linux-kernel - [PATCH v12 10/16] KVM: x86/vmx: Check Arch LBR config when return perf capabilities

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Date:   Tue, 17 May 2022 11:40:54 -0400
From:   Yang Weijiang <weijiang.yang@...el.com>
To:     pbonzini@...hat.com, jmattson@...gle.com, seanjc@...gle.com,
        like.xu.linux@...il.com, vkuznets@...hat.com,
        kan.liang@...ux.intel.com, wei.w.wang@...el.com,
        kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     Yang Weijiang <weijiang.yang@...el.com>,
        Like Xu <like.xu@...ux.intel.com>
Subject: [PATCH v12 10/16] KVM: x86/vmx: Check Arch LBR config when return perf capabilities

Two new bit fields(VM_EXIT_CLEAR_IA32_LBR_CTL, VM_ENTRY_LOAD_IA32_LBR_CTL)
are added to support guest Arch LBR. These two bits should be set in order
to make Arch LBR workable in both guest and host.

Co-developed-by: Like Xu <like.xu@...ux.intel.com>
Signed-off-by: Like Xu <like.xu@...ux.intel.com>
Signed-off-by: Yang Weijiang <weijiang.yang@...el.com>
---
 arch/x86/include/asm/vmx.h      |  2 ++
 arch/x86/kvm/vmx/capabilities.h |  9 +++++++++
 arch/x86/kvm/vmx/vmx.c          | 10 ++++++++--
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index a84d902952ce..ba991066f4a9 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -101,6 +101,7 @@
 #define VM_EXIT_CLEAR_BNDCFGS                   0x00800000
 #define VM_EXIT_PT_CONCEAL_PIP			0x01000000
 #define VM_EXIT_CLEAR_IA32_RTIT_CTL		0x02000000
+#define VM_EXIT_CLEAR_IA32_LBR_CTL		0x04000000
 
 #define VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR	0x00036dff
 
@@ -114,6 +115,7 @@
 #define VM_ENTRY_LOAD_BNDCFGS                   0x00010000
 #define VM_ENTRY_PT_CONCEAL_PIP			0x00020000
 #define VM_ENTRY_LOAD_IA32_RTIT_CTL		0x00040000
+#define VM_ENTRY_LOAD_IA32_LBR_CTL		0x00200000
 
 #define VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR	0x000011ff
 
diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index f14c4bef97e0..dc2cb8a16e76 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -404,6 +404,12 @@ static inline bool vmx_pebs_supported(void)
 	return boot_cpu_has(X86_FEATURE_PEBS) && kvm_pmu_cap.pebs_ept;
 }
 
+static inline bool cpu_has_vmx_arch_lbr(void)
+{
+	return (vmcs_config.vmexit_ctrl & VM_EXIT_CLEAR_IA32_LBR_CTL) &&
+		(vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_LBR_CTL);
+}
+
 static inline u64 vmx_get_perf_capabilities(void)
 {
 	u64 perf_cap = PMU_CAP_FW_WRITES;
@@ -420,6 +426,9 @@ static inline u64 vmx_get_perf_capabilities(void)
 			perf_cap &= ~PERF_CAP_PEBS_BASELINE;
 	}
 
+	if (boot_cpu_has(X86_FEATURE_ARCH_LBR) && !cpu_has_vmx_arch_lbr())
+		perf_cap &= ~PMU_CAP_LBR_FMT;
+
 	return perf_cap;
 }
 
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index e442b30f1ca3..7238628acb90 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2564,7 +2564,8 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
 	      VM_EXIT_LOAD_IA32_EFER |
 	      VM_EXIT_CLEAR_BNDCFGS |
 	      VM_EXIT_PT_CONCEAL_PIP |
-	      VM_EXIT_CLEAR_IA32_RTIT_CTL;
+	      VM_EXIT_CLEAR_IA32_RTIT_CTL |
+	      VM_EXIT_CLEAR_IA32_LBR_CTL;
 	if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_EXIT_CTLS,
 				&_vmexit_control) < 0)
 		return -EIO;
@@ -2588,7 +2589,8 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
 	      VM_ENTRY_LOAD_IA32_EFER |
 	      VM_ENTRY_LOAD_BNDCFGS |
 	      VM_ENTRY_PT_CONCEAL_PIP |
-	      VM_ENTRY_LOAD_IA32_RTIT_CTL;
+	      VM_ENTRY_LOAD_IA32_RTIT_CTL |
+	      VM_ENTRY_LOAD_IA32_LBR_CTL;
 	if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_ENTRY_CTLS,
 				&_vmentry_control) < 0)
 		return -EIO;
@@ -6024,6 +6026,10 @@ void dump_vmcs(struct kvm_vcpu *vcpu)
 	    vmentry_ctl & VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL)
 		pr_err("PerfGlobCtl = 0x%016llx\n",
 		       vmcs_read64(GUEST_IA32_PERF_GLOBAL_CTRL));
+	if (kvm_cpu_cap_has(X86_FEATURE_ARCH_LBR) &&
+	    vmentry_ctl & VM_ENTRY_LOAD_IA32_LBR_CTL)
+		pr_err("ArchLBRCtl = 0x%016llx\n",
+		       vmcs_read64(GUEST_IA32_LBR_CTL));
 	if (vmentry_ctl & VM_ENTRY_LOAD_BNDCFGS)
 		pr_err("BndCfgS = 0x%016llx\n", vmcs_read64(GUEST_BNDCFGS));
 	pr_err("Interruptibility = %08x  ActivityState = %08x\n",
-- 
2.27.0