Commit c3392d0a authored by Melody Wang's avatar Melody Wang Committed by Sean Christopherson
Browse files

KVM: SVM: Provide helpers to set the error code 



Provide helpers to set the error code when converting VMGEXIT SW_EXITINFO1 and
SW_EXITINFO2 codes from plain numbers to proper defines. Add comments for
better code readability.

No functionality changed.

Suggested-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarMelody Wang <huibo.wang@amd.com>
Link: https://lore.kernel.org/r/20250225213937.2471419-3-huibo.wang@amd.com


[sean: tweak comments, fix formatting goofs]
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent ea4c2f2f

arch/x86/kvm/svm/sev.c

+19 −18
Original line number Diff line number Diff line
@@ -3410,8 +3410,7 @@ static int sev_es_validate_vmgexit(struct vcpu_svm *svm) 
		dump_ghcb(svm);

	}



	ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, GHCB_HV_RESP_MALFORMED_INPUT);

	ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, reason);

	svm_vmgexit_bad_input(svm, reason);



	/* Resume the guest to "return" the error code. */

	return 1;
@@ -3554,8 +3553,7 @@ static int setup_vmgexit_scratch(struct vcpu_svm *svm, bool sync, u64 len) 
	return 0;



e_scratch:

	ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, GHCB_HV_RESP_MALFORMED_INPUT);

	ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_SCRATCH_AREA);

	svm_vmgexit_bad_input(svm, GHCB_ERR_INVALID_SCRATCH_AREA);



	return 1;

}
@@ -3655,7 +3653,14 @@ static void snp_complete_psc(struct vcpu_svm *svm, u64 psc_ret) 
	svm->sev_es.psc_inflight = 0;

	svm->sev_es.psc_idx = 0;

	svm->sev_es.psc_2m = false;

	ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, psc_ret);



	/*

	 * PSC requests always get a "no action" response in SW_EXITINFO1, with

	 * a PSC-specific return code in SW_EXITINFO2 that provides the "real"

	 * return code.  E.g. if the PSC request was interrupted, the need to

	 * retry is communicated via SW_EXITINFO2, not SW_EXITINFO1.

	 */

	svm_vmgexit_no_action(svm, psc_ret);

}



static void __snp_complete_one_psc(struct vcpu_svm *svm)
@@ -4058,7 +4063,8 @@ static int snp_handle_guest_req(struct vcpu_svm *svm, gpa_t req_gpa, gpa_t resp_ 
		goto out_unlock;

	}



	ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, SNP_GUEST_ERR(0, fw_err));

	/* No action is requested *from KVM* if there was a firmware error. */

	svm_vmgexit_no_action(svm, SNP_GUEST_ERR(0, fw_err));



	ret = 1; /* resume guest */
@@ -4114,8 +4120,7 @@ static int snp_handle_ext_guest_req(struct vcpu_svm *svm, gpa_t req_gpa, gpa_t r 
	return snp_handle_guest_req(svm, req_gpa, resp_gpa);



request_invalid:

	ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, GHCB_HV_RESP_MALFORMED_INPUT);

	ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_INPUT);

	svm_vmgexit_bad_input(svm, GHCB_ERR_INVALID_INPUT);

	return 1; /* resume guest */

}
@@ -4307,8 +4312,7 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu) 
	if (ret)

		return ret;



	ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, GHCB_HV_RESP_NO_ACTION);

	ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, 0);

	svm_vmgexit_success(svm, 0);



	exit_code = kvm_ghcb_get_sw_exit_code(control);

	switch (exit_code) {
@@ -4352,21 +4356,19 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu) 
			break;

		case 1:

			/* Get AP jump table address */

			ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, sev->ap_jump_table);

			svm_vmgexit_success(svm, sev->ap_jump_table);

			break;

		default:

			pr_err("svm: vmgexit: unsupported AP jump table request - exit_info_1=%#llx\n",

			       control->exit_info_1);

			ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, GHCB_HV_RESP_MALFORMED_INPUT);

			ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_INPUT);

			svm_vmgexit_bad_input(svm, GHCB_ERR_INVALID_INPUT);

		}



		ret = 1;

		break;

	}

	case SVM_VMGEXIT_HV_FEATURES:

		ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_HV_FT_SUPPORTED);



		svm_vmgexit_success(svm, GHCB_HV_FT_SUPPORTED);

		ret = 1;

		break;

	case SVM_VMGEXIT_TERM_REQUEST:
@@ -4387,8 +4389,7 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu) 
	case SVM_VMGEXIT_AP_CREATION:

		ret = sev_snp_ap_creation(svm);

		if (ret) {

			ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, GHCB_HV_RESP_MALFORMED_INPUT);

			ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_INPUT);

			svm_vmgexit_bad_input(svm, GHCB_ERR_INVALID_INPUT);

		}



		ret = 1;
@@ -4624,7 +4625,7 @@ void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector) 
		 * Return from an AP Reset Hold VMGEXIT, where the guest will

		 * set the CS and RIP. Set SW_EXIT_INFO_2 to a non-zero value.

		 */

		ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, 1);

		svm_vmgexit_success(svm, 1);

		break;

	case AP_RESET_HOLD_MSR_PROTO:

		/*

arch/x86/kvm/svm/svm.c

+1 −5
Original line number Diff line number Diff line
@@ -2973,11 +2973,7 @@ static int svm_complete_emulated_msr(struct kvm_vcpu *vcpu, int err) 
	if (!err || !sev_es_guest(vcpu->kvm) || WARN_ON_ONCE(!svm->sev_es.ghcb))

		return kvm_complete_insn_gp(vcpu, err);



	ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, GHCB_HV_RESP_ISSUE_EXCEPTION);

	ghcb_set_sw_exit_info_2(svm->sev_es.ghcb,

				X86_TRAP_GP |

				SVM_EVTINJ_TYPE_EXEPT |

				SVM_EVTINJ_VALID);

	svm_vmgexit_inject_exception(svm, X86_TRAP_GP);

	return 1;

}

arch/x86/kvm/svm/svm.h

+29 −0
Original line number Diff line number Diff line
@@ -579,6 +579,35 @@ static inline bool is_vnmi_enabled(struct vcpu_svm *svm) 
		return false;

}



static inline void svm_vmgexit_set_return_code(struct vcpu_svm *svm,

						u64 response, u64 data)

{

	ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, response);

	ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, data);

}



static inline void svm_vmgexit_inject_exception(struct vcpu_svm *svm, u8 vector)

{

	u64 data = SVM_EVTINJ_VALID | SVM_EVTINJ_TYPE_EXEPT | vector;



	svm_vmgexit_set_return_code(svm, GHCB_HV_RESP_ISSUE_EXCEPTION, data);

}



static inline void svm_vmgexit_bad_input(struct vcpu_svm *svm, u64 suberror)

{

	svm_vmgexit_set_return_code(svm, GHCB_HV_RESP_MALFORMED_INPUT, suberror);

}



static inline void svm_vmgexit_success(struct vcpu_svm *svm, u64 data)

{

	svm_vmgexit_set_return_code(svm, GHCB_HV_RESP_NO_ACTION, data);

}



static inline void svm_vmgexit_no_action(struct vcpu_svm *svm, u64 data)

{

	svm_vmgexit_set_return_code(svm, GHCB_HV_RESP_NO_ACTION, data);

}



/* svm.c */

#define MSR_INVALID				0xffffffffU