Re: [libvirt] [PATCH 8/9] qemu: Only setup vhost if virtType == "kvm"
On Thu, Aug 01, 2013 at 03:06:41AM -0400, Laine Stump wrote:
On 07/31/2013 10:14 PM, Cole Robinson wrote:
> vhost only works in KVM mode AIUI,
What's your definition of "AIUI"? :-) That makes sense, but in case you
haven't yet asked MST, I'm CC'ing him to get it straight from the
source. MST?
If that's true, then ACK (and we might want to backport this to some
older releases)
That's true at the moment but I'm not sure about the future:
fundamentally there's nothing kvm specific in vhost,
it's just that qemu doesn't yet support ioeventfd
and irqfd without kvm.
So I think we really should design something to detect
whether vhost-net is supported, I will look into this.
It's up to you guys whether to wait for that
and look into how to do this properly, or
apply this patch and re-do the change again
once qemu has this support.
> and is infact compiled out if
> the emulator is built for non-native architecture.
> ---
> src/qemu/qemu_command.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
> index 3b275e3..f611940 100644
> --- a/src/qemu/qemu_command.c
> +++ b/src/qemu/qemu_command.c
> @@ -462,8 +462,10 @@ qemuOpenVhostNet(virDomainDefPtr def,
> {
> size_t i;
>
> - /* If the config says explicitly to not use vhost, return now */
> - if (net->driver.virtio.name == VIR_DOMAIN_NET_BACKEND_TYPE_QEMU) {
> + /* If running a plain QEMU guest, or
> + * if the config says explicitly to not use vhost, return now*/
> + if (def->virtType != VIR_DOMAIN_VIRT_KVM ||
> + net->driver.virtio.name == VIR_DOMAIN_NET_BACKEND_TYPE_QEMU) {
> *vhostfdSize = 0;
> return 0;
> }