KVM: X86: Add parameter struct kvm_mmu *mmu into mmu->gva_to_gpa()

The mmu->gva_to_gpa() has no "struct kvm_mmu *mmu", so an extra
FNAME(gva_to_gpa_nested) is needed.

Add the parameter can simplify the code.  And it makes it explicit that
the walk is upon vcpu->arch.walk_mmu for gva and vcpu->arch.mmu for L2
gpa in translate_nested_gpa() via the new parameter.
Signed-off-by: NLai Jiangshan <laijs@linux.alibaba.com>
Message-Id: <20211124122055.64424-3-jiangshanlai@gmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/kvm_host.h

@@ -426,8 +426,9 @@ struct kvm_mmu {
 	int (*page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault);
 	void (*inject_page_fault)(struct kvm_vcpu *vcpu,
 				  struct x86_exception *fault);
-	gpa_t (*gva_to_gpa)(struct kvm_vcpu *vcpu, gpa_t gva_or_gpa,
-			    u32 access, struct x86_exception *exception);
+	gpa_t (*gva_to_gpa)(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
+			    gpa_t gva_or_gpa, u32 access,
+			    struct x86_exception *exception);
 	gpa_t (*translate_gpa)(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access,
 			       struct x86_exception *exception);
 	int (*sync_page)(struct kvm_vcpu *vcpu,

arch/x86/kvm/mmu/mmu.c

@@ -3732,21 +3732,13 @@ void kvm_mmu_sync_prev_roots(struct kvm_vcpu *vcpu)
 	kvm_mmu_free_roots(vcpu, vcpu->arch.mmu, roots_to_free);
 }
 
-static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gpa_t vaddr,
-				  u32 access, struct x86_exception *exception)
+static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
+				  gpa_t vaddr, u32 access,
+				  struct x86_exception *exception)
 {
 	if (exception)
 		exception->error_code = 0;
-	return vaddr;
-}
-
-static gpa_t nonpaging_gva_to_gpa_nested(struct kvm_vcpu *vcpu, gpa_t vaddr,
-					 u32 access,
-					 struct x86_exception *exception)
-{
-	if (exception)
-		exception->error_code = 0;
-	return vcpu->arch.nested_mmu.translate_gpa(vcpu, vaddr, access, exception);
+	return mmu->translate_gpa(vcpu, vaddr, access, exception);
 }
 
 static bool mmio_info_in_cache(struct kvm_vcpu *vcpu, u64 addr, bool direct)
@@ -5001,13 +4993,13 @@ static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu)
 	 * the gva_to_gpa functions between mmu and nested_mmu are swapped.
 	 */
 	if (!is_paging(vcpu))
-		g_context->gva_to_gpa = nonpaging_gva_to_gpa_nested;
+		g_context->gva_to_gpa = nonpaging_gva_to_gpa;
 	else if (is_long_mode(vcpu))
-		g_context->gva_to_gpa = paging64_gva_to_gpa_nested;
+		g_context->gva_to_gpa = paging64_gva_to_gpa;
 	else if (is_pae(vcpu))
-		g_context->gva_to_gpa = paging64_gva_to_gpa_nested;
+		g_context->gva_to_gpa = paging64_gva_to_gpa;
 	else
-		g_context->gva_to_gpa = paging32_gva_to_gpa_nested;
+		g_context->gva_to_gpa = paging32_gva_to_gpa;
 
 	reset_guest_paging_metadata(vcpu, g_context);
 }

arch/x86/kvm/mmu/paging_tmpl.h

@@ -547,16 +547,6 @@ static int FNAME(walk_addr)(struct guest_walker *walker,
 					access);
 }
 
-#if PTTYPE != PTTYPE_EPT
-static int FNAME(walk_addr_nested)(struct guest_walker *walker,
-				   struct kvm_vcpu *vcpu, gva_t addr,
-				   u32 access)
-{
-	return FNAME(walk_addr_generic)(walker, vcpu, &vcpu->arch.nested_mmu,
-					addr, access);
-}
-#endif
-
 static bool
 FNAME(prefetch_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
 		     u64 *spte, pt_element_t gpte, bool no_dirty_log)
@@ -1000,50 +990,29 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root_hpa)
 }
 
 /* Note, @addr is a GPA when gva_to_gpa() translates an L2 GPA to an L1 GPA. */
-static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gpa_t addr, u32 access,
+static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
+			       gpa_t addr, u32 access,
 			       struct x86_exception *exception)
 {
 	struct guest_walker walker;
 	gpa_t gpa = UNMAPPED_GVA;
 	int r;
 
