From 45305ab202fa2191962152e5a501a9a13e31a0b2 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= Date: Tue, 23 Aug 2022 20:30:26 +0200 Subject: [PATCH 11/23] vhost: stop transfer elem ownership in vhost_handle_guest_kick MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Eugenio Pérez RH-MergeRequest: 116: vdpa: Restore device state on destination RH-Bugzilla: 2114060 RH-Acked-by: Cindy Lu RH-Acked-by: Miroslav Rezanina RH-Commit: [10/21] 697a5c0ad59efe27abf447f7965091993bc39756 (eperezmartin/qemu-kvm) Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2114060 Upstream status: git@github.com:jasowang/qemu.git net-next It was easier to allow vhost_svq_add to handle the memory. Now that we will allow qemu to add elements to a SVQ without the guest's knowledge, it's better to handle it in the caller. Signed-off-by: Eugenio Pérez Acked-by: Jason Wang Signed-off-by: Jason Wang (cherry picked from commit eb42df8bb2c92a7313343d97409cd99ccba25b25) --- hw/virtio/vhost-shadow-virtqueue.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c index f420311b89..2ae47d90a1 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -233,9 +233,6 @@ static void vhost_svq_kick(VhostShadowVirtqueue *svq) /** * Add an element to a SVQ. * - * The caller must check that there is enough slots for the new element. It - * takes ownership of the element: In case of failure not ENOSPC, it is free. - * * Return -EINVAL if element is invalid, -ENOSPC if dev queue is full */ int vhost_svq_add(VhostShadowVirtqueue *svq, const struct iovec *out_sg, @@ -252,7 +249,6 @@ int vhost_svq_add(VhostShadowVirtqueue *svq, const struct iovec *out_sg, ok = vhost_svq_add_split(svq, out_sg, out_num, in_sg, in_num, &qemu_head); if (unlikely(!ok)) { - g_free(elem); return -EINVAL; } @@ -293,7 +289,7 @@ static void vhost_handle_guest_kick(VhostShadowVirtqueue *svq) virtio_queue_set_notification(svq->vq, false); while (true) { - VirtQueueElement *elem; + g_autofree VirtQueueElement *elem; int r; if (svq->next_guest_avail_elem) { @@ -324,12 +320,14 @@ static void vhost_handle_guest_kick(VhostShadowVirtqueue *svq) * queue the current guest descriptor and ignore kicks * until some elements are used. */ - svq->next_guest_avail_elem = elem; + svq->next_guest_avail_elem = g_steal_pointer(&elem); } /* VQ is full or broken, just return and ignore kicks */ return; } + /* elem belongs to SVQ or external caller now */ + elem = NULL; } virtio_queue_set_notification(svq->vq, true); -- 2.31.1