Re: [Qemu-devel] [PATCH] vfio-pci: Add missing kvm_enabled() checks

[Stefan Hajnoczi]

On Thu, Dec 20, 2012 at 11:35 PM, Alex Williamson
<address@hidden> wrote:
> On Thu, 2012-12-20 at 22:14 +0100, Stefan Hajnoczi wrote:
>> It's necessary to check kvm_enabled() since a QEMU binary can be
>> compiled with KVM support but TCG can be used at run-time.
>> kvm_check_extension() segfaults if kvm_state is NULL.
>
> Ugh, this is exactly why we added kvm_irqfds_enabled() which doesn't
> call kvm_check_extension().  How is it possible to fall through to a
> kvm_check_extension() with that in place?  Thanks,

Ah, this explains it: Joe was using QEMU 1.3.0 which does not contain
the kvm_irqfds_enabled() fix.

My patch is unnecessary and can be dropped.

Stefan