Re: [PATCH] KVM: X86: Expose KVM_HINTS_REALTIME in KVM_GET_SUPPORTED_CPUID

[Jim Mattson]

On Thu, Oct 22, 2020 at 6:02 AM Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
>
> On 22/10/20 03:34, Wanpeng Li wrote:
> > From: Wanpeng Li <wanpengli@xxxxxxxxxxx>
> >
> > Per KVM_GET_SUPPORTED_CPUID ioctl documentation:
> >
> > This ioctl returns x86 cpuid features which are supported by both the
> > hardware and kvm in its default configuration.
> >
> > A well-behaved userspace should not set the bit if it is not supported.
> >
> > Suggested-by: Jim Mattson <jmattson@xxxxxxxxxx>
> > Signed-off-by: Wanpeng Li <wanpengli@xxxxxxxxxxx>
>
> It's common for userspace to copy all supported CPUID bits to
> KVM_SET_CPUID2, I don't think this is the right behavior for
> KVM_HINTS_REALTIME.

That is not how the API is defined, but I'm sure you know that. :-)

> (But maybe this was discussed already; if so, please point me to the
> previous discussion).
>
> Paolo