-	r = FNAME(walk_addr)(&walker, vcpu, addr, access);
-
-	if (r) {
-		gpa = gfn_to_gpa(walker.gfn);
-		gpa |= addr & ~PAGE_MASK;
-	} else if (exception)
-		*exception = walker.fault;
-
-	return gpa;
-}
-
-#if PTTYPE != PTTYPE_EPT
-/* Note, gva_to_gpa_nested() is only used to translate L2 GVAs. */
-static gpa_t FNAME(gva_to_gpa_nested)(struct kvm_vcpu *vcpu, gpa_t vaddr,
-				      u32 access,
-				      struct x86_exception *exception)
-{
-	struct guest_walker walker;
-	gpa_t gpa = UNMAPPED_GVA;
-	int r;
-
 #ifndef CONFIG_X86_64
 	/* A 64-bit GVA should be impossible on 32-bit KVM. */
-	WARN_ON_ONCE(vaddr >> 32);
+	WARN_ON_ONCE((addr >> 32) && mmu == vcpu->arch.walk_mmu);
 #endif
 
-	r = FNAME(walk_addr_nested)(&walker, vcpu, vaddr, access);
+	r = FNAME(walk_addr_generic)(&walker, vcpu, mmu, addr, access);
 
 	if (r) {
 		gpa = gfn_to_gpa(walker.gfn);
-		gpa |= vaddr & ~PAGE_MASK;
+		gpa |= addr & ~PAGE_MASK;
 	} else if (exception)
 		*exception = walker.fault;
 
 	return gpa;
 }
-#endif
 
 /*
  * Using the cached information from sp->gfns is safe because:

arch/x86/kvm/x86.c

@@ -6506,13 +6506,14 @@ void kvm_get_segment(struct kvm_vcpu *vcpu,
 gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access,
 			   struct x86_exception *exception)
 {
+	struct kvm_mmu *mmu = vcpu->arch.mmu;
 	gpa_t t_gpa;
 
 	BUG_ON(!mmu_is_nested(vcpu));
 
 	/* NPT walks are always user-walks */
 	access |= PFERR_USER_MASK;
-	t_gpa  = vcpu->arch.mmu->gva_to_gpa(vcpu, gpa, access, exception);
+	t_gpa  = mmu->gva_to_gpa(vcpu, mmu, gpa, access, exception);
 
 	return t_gpa;
 }
@@ -6520,25 +6521,31 @@ gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access,
 gpa_t kvm_mmu_gva_to_gpa_read(struct kvm_vcpu *vcpu, gva_t gva,
 			      struct x86_exception *exception)
 {
+	struct kvm_mmu *mmu = vcpu->arch.walk_mmu;
+
 	u32 access = (static_call(kvm_x86_get_cpl)(vcpu) == 3) ? PFERR_USER_MASK : 0;
-	return vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, access, exception);
+	return mmu->gva_to_gpa(vcpu, mmu, gva, access, exception);
 }
 EXPORT_SYMBOL_GPL(kvm_mmu_gva_to_gpa_read);
 
  gpa_t kvm_mmu_gva_to_gpa_fetch(struct kvm_vcpu *vcpu, gva_t gva,
 				struct x86_exception *exception)
 {
+	struct kvm_mmu *mmu = vcpu->arch.walk_mmu;
+
 	u32 access = (static_call(kvm_x86_get_cpl)(vcpu) == 3) ? PFERR_USER_MASK : 0;
 	access |= PFERR_FETCH_MASK;
-	return vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, access, exception);
+	return mmu->gva_to_gpa(vcpu, mmu, gva, access, exception);
 }
 
 gpa_t kvm_mmu_gva_to_gpa_write(struct kvm_vcpu *vcpu, gva_t gva,
 			       struct x86_exception *exception)
 {
+	struct kvm_mmu *mmu = vcpu->arch.walk_mmu;
+
 	u32 access = (static_call(kvm_x86_get_cpl)(vcpu) == 3) ? PFERR_USER_MASK : 0;
 	access |= PFERR_WRITE_MASK;
-	return vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, access, exception);
+	return mmu->gva_to_gpa(vcpu, mmu, gva, access, exception);
 }
 EXPORT_SYMBOL_GPL(kvm_mmu_gva_to_gpa_write);
 
