On Thu, 21 Mar 2019 at 17:35, Laszlo Ersek <lersek(a)redhat.com> wrote:
It simply keeps the status quo from before the patchset.
The specific emulation targets that virtio-vga should not be enabled for
(regardless of other targets / machine types) are arm/aarch64. IOW, in
the longer term, it's not that virtio-vga is suitable only for PC ||
DINO || PSERIES, but that it's *not* suitable for arm/aarch64.
Relying on the device not being present for aarch64 seems
fragile to me. It will break if we add a different
aarch64 machine other than "virt" and want that other
machine to have virtio-vga. It will also break if we
ever manage to get full heterogenous-CPU support and
end up with a single qemu-system binary that can emulate
both AArch64 virt and x86-64 pc machines :-)
If what you want is "don't use virtio-vga when using KVM
on aarch64" then why not have logic that implements that?
For 4.0 we should definitely just retain what we had
before the introduction of KConfig, but as a general
thing we should look to not have to have this odd
wrinkle.
(AFAIK virtio-vga is no different in this regard to the other
vga PCI devices, which also won't work in KVM setups.)
thanks
-- PMM