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From: Xiong Zhang <xiong.y.zhang@linux.intel.com>
To: seanjc@google.com,
	pbonzini@redhat.com,
	peterz@infradead.org,
	mizhang@google.com,
	kan.liang@intel.com,
	zhenyuw@linux.intel.com,
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Cc: kvm@vger.kernel.org,
	linux-perf-users@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	zhiyuan.lv@intel.com,
	eranian@google.com,
	irogers@google.com,
	samantha.alt@intel.com,
	like.xu.linux@gmail.com,
	chao.gao@intel.com,
	xiong.y.zhang@linux.intel.com,
	Xiong Zhang <xiong.y.zhang@intel.com>
Subject: [RFC PATCH 15/41] KVM: x86/pmu: Manage MSR interception for IA32_PERF_GLOBAL_CTRL
Date: Fri, 26 Jan 2024 16:54:18 +0800
Message-Id: <20240126085444.324918-16-xiong.y.zhang@linux.intel.com>
In-Reply-To: <20240126085444.324918-1-xiong.y.zhang@linux.intel.com>
References: <20240126085444.324918-1-xiong.y.zhang@linux.intel.com>
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From: Xiong Zhang <xiong.y.zhang@intel.com>

In PMU passthrough mode, there are three requirements to manage
IA32_PERF_GLOBAL_CTRL:
 - guest IA32_PERF_GLOBAL_CTRL MSR must be saved at vm exit.
 - IA32_PERF_GLOBAL_CTRL MSR must be cleared at vm exit to avoid any
   counter of running within KVM runloop.
 - guest IA32_PERF_GLOBAL_CTRL MSR must be restored at vm entry.

Introduce vmx_set_perf_global_ctrl() function to auto switching
IA32_PERF_GLOBAL_CTR and invoke it after the VMM finishes setting up the
CPUID bits.

Signed-off-by: Xiong Zhang <xiong.y.zhang@intel.com>
Signed-off-by: Mingwei Zhang <mizhang@google.com>
---
 arch/x86/include/asm/vmx.h |  1 +
 arch/x86/kvm/vmx/vmx.c     | 89 ++++++++++++++++++++++++++++++++------
 arch/x86/kvm/vmx/vmx.h     |  3 +-
 3 files changed, 78 insertions(+), 15 deletions(-)

diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index 0e73616b82f3..f574e7b429a3 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -104,6 +104,7 @@
 #define VM_EXIT_CLEAR_BNDCFGS                   0x00800000
 #define VM_EXIT_PT_CONCEAL_PIP			0x01000000
 #define VM_EXIT_CLEAR_IA32_RTIT_CTL		0x02000000
+#define VM_EXIT_SAVE_IA32_PERF_GLOBAL_CTRL      0x40000000
 
 #define VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR	0x00036dff
 
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 33cb69ff0804..8ab266e1e2a7 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4387,6 +4387,74 @@ static u32 vmx_pin_based_exec_ctrl(struct vcpu_vmx *vmx)
 	return pin_based_exec_ctrl;
 }
 
