linux-kernel - Re: [RFC PATCH 4/4] KVM: vmx: add support for emulating UMIP

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Date:	Thu, 14 Jul 2016 14:54:31 +0200
From:	Paolo Bonzini <pbonzini@...hat.com>
To:	Radim Krčmář <rkrcmar@...hat.com>
Cc:	linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Subject: Re: [RFC PATCH 4/4] KVM: vmx: add support for emulating UMIP



On 14/07/2016 14:36, Radim Krčmář wrote:
>>> And we could then return true in vmx_umip_emulated() when
>>> boot_cpu_has(X86_FEATURE_UMIP).
>>> (Just for self-documentation, because occurrence of X86_FEATURE_UMIP is
>>>  most likely a subset of SECONDARY_EXEC_DESC.)
>>
>> This is not necessary because this is how KVM computes
>> CPUID[EAX=7,EBX=0].ECX:
>>
>>         unsigned f_umip = kvm_x86_ops->umip_emulated() ? F(UMIP) : 0;
>> 	...
>>         const u32 kvm_cpuid_7_0_ecx_x86_features = F(PKU) | F(UMIP);
> 
> and that too, I'm really sorry for the review.

At least in the latter case, that says something about the code quality too.

Paolo