diff options
author | Borislav Petkov (AMD) <bp@alien8.de> | 2024-03-27 18:43:17 +0300 |
---|---|---|
committer | Borislav Petkov (AMD) <bp@alien8.de> | 2024-04-04 11:40:30 +0300 |
commit | 0ecaefb303de69929dc0036d5021d01cec7ea052 (patch) | |
tree | be2be2168e4dd2f405e704f751889f23e617593b /arch/x86/kernel | |
parent | bc6f707fc0feec72acc2f49c312eb31d257363a3 (diff) | |
download | linux-0ecaefb303de69929dc0036d5021d01cec7ea052.tar.xz |
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) <bp@alien8.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Tested-by: Srikanth Aithal <sraithal@amd.com>
Link: https://lore.kernel.org/r/20240327154317.29909-6-bp@alien8.de
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r-- | arch/x86/kernel/cpu/amd.c | 38 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/mtrr/generic.c | 2 | ||||
-rw-r--r-- | arch/x86/kernel/sev.c | 10 |
3 files changed, 24 insertions, 26 deletions
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: diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c index 422a4ddc2ab7..7b29ebda024f 100644 --- a/arch/x86/kernel/cpu/mtrr/generic.c +++ b/arch/x86/kernel/cpu/mtrr/generic.c @@ -108,7 +108,7 @@ static inline void k8_check_syscfg_dram_mod_en(void) (boot_cpu_data.x86 >= 0x0f))) return; - if (cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + if (cc_platform_has(CC_ATTR_HOST_SEV_SNP)) return; rdmsr(MSR_AMD64_SYSCFG, lo, hi); diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index 7e1e63cc48e6..38ad066179d8 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -2284,16 +2284,6 @@ static int __init snp_init_platform_device(void) } device_initcall(snp_init_platform_device); -void kdump_sev_callback(void) -{ - /* - * Do wbinvd() on remote CPUs when SNP is enabled in order to - * safely do SNP_SHUTDOWN on the local CPU. - */ - if (cpu_feature_enabled(X86_FEATURE_SEV_SNP)) - wbinvd(); -} - void sev_show_status(void) { int i; |