[RFC PATCH v4 04/18] kvm: x86: add kvm_mmu_nested_guest_page_fault() and kvmi_mmu_fault_gla()

["Adalber Lazăr" <alazar@bitdefender.com>]

From: Adalbert Lazar <alazar@bitdefender.com>

These are helper functions used by the VM introspection subsytem on the
PF call path.

Signed-off-by: Mihai DonE?u <mdontu@bitdefender.com>
---
 arch/x86/include/asm/kvm_host.h |  7 +++++++
 arch/x86/include/asm/vmx.h      |  2 ++
 arch/x86/kvm/mmu.c              | 10 ++++++++++
 arch/x86/kvm/svm.c              |  8 ++++++++
 arch/x86/kvm/vmx.c              |  9 +++++++++
 5 files changed, 36 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 8842d8e1e4ee..239eb628f8fb 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -692,6 +692,9 @@ struct kvm_vcpu_arch {
 	/* set at EPT violation at this point */
 	unsigned long exit_qualification;
 
+	/* #PF translated error code from EPT/NPT exit reason */
+	u64 error_code;
+
 	/* pv related host specific info */
 	struct {
 		bool pv_unhalted;
@@ -1081,6 +1084,7 @@ struct kvm_x86_ops {
 	int (*enable_smi_window)(struct kvm_vcpu *vcpu);
 
 	void (*msr_intercept)(struct kvm_vcpu *vcpu, unsigned int msr, bool enable);
+	u64 (*fault_gla)(struct kvm_vcpu *vcpu);
 };
 
 struct kvm_arch_async_pf {
@@ -1455,4 +1459,7 @@ void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
 
 void kvm_arch_msr_intercept(struct kvm_vcpu *vcpu, unsigned int msr,
 				bool enable);
+u64 kvm_mmu_fault_gla(struct kvm_vcpu *vcpu);
+bool kvm_mmu_nested_guest_page_fault(struct kvm_vcpu *vcpu);
+
 #endif /* _ASM_X86_KVM_HOST_H */
diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index 8b6780751132..7036125349dd 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -530,6 +530,7 @@ struct vmx_msr_entry {
 #define EPT_VIOLATION_READABLE_BIT	3
 #define EPT_VIOLATION_WRITABLE_BIT	4
 #define EPT_VIOLATION_EXECUTABLE_BIT	5
+#define EPT_VIOLATION_GLA_VALID_BIT	7
 #define EPT_VIOLATION_GVA_TRANSLATED_BIT 8
 #define EPT_VIOLATION_ACC_READ		(1 << EPT_VIOLATION_ACC_READ_BIT)
 #define EPT_VIOLATION_ACC_WRITE		(1 << EPT_VIOLATION_ACC_WRITE_BIT)
@@ -537,6 +538,7 @@ struct vmx_msr_entry {
 #define EPT_VIOLATION_READABLE		(1 << EPT_VIOLATION_READABLE_BIT)
 #define EPT_VIOLATION_WRITABLE		(1 << EPT_VIOLATION_WRITABLE_BIT)
 #define EPT_VIOLATION_EXECUTABLE	(1 << EPT_VIOLATION_EXECUTABLE_BIT)
+#define EPT_VIOLATION_GLA_VALID		(1 << EPT_VIOLATION_GLA_VALID_BIT)
 #define EPT_VIOLATION_GVA_TRANSLATED	(1 << EPT_VIOLATION_GVA_TRANSLATED_BIT)
 
 /*
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index c4deb1f34faa..55fcb0292724 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -5530,3 +5530,13 @@ void kvm_mmu_module_exit(void)
 	unregister_shrinker(&mmu_shrinker);
 	mmu_audit_disable();
 }
+
+u64 kvm_mmu_fault_gla(struct kvm_vcpu *vcpu)
+{
+	return kvm_x86_ops->fault_gla(vcpu);
+}
+
+bool kvm_mmu_nested_guest_page_fault(struct kvm_vcpu *vcpu)
+{
+	return !!(vcpu->arch.error_code & PFERR_GUEST_PAGE_MASK);
+}
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 5f7482851223..f41e4d7008d7 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2145,6 +2145,8 @@ static int pf_interception(struct vcpu_svm *svm)
 	u64 fault_address = svm->vmcb->control.exit_info_2;
 	u64 error_code = svm->vmcb->control.exit_info_1;
 
+	svm->vcpu.arch.error_code = error_code;
+
 	return kvm_handle_page_fault(&svm->vcpu, error_code, fault_address,
 			svm->vmcb->control.insn_bytes,
 			svm->vmcb->control.insn_len);
@@ -5514,6 +5516,11 @@ static void svm_msr_intercept(struct kvm_vcpu *vcpu, unsigned int msr,
 	set_msr_interception(msrpm, msr, enable, enable);
 }
 
+static u64 svm_fault_gla(struct kvm_vcpu *vcpu)
+{
+	return ~0ull;
+}
+
 static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.cpu_has_kvm_support = has_svm,
 	.disabled_by_bios = is_disabled,
@@ -5631,6 +5638,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.enable_smi_window = enable_smi_window,
 
 	.msr_intercept = svm_msr_intercept,
+	.fault_gla = svm_fault_gla
 };
 
 static int __init svm_init(void)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 9c984bbe263e..5487e0242030 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6541,6 +6541,7 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu)
 	       PFERR_GUEST_FINAL_MASK : PFERR_GUEST_PAGE_MASK;
 
 	vcpu->arch.exit_qualification = exit_qualification;
+	vcpu->arch.error_code = error_code;
 	return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0);
 }
 
@@ -12120,6 +12121,13 @@ static void vmx_msr_intercept(struct kvm_vcpu *vcpu, unsigned int msr,
 	}
 }
 
+static u64 vmx_fault_gla(struct kvm_vcpu *vcpu)
+{
+	if (vcpu->arch.exit_qualification & EPT_VIOLATION_GLA_VALID)
+		return vmcs_readl(GUEST_LINEAR_ADDRESS);
+	return ~0ul;
+}
+
 static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.cpu_has_kvm_support = cpu_has_kvm_support,
 	.disabled_by_bios = vmx_disabled_by_bios,
@@ -12252,6 +12260,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.enable_smi_window = enable_smi_window,
 
 	.msr_intercept = vmx_msr_intercept,
+	.fault_gla = vmx_fault_gla
 };
 
 static int __init vmx_init(void)

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