Re: [Qemu-devel] [PATCH V3] hw/virtio: Add PCIe capability to virtio devices

[Cornelia Huck]

On Mon, 2 Nov 2015 12:01:06 +0200
Marcel Apfelbaum <address@hidden> wrote:

> On 11/02/2015 11:54 AM, Cornelia Huck wrote:
> > On Mon, 2 Nov 2015 11:20:50 +0200
> > Marcel Apfelbaum <address@hidden> wrote:
> >
> >> On 11/02/2015 11:07 AM, Cornelia Huck wrote:
> >>> On Sun, 1 Nov 2015 11:15:24 +0200
> >>> Marcel Apfelbaum <address@hidden> wrote:
> >>>
> >>>> By the way, HW_COMPAT_2_3 sets any-layout to off only for a few virtio 
> >>>> devices,
> >>>> not for all. Does anybody know if is in purpose or can we do the same 
> >>>> for them too?
> >>>
> >>> net and scsi already defaulted any_layout to true before.
> >>>
> >>> Are any others missing?
> >>>
> >>
> >> Hi,
> >>
> >> The whole list is:
> >>    name "virtio-blk-pci", bus PCI, alias "virtio-blk"
> >>    name "virtio-scsi-pci", bus PCI
> >>    name "virtio-net-pci", bus PCI, alias "virtio-net"
> >>    name "virtio-input-host-pci", bus PCI
> >>    name "virtio-keyboard-pci", bus PCI
> >>    name "virtio-mouse-pci", bus PCI
> >>    name "virtio-serial-pci", bus PCI, alias "virtio-serial"
> >>    name "virtio-tablet-pci", bus PCI
> >>    name "virtio-gpu-pci", bus PCI
> >>    name "virtio-balloon-pci", bus PCI, alias "virtio-balloon"
> >>    name "virtio-rng-pci", bus PCI
> >>
> >>
> >> HW_COMPAT_2_3 has:
> >>     - virtio-blk-pci
> >>     - virtio-balloon-pci
> >>     - virtio-serial-pci
> >>     - virtio-9p-pci
> >>     - virtio-rng-pci
> >>
> >> You mentioned:
> >>     - virtio-scsi-pci
> >>     - virtio-net-pci
> >>
> >> I guess the remaining list is:
> >>    - virtio-input-host-pci
> >>    - virtio-keyboard-pci
> >>    - virtio-mouse-pci
> >>    - virtio-tablet-pci
> >>    - virtio-gpu-pci
> >>
> >> I don't know if is is applicable to them, or if they have it defaulted to 
> >> any_layout,
> >> however the above devices are part of QEMU 2.3.
> >
> > Hm, unless I'm fumbling git commands here, they were all added post-2.3?
> 
> I misspoke, I wanted to say that when I run (latest master branch):
>   <qemu-bin>  -M pc-q35-2.3  -device help 2>&1 | grep virtio | grep pci
> the devices are there.

What's the word on compat machines and new device types, btw.? If we
fire up a compat machine, we can still specify devices that were added
with later machine versions, but of course we can't migrate to an old
machine as the device types did not exist there. Do we want to give the
user a hint here by disallowing new device types?