| Message ID | 20200921083807.48380-3-sgarzare@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | vhost-vsock: force virtio version 1 | expand |
On Mon, 21 Sep 2020 10:38:05 +0200 Stefano Garzarella <sgarzare@redhat.com> wrote: > 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). Maybe add "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 <caiqian@redhat.com> > Reported-by: Qinghua Cheng <qcheng@redhat.com> > Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1868449 > Suggested-by: Cornelia Huck <cohuck@redhat.com> > Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> > --- > v3: > - forced virtio version 1 only with new machine types > v2: > - fixed commit message [Cornelia] > --- > hw/virtio/vhost-vsock-pci.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > Reviewed-by: Cornelia Huck <cohuck@redhat.com>
On Mon, Sep 21, 2020 at 11:46:02AM +0200, Cornelia Huck wrote: > On Mon, 21 Sep 2020 10:38:05 +0200 > Stefano Garzarella <sgarzare@redhat.com> wrote: > > > 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). > > Maybe add > > "As the transitional device name is not commonly used, we do not > provide compatibility handling for it." ? Yes, I'll add in v5. > > > > > Cc: qemu-stable@nongnu.org > > Reported-by: Qian Cai <caiqian@redhat.com> > > Reported-by: Qinghua Cheng <qcheng@redhat.com> > > Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1868449 > > Suggested-by: Cornelia Huck <cohuck@redhat.com> > > Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> > > --- > > v3: > > - forced virtio version 1 only with new machine types > > v2: > > - fixed commit message [Cornelia] > > --- > > hw/virtio/vhost-vsock-pci.c | 10 +++++++++- > > 1 file changed, 9 insertions(+), 1 deletion(-) > > > > Reviewed-by: Cornelia Huck <cohuck@redhat.com> Thanks, Stefano
diff --git a/hw/virtio/vhost-vsock-pci.c b/hw/virtio/vhost-vsock-pci.c index e56067b427..205da8d1f5 100644 --- a/hw/virtio/vhost-vsock-pci.c +++ b/hw/virtio/vhost-vsock-pci.c @@ -44,6 +44,15 @@ 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); } @@ -73,7 +82,6 @@ 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,
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). Cc: qemu-stable@nongnu.org Reported-by: Qian Cai <caiqian@redhat.com> Reported-by: Qinghua Cheng <qcheng@redhat.com> Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1868449 Suggested-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> --- v3: - forced virtio version 1 only with new machine types v2: - fixed commit message [Cornelia] --- hw/virtio/vhost-vsock-pci.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)