Re: [PATCH AUTOSEL 5.3 28/68] KVM: x86: Expose XSAVEERPTR to the guest

From: Paolo Bonzini
Date: Wed Oct 09 2019 - 18:50:19 EST


On 09/10/19 23:40, Sebastian Andrzej Siewior wrote:
>>> const u32 kvm_cpuid_8000_0008_ebx_x86_features =
>>> + F(XSAVEERPTR) |
>>> F(WBNOINVD) | F(AMD_IBPB) | F(AMD_IBRS) | F(AMD_SSBD) | F(VIRT_SSBD) |
>>> F(AMD_SSB_NO) | F(AMD_STIBP) | F(AMD_STIBP_ALWAYS_ON);
>>>
>>>
>> Yet another example of a patch that shouldn't be stable material (in
>> this case it's fine, but there can certainly be cases where just adding
>> a single flag depends on core kernel changes).
>
> Also, taking advantage of this feature requires changes which just
> landed in qemu's master branch.

That's not a big deal, every QEMU supports every kernel and vice versa.

Paolo