On Fri, 16 Jul 2021 14:12:06 +0200
Vitaly Kuznetsov <vkuzn...@redhat.com> wrote:
> Igor Mammedov <imamm...@redhat.com> writes:
>
> > On Thu, 8 Jul 2021 17:02:22 -0400
> > Eduardo Habkost <ehabk...@redhat.com> wrote:
> >
> >> On Tue, Jun 08, 2021 at 02:08:17PM +0200, Vitaly Kuznetsov wrote:
> >> > For the beginning, just test 'hv-passthrough' and a couple of custom
> >> > Hyper-V enlightenments configurations through QMP. Later, it would
> >> > be great to complement this by checking CPUID values from within the
> >> > guest.
> >> >
> >> > Signed-off-by: Vitaly Kuznetsov <vkuzn...@redhat.com>
> >> [...]
> >> > +static bool kvm_has_sys_hyperv_cpuid(void)
> >> > +{
> >> > + int fd = open("/dev/kvm", O_RDWR);
> >> > + int ret;
> >> > +
> >> > + g_assert(fd > 0);
> >>
>
> g_assert() was an overkill, just 'return false' would do.
>
> >> This crashes when /dev/kvm doesn't exist. See:
> >> https://gitlab.com/ehabkost/qemu/-/jobs/1404084459
> >
> > maybe reuse qtest_has_accel()
> > https://lists.gnu.org/archive/html/qemu-devel/2021-06/msg06864.html
> >
> > instead of op encoding it.
>
> The purpose of this function is to check if KVM_CAP_SYS_HYPERV_CPUID is
> supported by KVM. It is certainly unsupported when KVM is not present
> :-) but an ioctl() is needed when it is.
>
> We already have a similar check in tests/qtest/migration-test.c where we
> test for KVM_CAP_DIRTY_LOG_RING, maybe we can create a library function
> but we don't seem to have any KVM-specific stuff in qtest at this moment
qtest_has_accel() is a such library function
in the same series see
https://lists.gnu.org/archive/html/qemu-devel/2021-06/msg06878.html
which replaces custom kvm probing in tests/qtest/migration-test.c
> ...
>
> >> I'm removing it from the queue.
>
> I'll fix g_assert() and send as a separate patch if it's fine.
>
