Re: [Qemu-devel] Re: virtio-blk performance and MSI

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Sun, Aug 09, 2009 at 09:13:13PM +0200, Christoph Hellwig wrote:
> On Sun, Aug 09, 2009 at 08:49:23PM +0300, Avi Kivity wrote:
> > Sorry, confused.  Upstream doesn't use kvm for msi (everything's done in 
> > userspace).  What exactly blocks us here?
> 
> Hmm, good question.  Michael, do you know if we can just enabled
> MSI unconditionally in upstream qemu, or are there guests that can't
> cope with it?

Upstream or not, block should request MSI by default, the code in hw/msi
checks that host kernel can support it and only enables when it's safe.

And AFAIK all guests can cope with it but only if they are rebooted.
So we must have a flag to change the # of vectors, to have ability
to load images and migrate from state stored by old qemu.
And of course this option is also useful for troubleshooting.

-- 
MST
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux