From d368c0b052ad95d3bf4fcc5a5d25715a35c91d4b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= Date: Tue, 23 Aug 2022 20:30:29 +0200 Subject: [PATCH] vhost: Do not depend on !NULL VirtQueueElement on vhost_svq_flush MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Acked-by: Jason Wang Signed-off-by: Jason Wang --- hw/virtio/vhost-shadow-virtqueue.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c index 8df5296f24..e8e5bbc368 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -499,17 +499,20 @@ static void vhost_svq_flush(VhostShadowVirtqueue *svq, size_t vhost_svq_poll(VhostShadowVirtqueue *svq) { int64_t start_us = g_get_monotonic_time(); + uint32_t len; + do { - uint32_t len; - VirtQueueElement *elem = vhost_svq_get_buf(svq, &len); - if (elem) { - return len; + if (vhost_svq_more_used(svq)) { + break; } if (unlikely(g_get_monotonic_time() - start_us > 10e6)) { return 0; } } while (true); + + vhost_svq_get_buf(svq, &len); + return len; } /**