Re: [PATCH] qemu-kvm: Switch to upstream -enable-kvm semantics

[Markus Armbruster <armbru@redhat.com>]

"Richard W.M. Jones" <rjones@redhat.com> writes:

> On Tue, Dec 21, 2010 at 04:41:03PM +0100, Markus Armbruster wrote:
>> Like this?
>> 
>> upstream qemu   |  default  |-enable-kvm
>> ----------------+-----------+-----------
>> KVM available   | disabled  |  enabled
>> KVM unavailable | disabled  |    fail
>> 
>> qemu-kvm        |  default  |-enable-kvm|  -no-kvm
>> ----------------+-----------+-----------+-----------
>> KVM available   |  enabled* |  enabled  |  disabled
>> KVM unavailable | disabled  |    fail   |  disabled
>> 
>> * differs from upstream
>
> libguestfs wants "best effort" behaviour, and libvirt wants "KVM or die"
> behaviour.

For what it's worth, default gives you exactly that with qemu-kvm.
Maybe that's good enough, on the theory that if you have KVM, you most
likely have libguestfs using qemu-kvm.

> Avi, can you comment on whether just opening /dev/kvm O_RDWR is a
> reasonable way to detect if KVM is available?
>
> Markus, any idea when we might get the -accel option appearing in
> released versions of qemu/KVM?

No idea.  Anthony?