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KVM: nVMX: WARN on failure to set IA32_PERF_GLOBAL_CTRL

PATCH Applied Oliver Upton 3 participants 4 messages Dec 14, 2019 – Jan 18, 2020

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#0 lore raw

PATCH 1/1 KVM: nVMX: WARN on failure to set IA32_PERF_GLOBAL_CTRL

Writes to MSR_CORE_PERF_GLOBAL_CONTROL should never fail if the VM-exit and VM-entry controls are exposed to L1. Promote the checks to perform a full WARN if kvm_set_msr() fails and remove the now unused macro SET_MSR_OR_WARN().

---
 arch/x86/kvm/vmx/nested.c | 18 ++++--------------
 1 file changed, 4 insertions(+), 14 deletions(-)
arch/x86/kvm/vmx/nested.c +4 -14
index 4aea7d304beb..fb502c62ee94 100644
@@ -28,16 +28,6 @@ module_param(nested_early_check, bool, S_IRUGO);
 	failed;								\
 })
 
-#define SET_MSR_OR_WARN(vcpu, idx, data)				\
-({									\
-	bool failed = kvm_set_msr(vcpu, idx, data);			\
-	if (failed)							\
-		pr_warn_ratelimited(					\
-				"%s cannot write MSR (0x%x, 0x%llx)\n",	\
-				__func__, idx, data);			\
-	failed;								\
-})
-
 /*
  * Hyper-V requires all of these, so mark them as supported even though
  * they are just treated the same as all-context.
@@ -2550,8 +2540,8 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
 		vcpu->arch.walk_mmu->inject_page_fault = vmx_inject_page_fault_nested;
 
 	if ((vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL) &&
-	    SET_MSR_OR_WARN(vcpu, MSR_CORE_PERF_GLOBAL_CTRL,
-			    vmcs12->guest_ia32_perf_global_ctrl))
+	    WARN_ON_ONCE(kvm_set_msr(vcpu, MSR_CORE_PERF_GLOBAL_CTRL,
+				     vmcs12->guest_ia32_perf_global_ctrl)))
 		return -EINVAL;
 
 	kvm_rsp_write(vcpu, vmcs12->guest_rsp);
@@ -3999,8 +3989,8 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu,
 		vcpu->arch.pat = vmcs12->host_ia32_pat;
 	}
 	if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL)
-		SET_MSR_OR_WARN(vcpu, MSR_CORE_PERF_GLOBAL_CTRL,
-				vmcs12->host_ia32_perf_global_ctrl);
+		WARN_ON_ONCE(kvm_set_msr(vcpu, MSR_CORE_PERF_GLOBAL_CTRL,
+					 vmcs12->host_ia32_perf_global_ctrl));
 
 	/* Set L1 segment info according to Intel SDM
 	    27.5.2 Loading Host Segment and Descriptor-Table Registers */
Signature · 1 line
2.24.1.735.g03f4e72817-goog
Reviewed-by on v1 1/1
#1 lore raw
Quoted 9 lines · Oliver Upton

Writes to MSR_CORE_PERF_GLOBAL_CONTROL should never fail if the VM-exit and VM-entry controls are exposed to L1. Promote the checks to perform a full WARN if kvm_set_msr() fails and remove the now unused macro SET_MSR_OR_WARN().

---

#2 lore raw
Quoted 6 lines · Sean Christopherson
Quoted 5 lines · Oliver Upton

Writes to MSR_CORE_PERF_GLOBAL_CONTROL should never fail if the VM-exit and VM-entry controls are exposed to L1. Promote the checks to perform a full WARN if kvm_set_msr() fails and remove the now unused macro SET_MSR_OR_WARN().

Quoted 6 lines
Quoted 4 lines

---

Ping :)

maintainer Applied
#3 lore raw
In reply to Oliver Upton
Quoted 46 lines · Oliver Upton

Writes to MSR_CORE_PERF_GLOBAL_CONTROL should never fail if the VM-exit and VM-entry controls are exposed to L1. Promote the checks to perform a full WARN if kvm_set_msr() fails and remove the now unused macro SET_MSR_OR_WARN().

---
 arch/x86/kvm/vmx/nested.c | 18 ++++--------------
 1 file changed, 4 insertions(+), 14 deletions(-)
arch/x86/kvm/vmx/nested.c +2 -12
index 4aea7d304beb..fb502c62ee94 100644
@@ -28,16 +28,6 @@ module_param(nested_early_check, bool, S_IRUGO);
 	failed;								\
 })
 
-#define SET_MSR_OR_WARN(vcpu, idx, data)				\
-({									\
-	bool failed = kvm_set_msr(vcpu, idx, data);			\
-	if (failed)							\
-		pr_warn_ratelimited(					\
-				"%s cannot write MSR (0x%x, 0x%llx)\n",	\
-				__func__, idx, data);			\
-	failed;								\
-})
-
 /*
  * Hyper-V requires all of these, so mark them as supported even though
  * they are just treated the same as all-context.
@@ -2550,8 +2540,8 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
 		vcpu->arch.walk_mmu->inject_page_fault = vmx_inject_page_fault_nested;
 
 	if ((vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL) &&
-	    SET_MSR_OR_WARN(vcpu, MSR_CORE_PERF_GLOBAL_CTRL,
-			    vmcs12->guest_ia32_perf_global_ctrl))
+	    WARN_ON_ONCE(kvm_set_msr(vcpu, MSR_CORE_PERF_GLOBAL_CTRL,
+				     vmcs12->guest_ia32_perf_global_ctrl)))
 		return -EINVAL;
 
 	kvm_rsp_write(vcpu, vmcs12->guest_rsp);

arch/x86/kvm/vmx/nested.c static void load_vmcs12_host_state(struct kvm_vcpu *vcpu, · line 3996

Quoted 10 lines
arch/x86/kvm/vmx/nested.c +2 -2
@@ -3999,8 +3989,8 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu,
 		vcpu->arch.pat = vmcs12->host_ia32_pat;
 	}
 	if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL)
-		SET_MSR_OR_WARN(vcpu, MSR_CORE_PERF_GLOBAL_CTRL,
-				vmcs12->host_ia32_perf_global_ctrl);
+		WARN_ON_ONCE(kvm_set_msr(vcpu, MSR_CORE_PERF_GLOBAL_CTRL,
+					 vmcs12->host_ia32_perf_global_ctrl));
 
 	/* Set L1 segment info according to Intel SDM
 	    27.5.2 Loading Host Segment and Descriptor-Table Registers */

Queued, thanks.

Paolo