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| author | Sean Christopherson <seanjc@google.com> | 2024-03-06 17:13:42 -0800 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2024-04-11 12:58:46 -0700 |
| commit | 447112d7edd77fa468938377418434233bcb3709 (patch) | |
| tree | a09c7abb357f62c358ce77af2fd47f200affb6de /arch | |
| parent | 7f2817ef52a1cc3ee0ace35eb8df7a39bd4fc9b7 (diff) | |
| download | linux-stable-447112d7edd77fa468938377418434233bcb3709.tar.gz linux-stable-447112d7edd77fa468938377418434233bcb3709.tar.bz2 linux-stable-447112d7edd77fa468938377418434233bcb3709.zip | |
KVM: VMX: Snapshot LBR capabilities during module initialization
Snapshot VMX's LBR capabilities once during module initialization instead
of calling into perf every time a vCPU reconfigures its vPMU. This will
allow massaging the LBR capabilities, e.g. if the CPU doesn't support
callstacks, without having to remember to update multiple locations.
Opportunistically tag vmx_get_perf_capabilities() with __init, as it's
only called from vmx_set_cpu_caps().
Reviewed-by: Mingwei Zhang <mizhang@google.com>
Link: https://lore.kernel.org/r/20240307011344.835640-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/vmx/pmu_intel.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 9 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.h | 2 |
3 files changed, 8 insertions, 5 deletions
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index 12ade343a17e..be40474de6e4 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -535,7 +535,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu) perf_capabilities = vcpu_get_perf_capabilities(vcpu); if (cpuid_model_is_consistent(vcpu) && (perf_capabilities & PMU_CAP_LBR_FMT)) - x86_perf_get_lbr(&lbr_desc->records); + memcpy(&lbr_desc->records, &vmx_lbr_caps, sizeof(vmx_lbr_caps)); else lbr_desc->records.nr = 0; diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index e3315bda6237..aca41d3419f9 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -218,6 +218,8 @@ module_param(ple_window_max, uint, 0444); int __read_mostly pt_mode = PT_MODE_SYSTEM; module_param(pt_mode, int, S_IRUGO); +struct x86_pmu_lbr __ro_after_init vmx_lbr_caps; + static DEFINE_STATIC_KEY_FALSE(vmx_l1d_should_flush); static DEFINE_STATIC_KEY_FALSE(vmx_l1d_flush_cond); static DEFINE_MUTEX(vmx_l1d_flush_mutex); @@ -7862,10 +7864,9 @@ static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) vmx_update_exception_bitmap(vcpu); } -static u64 vmx_get_perf_capabilities(void) +static __init u64 vmx_get_perf_capabilities(void) { u64 perf_cap = PMU_CAP_FW_WRITES; - struct x86_pmu_lbr lbr; u64 host_perf_cap = 0; if (!enable_pmu) @@ -7875,8 +7876,8 @@ static u64 vmx_get_perf_capabilities(void) rdmsrl(MSR_IA32_PERF_CAPABILITIES, host_perf_cap); if (!cpu_feature_enabled(X86_FEATURE_ARCH_LBR)) { - x86_perf_get_lbr(&lbr); - if (lbr.nr) + x86_perf_get_lbr(&vmx_lbr_caps); + if (vmx_lbr_caps.nr) perf_cap |= host_perf_cap & PMU_CAP_LBR_FMT; } diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index 1742c88ba9c8..90f9e4434646 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -110,6 +110,8 @@ struct lbr_desc { bool msr_passthrough; }; +extern struct x86_pmu_lbr vmx_lbr_caps; + /* * The nested_vmx structure is part of vcpu_vmx, and holds information we need * for correct emulation of VMX (i.e., nested VMX) on this vcpu. |