On Fri, Jan 04, 2019 at 01:22:26AM -0200, Eduardo Habkost wrote:
> The virtio-pci entries in HW_COMPAT_2_6 had an implicit
> assumption: that all virtio-pci subclasses support the
> disable-legacy and disable-modern options.
>
> That assumption was broken by commit f6e501a28ef9 ("virtio:
> Provide version-specific variants of virtio PCI devices"). This
> caused QEMU to crash if using the new -non-transitional or
> -transitional device types:
>
> $ qemu-system-x86_64 -machine pc-i440fx-2.6 \
> -device virtio-net-pci-non-transitional
> Unexpected error in object_property_find() at qom/object.c:1092:
> qemu-system-x86_64: -device virtio-net-pci-non-transitional: can't apply \
> global virtio-pci.disable-modern=on: Property '.disable-modern' not found
> Aborted (core dumped)
>
> Replace the virtio-pci.disable-legacy=off and
> virtio-pci.disable-modern=on entries on HW_COMPAT_2_6 with
> explicit entries for each generic virtio device type.
>
> The full list of generic virtio device types was extracted by
> just grepping for ".generic_name". Note that we don't need to
> worry about listing new virtio-pci devices in HW_COMPAT_2_6 in
> the future, because new devices won't require QEMU 2.6
> compatibility.
I fully expect that e.g. packed ring support will need
to affect all virtio devices too. And it's likely
that we'll have some new virtio-pci transport features too.
> This makes the compat entries annoyingly verbose, but is simpler
> than the alternative of making the virtio-pci type inheritance
> rules even more complex.
God forbid we forgot something, the only way to notice is to
run a cross version migration with an old qemu.
I think we need to come up with something less verbose and fragile.
> Reported-by: Thomas Huth <th...@redhat.com>
> Signed-off-by: Eduardo Habkost <ehabk...@redhat.com>
> ---
> ---
> include/hw/compat.h | 140 +++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 138 insertions(+), 2 deletions(-)
>
> diff --git a/include/hw/compat.h b/include/hw/compat.h
> index 3ca85b037c..fbb6c1138a 100644
> --- a/include/hw/compat.h
> +++ b/include/hw/compat.h
> @@ -163,11 +163,147 @@
> .property = "format_transport_address",\
> .value = "off",\
> },{\
> - .driver = "virtio-pci",\
> + .driver = "vhost-scsi-pci",\
> .property = "disable-modern",\
> .value = "on",\
> },{\
> - .driver = "virtio-pci",\
> + .driver = "vhost-scsi-pci",\
> + .property = "disable-legacy",\
> + .value = "off",\
> + },{\
> + .driver = "vhost-user-blk-pci",\
> + .property = "disable-modern",\
> + .value = "on",\
> + },{\
> + .driver = "vhost-user-blk-pci",\
> + .property = "disable-legacy",\
> + .value = "off",\
> + },{\
> + .driver = "vhost-user-scsi-pci",\
> + .property = "disable-modern",\
> + .value = "on",\
> + },{\
> + .driver = "vhost-user-scsi-pci",\
> + .property = "disable-legacy",\
> + .value = "off",\
> + },{\
> + .driver = "vhost-vsock-pci",\
> + .property = "disable-modern",\
> + .value = "on",\
> + },{\
> + .driver = "vhost-vsock-pci",\
> + .property = "disable-legacy",\
> + .value = "off",\
> + },{\
> + .driver = "virtio-9p-pci",\
> + .property = "disable-modern",\
> + .value = "on",\
> + },{\
> + .driver = "virtio-9p-pci",\
> + .property = "disable-legacy",\
> + .value = "off",\
> + },{\
> + .driver = "virtio-balloon-pci",\
> + .property = "disable-modern",\
> + .value = "on",\
> + },{\
> + .driver = "virtio-balloon-pci",\
> + .property = "disable-legacy",\
> + .value = "off",\
> + },{\
> + .driver = "virtio-blk-pci",\
> + .property = "disable-modern",\
> + .value = "on",\
> + },{\
> + .driver = "virtio-blk-pci",\
> + .property = "disable-legacy",\
> + .value = "off",\
> + },{\
> + .driver = "virtio-crypto-pci",\
> + .property = "disable-modern",\
> + .value = "on",\
> + },{\
> + .driver = "virtio-crypto-pci",\
> + .property = "disable-legacy",\
> + .value = "off",\
> + },{\
> + .driver = "virtio-gpu-pci",\
> + .property = "disable-modern",\
> + .value = "on",\
> + },{\
> + .driver = "virtio-gpu-pci",\
> + .property = "disable-legacy",\
> + .value = "off",\
> + },{\
> + .driver = "virtio-input-host-pci",\
> + .property = "disable-modern",\
> + .value = "on",\
> + },{\
> + .driver = "virtio-input-host-pci",\
> + .property = "disable-legacy",\
> + .value = "off",\
> + },{\
> + .driver = "virtio-keyboard-pci",\
> + .property = "disable-modern",\
> + .value = "on",\
> + },{\
> + .driver = "virtio-keyboard-pci",\
> + .property = "disable-legacy",\
> + .value = "off",\
> + },{\
> + .driver = "virtio-mouse-pci",\
> + .property = "disable-modern",\
> + .value = "on",\
> + },{\
> + .driver = "virtio-mouse-pci",\
> + .property = "disable-legacy",\
> + .value = "off",\
> + },{\
> + .driver = "virtio-net-pci",\
> + .property = "disable-modern",\
> + .value = "on",\
> + },{\
> + .driver = "virtio-net-pci",\
> + .property = "disable-legacy",\
> + .value = "off",\
> + },{\
> + .driver = "virtio-rng-pci",\
> + .property = "disable-modern",\
> + .value = "on",\
> + },{\
> + .driver = "virtio-rng-pci",\
> + .property = "disable-legacy",\
> + .value = "off",\
> + },{\
> + .driver = "virtio-scsi-pci",\
> + .property = "disable-modern",\
> + .value = "on",\
> + },{\
> + .driver = "virtio-scsi-pci",\
> + .property = "disable-legacy",\
> + .value = "off",\
> + },{\
> + .driver = "virtio-serial-pci",\
> + .property = "disable-modern",\
> + .value = "on",\
> + },{\
> + .driver = "virtio-serial-pci",\
> + .property = "disable-legacy",\
> + .value = "off",\
> + },{\
> + .driver = "virtio-tablet-pci",\
> + .property = "disable-modern",\
> + .value = "on",\
> + },{\
> + .driver = "virtio-tablet-pci",\
> + .property = "disable-legacy",\
> + .value = "off",\
> + },{\
> + .driver = "virtio-vga",\
> + .property = "disable-modern",\
> + .value = "on",\
> + },{\
> + .driver = "virtio-vga",\
> .property = "disable-legacy",\
> .value = "off",\
> },
> --
> 2.18.0.rc1.1.g3f1ff2140
