Maxime Coquelin 66d1c4c19f virtio-pci: Fix cross-version migration with older machines ... This patch fixes a cross-version migration regression introduced by commit d1b4259f ("virtio-bus: Plug devices after features are negotiated"). The problem is encountered when host's vhost backend does not support VIRTIO_F_VERSION_1, and migration is initiated from a v2.7 or prior machine with virtio-pci modern capabilities enabled to a v2.8 machine. In this case, modern capabilities get exposed to the guest by the source, whereas the target will detect version 1 is not supported so will only expose legacy capabilities. The problem is fixed by introducing a new "x-ignore-backend-features" property, which is set in v2.7 and prior compatibility modes. Doing this, v2.7 machine keeps its broken behaviour (enabling modern while version is not supported), and newer machines will behave correctly. Reported-by: Michael Roth <mdroth@linux.vnet.ibm.com> Reviewed-by: Marcel Apfelbaum <marcel@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com> Message-id: 20161214163035.3297-1-maxime.coquelin@redhat.com Suggested-by: Stefan Hajnoczi <stefanha@redhat.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Marcel Apfelbaum <marcel@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Tested-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>		2016-12-15 07:35:19 +00:00
..
Makefile.objs	virtio-crypto-pci: add virtio crypto pci support	2016-11-01 19:21:08 +02:00
trace-events	virtio: set ISR on dataplane notifications	2016-11-18 17:29:25 +02:00
vhost-backend.c	vhost-vsock: add virtio sockets device	2016-09-10 00:28:08 +03:00
vhost-user.c	char: use qemu_chr_fe* functions with CharBackend argument	2016-10-24 15:27:21 +02:00
vhost-vsock.c	virtio: cleanup VMSTATE_VIRTIO_DEVICE	2016-10-10 02:21:43 +03:00
vhost.c	virtio: introduce grab/release_ioeventfd to fix vhost	2016-11-18 17:29:25 +02:00
virtio-balloon.c	virtio: rename virtqueue_discard to virtqueue_unpop	2016-11-15 17:20:36 +02:00
virtio-bus.c	virtio: introduce grab/release_ioeventfd to fix vhost	2016-11-18 17:29:25 +02:00
virtio-crypto-pci.c	virtio-crypto: tag as not hotpluggable and migration	2016-11-15 17:20:36 +02:00
virtio-crypto.c	virtio-crypto: fix uninitialized variables	2016-11-30 04:22:18 +02:00
virtio-mmio.c	virtio: access ISR atomically	2016-11-18 17:29:25 +02:00
virtio-pci.c	virtio-pci: Fix cross-version migration with older machines	2016-12-15 07:35:19 +00:00
virtio-pci.h	virtio-pci: Fix cross-version migration with older machines	2016-12-15 07:35:19 +00:00
virtio-rng.c	virtio: cleanup VMSTATE_VIRTIO_DEVICE	2016-10-10 02:21:43 +03:00
virtio.c	virtio: set ISR on dataplane notifications	2016-11-18 17:29:25 +02:00