From 0ecaefb303de69929dc0036d5021d01cec7ea052 Mon Sep 17 00:00:00 2001 From: "Borislav Petkov (AMD)" Date: Wed, 27 Mar 2024 16:43:17 +0100 Subject: [PATCH] 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/include/asm/sev.h | 4 ++-- arch/x86/kernel/cpu/amd.c | 38 ++++++++++++++++++------------ arch/x86/kernel/cpu/mtrr/generic.c | 2 +- arch/x86/kernel/sev.c | 10 -------- arch/x86/kvm/svm/sev.c | 2 +- arch/x86/virt/svm/sev.c | 26 +++++++++++++------- drivers/crypto/ccp/sev-dev.c | 2 +- drivers/iommu/amd/init.c | 4 +++- 8 files changed, 49 insertions(+), 39 deletions(-) diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h index 07e125f32528..7f57382afee4 100644 --- a/arch/x86/include/asm/sev.h +++ b/arch/x86/include/asm/sev.h @@ -228,7 +228,6 @@ int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct sn void snp_accept_memory(phys_addr_t start, phys_addr_t end); u64 snp_get_unsupported_features(u64 status); u64 sev_get_status(void); -void kdump_sev_callback(void); void sev_show_status(void); #else static inline void sev_es_ist_enter(struct pt_regs *regs) { } @@ -258,7 +257,6 @@ static inline int snp_issue_guest_request(u64 exit_code, struct snp_req_data *in static inline void snp_accept_memory(phys_addr_t start, phys_addr_t end) { } static inline u64 snp_get_unsupported_features(u64 status) { return 0; } static inline u64 sev_get_status(void) { return 0; } -static inline void kdump_sev_callback(void) { } static inline void sev_show_status(void) { } #endif @@ -270,6 +268,7 @@ int psmash(u64 pfn); int rmp_make_private(u64 pfn, u64 gpa, enum pg_level level, u32 asid, bool immutable); int rmp_make_shared(u64 pfn, enum pg_level level); void snp_leak_pages(u64 pfn, unsigned int npages); +void kdump_sev_callback(void); #else static inline bool snp_probe_rmptable_info(void) { return false; } static inline int snp_lookup_rmpentry(u64 pfn, bool *assigned, int *level) { return -ENODEV; } @@ -282,6 +281,7 @@ static inline int rmp_make_private(u64 pfn, u64 gpa, enum pg_level level, u32 as } static inline int rmp_make_shared(u64 pfn, enum pg_level level) { return -ENODEV; } static inline void snp_leak_pages(u64 pfn, unsigned int npages) {} +static inline void kdump_sev_callback(void) { } #endif #endif 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; diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index ae0ac12382b9..3d310b473e05 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -3174,7 +3174,7 @@ struct page *snp_safe_alloc_page(struct kvm_vcpu *vcpu) unsigned long pfn; struct page *p; - if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP)) return alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO); /* diff --git a/arch/x86/virt/svm/sev.c b/arch/x86/virt/svm/sev.c index cffe1157a90a..ab0e8448bb6e 100644 --- a/arch/x86/virt/svm/sev.c +++ b/arch/x86/virt/svm/sev.c @@ -77,7 +77,7 @@ static int __mfd_enable(unsigned int cpu) { u64 val; - if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP)) return 0; rdmsrl(MSR_AMD64_SYSCFG, val); @@ -98,7 +98,7 @@ static int __snp_enable(unsigned int cpu) { u64 val; - if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP)) return 0; rdmsrl(MSR_AMD64_SYSCFG, val); @@ -174,11 +174,11 @@ static int __init snp_rmptable_init(void) u64 rmptable_size; u64 val; - if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP)) return 0; if (!amd_iommu_snp_en) - return 0; + goto nosnp; if (!probed_rmp_size) goto nosnp; @@ -225,7 +225,7 @@ skip_enable: return 0; nosnp: - setup_clear_cpu_cap(X86_FEATURE_SEV_SNP); + cc_platform_clear(CC_ATTR_HOST_SEV_SNP); return -ENOSYS; } @@ -246,7 +246,7 @@ static struct rmpentry *__snp_lookup_rmpentry(u64 pfn, int *level) { struct rmpentry *large_entry, *entry; - if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP)) return ERR_PTR(-ENODEV); entry = get_rmpentry(pfn); @@ -363,7 +363,7 @@ int psmash(u64 pfn) unsigned long paddr = pfn << PAGE_SHIFT; int ret; - if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP)) return -ENODEV; if (!pfn_valid(pfn)) @@ -472,7 +472,7 @@ static int rmpupdate(u64 pfn, struct rmp_state *state) unsigned long paddr = pfn << PAGE_SHIFT; int ret, level; - if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP)) return -ENODEV; level = RMP_TO_PG_LEVEL(state->pagesize); @@ -558,3 +558,13 @@ void snp_leak_pages(u64 pfn, unsigned int npages) spin_unlock(&snp_leaked_pages_list_lock); } EXPORT_SYMBOL_GPL(snp_leak_pages); + +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 (cc_platform_has(CC_ATTR_HOST_SEV_SNP)) + wbinvd(); +} diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c index f44efbb89c34..2102377f727b 100644 --- a/drivers/crypto/ccp/sev-dev.c +++ b/drivers/crypto/ccp/sev-dev.c @@ -1090,7 +1090,7 @@ static int __sev_snp_init_locked(int *error) void *arg = &data; int cmd, rc = 0; - if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP)) return -ENODEV; sev = psp->sev_data; diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c index e7a44929f0da..33228c1c8980 100644 --- a/drivers/iommu/amd/init.c +++ b/drivers/iommu/amd/init.c @@ -3228,7 +3228,7 @@ out: static void iommu_snp_enable(void) { #ifdef CONFIG_KVM_AMD_SEV - if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP)) return; /* * The SNP support requires that IOMMU must be enabled, and is @@ -3236,12 +3236,14 @@ static void iommu_snp_enable(void) */ if (no_iommu || iommu_default_passthrough()) { pr_err("SNP: IOMMU disabled or configured in passthrough mode, SNP cannot be supported.\n"); + cc_platform_clear(CC_ATTR_HOST_SEV_SNP); return; } amd_iommu_snp_en = check_feature(FEATURE_SNP); if (!amd_iommu_snp_en) { pr_err("SNP: IOMMU SNP feature not enabled, SNP cannot be supported.\n"); + cc_platform_clear(CC_ATTR_HOST_SEV_SNP); return; }