linux-kernel - Re: [PATCH v4 2/5] KVM: x86: Move CPUID.(EAX=0x12,ECX=1) mangling to __kvm_update_cpuid

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Date:   Sat, 22 Jan 2022 09:17:43 +0100
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     Paolo Bonzini <pbonzini@...hat.com>, kvm@...r.kernel.org
Cc:     Sean Christopherson <seanjc@...gle.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Igor Mammedov <imammedo@...hat.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 2/5] KVM: x86: Move CPUID.(EAX=0x12,ECX=1) mangling
 to __kvm_update_cpuid_runtime()

Paolo Bonzini <pbonzini@...hat.com> writes:

> On 1/21/22 14:28, Vitaly Kuznetsov wrote:
>> To support comparing CPUID data update with what's already set for a vCPU
>> all mangling needs to happen in __kvm_update_cpuid_runtime(), before
>> 'vcpu->arch.cpuid_entries' is updated. CPUID.(EAX=0x12,ECX=1) is currently
>> being mangled in kvm_vcpu_after_set_cpuid(), move it to
>> __kvm_update_cpuid_runtime(). Split off cpuid_get_supported_xcr0() helper
>> as 'vcpu->arch.guest_supported_xcr0' update needs (logically) to stay in
>> kvm_vcpu_after_set_cpuid().
>> 
>> No functional change intended.
>
> Since v3 is already on its way to Linus, I'll merge this patch next week.
>

Thanks,

there is also a change in "[PATCH v4 3/5] KVM: x86: Partially allow
KVM_SET_CPUID{,2} after KVM_RUN" where I switch to memcmp (as suggested
by Sean). I can send an incremental patch if needed.

-- 
Vitaly