[PATCH 3/6] KVM: nSVM: Use CLASS(kvm_vcpu_map_local) for SMM VMCB mappings

[Sean Christopherson <seanjc@google.com>]

Convert the kvm_vcpu_map() usage in the enter/leave SMM flows to the new
CLASS(kvm_vcpu_map_local) implementations, to eliminate the need to
manually do unmap() in error paths, and more importantly to eliminate more
of the open-coded on-stack "struct kvm_host_map" declarations.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/svm/svm.c | 38 ++++++++++++++------------------------
 1 file changed, 14 insertions(+), 24 deletions(-)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index bf10483c0e8a..7a417e717fd9 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4987,7 +4987,6 @@ static int svm_smi_allowed(struct kvm_vcpu *vcpu, bool for_injection)
 static int svm_enter_smm(struct kvm_vcpu *vcpu, union kvm_smram *smram)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
-	struct kvm_host_map map_save;
 
 	if (!is_guest_mode(vcpu))
 		return 0;
@@ -5021,24 +5020,20 @@ static int svm_enter_smm(struct kvm_vcpu *vcpu, union kvm_smram *smram)
 	 * that, see svm_prepare_switch_to_guest()) which must be
 	 * preserved.
 	 */
-	if (kvm_vcpu_map(vcpu, gpa_to_gfn(svm->nested.hsave_msr), &map_save))
+	CLASS(kvm_vcpu_map_local, m_save)(vcpu, gpa_to_gfn(svm->nested.hsave_msr));
+	if (m_save.ret)
 		return 1;
 
 	BUILD_BUG_ON(offsetof(struct vmcb, save) != 0x400);
 
-	svm_copy_vmrun_state(map_save.hva + 0x400,
-			     &svm->vmcb01.ptr->save);
-
-	kvm_vcpu_unmap(vcpu, &map_save);
+	svm_copy_vmrun_state(m_save.map.hva + 0x400, &svm->vmcb01.ptr->save);
 	return 0;
 }
 
 static int svm_leave_smm(struct kvm_vcpu *vcpu, const union kvm_smram *smram)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
-	struct kvm_host_map map, map_save;
 	struct vmcb *vmcb12;
-	int ret;
 
 	const struct kvm_smram_state_64 *smram64 = &smram->smram64;
 
@@ -5055,22 +5050,23 @@ static int svm_leave_smm(struct kvm_vcpu *vcpu, const union kvm_smram *smram)
 	if (!(smram64->efer & EFER_SVME))
 		return 1;
 
-	if (kvm_vcpu_map(vcpu, gpa_to_gfn(smram64->svm_guest_vmcb_gpa), &map))
+	CLASS(kvm_vcpu_map_local, m)(vcpu, gpa_to_gfn(smram64->svm_guest_vmcb_gpa));
+	if (m.ret)
 		return 1;
 
-	ret = 1;
-	if (kvm_vcpu_map(vcpu, gpa_to_gfn(svm->nested.hsave_msr), &map_save))
-		goto unmap_map;
+	CLASS(kvm_vcpu_map_local, m_save)(vcpu, gpa_to_gfn(svm->nested.hsave_msr));
+	if (m_save.ret)
+		return 1;
 
 	if (svm_allocate_nested(svm))
-		goto unmap_save;
+		return 1;
 
 	/*
 	 * Restore L1 host state from L1 HSAVE area as VMCB01 was
 	 * used during SMM (see svm_enter_smm())
 	 */
 
-	svm_copy_vmrun_state(&svm->vmcb01.ptr->save, map_save.hva + 0x400);
+	svm_copy_vmrun_state(&svm->vmcb01.ptr->save, m_save.map.hva + 0x400);
 
 	/*
 	 * Enter the nested guest now
@@ -5078,24 +5074,18 @@ static int svm_leave_smm(struct kvm_vcpu *vcpu, const union kvm_smram *smram)
 
 	vmcb_mark_all_dirty(svm->vmcb01.ptr);
 
-	vmcb12 = map.hva;
+	vmcb12 = m.map.hva;
 	nested_copy_vmcb_control_to_cache(svm, &vmcb12->control);
 	nested_copy_vmcb_save_to_cache(svm, &vmcb12->save);
 
 	if (nested_svm_check_cached_vmcb12(vcpu) < 0)
-		goto unmap_save;
+		return 1;
 
 	if (enter_svm_guest_mode(vcpu, smram64->svm_guest_vmcb_gpa, false) != 0)
-		goto unmap_save;
+		return 1;
 
-	ret = 0;
 	vcpu->arch.nested_run_pending = KVM_NESTED_RUN_PENDING;
-
-unmap_save:
-	kvm_vcpu_unmap(vcpu, &map_save);
-unmap_map:
-	kvm_vcpu_unmap(vcpu, &map);
-	return ret;
+	return 0;
 }
 
 static void svm_enable_smi_window(struct kvm_vcpu *vcpu)
-- 
2.55.0.229.g6434b31f56-goog