RE: [PATCH v5 3/3] KVM: x86: Enable Intel MPX for guest

From: Liu, Jinsong
Date: Mon Feb 24 2014 - 10:37:37 EST


Paolo Bonzini wrote:
> Il 24/02/2014 11:58, Liu, Jinsong ha scritto:
>> @@ -599,6 +599,9 @@ int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32
>> index, u64 xcr) u64 old_xcr0 = vcpu->arch.xcr0;
>> u64 valid_bits;
>>
>> + if (!kvm_x86_ops->mpx_supported || !kvm_x86_ops->mpx_supported())
>> + xcr0 &= ~(XSTATE_BNDREGS | XSTATE_BNDCSR);
>> +
>> /* Only support XCR_XFEATURE_ENABLED_MASK(xcr0) now */
>> if (index != XCR_XFEATURE_ENABLED_MASK)
>> return 1;
>
> This hunk is incorrect, and I can simply drop it when applying. If
> MPX is not supported, it should not be in the 0Dh CPUID leaf and thus
> in vcpu->arch.guest_supported_xcr0.
>
> This however relies on userspace passing a "sensible" value of CPUID.
> I'll send a patch to strengthen the computation of
> guest_supported_xcr0.
>
> Thanks!
>
> Paolo

So patch v5 would be applied except you will remove the incorrect hunk, and you will send a patch strengthenning guest_supported_xcr0?

Thanks,
Jinsong--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/