From c688bd5dc94ee2677f820e4a566fbe98018847ff Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Fri, 1 Oct 2021 11:41:05 +0200 Subject: [PATCH] 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: Borislav Petkov Link: https://lore.kernel.org/r/YVbYWz%2B8J7iMTJjc@zn.tnic --- arch/x86/kernel/sev-shared.c | 53 ++++++++++++++++++++++++-------------------- 1 file changed, 29 insertions(+), 24 deletions(-) diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c index bf1033a..4579c38 100644 --- a/arch/x86/kernel/sev-shared.c +++ b/arch/x86/kernel/sev-shared.c @@ -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; + u32 ret; - /* Fill in protocol and format specifiers */ - ghcb->protocol_version = GHCB_PROTOCOL_MAX; - ghcb->ghcb_usage = GHCB_DEFAULT_USAGE; + ret = ghcb->save.sw_exit_info_1 & GENMASK_ULL(31, 0); + if (!ret) + return ES_OK; - 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(); - - 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); } /* -- 2.7.4