From 0ecaefb303de69929dc0036d5021d01cec7ea052 Mon Sep 17 00:00:00 2001 From: "Borislav Petkov (AMD)" Date: Wed, 27 Mar 2024 16:43:17 +0100 Subject: x86/CPU/AMD: Track SNP host status with cc_platform_*() The host SNP worthiness can determined later, after alternatives have been patched, in snp_rmptable_init() depending on cmdline options like iommu=pt which is incompatible with SNP, for example. Which means that one cannot use X86_FEATURE_SEV_SNP and will need to have a special flag for that control. Use that newly added CC_ATTR_HOST_SEV_SNP in the appropriate places. Move kdump_sev_callback() to its rightful place, while at it. Fixes: 216d106c7ff7 ("x86/sev: Add SEV-SNP host initialization support") Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Tom Lendacky Tested-by: Srikanth Aithal Link: https://lore.kernel.org/r/20240327154317.29909-6-bp@alien8.de --- arch/x86/kernel/cpu/amd.c | 38 +++++++++++++++++++++++--------------- 1 file changed, 23 insertions(+), 15 deletions(-) (limited to 'arch/x86/kernel/cpu/amd.c') diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 6d8677e80ddb..9bf17c9c29da 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -345,6 +345,28 @@ static void srat_detect_node(struct cpuinfo_x86 *c) #endif } +static void bsp_determine_snp(struct cpuinfo_x86 *c) +{ +#ifdef CONFIG_ARCH_HAS_CC_PLATFORM + cc_vendor = CC_VENDOR_AMD; + + if (cpu_has(c, X86_FEATURE_SEV_SNP)) { + /* + * RMP table entry format is not architectural and is defined by the + * per-processor PPR. Restrict SNP support on the known CPU models + * for which the RMP table entry format is currently defined for. + */ + if (!cpu_has(c, X86_FEATURE_HYPERVISOR) && + c->x86 >= 0x19 && snp_probe_rmptable_info()) { + cc_platform_set(CC_ATTR_HOST_SEV_SNP); + } else { + setup_clear_cpu_cap(X86_FEATURE_SEV_SNP); + cc_platform_clear(CC_ATTR_HOST_SEV_SNP); + } + } +#endif +} + static void bsp_init_amd(struct cpuinfo_x86 *c) { if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) { @@ -452,21 +474,7 @@ static void bsp_init_amd(struct cpuinfo_x86 *c) break; } - if (cpu_has(c, X86_FEATURE_SEV_SNP)) { - /* - * RMP table entry format is not architectural and it can vary by processor - * and is defined by the per-processor PPR. Restrict SNP support on the - * known CPU model and family for which the RMP table entry format is - * currently defined for. - */ - if (!boot_cpu_has(X86_FEATURE_ZEN3) && - !boot_cpu_has(X86_FEATURE_ZEN4) && - !boot_cpu_has(X86_FEATURE_ZEN5)) - setup_clear_cpu_cap(X86_FEATURE_SEV_SNP); - else if (!snp_probe_rmptable_info()) - setup_clear_cpu_cap(X86_FEATURE_SEV_SNP); - } - + bsp_determine_snp(c); return; warn: -- cgit v1.2.3