KVM: X86: Remove mmu->translate_gpa

Reduce an indirect function call (retpoline) and some intialization
code.
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Message-Id: <20211124122055.64424-4-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/kvm_host.h

@@ -429,8 +429,6 @@ struct kvm_mmu {
 	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,
 			 struct kvm_mmu_page *sp);
 	void (*invlpg)(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root_hpa);
@@ -1766,8 +1764,6 @@ int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn);
 void kvm_mmu_free_roots(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
 			ulong roots_to_free);
 void kvm_mmu_free_guest_mode_roots(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu);
-gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access,
-			   struct x86_exception *exception);
 gpa_t kvm_mmu_gva_to_gpa_read(struct kvm_vcpu *vcpu, gva_t gva,
 			      struct x86_exception *exception);
 gpa_t kvm_mmu_gva_to_gpa_fetch(struct kvm_vcpu *vcpu, gva_t gva,

arch/x86/kvm/mmu.h

@@ -351,4 +351,17 @@ static inline void kvm_update_page_stats(struct kvm *kvm, int level, int count)
 {
 	atomic64_add(count, &kvm->stat.pages[level - 1]);
 }
+
+gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access,
+			   struct x86_exception *exception);
+
+static inline gpa_t kvm_translate_gpa(struct kvm_vcpu *vcpu,
+				      struct kvm_mmu *mmu,
+				      gpa_t gpa, u32 access,
+				      struct x86_exception *exception)
+{
+	if (mmu != &vcpu->arch.nested_mmu)
+		return gpa;
+	return translate_nested_gpa(vcpu, gpa, access, exception);
+}
 #endif

arch/x86/kvm/mmu/mmu.c

@@ -335,12 +335,6 @@ static bool check_mmio_spte(struct kvm_vcpu *vcpu, u64 spte)
 	return likely(kvm_gen == spte_gen);
 }
 
-static gpa_t translate_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access,
-                                  struct x86_exception *exception)
-{
-        return gpa;
-}
-
 static int is_cpuid_PSE36(void)
 {
 	return 1;
@@ -3738,7 +3732,7 @@ static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
 {
 	if (exception)
 		exception->error_code = 0;
-	return mmu->translate_gpa(vcpu, vaddr, access, exception);
+	return kvm_translate_gpa(vcpu, mmu, vaddr, access, exception);
 }
 
 static bool mmio_info_in_cache(struct kvm_vcpu *vcpu, u64 addr, bool direct)
@@ -5500,7 +5494,6 @@ static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu)
 
 	mmu->root_hpa = INVALID_PAGE;
 	mmu->root_pgd = 0;
-	mmu->translate_gpa = translate_gpa;
 	for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++)
 		mmu->prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID;
 
@@ -5562,8 +5555,6 @@ int kvm_mmu_create(struct kvm_vcpu *vcpu)
 	vcpu->arch.mmu = &vcpu->arch.root_mmu;
 	vcpu->arch.walk_mmu = &vcpu->arch.root_mmu;
 
-	vcpu->arch.nested_mmu.translate_gpa = translate_nested_gpa;
-
 	ret = __kvm_mmu_create(vcpu, &vcpu->arch.guest_mmu);
 	if (ret)
 		return ret;

arch/x86/kvm/mmu/paging_tmpl.h

@@ -403,9 +403,8 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker,
 		walker->table_gfn[walker->level - 1] = table_gfn;
 		walker->pte_gpa[walker->level - 1] = pte_gpa;
 
-		real_gpa = mmu->translate_gpa(vcpu, gfn_to_gpa(table_gfn),
-					      nested_access,
-					      &walker->fault);
+		real_gpa = kvm_translate_gpa(vcpu, mmu, gfn_to_gpa(table_gfn),
+					     nested_access, &walker->fault);
 
 		/*
 		 * FIXME: This can happen if emulation (for of an INS/OUTS
@@ -467,7 +466,7 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker,
 	if (PTTYPE == 32 && walker->level > PG_LEVEL_4K && is_cpuid_PSE36())
 		gfn += pse36_gfn_delta(pte);
 
-	real_gpa = mmu->translate_gpa(vcpu, gfn_to_gpa(gfn), access, &walker->fault);
+	real_gpa = kvm_translate_gpa(vcpu, mmu, gfn_to_gpa(gfn), access, &walker->fault);
 	if (real_gpa == UNMAPPED_GVA)
 		return 0;
 

arch/x86/kvm/x86.c

@@ -810,8 +810,8 @@ int load_pdptrs(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, unsigned long cr3)
 	 * If the MMU is nested, CR3 holds an L2 GPA and needs to be translated
 	 * to an L1 GPA.
 	 */
-	real_gpa = mmu->translate_gpa(vcpu, gfn_to_gpa(pdpt_gfn),
-				      PFERR_USER_MASK | PFERR_WRITE_MASK, NULL);
+	real_gpa = kvm_translate_gpa(vcpu, mmu, gfn_to_gpa(pdpt_gfn),
+				     PFERR_USER_MASK | PFERR_WRITE_MASK, NULL);
 	if (real_gpa == UNMAPPED_GVA)
 		return 0;