From a1bead2abaa162e5e67ad258a06c9d71dddad00d Mon Sep 17 00:00:00 2001
From: Sean Christopherson <sean.j.christopherson@intel.com>
Date: Mon, 2 Mar 2020 15:57:00 -0800
Subject: [PATCH] KVM: VMX: Directly query Intel PT mode when refreshing PMUs

Use vmx_pt_mode_is_host_guest() in intel_pmu_refresh() instead of
bouncing through kvm_x86_ops->pt_supported, and remove ->pt_supported()
as the PMU code was the last remaining user.

Opportunistically clean up the wording of a comment that referenced
kvm_x86_ops->pt_supported().

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/include/asm/kvm_host.h | 2 --
 arch/x86/kvm/svm.c              | 7 -------
 arch/x86/kvm/vmx/pmu_intel.c    | 2 +-
 arch/x86/kvm/vmx/vmx.c          | 6 ------
 arch/x86/kvm/x86.c              | 7 +++----
 5 files changed, 4 insertions(+), 20 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 00a1be55e90a..143d0ce493d5 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1176,8 +1176,6 @@ struct kvm_x86_ops {
 	void (*handle_exit_irqoff)(struct kvm_vcpu *vcpu,
 		enum exit_fastpath_completion *exit_fastpath);
 
-	bool (*pt_supported)(void);
-
 	int (*check_nested_events)(struct kvm_vcpu *vcpu);
 	void (*request_immediate_exit)(struct kvm_vcpu *vcpu);
 
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index f802d9c196e9..e0be6d0bca9e 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6074,11 +6074,6 @@ static int svm_get_lpage_level(void)
 	return PT_PDPE_LEVEL;
 }
 
-static bool svm_pt_supported(void)
-{
-	return false;
-}
-
 static bool svm_has_wbinvd_exit(void)
 {
 	return true;
@@ -7440,8 +7435,6 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 
 	.cpuid_update = svm_cpuid_update,
 
-	.pt_supported = svm_pt_supported,
-
 	.set_supported_cpuid = svm_set_supported_cpuid,
 
 	.has_wbinvd_exit = svm_has_wbinvd_exit,
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index e933541751fb..7c857737b438 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -335,7 +335,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
 	pmu->global_ovf_ctrl_mask = pmu->global_ctrl_mask
 			& ~(MSR_CORE_PERF_GLOBAL_OVF_CTRL_OVF_BUF |
 			    MSR_CORE_PERF_GLOBAL_OVF_CTRL_COND_CHGD);
-	if (kvm_x86_ops->pt_supported())
+	if (vmx_pt_mode_is_host_guest())
 		pmu->global_ovf_ctrl_mask &=
 				~MSR_CORE_PERF_GLOBAL_OVF_CTRL_TRACE_TOPA_PMI;
 
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index e5aeb6f038e6..75f61fb9c3b2 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6306,11 +6306,6 @@ static bool vmx_has_emulated_msr(int index)
 	}
 }
 
-static bool vmx_pt_supported(void)
-{
-	return vmx_pt_mode_is_host_guest();
-}
-
 static void vmx_recover_nmi_blocking(struct vcpu_vmx *vmx)
 {
 	u32 exit_intr_info;
@@ -7945,7 +7940,6 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 
 	.check_intercept = vmx_check_intercept,
 	.handle_exit_irqoff = vmx_handle_exit_irqoff,
-	.pt_supported = vmx_pt_supported,
 
 	.request_immediate_exit = vmx_request_immediate_exit,
 
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f3fac68f0612..5be4961d49dd 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2820,10 +2820,9 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		    !guest_cpuid_has(vcpu, X86_FEATURE_XSAVES))
 			return 1;
 		/*
-		 * We do support PT if kvm_x86_ops->pt_supported(), but we do
-		 * not support IA32_XSS[bit 8]. Guests will have to use
-		 * RDMSR/WRMSR rather than XSAVES/XRSTORS to save/restore PT
-		 * MSRs.
+		 * KVM supports exposing PT to the guest, but does not support
+		 * IA32_XSS[bit 8]. Guests have to use RDMSR/WRMSR rather than
+		 * XSAVES/XRSTORS to save/restore PT MSRs.
 		 */
 		if (data != 0)
 			return 1;
-- 
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