Re: [libvirt] [PATCH v3 11/18] qemu: assign virtio devices to PCIe slot when appropriate
On 11/16/2016 03:43 AM, Gerd Hoffmann wrote:
Hi,
> I looked at "lspci" of a guest that has virtio-gpu directly connected to
> pci-root, and found that it does show up as a legacy device in that
> case, which I guess is what we want, right?
>
> Let's ask the author of virtio-gpu: Gerd, what is your opinion - when
> using virtio-gpu as the primary video device, is it better to have it
> directly plugged into 00:01.0 (i.e. a legacy integrated device)? Or is
> it better to plug it into a pcie-root-port?
virtio-vga or virtio-gpu-pci?
Ah, I didn't realize it until you asked, but libvirt uses virtio-vga for
the primary video device (if model is set to "virtio"), and
virtio-gpu-pci for any secondary video devices, and I had only specified
a single device.
virtio-gpu-pci should have zero issues in a pcie-root-port.
For virtio-vga I'd tend to place it directly in 00:01.0, to avoid ioport
access issues for the vga compatibility part of the device.
Okay, since this question is specifically for the primary video device,
and vga compatibility is highly desired for that, I guess that's our
answer - so the primary virtio video will stay on 00:01.0, and any
additional virtio video devices will be plugged into a pcie-root-port.
Thanks!