From: Eugenio Pérez <epere...@redhat.com> A guest's buffer continuos on GPA may need multiple descriptors on qemu's VA, so SVQ should track its length sepparatedly.
Signed-off-by: Eugenio Pérez <epere...@redhat.com> Reviewed-by: Michael S. Tsirkin <m...@redhat.com> Signed-off-by: Jason Wang <jasow...@redhat.com> --- hw/virtio/vhost-shadow-virtqueue.c | 4 ++-- hw/virtio/vhost-shadow-virtqueue.h | 6 ++++++ 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c index e4c09e2..8314405 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -257,6 +257,7 @@ static int vhost_svq_add(VhostShadowVirtqueue *svq, const struct iovec *out_sg, } svq->desc_state[qemu_head].elem = elem; + svq->desc_state[qemu_head].ndescs = ndescs; vhost_svq_kick(svq); return 0; } @@ -418,8 +419,7 @@ static VirtQueueElement *vhost_svq_get_buf(VhostShadowVirtqueue *svq, return NULL; } - num = svq->desc_state[used_elem.id].elem->in_num + - svq->desc_state[used_elem.id].elem->out_num; + num = svq->desc_state[used_elem.id].ndescs; 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; diff --git a/hw/virtio/vhost-shadow-virtqueue.h b/hw/virtio/vhost-shadow-virtqueue.h index d646c35..5c7e7cb 100644 --- a/hw/virtio/vhost-shadow-virtqueue.h +++ b/hw/virtio/vhost-shadow-virtqueue.h @@ -17,6 +17,12 @@ typedef struct SVQDescState { VirtQueueElement *elem; + + /* + * Number of descriptors exposed to the device. May or may not match + * guest's + */ + unsigned int ndescs; } SVQDescState; /* Shadow virtqueue to relay notifications */ -- 2.7.4