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Re: [RFC PATCH 0/3] kvm: x86: speedups for APICv

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2016-09-29 17:41-0400, Paolo Bonzini:
>> Another possible optimization: when delivering an IPI, don't write the
>> vector to PIR, but directly to VIRR.  If the guest is not in VMX
>> non-root mode, then vm entry will take care of the injection; in the
>> other case, we'll send POSTED_INTR_VECTOR.
>> It seems that we don't even have to set PI.ON -- SDM doesn't say it is
>> necessary to evaluate pending virtual interrupts after receiving the
>> notification interrupt.  If we have to set PI.ON, we can just skip the
>> PIR->VIRR sync as long as the VM doesn't have an assigned device,
>> because we know that PIR is empty.
> 
> Nope, you cannot write to the APIC page while the VM is running.

True, thanks.

> (We're already reading the manual in such a way as to "allow" us to
> write TMR while the VM is running, but that should not be extended.
> For example the SDM doesn't say that the processor accesses VIRR with
> atomic instructions, in fact it probably doesn't).

Yeah, TMR is not used by the hardware ...

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[RFC PATCH 0/3] kvm: x86: speedups for APICv Paolo Bonzini <pbonzini@redhat.com> - 2016-09-27 23:30 +0200
  [PATCH 3/3] KVM: x86: do not scan IRR twice on APICv vmentry Paolo Bonzini <pbonzini@redhat.com> - 2016-09-27 23:30 +0200
    Re: [PATCH 3/3] KVM: x86: do not scan IRR twice on APICv vmentry "Michael S. Tsirkin" <mst@redhat.com> - 2016-09-28 16:10 +0200
      Re: [PATCH 3/3] KVM: x86: do not scan IRR twice on APICv vmentry Paolo Bonzini <pbonzini@redhat.com> - 2016-09-28 16:50 +0200
    RE: [PATCH 3/3] KVM: x86: do not scan IRR twice on APICv vmentry "Wu, Feng" <feng.wu@intel.com> - 2016-09-29 05:00 +0200
  [PATCH 2/3] kvm: x86: do not use KVM_REQ_EVENT for APICv interrupt injection Paolo Bonzini <pbonzini@redhat.com> - 2016-09-27 23:30 +0200
    Re: [PATCH 2/3] kvm: x86: do not use KVM_REQ_EVENT for APICv  interrupt injection "Michael S. Tsirkin" <mst@redhat.com> - 2016-09-28 01:10 +0200
      Re: [PATCH 2/3] kvm: x86: do not use KVM_REQ_EVENT for APICv  interrupt injection Paolo Bonzini <pbonzini@redhat.com> - 2016-09-28 10:30 +0200
        RE: [PATCH 2/3] kvm: x86: do not use KVM_REQ_EVENT for APICv  interrupt injection "Wu, Feng" <feng.wu@intel.com> - 2016-09-28 13:50 +0200
          Re: [PATCH 2/3] kvm: x86: do not use KVM_REQ_EVENT for APICv  interrupt injection Paolo Bonzini <pbonzini@redhat.com> - 2016-09-28 14:00 +0200
            RE: [PATCH 2/3] kvm: x86: do not use KVM_REQ_EVENT for APICv  interrupt injection "Wu, Feng" <feng.wu@intel.com> - 2016-09-28 14:10 +0200
              Re: [PATCH 2/3] kvm: x86: do not use KVM_REQ_EVENT for APICv  interrupt injection Paolo Bonzini <pbonzini@redhat.com> - 2016-09-28 14:20 +0200
        Re: [PATCH 2/3] kvm: x86: do not use KVM_REQ_EVENT for APICv  interrupt injection "Michael S. Tsirkin" <mst@redhat.com> - 2016-09-28 15:50 +0200
          Re: [PATCH 2/3] kvm: x86: do not use KVM_REQ_EVENT for APICv  interrupt injection Paolo Bonzini <pbonzini@redhat.com> - 2016-09-28 16:10 +0200
    RE: [PATCH 2/3] kvm: x86: do not use KVM_REQ_EVENT for APICv  interrupt injection "Wu, Feng" <feng.wu@intel.com> - 2016-09-28 12:10 +0200
      Re: [PATCH 2/3] kvm: x86: do not use KVM_REQ_EVENT for APICv  interrupt injection Paolo Bonzini <pbonzini@redhat.com> - 2016-09-28 12:20 +0200
        Re: [PATCH 2/3] kvm: x86: do not use KVM_REQ_EVENT for APICv  interrupt injection Paolo Bonzini <pbonzini@redhat.com> - 2016-09-28 14:00 +0200
          RE: [PATCH 2/3] kvm: x86: do not use KVM_REQ_EVENT for APICv  interrupt injection "Wu, Feng" <feng.wu@intel.com> - 2016-09-28 14:10 +0200
        RE: [PATCH 2/3] kvm: x86: do not use KVM_REQ_EVENT for APICv  interrupt injection "Wu, Feng" <feng.wu@intel.com> - 2016-09-28 14:00 +0200
  Re: [RFC PATCH 0/3] kvm: x86: speedups for APICv Radim Krčmář <rkrcmar@redhat.com> - 2016-09-29 22:00 +0200
    Re: [RFC PATCH 0/3] kvm: x86: speedups for APICv Paolo Bonzini <pbonzini@redhat.com> - 2016-09-29 23:50 +0200
      Re: [RFC PATCH 0/3] kvm: x86: speedups for APICv Radim Krčmář <rkrcmar@redhat.com> - 2016-09-30 15:30 +0200
      Re: [RFC PATCH 0/3] kvm: x86: speedups for APICv Radim Krčmář <rkrcmar@redhat.com> - 2016-09-30 15:40 +0200

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