case
where the avail_idx has already wrapped but used_idx not yet.
Also change the type of the VirtQueue.inuse to unsigned int. This is
done to be consistent with other members representing sizes (VRing.num),
and because C99 guarantees max ring size < UINT_MAX but does not
guarantee max ring size < INT_MAX.
Signed-off-by: Halil Pasic <address@hidden>
Fixes: bccdef6b ("virtio: recalculate vq->inuse after migration")
CC: address@hidden
Reviewed-by: Michael S. Tsirkin <address@hidden>
Signed-off-by: Michael S. Tsirkin <address@hidden>
Reviewed-by: Stefan Hajnoczi <address@hidden>
---
hw/virtio/virtio.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 933a3d7..8357218 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -93,7 +93,7 @@ struct VirtQueue
uint16_t queue_index;
- int inuse;
+ unsigned int inuse;
uint16_t vector;
VirtIOHandleOutput handle_output;
@@ -1878,9 +1878,11 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int
version_id)
/*
* Some devices migrate VirtQueueElements that have been popped
* from the avail ring but not yet returned to the used ring.
+ * Since max ring size < UINT16_MAX it's safe to use modulo
+ * UINT16_MAX + 1 subtraction.
*/
- vdev->vq[i].inuse = vdev->vq[i].last_avail_idx -
- vdev->vq[i].used_idx;
+ vdev->vq[i].inuse = (uint16_t)(vdev->vq[i].last_avail_idx -
+ vdev->vq[i].used_idx);
if (vdev->vq[i].inuse > vdev->vq[i].vring.num) {
error_report("VQ %d size 0x%x < last_avail_idx 0x%x - "
"used_idx 0x%x",
--
MST
- [Qemu-devel] [PULL 12/41] memory: handle alias in memory_region_is_iommu(), (continued)
- [Qemu-devel] [PULL 12/41] memory: handle alias in memory_region_is_iommu(), Michael S. Tsirkin, 2017/01/10
- [Qemu-devel] [PULL 13/41] doc/pcie: correct command line examples, Michael S. Tsirkin, 2017/01/10
- [Qemu-devel] [PULL 14/41] virtio-crypto: use the correct length for cipher operation, Michael S. Tsirkin, 2017/01/10
- [Qemu-devel] [PULL 15/41] cryptodev: introduce a new is_used property, Michael S. Tsirkin, 2017/01/10
- [Qemu-devel] [PULL 16/41] cryptodev: wrap the ready flag, Michael S. Tsirkin, 2017/01/10
- [Qemu-devel] [PULL 17/41] virtio-crypto-pci: add check for cryptodev object, Michael S. Tsirkin, 2017/01/10
- [Qemu-devel] [PULL 18/41] virtio-crypto: avoid one cryptodev device is used by multiple virtio crypto devices, Michael S. Tsirkin, 2017/01/10
- [Qemu-devel] [PULL 19/41] virtio-crypto-pci: tag virtio-crypto device hot pluggable, Michael S. Tsirkin, 2017/01/10
- [Qemu-devel] [PULL 20/41] virtio-crypto: zeroize the key material before free, Michael S. Tsirkin, 2017/01/10
- [Qemu-devel] [PULL 21/41] pcie_aer: Convert pcie_aer_init to Error, Michael S. Tsirkin, 2017/01/10
- [Qemu-devel] [PULL 23/41] virtio: fix vq->inuse recalc after migr,
Michael S. Tsirkin <=
- [Qemu-devel] [PULL 22/41] pcie_aer: support configurable AER capa version, Michael S. Tsirkin, 2017/01/10
- [Qemu-devel] [PULL 24/41] balloon: Don't balloon roms, Michael S. Tsirkin, 2017/01/10
- [Qemu-devel] [PULL 25/41] net: Add virtio queue interface to update used index from vring state, Michael S. Tsirkin, 2017/01/10
- [Qemu-devel] [PULL 27/41] virtio: Introduce virtqueue_drop_all procedure, Michael S. Tsirkin, 2017/01/10
- [Qemu-devel] [PULL 26/41] net: vhost stop updates virtio queue state, Michael S. Tsirkin, 2017/01/10
- [Qemu-devel] [PULL 28/41] net: virtio-net discards TX data after link down, Michael S. Tsirkin, 2017/01/10
- [Qemu-devel] [PULL 29/41] vhost-user: Add MTU protocol feature and op, Michael S. Tsirkin, 2017/01/10
- [Qemu-devel] [PULL 30/41] vhost-net: Notify the backend about the host MTU, Michael S. Tsirkin, 2017/01/10
- [Qemu-devel] [PULL 31/41] virtio-net: Add MTU feature support, Michael S. Tsirkin, 2017/01/10
- [Qemu-devel] [PULL 32/41] tests: pc: add memory hotplug acpi tables tests, Michael S. Tsirkin, 2017/01/10