From: Sean Christopherson <seanjc@google.com>
To: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>,
linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, Like Xu <like.xu.linux@gmail.com>
Subject: [PATCH v5 3/8] KVM: VMX: Fold vmx_supported_debugctl() into vcpu_supported_debugctl()
Date: Thu, 6 Oct 2022 00:03:09 +0000 [thread overview]
Message-ID: <20221006000314.73240-4-seanjc@google.com> (raw)
In-Reply-To: <20221006000314.73240-1-seanjc@google.com>
Fold vmx_supported_debugctl() into vcpu_supported_debugctl(), its only
caller. Setting bits only to clear them a few instructions later is
rather silly, and splitting the logic makes things seem more complicated
than they actually are.
Opportunistically drop DEBUGCTLMSR_LBR_MASK now that there's a single
reference to the pair of bits. The extra layer of indirection provides
no meaningful value and makes it unnecessarily tedious to understand
what KVM is doing.
No functional change.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/vmx/capabilities.h | 15 ---------------
arch/x86/kvm/vmx/vmx.c | 12 +++++++-----
2 files changed, 7 insertions(+), 20 deletions(-)
diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index a6689bf06542..479124e49bbd 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -24,8 +24,6 @@ extern int __read_mostly pt_mode;
#define PMU_CAP_FW_WRITES (1ULL << 13)
#define PMU_CAP_LBR_FMT 0x3f
-#define DEBUGCTLMSR_LBR_MASK (DEBUGCTLMSR_LBR | DEBUGCTLMSR_FREEZE_LBRS_ON_PMI)
-
struct nested_vmx_msrs {
/*
* We only store the "true" versions of the VMX capability MSRs. We
@@ -422,19 +420,6 @@ static inline u64 vmx_get_perf_capabilities(void)
return perf_cap;
}
-static inline u64 vmx_supported_debugctl(void)
-{
- u64 debugctl = 0;
-
- if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT))
- debugctl |= DEBUGCTLMSR_BUS_LOCK_DETECT;
-
- if (vmx_get_perf_capabilities() & PMU_CAP_LBR_FMT)
- debugctl |= DEBUGCTLMSR_LBR_MASK;
-
- return debugctl;
-}
-
static inline bool cpu_has_notify_vmexit(void)
{
return vmcs_config.cpu_based_2nd_exec_ctrl &
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 9dba04b6b019..97fc873c37fa 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2023,13 +2023,15 @@ static u64 nested_vmx_truncate_sysenter_addr(struct kvm_vcpu *vcpu,
static u64 vcpu_supported_debugctl(struct kvm_vcpu *vcpu)
{
- u64 debugctl = vmx_supported_debugctl();
+ u64 debugctl = 0;
- if (!intel_pmu_lbr_is_enabled(vcpu))
- debugctl &= ~DEBUGCTLMSR_LBR_MASK;
+ if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT) &&
+ guest_cpuid_has(vcpu, X86_FEATURE_BUS_LOCK_DETECT))
+ debugctl |= DEBUGCTLMSR_BUS_LOCK_DETECT;
- if (!guest_cpuid_has(vcpu, X86_FEATURE_BUS_LOCK_DETECT))
- debugctl &= ~DEBUGCTLMSR_BUS_LOCK_DETECT;
+ if ((vmx_get_perf_capabilities() & PMU_CAP_LBR_FMT) &&
+ intel_pmu_lbr_is_enabled(vcpu))
+ debugctl |= DEBUGCTLMSR_LBR | DEBUGCTLMSR_FREEZE_LBRS_ON_PMI;
return debugctl;
}
--
2.38.0.rc1.362.ged0d419d3c-goog
next prev parent reply other threads:[~2022-10-06 0:03 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-06 0:03 [PATCH v5 0/8] KVM: x86: Intel LBR related perf cleanups Sean Christopherson
2022-10-06 0:03 ` [PATCH v5 1/8] perf/x86/core: Zero @lbr instead of returning -1 in x86_perf_get_lbr() stub Sean Christopherson
2022-10-06 0:03 ` [PATCH v5 2/8] KVM: VMX: Advertise PMU LBRs if and only if perf supports LBRs Sean Christopherson
2022-10-06 0:03 ` Sean Christopherson [this message]
2022-10-06 0:03 ` [PATCH v5 4/8] KVM: VMX: Ignore guest CPUID for host userspace writes to DEBUGCTL Sean Christopherson
2022-10-06 0:03 ` [PATCH v5 5/8] KVM: x86: Track supported PERF_CAPABILITIES in kvm_caps Sean Christopherson
2022-10-14 9:25 ` Like Xu
2022-10-06 0:03 ` [PATCH v5 6/8] KVM: x86: Init vcpu->arch.perf_capabilities in common x86 code Sean Christopherson
2022-10-06 0:03 ` [PATCH v5 7/8] KVM: x86: Handle PERF_CAPABILITIES in common x86's kvm_get_msr_feature() Sean Christopherson
2022-10-06 0:03 ` [PATCH v5 8/8] KVM: x86: Directly query supported PERF_CAPABILITIES for WRMSR checks Sean Christopherson
2022-11-02 17:18 ` [PATCH v5 0/8] KVM: x86: Intel LBR related perf cleanups Paolo Bonzini
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