[PATCH v4 2/5] KVM: x86: Tell ->inject_page_fault() whether or a fault came from hardware

[Sean Christopherson]

When injecting a page fault (including nested TDP faults into L1), tell the
injection routine whether or not the fault originated in hardware, i.e. if
KVM is effectively forwarding a fault it intercept.  For nested TDP fault
injection, KVM needs to grab PAGE_WALK vs. GUEST_FINAL information from the
VMCB/VMCS, _if_ the fault originated in hardware.

No functional change intended (nothing uses the new param, yet...).

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
 arch/x86/include/asm/kvm_host.h | 18 ++++++++++++++----
 arch/x86/kvm/mmu/paging_tmpl.h  |  2 +-
 arch/x86/kvm/svm/nested.c       |  3 ++-
 arch/x86/kvm/vmx/nested.c       |  3 ++-
 arch/x86/kvm/x86.c              | 16 +++++++++-------
 5 files changed, 28 insertions(+), 14 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 271bdd109a98..d11063c36f03 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -484,7 +484,8 @@ struct kvm_mmu {
 	u64 (*get_pdptr)(struct kvm_vcpu *vcpu, int index);
 	int (*page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault);
 	void (*inject_page_fault)(struct kvm_vcpu *vcpu,
-				  struct x86_exception *fault);
+				  struct x86_exception *fault,
+				  bool from_hardware);
 	gpa_t (*gva_to_gpa)(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
 			    gpa_t gva_or_gpa, u64 access,
 			    struct x86_exception *exception);
@@ -2305,9 +2306,18 @@ void kvm_queue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code);
 void kvm_queue_exception_p(struct kvm_vcpu *vcpu, unsigned nr, unsigned long payload);
 void kvm_requeue_exception(struct kvm_vcpu *vcpu, unsigned int nr,
 			   bool has_error_code, u32 error_code);
-void kvm_inject_page_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault);
-void kvm_inject_emulated_page_fault(struct kvm_vcpu *vcpu,
-				    struct x86_exception *fault);
+void kvm_inject_page_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault,
+			   bool from_hardware);
+void __kvm_inject_emulated_page_fault(struct kvm_vcpu *vcpu,
+				      struct x86_exception *fault,
+				      bool from_hardware);
+
+static inline void kvm_inject_emulated_page_fault(struct kvm_vcpu *vcpu,
+						  struct x86_exception *fault)
+{
+	__kvm_inject_emulated_page_fault(vcpu, fault, false);
+}
+
 bool kvm_require_cpl(struct kvm_vcpu *vcpu, int required_cpl);
 bool kvm_require_dr(struct kvm_vcpu *vcpu, int dr);
 
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index 51f8b4522314..cc9c7deb34bc 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -813,7 +813,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 	 */
 	if (!r) {
 		if (!fault->prefetch)
-			kvm_inject_emulated_page_fault(vcpu, &walker.fault);
+			__kvm_inject_emulated_page_fault(vcpu, &walker.fault, true);
 
 		return RET_PF_RETRY;
 	}
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 4ef9bc6a553f..1c1a5e322d18 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -34,7 +34,8 @@
 #define CC KVM_NESTED_VMENTER_CONSISTENCY_CHECK
 
 static void nested_svm_inject_npf_exit(struct kvm_vcpu *vcpu,
-				       struct x86_exception *fault)
+				       struct x86_exception *fault,
+				       bool from_hardware)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
 	struct vmcb *vmcb = svm->vmcb;
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 4690a4d23709..3bb7eaa7b2a5 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -411,7 +411,8 @@ static void nested_ept_invalidate_addr(struct kvm_vcpu *vcpu, gpa_t eptp,
 }
 
 static void nested_ept_inject_page_fault(struct kvm_vcpu *vcpu,
-		struct x86_exception *fault)
+					 struct x86_exception *fault,
+					 bool from_hardware)
 {
 	struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index cecb2f84e5e0..aa2f8f43d94c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -969,7 +969,8 @@ static int complete_emulated_insn_gp(struct kvm_vcpu *vcpu, int err)
 				       EMULTYPE_COMPLETE_USER_EXIT);
 }
 
-void kvm_inject_page_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault)
+void kvm_inject_page_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault,
+			   bool from_hardware)
 {
 	++vcpu->stat.pf_guest;
 
@@ -986,8 +987,9 @@ void kvm_inject_page_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault)
 					fault->address);
 }
 
-void kvm_inject_emulated_page_fault(struct kvm_vcpu *vcpu,
-				    struct x86_exception *fault)
+void __kvm_inject_emulated_page_fault(struct kvm_vcpu *vcpu,
+				      struct x86_exception *fault,
+				      bool from_hardware)
 {
 	struct kvm_mmu *fault_mmu;
 	WARN_ON_ONCE(fault->vector != PF_VECTOR);
@@ -1004,9 +1006,9 @@ void kvm_inject_emulated_page_fault(struct kvm_vcpu *vcpu,
 		kvm_mmu_invalidate_addr(vcpu, fault_mmu, fault->address,
 					KVM_MMU_ROOT_CURRENT);
 
-	fault_mmu->inject_page_fault(vcpu, fault);
+	fault_mmu->inject_page_fault(vcpu, fault, from_hardware);
 }
-EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_inject_emulated_page_fault);
+EXPORT_SYMBOL_FOR_KVM_INTERNAL(__kvm_inject_emulated_page_fault);
 
 void kvm_inject_nmi(struct kvm_vcpu *vcpu)
 {
@@ -14065,7 +14067,7 @@ bool kvm_arch_async_page_not_present(struct kvm_vcpu *vcpu,
 		fault.nested_page_fault = false;
 		fault.address = work->arch.token;
 		fault.async_page_fault = true;
-		kvm_inject_page_fault(vcpu, &fault);
+		kvm_inject_page_fault(vcpu, &fault, false);
 		return true;
 	} else {
 		/*
@@ -14236,7 +14238,7 @@ void kvm_fixup_and_inject_pf_error(struct kvm_vcpu *vcpu, gva_t gva, u16 error_c
 		fault.address = gva;
 		fault.async_page_fault = false;
 	}
-	vcpu->arch.walk_mmu->inject_page_fault(vcpu, &fault);
+	vcpu->arch.walk_mmu->inject_page_fault(vcpu, &fault, true);
 }
 EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_fixup_and_inject_pf_error);
 
-- 
2.54.0.794.g4f17f83d09-goog