Re: [PATCH 1/4] KVM: nVMX: support restore of VMX capability MSRs

From	David Matlack <dmatlack@google.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 1/4] KVM: nVMX: support restore of VMX capability MSRs
Date	2016-11-28 22:20 +0100
Message-ID	<sIBvb-7oU-3@gated-at.bofh.it> (permalink)
References	<sGuo9-6vC-5@gated-at.bofh.it> <sGuo9-6vC-17@gated-at.bofh.it> <sGEdQ-4jn-19@gated-at.bofh.it>
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On Wed, Nov 23, 2016 at 3:44 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> On 23/11/2016 02:14, David Matlack wrote:
>>       switch (msr_index) {
>>       case MSR_IA32_VMX_BASIC:
>> +             return vmx_restore_vmx_basic(vmx, data);
>> +     case MSR_IA32_VMX_TRUE_PINBASED_CTLS:
>> +     case MSR_IA32_VMX_PINBASED_CTLS:
>> +     case MSR_IA32_VMX_TRUE_PROCBASED_CTLS:
>> +     case MSR_IA32_VMX_PROCBASED_CTLS:
>> +     case MSR_IA32_VMX_TRUE_EXIT_CTLS:
>> +     case MSR_IA32_VMX_EXIT_CTLS:
>> +     case MSR_IA32_VMX_TRUE_ENTRY_CTLS:
>> +     case MSR_IA32_VMX_ENTRY_CTLS:
>
> PINBASED_CTLS, PROCBASED_CTLS, EXIT_CTLS and ENTRY_CTLS can be derived
> from their "true" counterparts, so I think it's better to remove the
> "non-true" ones from struct nested_vmx (and/or add the "true" ones when
> missing) and make them entirely computed.  But it can be done on top.

Good point. And that would mean userspace does not need to restore the
non-true MSRs, right? KVM does not emulate MSR_IA32_VMX_BASIC[55]=0,
and will probably never want to.

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Re: [PATCH 1/4] KVM: nVMX: support restore of VMX capability MSRs David Matlack <dmatlack@google.com> - 2016-11-28 22:20 +0100
  Re: [PATCH 1/4] KVM: nVMX: support restore of VMX capability MSRs Paolo Bonzini <pbonzini@redhat.com> - 2016-11-28 23:50 +0100
    Re: [PATCH 1/4] KVM: nVMX: support restore of VMX capability MSRs David Matlack <dmatlack@google.com> - 2016-11-29 00:00 +0100
      Re: [PATCH 1/4] KVM: nVMX: support restore of VMX capability MSRs Paolo Bonzini <pbonzini@redhat.com> - 2016-11-29 09:10 +0100
        Re: [PATCH 1/4] KVM: nVMX: support restore of VMX capability MSRs David Matlack <dmatlack@google.com> - 2016-11-29 18:50 +0100

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