From: Like Xu <like.xu@linux.intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
wei.w.wang@intel.com, ak@linux.intel.com,
Like Xu <like.xu@linux.intel.com>
Subject: [PATCH v10 10/11] KVM: x86: Expose MSR_IA32_PERF_CAPABILITIES for LBR record format
Date: Thu, 23 Apr 2020 16:14:11 +0800 [thread overview]
Message-ID: <20200423081412.164863-11-like.xu@linux.intel.com> (raw)
In-Reply-To: <20200423081412.164863-1-like.xu@linux.intel.com>
The MSR_IA32_PERF_CAPABILITIES is a read only MSR that enumerates the
existence of performance monitoring features. Bits [0, 5] of it tells
about the LBR format of the branch record addresses stored in the LBR
stack. Expose those bits to the guest when the guest LBR is enabled.
Co-developed-by: Wei Wang <wei.w.wang@intel.com>
Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Signed-off-by: Like Xu <like.xu@linux.intel.com>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/vmx/capabilities.h | 15 +++++++++++++++
arch/x86/kvm/vmx/pmu_intel.c | 13 +++++++++++++
arch/x86/kvm/vmx/vmx.c | 2 ++
4 files changed, 31 insertions(+)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index f73c9b789bff..137097981180 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -487,6 +487,7 @@ struct kvm_pmu {
u64 global_ctrl_mask;
u64 global_ovf_ctrl_mask;
u64 reserved_bits;
+ u64 perf_capabilities;
u8 version;
struct kvm_pmc gp_counters[INTEL_PMC_MAX_GENERIC];
struct kvm_pmc fixed_counters[INTEL_PMC_MAX_FIXED];
diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index 8903475f751e..be61cd5bce0c 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -367,4 +367,19 @@ static inline bool vmx_pt_mode_is_host_guest(void)
return pt_mode == PT_MODE_HOST_GUEST;
}
+#define PERF_CAP_LBR_FMT 0x3f
+
+static inline u64 vmx_supported_perf_capabilities(void)
+{
+ u64 perf_cap = 0;
+
+ if (boot_cpu_has(X86_FEATURE_PDCM))
+ rdmsrl(MSR_IA32_PERF_CAPABILITIES, perf_cap);
+
+ /* Currently, KVM only supports LBR. */
+ perf_cap &= PERF_CAP_LBR_FMT;
+
+ return perf_cap;
+}
+
#endif /* __KVM_X86_VMX_CAPS_H */
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index 37088bbcde7f..c64c53bdc77d 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -182,6 +182,9 @@ static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
case MSR_IA32_DEBUGCTLMSR:
ret = pmu->version > 1;
break;
+ case MSR_IA32_PERF_CAPABILITIES:
+ ret = guest_cpuid_has(vcpu, X86_FEATURE_PDCM);
+ break;
default:
ret = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0) ||
get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0) ||
@@ -346,6 +349,9 @@ static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
case MSR_IA32_DEBUGCTLMSR:
msr_info->data = vmcs_read64(GUEST_IA32_DEBUGCTL);
return 0;
+ case MSR_IA32_PERF_CAPABILITIES:
+ msr_info->data = pmu->perf_capabilities;
+ return 0;
default:
if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0))) {
u64 val = pmc_read_counter(pmc);
@@ -414,6 +420,8 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
intel_pmu_create_lbr_event(vcpu);
__set_bit(KVM_PMU_LBR_IN_USE_IDX, pmu->pmc_in_use);
return 0;
+ case MSR_IA32_PERF_CAPABILITIES:
+ return 1; /* RO MSR */
default:
if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0))) {
if (!msr_info->host_initiated)
@@ -458,6 +466,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
pmu->version = 0;
pmu->reserved_bits = 0xffffffff00200000ull;
vcpu->kvm->arch.lbr_in_guest = false;
+ pmu->perf_capabilities = 0;
entry = kvm_find_cpuid_entry(vcpu, 0xa, 0);
if (!entry)
@@ -470,6 +479,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
return;
perf_get_x86_pmu_capability(&x86_pmu);
+ pmu->perf_capabilities = vmx_supported_perf_capabilities();
pmu->nr_arch_gp_counters = min_t(int, eax.split.num_counters,
x86_pmu.num_counters_gp);
@@ -497,6 +507,9 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
pmu->global_ovf_ctrl_mask &=
~MSR_CORE_PERF_GLOBAL_OVF_CTRL_TRACE_TOPA_PMI;
+ if (!vcpu->kvm->arch.lbr_in_guest)
+ pmu->perf_capabilities &= ~PERF_CAP_LBR_FMT;
+
entry = kvm_find_cpuid_entry(vcpu, 7, 0);
if (entry &&
(boot_cpu_has(X86_FEATURE_HLE) || boot_cpu_has(X86_FEATURE_RTM)) &&
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 31c294b2d941..ae2cb7967018 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7201,6 +7201,8 @@ static __init void vmx_set_cpu_caps(void)
kvm_cpu_cap_check_and_set(X86_FEATURE_INVPCID);
if (vmx_pt_mode_is_host_guest())
kvm_cpu_cap_check_and_set(X86_FEATURE_INTEL_PT);
+ if (vmx_supported_perf_capabilities())
+ kvm_cpu_cap_check_and_set(X86_FEATURE_PDCM);
/* PKU is not yet implemented for shadow paging. */
if (enable_ept && boot_cpu_has(X86_FEATURE_OSPKE))
--
2.21.1
next prev parent reply other threads:[~2020-04-23 8:18 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-23 8:14 [PATCH v10 00/11] Guest Last Branch Recording Enabling Like Xu
2020-04-23 8:14 ` [PATCH v10 01/11] perf/x86: Fix variable type for LBR registers Like Xu
2020-04-23 8:14 ` [PATCH v10 02/11] perf/x86/core: Refactor hw->idx checks and cleanup Like Xu
2020-04-23 8:14 ` [PATCH v10 03/11] perf/x86/lbr: Add interface to get basic information about LBR stack Like Xu
2020-04-23 8:14 ` [PATCH v10 04/11] perf/x86: Add constraint to create guest LBR event without hw counter Like Xu
2020-04-23 8:14 ` [PATCH v10 05/11] perf/x86: Keep LBR stack unchanged in host context for guest LBR event Like Xu
2020-04-23 8:14 ` [PATCH v10 06/11] KVM: x86: Add KVM_CAP_X86_GUEST_LBR to dis/enable LBR from user-space Like Xu
2020-04-23 8:14 ` [PATCH v10 07/11] KVM: x86/pmu: Tweak kvm_pmu_get_msr to pass 'struct msr_data' in Like Xu
2020-04-23 8:14 ` [PATCH v10 08/11] KVM: x86/pmu: Add LBR feature emulation via guest LBR event Like Xu
2020-04-24 12:16 ` Peter Zijlstra
2020-04-27 3:16 ` Like Xu
2020-05-08 8:48 ` Like Xu
2020-05-08 13:09 ` Peter Zijlstra
2020-05-12 4:58 ` Xu, Like
2020-04-23 8:14 ` [PATCH v10 09/11] KVM: x86/pmu: Release guest LBR event via vPMU lazy release mechanism Like Xu
2020-04-28 5:06 ` kbuild test robot
2020-04-28 5:06 ` [RFC PATCH] KVM: x86/pmu: kvm_pmu_lbr_cleanup() can be static kbuild test robot
2020-04-23 8:14 ` Like Xu [this message]
2020-04-23 8:14 ` [PATCH v10 11/11] KVM: x86: Remove the common trap handler of the MSR_IA32_DEBUGCTLMSR Like Xu
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