linux-kernel - [PATCH v2 57/66] KVM: VMX: Directly query Intel PT mode when refreshing PMUs

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Date:   Mon,  2 Mar 2020 15:57:00 -0800
From:   Sean Christopherson <sean.j.christopherson@...el.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <sean.j.christopherson@...el.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Xiaoyao Li <xiaoyao.li@...el.com>
Subject: [PATCH v2 57/66] 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@...hat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.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 25d9a0d45cc6..4fbff24aed8a 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1168,8 +1168,6 @@ 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, bool external_intr);
 	void (*request_immediate_exit)(struct kvm_vcpu *vcpu);
 
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 692b8ffdbad3..9dc614cfd129 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6070,11 +6070,6 @@ 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;
@@ -7434,8 +7429,6 @@ 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 bb54974f950f..836f8a8d83df 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6302,11 +6302,6 @@ 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;
@@ -7941,7 +7936,6 @@ 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 9b8764255455..4fdf5b04f148 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2805,10 +2805,9 @@ 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;
-- 
2.24.1