KVM: SEV: Remove sometimes-used function-scoped "ret" from #VMGEXIT handler

Now that only two case-statements actually need a local "ret" variable,
refactor sev_handle_vmgexit() to have all flows return directly when
possible, and bury "ret" as "r" in the two paths that need to propagate a
return value from a helper.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260501202250.2115252-25-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20260529183549.1104619-25-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index bb70df2bf1a4845bcec06f03ba3803a04b5fa336..bc9dd39778a1b32db90aecdbca29b18b9d7e1da9 100644 (file)
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -4418,7 +4418,6 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
        struct vcpu_svm *svm = to_svm(vcpu);
        struct vmcb_control_area *control = &svm->vmcb->control;
        u64 ghcb_gpa;
-       int ret;
 
        /* Validate the GHCB */
        ghcb_gpa = control->ghcb_gpa;
@@ -4503,12 +4502,12 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
        case SVM_EXIT_WBINVD:
        case SVM_EXIT_MONITOR:
        case SVM_EXIT_MWAIT:
-               ret = svm_invoke_exit_handler(vcpu, control->exit_code);
-               break;
+               return svm_invoke_exit_handler(vcpu, control->exit_code);
        case SVM_VMGEXIT_MMIO_READ:
        case SVM_VMGEXIT_MMIO_WRITE: {
                bool is_write = control->exit_code == SVM_VMGEXIT_MMIO_WRITE;
                u64 len = control->exit_info_2;
+               int r;
 
                if (!len)
                        return 1;
@@ -4518,24 +4517,21 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
                        return 1;
                }
 
-               ret = setup_vmgexit_scratch(svm, !is_write, len);
-               if (ret)
-                       break;
+               r = setup_vmgexit_scratch(svm, !is_write, len);
+               if (r)
+                       return r;
 
-               ret = kvm_sev_es_mmio(vcpu, is_write, control->exit_info_1, len,
-                                     svm->sev_es.ghcb_sa);
-               break;
+               return kvm_sev_es_mmio(vcpu, is_write, control->exit_info_1, len,
+                                      svm->sev_es.ghcb_sa);
        }
        case SVM_VMGEXIT_NMI_COMPLETE:
                ++vcpu->stat.nmi_window_exits;
                svm->nmi_masked = false;
                kvm_make_request(KVM_REQ_EVENT, vcpu);
-               ret = 1;
-               break;
+               return 1;
        case SVM_VMGEXIT_AP_HLT_LOOP:
                svm->sev_es.ap_reset_hold_type = AP_RESET_HOLD_NAE_EVENT;
-               ret = kvm_emulate_ap_reset_hold(vcpu);
-               break;
+               return kvm_emulate_ap_reset_hold(vcpu);
        case SVM_VMGEXIT_AP_JUMP_TABLE: {
                struct kvm_sev_info *sev = to_kvm_sev_info(vcpu->kvm);
 
@@ -4553,14 +4549,11 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
                               control->exit_info_1);
                        svm_vmgexit_bad_input(svm, GHCB_ERR_INVALID_INPUT);
                }
-
-               ret = 1;
-               break;
+               return 1;
        }
        case SVM_VMGEXIT_HV_FEATURES:
                svm_vmgexit_success(svm, GHCB_HV_FT_SUPPORTED);
-               ret = 1;
-               break;
+               return 1;
        case SVM_VMGEXIT_TERM_REQUEST:
                pr_info("SEV-ES guest requested termination: reason %#llx info %#llx\n",
                        control->exit_info_1, control->exit_info_2);
@@ -4568,23 +4561,20 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
                vcpu->run->system_event.type = KVM_SYSTEM_EVENT_SEV_TERM;
                vcpu->run->system_event.ndata = 1;
                vcpu->run->system_event.data[0] = control->ghcb_gpa;
-               ret = 0;
-               break;
-       case SVM_VMGEXIT_PSC:
-               ret = setup_vmgexit_scratch(svm, true, sizeof(struct psc_hdr));
-               if (ret)
-                       break;
+               return 0;
+       case SVM_VMGEXIT_PSC: {
+               int r;
 
-               ret = snp_begin_psc(svm);
-               break;
+               r = setup_vmgexit_scratch(svm, true, sizeof(struct psc_hdr));
+               if (r)
+                       return r;
+
+               return snp_begin_psc(svm);
+       }
        case SVM_VMGEXIT_AP_CREATION:
-               ret = sev_snp_ap_creation(svm);
-               if (ret) {
+               if (sev_snp_ap_creation(svm))
                        svm_vmgexit_bad_input(svm, GHCB_ERR_INVALID_INPUT);
-               }
-
-               ret = 1;
-               break;
+               return 1;
        case SVM_VMGEXIT_GUEST_REQUEST:
        case SVM_VMGEXIT_EXT_GUEST_REQUEST:
                if (!PAGE_ALIGNED(control->exit_info_1) ||
@@ -4595,12 +4585,11 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
                }
 
                if (control->exit_code == SVM_VMGEXIT_GUEST_REQUEST)
-                       ret = snp_handle_guest_req(svm, control->exit_info_1,
-                                                  control->exit_info_2);
-               else
-                       ret = snp_handle_ext_guest_req(svm, control->exit_info_1,
-                                                      control->exit_info_2);
-               break;
+                       return snp_handle_guest_req(svm, control->exit_info_1,
+                                                   control->exit_info_2);
+
+               return snp_handle_ext_guest_req(svm, control->exit_info_1,
+                                               control->exit_info_2);
        case SVM_VMGEXIT_UNSUPPORTED_EVENT:
                /*
                 * Note, the _guest_ is reporting an unsupported #VC, i.e. this
@@ -4609,17 +4598,16 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
                vcpu_unimpl(vcpu,
                            "vmgexit: unsupported event - exit_info_1=%#llx, exit_info_2=%#llx\n",
                            control->exit_info_1, control->exit_info_2);
-               ret = -EINVAL;
-               break;
+               return -EINVAL;
        default:
                vcpu_unimpl(vcpu, "vmgexit: exit code %#llx is not valid\n",
                            control->exit_code);
                svm_vmgexit_bad_input(svm, GHCB_ERR_INVALID_EVENT);
-               ret = 1;
-               break;
+               return 1;
        }
 
-       return ret;
+       KVM_BUG_ON(1, vcpu->kvm);
+       return -EIO;
 }
 
 int sev_es_string_io(struct vcpu_svm *svm, int size, unsigned int port, int in)