On Thu, Jan 10, 2019 at 12:35:26PM +0400, Marc-André Lureau wrote:
> Hi
>
> On Thu, Jan 10, 2019 at 6:05 AM Eduardo Habkost <ehabk...@redhat.com> wrote:
> >
> > The disable-legacy and disable-modern properties apply only to
> > some virtio-pci devices. Make those properties optional.
> >
> > This fixes the crash introduced by commit f6e501a28ef9 ("virtio: Provide
> > version-specific variants of virtio PCI devices"):
> >
> > $ 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)
> >
> > Reported-by: Thomas Huth <th...@redhat.com>
> > Fixes: f6e501a28ef9 ("virtio: Provide version-specific variants of virtio
> > PCI devices")
> > Signed-off-by: Eduardo Habkost <ehabk...@redhat.com>
> > ---
> > hw/core/machine.c | 5 +++--
> > 1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/hw/core/machine.c b/hw/core/machine.c
> > index 5530b71981..a19143aa44 100644
> > --- a/hw/core/machine.c
> > +++ b/hw/core/machine.c
> > @@ -91,8 +91,9 @@ const size_t hw_compat_2_7_len =
> > G_N_ELEMENTS(hw_compat_2_7);
> >
> > GlobalProperty hw_compat_2_6[] = {
> > { "virtio-mmio", "format_transport_address", "off" },
> > - { "virtio-pci", "disable-modern", "on" },
> > - { "virtio-pci", "disable-legacy", "off" },
> > + /* Optional because not all virtio-pci devices support legacy mode */
> > + { "virtio-pci", "disable-modern", "on", .optional = true },
> > + { "virtio-pci", "disable-legacy", "off", .optional = true },
>
> Could the generic devices implement a specific interface instead?
> virtio-pci-generic?
This is the kind of complexity I wanted to avoid. We already
have too many interface names for subsets of PCI and virtio
devices.
>
> Adding "optional" handling looks like it may hide some other errors.
What if we just make "optional" mean "skip if the property
doesn't exist", as suggested by Cornelia and Dave?
--
Eduardo
