From: Like Xu <like.xu.linux@gmail.com>
To: Jim Mattson <jmattson@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Joerg Roedel <joro@8bytes.org>,
ak@linux.intel.com, wei.w.wang@intel.com, kan.liang@intel.com,
alex.shi@linux.alibaba.com, kvm@vger.kernel.org, x86@kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v14 00/11] KVM: x86/pmu: Guest Last Branch Recording Enabling
Date: Mon, 19 Sep 2022 15:26:01 +0800 [thread overview]
Message-ID: <ec0f97e9-33b7-61d8-25b8-50175544dbdd@gmail.com> (raw)
In-Reply-To: <CALMp9eRC2APJgB3Y7S4MWsTs9wom3iQycd60kM2eJg39N_L4Ag@mail.gmail.com>
On 14/9/2022 7:42 am, Jim Mattson wrote:
> How does live migration work? I don't see any mechanism for recording
> the current LBR MSRs on suspend or restoring them on resume.
Considering that LBR is still a model specific feature, migration is less
valuable unless
both LBR_FMT values of the migration side are the same, the compatibility check
(based on cpu models) is required (gathering dust in my to-do list);
and there is another dusty missing piece is how to ensure that vcpu can get LBR
hardware in
vmx transition when KVM lbr event fails in host lbr event competition, the
complexity here is
that the host and guest may have different LBR filtering options.
The good news is the Architecture LBR will add save/restore support since Paolo
is not averse to
putting more msr's into msrs_to_save_all[], perhaps a dynamic addition mechanism
is a prerequisite.
Please let me know what your priority preferences are for these tasks above.
next prev parent reply other threads:[~2022-09-19 7:26 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-01 5:10 [PATCH v14 00/11] KVM: x86/pmu: Guest Last Branch Recording Enabling Like Xu
2021-02-01 5:10 ` [PATCH v14 01/11] KVM: x86/vmx: Make vmx_set_intercept_for_msr() non-static Like Xu
2021-02-01 5:10 ` [PATCH v14 02/11] KVM: x86/pmu: Set up IA32_PERF_CAPABILITIES if PDCM bit is available Like Xu
2021-02-02 11:48 ` Paolo Bonzini
2021-02-01 5:10 ` [PATCH v14 03/11] KVM: vmx/pmu: Add PMU_CAP_LBR_FMT check when guest LBR is enabled Like Xu
2021-02-02 12:00 ` Paolo Bonzini
2021-02-01 5:10 ` [PATCH v14 04/11] KVM: vmx/pmu: Expose DEBUGCTLMSR_LBR in the MSR_IA32_DEBUGCTLMSR Like Xu
2021-02-01 5:10 ` [PATCH v14 05/11] KVM: vmx/pmu: Create a guest LBR event when vcpu sets DEBUGCTLMSR_LBR Like Xu
2021-02-01 5:10 ` [PATCH v14 06/11] KVM: vmx/pmu: Pass-through LBR msrs when the guest LBR event is ACTIVE Like Xu
2021-02-01 5:10 ` [PATCH v14 07/11] KVM: vmx/pmu: Reduce the overhead of LBR pass-through or cancellation Like Xu
2021-02-01 5:10 ` [PATCH v14 08/11] KVM: vmx/pmu: Emulate legacy freezing LBRs on virtual PMI Like Xu
2021-02-01 5:10 ` [PATCH v14 09/11] KVM: vmx/pmu: Release guest LBR event via lazy release mechanism Like Xu
2021-02-01 5:10 ` [PATCH v14 10/11] KVM: vmx/pmu: Expose LBR_FMT in the MSR_IA32_PERF_CAPABILITIES Like Xu
2021-02-01 5:10 ` [PATCH v14 11/11] selftests: kvm/x86: add test for pmu msr MSR_IA32_PERF_CAPABILITIES Like Xu
2021-02-01 6:01 ` [PATCH v14 07/11] KVM: vmx/pmu: Reduce the overhead of LBR pass-through or cancellation Like Xu
2021-02-01 6:01 ` [PATCH v14 08/11] KVM: vmx/pmu: Emulate legacy freezing LBRs on virtual PMI Like Xu
2021-02-01 6:01 ` [PATCH v14 09/11] KVM: vmx/pmu: Release guest LBR event via lazy release mechanism Like Xu
2021-02-01 6:01 ` [PATCH v14 10/11] KVM: vmx/pmu: Expose LBR_FMT in the MSR_IA32_PERF_CAPABILITIES Like Xu
2021-02-01 6:01 ` [PATCH v14 11/11] selftests: kvm/x86: add test for pmu msr MSR_IA32_PERF_CAPABILITIES Like Xu
2021-02-02 14:53 ` Paolo Bonzini
2021-02-02 12:37 ` [PATCH v14 00/11] KVM: x86/pmu: Guest Last Branch Recording Enabling Paolo Bonzini
2021-07-29 12:40 ` Liuxiangdong
2021-07-30 3:15 ` Liuxiangdong
2021-07-30 3:28 ` Like Xu
2022-09-13 23:42 ` Jim Mattson
2022-09-19 7:26 ` Like Xu [this message]
2022-09-19 18:08 ` Jim Mattson
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