On 2/18/25 19:27, Sean Christopherson wrote:
> Use guard(mutex) in sev_snp_ap_creation() and modify the error paths to
> return directly instead of jumping to a common exit point.
>
> No functional change intended.
Reviewed-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> ---
> arch/x86/kvm/svm/sev.c | 22 ++++++----------------
> 1 file changed, 6 insertions(+), 16 deletions(-)
>
> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> index 7f6c8fedb235..241cf7769508 100644
> --- a/arch/x86/kvm/svm/sev.c
> +++ b/arch/x86/kvm/svm/sev.c
> @@ -3940,7 +3940,6 @@ static int sev_snp_ap_creation(struct vcpu_svm *svm)
> struct vcpu_svm *target_svm;
> unsigned int request;
> unsigned int apic_id;
> - int ret;
>
> request = lower_32_bits(svm->vmcb->control.exit_info_1);
> apic_id = upper_32_bits(svm->vmcb->control.exit_info_1);
> @@ -3953,11 +3952,9 @@ static int sev_snp_ap_creation(struct vcpu_svm *svm)
> return -EINVAL;
> }
>
> - ret = 0;
> -
> target_svm = to_svm(target_vcpu);
>
> - mutex_lock(&target_svm->sev_es.snp_vmsa_mutex);
> + guard(mutex)(&target_svm->sev_es.snp_vmsa_mutex);
>
> switch (request) {
> case SVM_VMGEXIT_AP_CREATE_ON_INIT:
> @@ -3965,15 +3962,13 @@ static int sev_snp_ap_creation(struct vcpu_svm *svm)
> if (vcpu->arch.regs[VCPU_REGS_RAX] != sev->vmsa_features) {
> vcpu_unimpl(vcpu, "vmgexit: mismatched AP sev_features [%#lx] != [%#llx] from guest\n",
> vcpu->arch.regs[VCPU_REGS_RAX], sev->vmsa_features);
> - ret = -EINVAL;
> - goto out;
> + return -EINVAL;
> }
>
> if (!page_address_valid(vcpu, svm->vmcb->control.exit_info_2)) {
> vcpu_unimpl(vcpu, "vmgexit: invalid AP VMSA address [%#llx] from guest\n",
> svm->vmcb->control.exit_info_2);
> - ret = -EINVAL;
> - goto out;
> + return -EINVAL;
> }
>
> /*
> @@ -3987,8 +3982,7 @@ static int sev_snp_ap_creation(struct vcpu_svm *svm)
> vcpu_unimpl(vcpu,
> "vmgexit: AP VMSA address [%llx] from guest is unsafe as it is 2M aligned\n",
> svm->vmcb->control.exit_info_2);
> - ret = -EINVAL;
> - goto out;
> + return -EINVAL;
> }
>
> target_svm->sev_es.snp_vmsa_gpa = svm->vmcb->control.exit_info_2;
> @@ -3999,8 +3993,7 @@ static int sev_snp_ap_creation(struct vcpu_svm *svm)
> default:
> vcpu_unimpl(vcpu, "vmgexit: invalid AP creation request [%#x] from guest\n",
> request);
> - ret = -EINVAL;
> - goto out;
> + return -EINVAL;
> }
>
> target_svm->sev_es.snp_ap_waiting_for_reset = true;
> @@ -4014,10 +4007,7 @@ static int sev_snp_ap_creation(struct vcpu_svm *svm)
> kvm_vcpu_kick(target_vcpu);
> }
>
> -out:
> - mutex_unlock(&target_svm->sev_es.snp_vmsa_mutex);
> -
> - return ret;
> + return 0;
> }
>
> static int snp_handle_guest_req(struct vcpu_svm *svm, gpa_t req_gpa, gpa_t resp_gpa)
