diff options
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/sev-shared.c | 20 | ||||
| -rw-r--r-- | arch/x86/kernel/sev.c | 14 |
2 files changed, 34 insertions, 0 deletions
diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c index 91105f5a02a8..4a876e684f67 100644 --- a/arch/x86/kernel/sev-shared.c +++ b/arch/x86/kernel/sev-shared.c @@ -48,6 +48,26 @@ static void __noreturn sev_es_terminate(unsigned int set, unsigned int reason) asm volatile("hlt\n" : : : "memory"); } +/* + * The hypervisor features are available from GHCB version 2 onward. + */ +static u64 get_hv_features(void) +{ + u64 val; + + if (ghcb_version < 2) + return 0; + + sev_es_wr_ghcb_msr(GHCB_MSR_HV_FT_REQ); + VMGEXIT(); + + val = sev_es_rd_ghcb_msr(); + if (GHCB_RESP_CODE(val) != GHCB_MSR_HV_FT_RESP) + return 0; + + return GHCB_MSR_HV_FT_RESP_VAL(val); +} + static bool sev_es_negotiate_protocol(void) { u64 val; diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index 19ad09712902..cb20fb0c608e 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -43,6 +43,9 @@ static struct ghcb boot_ghcb_page __bss_decrypted __aligned(PAGE_SIZE); */ static struct ghcb __initdata *boot_ghcb; +/* Bitmap of SEV features supported by the hypervisor */ +static u64 sev_hv_features __ro_after_init; + /* #VC handler runtime per-CPU data */ struct sev_es_runtime_data { struct ghcb ghcb_page; @@ -766,6 +769,17 @@ void __init sev_es_init_vc_handling(void) if (!sev_es_check_cpu_features()) panic("SEV-ES CPU Features missing"); + /* + * SNP is supported in v2 of the GHCB spec which mandates support for HV + * features. + */ + if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) { + sev_hv_features = get_hv_features(); + + if (!(sev_hv_features & GHCB_HV_FT_SNP)) + sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED); + } + /* Enable SEV-ES special handling */ static_branch_enable(&sev_es_enable_key); |