From: Yang Weijiang <weijiang.yang@intel.com>
To: pbonzini@redhat.com
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
weijiang.yang@intel.com, wei.w.wang@intel.com,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RESEND PATCH v4 00/10] KVM: x86/pmu: Guest Architectural LBR Enabling
Date: Tue, 22 Jun 2021 17:01:52 +0800 [thread overview]
Message-ID: <20210622090152.GA13141@intel.com> (raw)
In-Reply-To: <20210510081535.94184-1-like.xu@linux.intel.com>
Hello, maintainers,
I took over the work from Like and will carry it forward. Here I'd like to
get your valuable comments on this patch series before I post next version.
Thanks a lot!
> Hi geniuses,
>
> A new kernel cycle has begun, and this version looks promising.
>
> >From the end user's point of view, the usage of Arch LBR is the same as
> the legacy LBR we have merged in the mainline, but it is much faster.
>
> The Architectural Last Branch Records (LBRs) is published
> in the 319433-040 release of Intel Architecture Instruction
> Set Extensions and Future Features Programming Reference[0].
>
> The main advantages for the Arch LBR users are [1]:
> - Faster context switching due to XSAVES support and faster reset of
> LBR MSRs via the new DEPTH MSR
> - Faster LBR read for a non-PEBS event due to XSAVES support, which
> lowers the overhead of the NMI handler.
> - Linux kernel can support the LBR features without knowing the model
> number of the current CPU.
>
> Please check more details in each commit and feel free to comment.
>
> [0] https://software.intel.com/content/www/us/en/develop/download/
> intel-architecture-instruction-set-extensions-and-future-features-programming-reference.html
> [1] https://lore.kernel.org/lkml/1593780569-62993-1-git-send-email-kan.liang@linux.intel.com/
>
> ---
> v13->v13 RESEND Changelog:
> - Rebase to kvm/queue tree tag: kvm-5.13-2;
> - Includes two XSS dependency patches from kvm/intel tree;
>
> v3->v4 Changelog:
> - Add one more host patch to reuse ARCH_LBR_CTL_MASK;
> - Add reserve_lbr_buffers() instead of using GFP_ATOMIC;
> - Fia a bug in the arch_lbr_depth_is_valid();
> - Add LBR_CTL_EN to unify DEBUGCTLMSR_LBR and ARCH_LBR_CTL_LBREN;
> - Add vmx->host_lbrctlmsr to save/restore host values;
> - Add KVM_SUPPORTED_XSS to refactoring supported_xss;
> - Clear Arch_LBR ans its XSS bit if it's not supported;
> - Add negative testing to the related kvm-unit-tests;
> - Refine code and commit messages;
>
> Previous:
> v4: https://lore.kernel.org/kvm/20210314155225.206661-1-like.xu@linux.intel.com/
> v3: https://lore.kernel.org/kvm/20210303135756.1546253-1-like.xu@linux.intel.com/
>
> Like Xu (8):
> perf/x86/intel: Fix the comment about guest LBR support on KVM
> perf/x86/lbr: Simplify the exposure check for the LBR_INFO registers
> KVM: vmx/pmu: Add MSR_ARCH_LBR_DEPTH emulation for Arch LBR
> KVM: vmx/pmu: Add MSR_ARCH_LBR_CTL emulation for Arch LBR
> KVM: vmx/pmu: Add Arch LBR emulation and its VMCS field
> KVM: x86: Expose Architectural LBR CPUID leaf
> KVM: x86: Refine the matching and clearing logic for supported_xss
> KVM: x86: Add XSAVE Support for Architectural LBRs
>
> Sean Christopherson (1):
> KVM: x86: Report XSS as an MSR to be saved if there are supported
> features
>
> Yang Weijiang (1):
> KVM: x86: Refresh CPUID on writes to MSR_IA32_XSS
>
> arch/x86/events/intel/core.c | 3 +-
> arch/x86/events/intel/lbr.c | 6 +-
> arch/x86/include/asm/kvm_host.h | 1 +
> arch/x86/include/asm/msr-index.h | 1 +
> arch/x86/include/asm/vmx.h | 4 ++
> arch/x86/kvm/cpuid.c | 46 ++++++++++++--
> arch/x86/kvm/vmx/capabilities.h | 25 +++++---
> arch/x86/kvm/vmx/pmu_intel.c | 103 ++++++++++++++++++++++++++++---
> arch/x86/kvm/vmx/vmx.c | 50 +++++++++++++--
> arch/x86/kvm/vmx/vmx.h | 4 ++
> arch/x86/kvm/x86.c | 19 +++++-
> 11 files changed, 226 insertions(+), 36 deletions(-)
>
> --
> 2.31.1
next prev parent reply other threads:[~2021-06-22 8:47 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-10 8:15 [RESEND PATCH v4 00/10] KVM: x86/pmu: Guest Architectural LBR Enabling Like Xu
2021-05-10 8:15 ` [RESEND PATCH v4 01/10] perf/x86/intel: Fix the comment about guest LBR support on KVM Like Xu
2021-05-10 8:15 ` [RESEND PATCH v4 02/10] perf/x86/lbr: Simplify the exposure check for the LBR_INFO registers Like Xu
2021-05-10 8:15 ` [RESEND PATCH v4 03/10] KVM: vmx/pmu: Add MSR_ARCH_LBR_DEPTH emulation for Arch LBR Like Xu
2021-06-23 18:03 ` Jim Mattson
2021-06-24 1:31 ` Yang Weijiang
2021-05-10 8:15 ` [RESEND PATCH v4 04/10] KVM: vmx/pmu: Add MSR_ARCH_LBR_CTL " Like Xu
2021-06-23 18:29 ` Jim Mattson
2021-06-24 1:35 ` Yang Weijiang
2021-05-10 8:15 ` [RESEND PATCH v4 05/10] KVM: vmx/pmu: Add Arch LBR emulation and its VMCS field Like Xu
2021-05-10 8:15 ` [RESEND PATCH v4 06/10] KVM: x86: Expose Architectural LBR CPUID leaf Like Xu
2021-05-10 8:15 ` [RESEND PATCH v4 07/10] KVM: x86: Refresh CPUID on writes to MSR_IA32_XSS Like Xu
2021-05-10 8:15 ` [RESEND PATCH v4 08/10] KVM: x86: Report XSS as an MSR to be saved if there are supported features Like Xu
2021-05-10 8:15 ` [RESEND PATCH v4 09/10] KVM: x86: Refine the matching and clearing logic for supported_xss Like Xu
2021-05-10 8:15 ` [RESEND PATCH v4 10/10] KVM: x86: Add XSAVE Support for Architectural LBRs Like Xu
2021-05-10 8:15 ` [RESEND kvm-unit-tests PATCH v2] x86: Update guest LBR tests for Architectural LBR Like Xu
2021-06-22 9:01 ` Yang Weijiang [this message]
2021-06-23 13:32 ` [RESEND PATCH v4 00/10] KVM: x86/pmu: Guest Architectural LBR Enabling Like Xu
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