From 01270bb66a4f7897a4fd06ba248eeeb41dc47571 Mon Sep 17 00:00:00 2001 From: Si-Wei Liu Date: Fri, 6 May 2022 19:28:16 -0700 Subject: [PATCH 18/24] vhost-vdpa: backend feature should set only once MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Jason Wang RH-MergeRequest: 187: Multiqueue fixes for vhost-vDPA RH-Commit: [5/7] 0ab13542cf25c129dc403db95c7db12cdb012744 RH-Bugzilla: 2069946 RH-Acked-by: Eugenio Pérez RH-Acked-by: Cindy Lu RH-Acked-by: Laurent Vivier The vhost_vdpa_one_time_request() branch in vhost_vdpa_set_backend_cap() incorrectly sends down ioctls on vhost_dev with non-zero index. This may end up with multiple VHOST_SET_BACKEND_FEATURES ioctl calls sent down on the vhost-vdpa fd that is shared between all these vhost_dev's. To fix it, send down ioctl only once via the first vhost_dev with index 0. Toggle the polarity of the vhost_vdpa_one_time_request() test should do the trick. Fixes: 4d191cfdc7de ("vhost-vdpa: classify one time request") Signed-off-by: Si-Wei Liu Reviewed-by: Stefano Garzarella Acked-by: Jason Wang Acked-by: Eugenio Pérez Message-Id: <1651890498-24478-6-git-send-email-si-wei.liu@oracle.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin (cherry picked from commit 6aee7e4233f6467f69531fcd352adff028f3f5ea) Signed-off-by: Jason Wang --- hw/virtio/vhost-vdpa.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c index 78da48a333..a9be24776a 100644 --- a/hw/virtio/vhost-vdpa.c +++ b/hw/virtio/vhost-vdpa.c @@ -525,7 +525,7 @@ static int vhost_vdpa_set_backend_cap(struct vhost_dev *dev) features &= f; - if (vhost_vdpa_one_time_request(dev)) { + if (!vhost_vdpa_one_time_request(dev)) { r = vhost_vdpa_call(dev, VHOST_SET_BACKEND_FEATURES, &features); if (r) { return -EFAULT; -- 2.35.3