From 4b28f0846ef6521b47ee95ea7d77c9d40a7baf29 Mon Sep 17 00:00:00 2001 From: Tycho Andersen Date: Thu, 16 Apr 2026 16:23:24 -0700 Subject: crypto/ccp: export firmware supported vm types In some configurations, the firmware does not support all VM types. The SEV firmware has an entry in the TCB_VERSION structure referred to as the Security Version Number in the SEV-SNP firmware specification and referred to as the "SPL" in SEV firmware release notes. The SEV firmware release notes say: On every SEV firmware release where a security mitigation has been added, the SNP SPL gets increased by 1. This is to let users know that it is important to update to this version. The SEV firmware release that fixed CVE-2025-48514 by disabling SEV-ES support on vulnerable platforms has this SVN increased to reflect the fix. The SVN is platform-specific, as is the structure of TCB_VERSION. Check CURRENT_TCB instead of REPORTED_TCB, since the firmware behaves with the CURRENT_TCB SVN level and will reject SEV-ES VMs accordingly. Parse the SVN, and mask off the SEV_ES supported VM type from the list of supported types if it is above the per-platform threshold for the relevant platforms. Signed-off-by: Tycho Andersen (AMD) Acked-by: Herbert Xu Reviewed-by: Tom Lendacky Tested-by: Tycho Andersen (AMD) Link: https://patch.msgid.link/20260416232329.3408497-3-seanjc@google.com Signed-off-by: Sean Christopherson --- include/linux/psp-sev.h | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'include/linux') diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h index d5099a2baca5..ce16bbc0b308 100644 --- a/include/linux/psp-sev.h +++ b/include/linux/psp-sev.h @@ -902,6 +902,42 @@ struct snp_feature_info { /* Feature bits in EBX */ #define SNP_SEV_TIO_SUPPORTED BIT(1) +/** + * struct sev_snp_tcb_version_genoa_milan + * + * @boot_loader: SVN of PSP bootloader + * @tee: SVN of PSP operating system + * @reserved: reserved + * @snp: SVN of SNP firmware + * @microcode: Lowest current patch level of all cores + */ +struct sev_snp_tcb_version_genoa_milan { + u8 boot_loader; + u8 tee; + u8 reserved[4]; + u8 snp; + u8 microcode; +}; + +/** + * struct sev_snp_tcb_version_turin + * + * @fmc: SVN of FMC firmware + * @boot_loader: SVN of PSP bootloader + * @tee: SVN of PSP operating system + * @snp: SVN of SNP firmware + * @reserved: reserved + * @microcode: Lowest current patch level of all cores + */ +struct sev_snp_tcb_version_turin { + u8 fmc; + u8 boot_loader; + u8 tee; + u8 snp; + u8 reserved[3]; + u8 microcode; +}; + #ifdef CONFIG_CRYPTO_DEV_SP_PSP /** @@ -1048,6 +1084,7 @@ void snp_free_firmware_page(void *addr); void sev_platform_shutdown(void); bool sev_is_snp_ciphertext_hiding_supported(void); u64 sev_get_snp_policy_bits(void); +int sev_firmware_supported_vm_types(void); #else /* !CONFIG_CRYPTO_DEV_SP_PSP */ -- cgit v1.2.3