From 6c0f74d678c94060932683738b3e227995b363d3 Mon Sep 17 00:00:00 2001 From: Brijesh Singh Date: Wed, 9 Feb 2022 12:10:04 -0600 Subject: [PATCH] x86/sev: Define the Linux-specific guest termination reasons The GHCB specification defines the reason code for reason set 0. The reason codes defined in the set 0 do not cover all possible causes for a guest to request termination. The reason sets 1 to 255 are reserved for the vendor-specific codes. Reserve the reason set 1 for the Linux guest. Define the error codes for reason set 1 so that one can have meaningful termination reasons and thus better guest failure diagnosis. While at it, change sev_es_terminate() to accept a reason set parameter. [ bp: Massage commit message. ] Signed-off-by: Brijesh Singh Signed-off-by: Borislav Petkov Reviewed-by: Venu Busireddy Link: https://lore.kernel.org/r/20220307213356.2797205-11-brijesh.singh@amd.com --- arch/x86/boot/compressed/sev.c | 6 +++--- arch/x86/include/asm/sev-common.h | 8 ++++++++ arch/x86/kernel/sev-shared.c | 11 ++++------- arch/x86/kernel/sev.c | 4 ++-- 4 files changed, 17 insertions(+), 12 deletions(-) diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c index 27ccd5a..56e941d5 100644 --- a/arch/x86/boot/compressed/sev.c +++ b/arch/x86/boot/compressed/sev.c @@ -119,7 +119,7 @@ static enum es_result vc_read_mem(struct es_em_ctxt *ctxt, static bool early_setup_sev_es(void) { if (!sev_es_negotiate_protocol()) - sev_es_terminate(GHCB_SEV_ES_PROT_UNSUPPORTED); + sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_PROT_UNSUPPORTED); if (set_page_decrypted((unsigned long)&boot_ghcb_page)) return false; @@ -172,7 +172,7 @@ void do_boot_stage2_vc(struct pt_regs *regs, unsigned long exit_code) enum es_result result; if (!boot_ghcb && !early_setup_sev_es()) - sev_es_terminate(GHCB_SEV_ES_GEN_REQ); + sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ); vc_ghcb_invalidate(boot_ghcb); result = vc_init_em_ctxt(&ctxt, regs, exit_code); @@ -199,7 +199,7 @@ finish: if (result == ES_OK) vc_finish_insn(&ctxt); else if (result != ES_RETRY) - sev_es_terminate(GHCB_SEV_ES_GEN_REQ); + sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ); } void sev_enable(struct boot_params *bp) diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h index 1b2fd32..94f0ea5 100644 --- a/arch/x86/include/asm/sev-common.h +++ b/arch/x86/include/asm/sev-common.h @@ -73,9 +73,17 @@ /* GHCBData[23:16] */ \ ((((u64)reason_val) & 0xff) << 16)) +/* Error codes from reason set 0 */ +#define SEV_TERM_SET_GEN 0 #define GHCB_SEV_ES_GEN_REQ 0 #define GHCB_SEV_ES_PROT_UNSUPPORTED 1 +/* Linux-specific reason codes (used with reason set 1) */ +#define SEV_TERM_SET_LINUX 1 +#define GHCB_TERM_REGISTER 0 /* GHCB GPA registration failure */ +#define GHCB_TERM_PSC 1 /* Page State Change failure */ +#define GHCB_TERM_PVALIDATE 2 /* Pvalidate failure */ + #define GHCB_RESP_CODE(v) ((v) & GHCB_MSR_INFO_MASK) /* diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c index ce98768..2abf8a7 100644 --- a/arch/x86/kernel/sev-shared.c +++ b/arch/x86/kernel/sev-shared.c @@ -24,15 +24,12 @@ static bool __init sev_es_check_cpu_features(void) return true; } -static void __noreturn sev_es_terminate(unsigned int reason) +static void __noreturn sev_es_terminate(unsigned int set, unsigned int reason) { u64 val = GHCB_MSR_TERM_REQ; - /* - * Tell the hypervisor what went wrong - only reason-set 0 is - * currently supported. - */ - val |= GHCB_SEV_TERM_REASON(0, reason); + /* Tell the hypervisor what went wrong. */ + val |= GHCB_SEV_TERM_REASON(set, reason); /* Request Guest Termination from Hypvervisor */ sev_es_wr_ghcb_msr(val); @@ -221,7 +218,7 @@ void __init do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code) fail: /* Terminate the guest */ - sev_es_terminate(GHCB_SEV_ES_GEN_REQ); + sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ); } static enum es_result vc_insn_string_read(struct es_em_ctxt *ctxt, diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index e6d316a..19ad097 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -1337,7 +1337,7 @@ DEFINE_IDTENTRY_VC_KERNEL(exc_vmm_communication) show_regs(regs); /* Ask hypervisor to sev_es_terminate */ - sev_es_terminate(GHCB_SEV_ES_GEN_REQ); + sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ); /* If that fails and we get here - just panic */ panic("Returned from Terminate-Request to Hypervisor\n"); @@ -1385,7 +1385,7 @@ bool __init handle_vc_boot_ghcb(struct pt_regs *regs) /* Do initial setup or terminate the guest */ if (unlikely(boot_ghcb == NULL && !sev_es_setup_ghcb())) - sev_es_terminate(GHCB_SEV_ES_GEN_REQ); + sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ); vc_ghcb_invalidate(boot_ghcb); -- 2.7.4