From: Eugenio Pérez Date: Tue, 23 Aug 2022 18:30:27 +0000 (+0200) Subject: vhost: use SVQ element ndescs instead of opaque data for desc validation X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=86f5f2546f03a3dfde421c715187b262e29b2848;p=qemu.git vhost: use SVQ element ndescs instead of opaque data for desc validation Since we're going to allow SVQ to add elements without the guest's knowledge and without its own VirtQueueElement, it's easier to check if an element is a valid head checking a different thing than the VirtQueueElement. Signed-off-by: Eugenio Pérez Acked-by: Jason Wang Signed-off-by: Jason Wang --- diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c index a1261d4a0f..b35aeef4bd 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -414,7 +414,7 @@ static VirtQueueElement *vhost_svq_get_buf(VhostShadowVirtqueue *svq, return NULL; } - if (unlikely(!svq->desc_state[used_elem.id].elem)) { + if (unlikely(!svq->desc_state[used_elem.id].ndescs)) { qemu_log_mask(LOG_GUEST_ERROR, "Device %s says index %u is used, but it was not available", svq->vdev->name, used_elem.id); @@ -422,6 +422,7 @@ static VirtQueueElement *vhost_svq_get_buf(VhostShadowVirtqueue *svq, } num = svq->desc_state[used_elem.id].ndescs; + svq->desc_state[used_elem.id].ndescs = 0; last_used_chain = vhost_svq_last_desc_of_chain(svq, num, used_elem.id); svq->desc_next[last_used_chain] = svq->free_head; svq->free_head = used_elem.id;