Commit 46332437 authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: SVM: Use guard(mutex) to simplify SNP AP Creation error handling 



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: default avatarTom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: default avatarPankaj Gupta <pankaj.gupta@amd.com>
Link: https://lore.kernel.org/r/20250227012541.3234589-8-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent c6e129fb

arch/x86/kvm/svm/sev.c

+6 −16
Original line number Diff line number Diff line
@@ -3944,7 +3944,6 @@ 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);
@@ -3957,11 +3956,9 @@ 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:
@@ -3969,15 +3966,13 @@ 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;

		}



		/*
@@ -3991,8 +3986,7 @@ 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;
@@ -4003,8 +3997,7 @@ 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;
@@ -4018,10 +4011,7 @@ 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)