KVM: SEV: use mutex guard in sev_mem_enc_ioctl()

Simplify the error paths in sev_mem_enc_ioctl() by using a mutex guard,
allowing early return instead of using gotos.

Signed-off-by: Carlos López <clopez@suse.de>
Link: https://patch.msgid.link/20260120201013.3931334-5-clopez@suse.de
Link: https://patch.msgid.link/20260310234829.2608037-18-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 96510b1ec4cc967547043500de27f516d36a3275..b7bc69f8b0f9752e10f36cd41161f100a8076791 100644 (file)
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2637,30 +2637,24 @@ int sev_mem_enc_ioctl(struct kvm *kvm, void __user *argp)
        if (copy_from_user(&sev_cmd, argp, sizeof(struct kvm_sev_cmd)))
                return -EFAULT;
 
-       mutex_lock(&kvm->lock);
+       guard(mutex)(&kvm->lock);
 
        /* Only the enc_context_owner handles some memory enc operations. */
        if (is_mirroring_enc_context(kvm) &&
-           !is_cmd_allowed_from_mirror(sev_cmd.id)) {
-               r = -EINVAL;
-               goto out;
-       }
+           !is_cmd_allowed_from_mirror(sev_cmd.id))
+               return -EINVAL;
 
        /*
         * Once KVM_SEV_INIT2 initializes a KVM instance as an SNP guest, only
         * allow the use of SNP-specific commands.
         */
-       if (sev_snp_guest(kvm) && sev_cmd.id < KVM_SEV_SNP_LAUNCH_START) {
-               r = -EPERM;
-               goto out;
-       }
+       if (sev_snp_guest(kvm) && sev_cmd.id < KVM_SEV_SNP_LAUNCH_START)
+               return -EPERM;
 
        switch (sev_cmd.id) {
        case KVM_SEV_ES_INIT:
-               if (!sev_es_enabled) {
-                       r = -ENOTTY;
-                       goto out;
-               }
+               if (!sev_es_enabled)
+                       return -ENOTTY;
                fallthrough;
        case KVM_SEV_INIT:
                r = sev_guest_init(kvm, &sev_cmd);
@@ -2732,15 +2726,12 @@ int sev_mem_enc_ioctl(struct kvm *kvm, void __user *argp)
                r = snp_enable_certs(kvm);
                break;
        default:
-               r = -EINVAL;
-               goto out;
+               return -EINVAL;
        }
 
        if (copy_to_user(argp, &sev_cmd, sizeof(struct kvm_sev_cmd)))
                r = -EFAULT;
 
-out:
-       mutex_unlock(&kvm->lock);
        return r;
 }