From 6cde15c70c86819033337771eb522e94e3ea9e34 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= Date: Tue, 23 Aug 2022 20:20:07 +0200 Subject: [PATCH 09/23] vhost: Always store new kick fd on vhost_svq_set_svq_kick_fd 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: [8/21] a09b8851c39d7cea67414560f6d322e988b9d59a (eperezmartin/qemu-kvm) Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2114060 Upstream status: git@github.com:jasowang/qemu.git net-next We can unbind twice a file descriptor if we call twice vhost_svq_set_svq_kick_fd because of this. Since it comes from vhost and not from SVQ, that file descriptor could be a different thing that guest's vhost notifier. Likewise, it can happens the same if a guest start and stop the device multiple times. Reported-by: Lei Yang Fixes: dff4426fa6 ("vhost: Add Shadow VirtQueue kick forwarding capabilities") Signed-off-by: Eugenio Pérez Acked-by: Jason Wang Signed-off-by: Jason Wang (cherry picked from commit 6867f29c1425add7e0e8d1d8d58cc0ffbb8df0e4) --- hw/virtio/vhost-shadow-virtqueue.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c index e53aac45f6..f420311b89 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -602,13 +602,13 @@ void vhost_svq_set_svq_kick_fd(VhostShadowVirtqueue *svq, int svq_kick_fd) event_notifier_set_handler(svq_kick, NULL); } + event_notifier_init_fd(svq_kick, svq_kick_fd); /* * event_notifier_set_handler already checks for guest's notifications if * they arrive at the new file descriptor in the switch, so there is no * need to explicitly check for them. */ if (poll_start) { - event_notifier_init_fd(svq_kick, svq_kick_fd); event_notifier_set(svq_kick); event_notifier_set_handler(svq_kick, vhost_handle_guest_kick_notifier); } @@ -655,7 +655,7 @@ void vhost_svq_start(VhostShadowVirtqueue *svq, VirtIODevice *vdev, */ void vhost_svq_stop(VhostShadowVirtqueue *svq) { - event_notifier_set_handler(&svq->svq_kick, NULL); + vhost_svq_set_svq_kick_fd(svq, VHOST_FILE_UNBIND); g_autofree VirtQueueElement *next_avail_elem = NULL; if (!svq->vq) { -- 2.31.1