Since QEMU will be able to inject new elements on CVQ to restore the
state, we need not to depend on a VirtQueueElement to know if a new
element has been used by the device or not. Instead of check that, check
if there are new elements only using used idx on vhost_svq_flush.
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
hw/virtio/vhost-shadow-virtqueue.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/hw/virtio/vhost-shadow-virtqueue.c
b/hw/virtio/vhost-shadow-virtqueue.c
index e6eebd0e8d..fdb550c31b 100644
--- a/hw/virtio/vhost-shadow-virtqueue.c
+++ b/hw/virtio/vhost-shadow-virtqueue.c
@@ -491,7 +491,7 @@ static void vhost_svq_flush(VhostShadowVirtqueue *svq,
/**
* Poll the SVQ for one device used buffer.
*
- * This function race with main event loop SVQ polling, so extra
+ * This function races with main event loop SVQ polling, so extra
* synchronization is needed.
*
* Return the length written by the device.
@@ -499,20 +499,20 @@ static void vhost_svq_flush(VhostShadowVirtqueue *svq,
size_t vhost_svq_poll(VhostShadowVirtqueue *svq)
{
int64_t start_us = g_get_monotonic_time();
- do {
+ while (true) {
uint32_t len;
- VirtQueueElement *elem = vhost_svq_get_buf(svq, &len);
- if (elem) {
- return len;
- }
if (unlikely(g_get_monotonic_time() - start_us > 10e6)) {
return 0;
}
- /* Make sure we read new used_idx */
- smp_rmb();
- } while (true);
+ if (!vhost_svq_more_used(svq)) {
+ continue;
+ }
+
+ vhost_svq_get_buf(svq, &len);