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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <80ed82a4-ed4e-9eb6-5530-9b621a5c11a6@redhat.com>
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