+static void vmx_set_perf_global_ctrl(struct vcpu_vmx *vmx)
+{
+	u32 vmentry_ctrl = vm_entry_controls_get(vmx);
+	u32 vmexit_ctrl = vm_exit_controls_get(vmx);
+	int i;
+
+       /*
+	* PERF_GLOBAL_CTRL is toggled dynamically in emulated vPMU.
+	*/
+	if (cpu_has_perf_global_ctrl_bug() ||
+	    !is_passthrough_pmu_enabled(&vmx->vcpu)) {
+		vmentry_ctrl &= ~VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL;
+		vmexit_ctrl &= ~VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL;
+		vmexit_ctrl &= ~VM_EXIT_SAVE_IA32_PERF_GLOBAL_CTRL;
+	}
+
+	if (is_passthrough_pmu_enabled(&vmx->vcpu)) {
+		/*
+		 * Setup auto restore guest PERF_GLOBAL_CTRL MSR at vm entry.
+		 */
+		if (vmentry_ctrl & VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL)
+			vmcs_write64(GUEST_IA32_PERF_GLOBAL_CTRL, 0);
+		else {
+			i = vmx_find_loadstore_msr_slot(&vmx->msr_autoload.guest,
+						       MSR_CORE_PERF_GLOBAL_CTRL);
+			if (i < 0) {
+				i = vmx->msr_autoload.guest.nr++;
+				vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT,
+					     vmx->msr_autoload.guest.nr);
+			}
+			vmx->msr_autoload.guest.val[i].index = MSR_CORE_PERF_GLOBAL_CTRL;
+			vmx->msr_autoload.guest.val[i].value = 0;
+		}
+		/*
+		 * Setup auto clear host PERF_GLOBAL_CTRL msr at vm exit.
+		 */
+		if (vmexit_ctrl & VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL)
+			vmcs_write64(HOST_IA32_PERF_GLOBAL_CTRL, 0);
+		else {
+			i = vmx_find_loadstore_msr_slot(&vmx->msr_autoload.host,
+							MSR_CORE_PERF_GLOBAL_CTRL);
+			if (i < 0) {
+				i = vmx->msr_autoload.host.nr++;
+				vmcs_write32(VM_EXIT_MSR_LOAD_COUNT,
+					     vmx->msr_autoload.host.nr);
+			}
+			vmx->msr_autoload.host.val[i].index = MSR_CORE_PERF_GLOBAL_CTRL;
+			vmx->msr_autoload.host.val[i].value = 0;
+		}
+		/*
+		 * Setup auto save guest PERF_GLOBAL_CTRL msr at vm exit
+		 */
+		if (!(vmexit_ctrl & VM_EXIT_SAVE_IA32_PERF_GLOBAL_CTRL)) {
+			i = vmx_find_loadstore_msr_slot(&vmx->msr_autostore.guest,
+							MSR_CORE_PERF_GLOBAL_CTRL);
+			if (i < 0) {
+				i = vmx->msr_autostore.guest.nr++;
+				vmcs_write32(VM_EXIT_MSR_STORE_COUNT,
+					     vmx->msr_autostore.guest.nr);
+			}
+			vmx->msr_autostore.guest.val[i].index = MSR_CORE_PERF_GLOBAL_CTRL;
+		}
+	}
+
+	vm_entry_controls_set(vmx, vmentry_ctrl);
+	vm_exit_controls_set(vmx, vmexit_ctrl);
+}
+
 static u32 vmx_vmentry_ctrl(void)
 {
 	u32 vmentry_ctrl = vmcs_config.vmentry_ctrl;
@@ -4394,15 +4462,9 @@ static u32 vmx_vmentry_ctrl(void)
 	if (vmx_pt_mode_is_system())
 		vmentry_ctrl &= ~(VM_ENTRY_PT_CONCEAL_PIP |
 				  VM_ENTRY_LOAD_IA32_RTIT_CTL);
-	/*
-	 * IA32e mode, and loading of EFER and PERF_GLOBAL_CTRL are toggled dynamically.
-	 */
-	vmentry_ctrl &= ~(VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL |
-			  VM_ENTRY_LOAD_IA32_EFER |
-			  VM_ENTRY_IA32E_MODE);
 
-	if (cpu_has_perf_global_ctrl_bug())
-		vmentry_ctrl &= ~VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL;
+	/* IA32e mode, and loading of EFER is toggled dynamically. */
+	vmentry_ctrl &= ~(VM_ENTRY_LOAD_IA32_EFER | VM_ENTRY_IA32E_MODE);
 
 	return vmentry_ctrl;
 }
@@ -4422,12 +4484,8 @@ static u32 vmx_vmexit_ctrl(void)
 		vmexit_ctrl &= ~(VM_EXIT_PT_CONCEAL_PIP |
 				 VM_EXIT_CLEAR_IA32_RTIT_CTL);
 
-	if (cpu_has_perf_global_ctrl_bug())
-		vmexit_ctrl &= ~VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL;
-
-	/* Loading of EFER and PERF_GLOBAL_CTRL are toggled dynamically */
-	return vmexit_ctrl &
-		~(VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL | VM_EXIT_LOAD_IA32_EFER);
+       /* Loading of EFER is toggled dynamically */
+       return vmexit_ctrl & ~VM_EXIT_LOAD_IA32_EFER;
 }
 
 static void vmx_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu)
@@ -4765,6 +4823,7 @@ static void init_vmcs(struct vcpu_vmx *vmx)
 		vmcs_write64(VM_FUNCTION_CONTROL, 0);
 
 	vmcs_write32(VM_EXIT_MSR_STORE_COUNT, 0);
+	vmcs_write64(VM_EXIT_MSR_STORE_ADDR, __pa(vmx->msr_autostore.guest.val));
 	vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, 0);
 	vmcs_write64(VM_EXIT_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.host.val));
 	vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, 0);
@@ -7822,6 +7881,8 @@ static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
 	if (is_passthrough_pmu_enabled(&vmx->vcpu))
 		exec_controls_clearbit(vmx, CPU_BASED_RDPMC_EXITING);
 
+	vmx_set_perf_global_ctrl(vmx);
+
 	/* Refresh #PF interception to account for MAXPHYADDR changes. */
 	vmx_update_exception_bitmap(vcpu);
 }
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index c2130d2c8e24..c89db35e1de8 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -502,7 +502,8 @@ static inline u8 vmx_get_rvi(void)
 	       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_SAVE_IA32_PERF_GLOBAL_CTRL)
 
 #define KVM_REQUIRED_VMX_PIN_BASED_VM_EXEC_CONTROL			\
 	(PIN_BASED_EXT_INTR_MASK |					\
-- 
2.34.1