Commit c688bd5d authored by Borislav Petkov's avatar Borislav Petkov
Browse files

x86/sev: Carve out HV call's return value verification 



Carve out the verification of the HV call return value into a separate
helper and make it more readable.

No functional changes.

Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/YVbYWz%2B8J7iMTJjc@zn.tnic
parent 64570fbc

arch/x86/kernel/sev-shared.c

+29 −24
Original line number Diff line number Diff line
@@ -94,25 +94,15 @@ static void vc_finish_insn(struct es_em_ctxt *ctxt) 
	ctxt->regs->ip += ctxt->insn.length;

}



static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,

					  struct es_em_ctxt *ctxt,

					  u64 exit_code, u64 exit_info_1,

					  u64 exit_info_2)

static enum es_result verify_exception_info(struct ghcb *ghcb, struct es_em_ctxt *ctxt)

{

	enum es_result ret;



	/* Fill in protocol and format specifiers */

	ghcb->protocol_version = GHCB_PROTOCOL_MAX;

	ghcb->ghcb_usage       = GHCB_DEFAULT_USAGE;



	ghcb_set_sw_exit_code(ghcb, exit_code);

	ghcb_set_sw_exit_info_1(ghcb, exit_info_1);

	ghcb_set_sw_exit_info_2(ghcb, exit_info_2);

	u32 ret;



	sev_es_wr_ghcb_msr(__pa(ghcb));

	VMGEXIT();

	ret = ghcb->save.sw_exit_info_1 & GENMASK_ULL(31, 0);

	if (!ret)

		return ES_OK;



	if ((ghcb->save.sw_exit_info_1 & 0xffffffff) == 1) {

	if (ret == 1) {

		u64 info = ghcb->save.sw_exit_info_2;

		unsigned long v;
@@ -124,19 +114,34 @@ static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb, 
		    ((v == X86_TRAP_GP) || (v == X86_TRAP_UD)) &&

		    ((info & SVM_EVTINJ_TYPE_MASK) == SVM_EVTINJ_TYPE_EXEPT)) {

			ctxt->fi.vector = v;



			if (info & SVM_EVTINJ_VALID_ERR)

				ctxt->fi.error_code = info >> 32;

			ret = ES_EXCEPTION;

		} else {

			ret = ES_VMM_ERROR;



			return ES_EXCEPTION;

		}

	} else if (ghcb->save.sw_exit_info_1 & 0xffffffff) {

		ret = ES_VMM_ERROR;

	} else {

		ret = ES_OK;

	}



	return ret;

	return ES_VMM_ERROR;

}



static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,

					  struct es_em_ctxt *ctxt,

					  u64 exit_code, u64 exit_info_1,

					  u64 exit_info_2)

{

	/* Fill in protocol and format specifiers */

	ghcb->protocol_version = GHCB_PROTOCOL_MAX;

	ghcb->ghcb_usage       = GHCB_DEFAULT_USAGE;



	ghcb_set_sw_exit_code(ghcb, exit_code);

	ghcb_set_sw_exit_info_1(ghcb, exit_info_1);

	ghcb_set_sw_exit_info_2(ghcb, exit_info_2);



	sev_es_wr_ghcb_msr(__pa(ghcb));

	VMGEXIT();



	return verify_exception_info(ghcb, ctxt);

}



/*