@@ -6546,19 +6553,21 @@ EXPORT_SYMBOL_GPL(kvm_mmu_gva_to_gpa_write);
 gpa_t kvm_mmu_gva_to_gpa_system(struct kvm_vcpu *vcpu, gva_t gva,
 				struct x86_exception *exception)
 {
-	return vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, 0, exception);
+	struct kvm_mmu *mmu = vcpu->arch.walk_mmu;
+
+	return mmu->gva_to_gpa(vcpu, mmu, gva, 0, exception);
 }
 
 static int kvm_read_guest_virt_helper(gva_t addr, void *val, unsigned int bytes,
 				      struct kvm_vcpu *vcpu, u32 access,
 				      struct x86_exception *exception)
 {
+	struct kvm_mmu *mmu = vcpu->arch.walk_mmu;
 	void *data = val;
 	int r = X86EMUL_CONTINUE;
 
 	while (bytes) {
-		gpa_t gpa = vcpu->arch.walk_mmu->gva_to_gpa(vcpu, addr, access,
-							    exception);
+		gpa_t gpa = mmu->gva_to_gpa(vcpu, mmu, addr, access, exception);
 		unsigned offset = addr & (PAGE_SIZE-1);
 		unsigned toread = min(bytes, (unsigned)PAGE_SIZE - offset);
 		int ret;
@@ -6586,13 +6595,14 @@ static int kvm_fetch_guest_virt(struct x86_emulate_ctxt *ctxt,
 				struct x86_exception *exception)
 {
 	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
+	struct kvm_mmu *mmu = vcpu->arch.walk_mmu;
 	u32 access = (static_call(kvm_x86_get_cpl)(vcpu) == 3) ? PFERR_USER_MASK : 0;
 	unsigned offset;
 	int ret;
 
 	/* Inline kvm_read_guest_virt_helper for speed.  */
-	gpa_t gpa = vcpu->arch.walk_mmu->gva_to_gpa(vcpu, addr, access|PFERR_FETCH_MASK,
-						    exception);
+	gpa_t gpa = mmu->gva_to_gpa(vcpu, mmu, addr, access|PFERR_FETCH_MASK,
+				    exception);
 	if (unlikely(gpa == UNMAPPED_GVA))
 		return X86EMUL_PROPAGATE_FAULT;
 
@@ -6651,13 +6661,12 @@ static int kvm_write_guest_virt_helper(gva_t addr, void *val, unsigned int bytes
 				      struct kvm_vcpu *vcpu, u32 access,
 				      struct x86_exception *exception)
 {
+	struct kvm_mmu *mmu = vcpu->arch.walk_mmu;
 	void *data = val;
 	int r = X86EMUL_CONTINUE;
 
 	while (bytes) {
-		gpa_t gpa =  vcpu->arch.walk_mmu->gva_to_gpa(vcpu, addr,
-							     access,
-							     exception);
+		gpa_t gpa = mmu->gva_to_gpa(vcpu, mmu, addr, access, exception);
 		unsigned offset = addr & (PAGE_SIZE-1);
 		unsigned towrite = min(bytes, (unsigned)PAGE_SIZE - offset);
 		int ret;
@@ -6744,6 +6753,7 @@ static int vcpu_mmio_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva,
 				gpa_t *gpa, struct x86_exception *exception,
 				bool write)
 {
+	struct kvm_mmu *mmu = vcpu->arch.walk_mmu;
 	u32 access = ((static_call(kvm_x86_get_cpl)(vcpu) == 3) ? PFERR_USER_MASK : 0)
 		| (write ? PFERR_WRITE_MASK : 0);
 
@@ -6761,7 +6771,7 @@ static int vcpu_mmio_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva,
 		return 1;
 	}
 
-	*gpa = vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, access, exception);
+	*gpa = mmu->gva_to_gpa(vcpu, mmu, gva, access, exception);
 
 	if (*gpa == UNMAPPED_GVA)
 		return -1;
@@ -12312,12 +12322,13 @@ EXPORT_SYMBOL_GPL(kvm_spec_ctrl_test_value);
 
 void kvm_fixup_and_inject_pf_error(struct kvm_vcpu *vcpu, gva_t gva, u16 error_code)
 {
+	struct kvm_mmu *mmu = vcpu->arch.walk_mmu;
 	struct x86_exception fault;
 	u32 access = error_code &
 		(PFERR_WRITE_MASK | PFERR_FETCH_MASK | PFERR_USER_MASK);
 
 	if (!(error_code & PFERR_PRESENT_MASK) ||
-	    vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, access, &fault) != UNMAPPED_GVA) {
+	    mmu->gva_to_gpa(vcpu, mmu, gva, access, &fault) != UNMAPPED_GVA) {
 		/*
 		 * If vcpu->arch.walk_mmu->gva_to_gpa succeeded, the page
 		 * tables probably do not match the TLB.  Just proceed