From 33c22dd3353f79a037f2473a69176932ac1a1c05 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 08/29] 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: Laurent Vivier RH-MergeRequest: 117: vDPA SVQ Multiqueue support RH-Jira: RHELX-57 RH-Acked-by: Jason Wang RH-Acked-by: Cindy Lu RH-Acked-by: Eugenio Pérez RH-Commit: [8/25] e9c6314fddeb1f7bc738efea90f2788cae27bab7 (redhat/centos-stream/src/qemu-kvm) 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 9c2ab2f1ec333be8614cc12272d4b91960704dbe) Signed-off-by: Laurent Vivier --- 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 82a784d250..a1261d4a0f 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