From: Stefano Garzarella Date: Mon, 21 Sep 2020 14:25:04 +0200 Subject: [PATCH] vhost-vsock-pci: force virtio version 1 Commit 9b3a35ec82 ("virtio: verify that legacy support is not accidentally on") added a safety check that requires to set 'disable-legacy=on' on vhost-vsock-pci device: $ ./qemu-system-x86_64 ... -device vhost-vsock-pci,guest-cid=5 qemu-system-x86_64: -device vhost-vsock-pci,guest-cid=5: device is modern-only, use disable-legacy=on virtio-vsock was introduced after the release of VIRTIO 1.0 specifications, so it should be 'modern-only'. In addition Cornelia verified that forcing a legacy mode on vhost-vsock-pci device using x86-64 host and s390x guest, so with different endianness, produces strange behaviours. This patch forces virtio version 1 and removes the 'transitional_name' property removing the need to specify 'disable-legacy=on' on vhost-vsock-pci device. To avoid migration issues, we force virtio version 1 only when legacy check is enabled in the new machine types (>= 5.1). As the transitional device name is not commonly used, we do not provide compatibility handling for it. Cc: qemu-stable@nongnu.org Reported-by: Qian Cai Reported-by: Qinghua Cheng Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1868449 Suggested-by: Cornelia Huck Reviewed-by: Cornelia Huck Signed-off-by: Stefano Garzarella Message-Id: <20200921122506.82515-3-sgarzare@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin (cherry picked from commit 6209070503989cf4f28549f228989419d4f0b236) --- hw/virtio/vhost-vsock-pci.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/hw/virtio/vhost-vsock-pci.c b/hw/virtio/vhost-vsock-pci.c index a815278e69..f11a38292f 100644 --- a/hw/virtio/vhost-vsock-pci.c +++ b/hw/virtio/vhost-vsock-pci.c @@ -43,6 +43,15 @@ static void vhost_vsock_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp) { VHostVSockPCI *dev = VHOST_VSOCK_PCI(vpci_dev); DeviceState *vdev = DEVICE(&dev->vdev); + VirtIODevice *virtio_dev = VIRTIO_DEVICE(vdev); + + /* + * To avoid migration issues, we force virtio version 1 only when + * legacy check is enabled in the new machine types (>= 5.1). + */ + if (!virtio_legacy_check_disabled(virtio_dev)) { + virtio_pci_force_virtio_1(vpci_dev); + } qdev_realize(vdev, BUS(&vpci_dev->bus), errp); } @@ -72,7 +81,6 @@ static void vhost_vsock_pci_instance_init(Object *obj) static const VirtioPCIDeviceTypeInfo vhost_vsock_pci_info = { .base_name = TYPE_VHOST_VSOCK_PCI, .generic_name = "vhost-vsock-pci", - .transitional_name = "vhost-vsock-pci-transitional", .non_transitional_name = "vhost-vsock-pci-non-transitional", .instance_size = sizeof(VHostVSockPCI), .instance_init = vhost_vsock_pci_instance_init,