[Qemu-devel] Re: [PATCH 2/2] virtio: enable msi-x for console+balloon

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Dec 07, 2009 at 03:30:09PM +0100, Gerd Hoffmann wrote:
> On 12/07/09 15:13, Michael S. Tsirkin wrote:
>> Gerd, any idea whether "one MSI-X vector" feature is worth pursuing?
>
> I'd rate it low priority.  First because virtio-enabled guests can use  
> virtio-net+blk.  Also because with the upcoming p35 support we'll get a  
> more modern pc emulation including a ioapic with all 24 IRQ lines being  
> wired up, which will help reducing IRQ sharing too.
>
> MSI support (no -X) could be more intresting (for emulated devices) as  
> it is older and thus support is more common.  My T60 for example has no  
> device with MSI-X support but 9 with MSI support.  Linux turns on MSI  
> for 7 of them (4 PCIe ports, e1000, ahci, iwl3945).
>
> cheers,
>   Gerd

Yes, but what matters is guest support I think.
On windows it seems that both msix and msi support
were added simulataneously.

It won't be hard to add MSI support, but let's determine
when is it needed.

-- 
MST