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From: Like Xu <like.xu@linux.intel.com>
To: 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>
Cc: Ingo Molnar <mingo@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Borislav Petkov <bp@alien8.de>, "H . Peter Anvin" <hpa@zytor.com>,
	ak@linux.intel.com, wei.w.wang@intel.com, kan.liang@intel.com,
	x86@kernel.org, kvm@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [RESEND v13 09/10] KVM: vmx/pmu: Expose LBR_FMT in the MSR_IA32_PERF_CAPABILITIES
Date: Fri,  8 Jan 2021 09:37:03 +0800	[thread overview]
Message-ID: <20210108013704.134985-10-like.xu@linux.intel.com> (raw)
In-Reply-To: <20210108013704.134985-1-like.xu@linux.intel.com>

Userspace could enable guest LBR feature when the exactly supported
LBR format value is initialized to the MSR_IA32_PERF_CAPABILITIES
and the LBR is also compatible with vPMU version and host cpu model.

Signed-off-by: Like Xu <like.xu@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
---
 arch/x86/kvm/vmx/capabilities.h | 9 ++++++++-
 arch/x86/kvm/vmx/vmx.c          | 7 +++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index 57b940c613ab..a9a7c4d1b634 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -378,7 +378,14 @@ static inline u64 vmx_get_perf_capabilities(void)
 	 * Since counters are virtualized, KVM would support full
 	 * width counting unconditionally, even if the host lacks it.
 	 */
-	return PMU_CAP_FW_WRITES;
+	u64 perf_cap = PMU_CAP_FW_WRITES;
+
+	if (boot_cpu_has(X86_FEATURE_PDCM))
+		rdmsrl(MSR_IA32_PERF_CAPABILITIES, perf_cap);
+
+	perf_cap |= perf_cap & PMU_CAP_LBR_FMT;
+
+	return perf_cap;
 }
 
 static inline u64 vmx_supported_debugctl(void)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index ad3b079f6700..9cb5b1e4fc27 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2229,6 +2229,13 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 	case MSR_IA32_PERF_CAPABILITIES:
 		if (data && !vcpu_to_pmu(vcpu)->version)
 			return 1;
+		if (data & PMU_CAP_LBR_FMT) {
+			if ((data & PMU_CAP_LBR_FMT) !=
+			    (vmx_get_perf_capabilities() & PMU_CAP_LBR_FMT))
+				return 1;
+			if (!intel_pmu_lbr_is_compatible(vcpu))
+				return 1;
+		}
 		ret = kvm_set_msr_common(vcpu, msr_info);
 		break;
 
-- 
2.29.2


  parent reply	other threads:[~2021-01-08  1:49 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-08  1:36 [RESEND v13 00/10] KVM: x86/pmu: Guest Last Branch Recording Enabling Like Xu
2021-01-08  1:36 ` [RESEND v13 01/10] KVM: x86: Move common set/get handler of MSR_IA32_DEBUGCTLMSR to VMX Like Xu
2021-01-26  9:25   ` Paolo Bonzini
2021-01-08  1:36 ` [RESEND v13 02/10] KVM: x86/vmx: Make vmx_set_intercept_for_msr() non-static Like Xu
2021-01-08  1:36 ` [RESEND v13 03/10] KVM: x86/pmu: Use IA32_PERF_CAPABILITIES to adjust features visibility Like Xu
2021-01-26  9:42   ` Paolo Bonzini
2021-01-27  6:04     ` Like Xu
2021-01-27  9:48       ` Paolo Bonzini
2021-02-01  5:28       ` Like Xu
2021-01-08  1:36 ` [RESEND v13 04/10] KVM: vmx/pmu: Clear PMU_CAP_LBR_FMT when guest LBR is disabled Like Xu
2021-01-08  1:36 ` [RESEND v13 05/10] KVM: vmx/pmu: Create a guest LBR event when vcpu sets DEBUGCTLMSR_LBR Like Xu
2021-01-08  1:37 ` [RESEND v13 06/10] KVM: vmx/pmu: Pass-through LBR msrs when the guest LBR event is ACTIVE Like Xu
2021-01-08  1:37 ` [RESEND v13 07/10] KVM: vmx/pmu: Reduce the overhead of LBR pass-through or cancellation Like Xu
2021-01-26  9:27   ` Paolo Bonzini
2021-01-08  1:37 ` [RESEND v13 08/10] KVM: vmx/pmu: Emulate legacy freezing LBRs on virtual PMI Like Xu
2021-01-08  1:37 ` Like Xu [this message]
2021-01-26  9:30   ` [RESEND v13 09/10] KVM: vmx/pmu: Expose LBR_FMT in the MSR_IA32_PERF_CAPABILITIES Paolo Bonzini
2021-01-27  5:45     ` Xu, Like
2021-01-27  9:49       ` Paolo Bonzini
2021-01-08  1:37 ` [RESEND v13 10/10] KVM: vmx/pmu: Release guest LBR event via lazy release mechanism Like Xu
2021-01-26  9:33   ` Paolo Bonzini
2021-01-15  8:19 ` [RESEND v13 00/10] KVM: x86/pmu: Guest Last Branch Recording Enabling Alex Shi
2021-01-15  8:51   ` Xu, Like

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