From: Stefan Hajnoczi Date: Mon, 27 Jan 2020 19:00:36 +0000 Subject: [PATCH] virtio-fs: fix MSI-X nvectors calculation The following MSI-X vectors are required: * VIRTIO Configuration Change * hiprio virtqueue * requests virtqueues Fix the calculation to reserve enough MSI-X vectors. Otherwise guest drivers fall back to a sub-optional configuration where all virtqueues share a single vector. This change does not break live migration compatibility since vhost-user-fs-pci devices are not migratable yet. Reported-by: Vivek Goyal Signed-off-by: Stefan Hajnoczi Message-Id: <20191209110759.35227-1-stefanha@redhat.com> Reviewed-by: Dr. David Alan Gilbert Reviewed-by: Michael S. Tsirkin Signed-off-by: Dr. David Alan Gilbert (cherry picked from commit 366844f3d1329c6423dd752891a28ccb3ee8fddd) --- hw/virtio/vhost-user-fs-pci.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/virtio/vhost-user-fs-pci.c b/hw/virtio/vhost-user-fs-pci.c index 933a3f265b..e3a649d4a6 100644 --- a/hw/virtio/vhost-user-fs-pci.c +++ b/hw/virtio/vhost-user-fs-pci.c @@ -40,7 +40,8 @@ static void vhost_user_fs_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp) DeviceState *vdev = DEVICE(&dev->vdev); if (vpci_dev->nvectors == DEV_NVECTORS_UNSPECIFIED) { - vpci_dev->nvectors = dev->vdev.conf.num_request_queues + 1; + /* Also reserve config change and hiprio queue vectors */ + vpci_dev->nvectors = dev->vdev.conf.num_request_queues + 2; } qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));