Re: [RFC PATCH v1 10/15] KVM: VMX: Use WRMSRNS or its immediate form when available

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

To: "H. Peter Anvin" <hpa@xxxxxxxxx>, Jim Mattson <jmattson@xxxxxxxxxx>, Sean Christopherson <seanjc@xxxxxxxxxx>
Subject: Re: [RFC PATCH v1 10/15] KVM: VMX: Use WRMSRNS or its immediate form when available
From: Xin Li <xin@xxxxxxxxx>
Date: Mon, 14 Apr 2025 10:48:47 -0700
Cc: linux-kernel@xxxxxxxxxxxxxxx, linux-perf-users@xxxxxxxxxxxxxxx, linux-hyperv@xxxxxxxxxxxxxxx, virtualization@xxxxxxxxxxxxxxx, linux-edac@xxxxxxxxxxxxxxx, kvm@xxxxxxxxxxxxxxx, xen-devel@xxxxxxxxxxxxxxxxxxxx, linux-ide@xxxxxxxxxxxxxxx, linux-pm@xxxxxxxxxxxxxxx, bpf@xxxxxxxxxxxxxxx, llvm@xxxxxxxxxxxxxxx, tglx@xxxxxxxxxxxxx, mingo@xxxxxxxxxx, bp@xxxxxxxxx, dave.hansen@xxxxxxxxxxxxxxx, x86@xxxxxxxxxx, jgross@xxxxxxxx, andrew.cooper3@xxxxxxxxxx, peterz@xxxxxxxxxxxxx, acme@xxxxxxxxxx, namhyung@xxxxxxxxxx, mark.rutland@xxxxxxx, alexander.shishkin@xxxxxxxxxxxxxxx, jolsa@xxxxxxxxxx, irogers@xxxxxxxxxx, adrian.hunter@xxxxxxxxx, kan.liang@xxxxxxxxxxxxxxx, wei.liu@xxxxxxxxxx, ajay.kaher@xxxxxxxxxxxx, bcm-kernel-feedback-list@xxxxxxxxxxxx, tony.luck@xxxxxxxxx, pbonzini@xxxxxxxxxx, vkuznets@xxxxxxxxxx, luto@xxxxxxxxxx, boris.ostrovsky@xxxxxxxxxx, kys@xxxxxxxxxxxxx, haiyangz@xxxxxxxxxxxxx, decui@xxxxxxxxxxxxx
In-reply-to: <EAB44BB2-99BB-4D4A-8306-0235D2931E72@zytor.com>
References: <20250331082251.3171276-1-xin@zytor.com> <20250331082251.3171276-11-xin@zytor.com> <Z_hTI8ywa3rTxFaz@google.com> <CALMp9eRJkzA2YXf1Dfxt3ONP+P9aTA=WPraOPJPJ6C6j677+6Q@mail.gmail.com> <fa16949e-7842-45f7-9715-1bdda13b762a@zytor.com> <EAB44BB2-99BB-4D4A-8306-0235D2931E72@zytor.com>
User-agent: Mozilla Thunderbird

On 4/12/2025 4:10 PM, H. Peter Anvin wrote:

Also,*in this specific case* IA32_SPEC_CTRL is architecturally nonserializing, i.e. WRMSR executes as WRMSRNS anyway.


While the immediate form WRMSRNS could be faster because the MSR index
is available *much* earlier in the pipeline, right?

Follow-Ups:
- Re: [RFC PATCH v1 10/15] KVM: VMX: Use WRMSRNS or its immediate form when available
  - From: H. Peter Anvin

References:
- [RFC PATCH v1 00/15] MSR refactor with new MSR instructions support
  - From: Xin Li (Intel)
- [RFC PATCH v1 10/15] KVM: VMX: Use WRMSRNS or its immediate form when available
  - From: Xin Li (Intel)
- Re: [RFC PATCH v1 10/15] KVM: VMX: Use WRMSRNS or its immediate form when available
  - From: Sean Christopherson
- Re: [RFC PATCH v1 10/15] KVM: VMX: Use WRMSRNS or its immediate form when available
  - From: Jim Mattson
- Re: [RFC PATCH v1 10/15] KVM: VMX: Use WRMSRNS or its immediate form when available
  - From: Xin Li
- Re: [RFC PATCH v1 10/15] KVM: VMX: Use WRMSRNS or its immediate form when available
  - From: H. Peter Anvin

Prev by Date: Re: [PATCH v1 1/1] Documentation: kvm: Fix a section number
Next by Date: Re: [PATCH v1 1/1] Documentation: kvm: Fix a section number
Previous by thread: Re: [RFC PATCH v1 10/15] KVM: VMX: Use WRMSRNS or its immediate form when available
Next by thread: Re: [RFC PATCH v1 10/15] KVM: VMX: Use WRMSRNS or its immediate form when available
Index(es):
- Date
- Thread

[Index of Archives] [KVM ARM] [KVM ia64] [KVM ppc] [Virtualization Tools] [Spice Development] [Libvirt] [Libvirt Users] [Linux USB Devel] [Linux Audio Users] [Yosemite Questions] [Linux Kernel] [Linux SCSI] [XFree86]