Commit 136a55c0 authored by Maxim Levitsky's avatar Maxim Levitsky Committed by Paolo Bonzini
Browse files

KVM: x86: nSVM: refactor svm_leave_smm and smm_enter_smm 



Use return statements instead of nested if, and fix error
path to free all the maps that were allocated.

Suggested-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210913140954.165665-2-mlevitsk@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent e85d3e7b

arch/x86/kvm/svm/svm.c

+69 −66
Original line number Diff line number Diff line
@@ -4285,7 +4285,9 @@ static int svm_enter_smm(struct kvm_vcpu *vcpu, char *smstate) 
	struct kvm_host_map map_save;

	int ret;



	if (is_guest_mode(vcpu)) {

	if (!is_guest_mode(vcpu))

		return 0;



	/* FED8h - SVM Guest */

	put_smstate(u64, smstate, 0x7ed8, 1);

	/* FEE0h - SVM Guest VMCB Physical Address */
@@ -4321,7 +4323,6 @@ static int svm_enter_smm(struct kvm_vcpu *vcpu, char *smstate) 
			     &svm->vmcb01.ptr->save);



	kvm_vcpu_unmap(vcpu, &map_save, true);

	}

	return 0;

}
@@ -4329,52 +4330,54 @@ static int svm_leave_smm(struct kvm_vcpu *vcpu, const char *smstate) 
{

	struct vcpu_svm *svm = to_svm(vcpu);

	struct kvm_host_map map, map_save;

	int ret = 0;



	if (guest_cpuid_has(vcpu, X86_FEATURE_LM)) {

		u64 saved_efer = GET_SMSTATE(u64, smstate, 0x7ed0);

		u64 guest = GET_SMSTATE(u64, smstate, 0x7ed8);

		u64 vmcb12_gpa = GET_SMSTATE(u64, smstate, 0x7ee0);

	u64 saved_efer, vmcb12_gpa;

	struct vmcb *vmcb12;

	int ret;



	if (!guest_cpuid_has(vcpu, X86_FEATURE_LM))

		return 0;



	/* Non-zero if SMI arrived while vCPU was in guest mode. */

	if (!GET_SMSTATE(u64, smstate, 0x7ed8))

		return 0;



		if (guest) {

	if (!guest_cpuid_has(vcpu, X86_FEATURE_SVM))

		return 1;



	saved_efer = GET_SMSTATE(u64, smstate, 0x7ed0);

	if (!(saved_efer & EFER_SVME))

		return 1;



			if (kvm_vcpu_map(vcpu,

					 gpa_to_gfn(vmcb12_gpa), &map) == -EINVAL)

	vmcb12_gpa = GET_SMSTATE(u64, smstate, 0x7ee0);

	if (kvm_vcpu_map(vcpu, gpa_to_gfn(vmcb12_gpa), &map) == -EINVAL)

		return 1;



			if (svm_allocate_nested(svm))

				return 1;

	ret = 1;

	if (kvm_vcpu_map(vcpu, gpa_to_gfn(svm->nested.hsave_msr), &map_save) == -EINVAL)

		goto unmap_map;



			kvm_vcpu_unmap(vcpu, &map, true);

	if (svm_allocate_nested(svm))

		goto unmap_save;



	/*

	 * Restore L1 host state from L1 HSAVE area as VMCB01 was

	 * used during SMM (see svm_enter_smm())

	 */

			if (kvm_vcpu_map(vcpu, gpa_to_gfn(svm->nested.hsave_msr),

					 &map_save) == -EINVAL)

				return 1;



			svm_copy_vmrun_state(&svm->vmcb01.ptr->save,

					     map_save.hva + 0x400);

	svm_copy_vmrun_state(&svm->vmcb01.ptr->save, map_save.hva + 0x400);



	/*

	 * Enter the nested guest now

	 */



	vmcb12 = map.hva;

	nested_load_control_from_vmcb12(svm, &vmcb12->control);

	ret = enter_svm_guest_mode(vcpu, vmcb12_gpa, vmcb12, false);



unmap_save:

	kvm_vcpu_unmap(vcpu, &map_save, true);

		}

	}



unmap_map:

	kvm_vcpu_unmap(vcpu, &map, true);

	return ret;

}