diff options
author | Ingo Molnar <mingo@kernel.org> | 2024-02-26 11:06:48 +0100 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2024-02-26 11:10:35 +0100 |
commit | 2e5fc4786b7ad311393a70894c773aa106c6dbb3 (patch) | |
tree | 5eb9d382795a6739f1c556eaf69fdcfa6b265b7e /arch | |
parent | Merge tag 'v6.8-rc6' into x86/boot, to pick up fixes (diff) | |
parent | crypto: ccp - Have it depend on AMD_IOMMU (diff) | |
download | linux-2e5fc4786b7ad311393a70894c773aa106c6dbb3.tar.xz linux-2e5fc4786b7ad311393a70894c773aa106c6dbb3.zip |
Merge branch 'x86/sev' into x86/boot, to resolve conflicts and to pick up dependent tree
We are going to queue up a number of patches that depend
on fresh changes in x86/sev - merge in that branch to
reduce the number of conflicts going forward.
Also resolve a current conflict with x86/sev.
Conflicts:
arch/x86/include/asm/coco.h
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
31 files changed, 927 insertions, 110 deletions
diff --git a/arch/x86/Kbuild b/arch/x86/Kbuild index 5a83da703e87..6a1f36df6a18 100644 --- a/arch/x86/Kbuild +++ b/arch/x86/Kbuild @@ -28,5 +28,7 @@ obj-y += net/ obj-$(CONFIG_KEXEC_FILE) += purgatory/ +obj-y += virt/svm/ + # for cleaning subdir- += boot tools diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 1a33575f98af..63535c8c8b2a 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1539,19 +1539,6 @@ config AMD_MEM_ENCRYPT This requires an AMD processor that supports Secure Memory Encryption (SME). -config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT - bool "Activate AMD Secure Memory Encryption (SME) by default" - depends on AMD_MEM_ENCRYPT - help - Say yes to have system memory encrypted by default if running on - an AMD processor that supports Secure Memory Encryption (SME). - - If set to Y, then the encryption of system memory can be - deactivated with the mem_encrypt=off command line option. - - If set to N, then the encryption of system memory can be - activated with the mem_encrypt=on command line option. - # Common NUMA Features config NUMA bool "NUMA Memory Allocation and Scheduler Support" diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c index 454acd7a2daf..073291832f44 100644 --- a/arch/x86/boot/compressed/sev.c +++ b/arch/x86/boot/compressed/sev.c @@ -304,6 +304,10 @@ void do_boot_stage2_vc(struct pt_regs *regs, unsigned long exit_code) if (result != ES_OK) goto finish; + result = vc_check_opcode_bytes(&ctxt, exit_code); + if (result != ES_OK) + goto finish; + switch (exit_code) { case SVM_EXIT_RDTSC: case SVM_EXIT_RDTSCP: diff --git a/arch/x86/coco/core.c b/arch/x86/coco/core.c index eeec9986570e..d07be9d05cd0 100644 --- a/arch/x86/coco/core.c +++ b/arch/x86/coco/core.c @@ -14,7 +14,7 @@ #include <asm/processor.h> enum cc_vendor cc_vendor __ro_after_init = CC_VENDOR_NONE; -static u64 cc_mask __ro_after_init; +u64 cc_mask __ro_after_init; static bool noinstr intel_cc_platform_has(enum cc_attr attr) { @@ -148,8 +148,3 @@ u64 cc_mkdec(u64 val) } } EXPORT_SYMBOL_GPL(cc_mkdec); - -__init void cc_set_mask(u64 mask) -{ - cc_mask = mask; -} diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h index fbcfec4dc4cc..ca8eed1d496a 100644 --- a/arch/x86/include/asm/asm.h +++ b/arch/x86/include/asm/asm.h @@ -113,6 +113,20 @@ #endif +#ifndef __ASSEMBLY__ +#ifndef __pic__ +static __always_inline __pure void *rip_rel_ptr(void *p) +{ + asm("leaq %c1(%%rip), %0" : "=r"(p) : "i"(p)); + + return p; +} +#define RIP_REL_REF(var) (*(typeof(&(var)))rip_rel_ptr(&(var))) +#else +#define RIP_REL_REF(var) (var) +#endif +#endif + /* * Macros to generate condition code outputs from inline assembly, * The output operand must be type "bool". diff --git a/arch/x86/include/asm/coco.h b/arch/x86/include/asm/coco.h index 76c310b19b11..8a1cd359248f 100644 --- a/arch/x86/include/asm/coco.h +++ b/arch/x86/include/asm/coco.h @@ -2,6 +2,7 @@ #ifndef _ASM_X86_COCO_H #define _ASM_X86_COCO_H +#include <asm/asm.h> #include <asm/types.h> enum cc_vendor { @@ -10,9 +11,14 @@ enum cc_vendor { CC_VENDOR_INTEL, }; +extern u64 cc_mask; #ifdef CONFIG_ARCH_HAS_CC_PLATFORM extern enum cc_vendor cc_vendor; -void cc_set_mask(u64 mask); +static inline void cc_set_mask(u64 mask) +{ + RIP_REL_REF(cc_mask) = mask; +} + u64 cc_mkenc(u64 val); u64 cc_mkdec(u64 val); #else diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 2b62cdd8dd12..e35842f7aed0 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -440,6 +440,7 @@ #define X86_FEATURE_SEV (19*32+ 1) /* AMD Secure Encrypted Virtualization */ #define X86_FEATURE_VM_PAGE_FLUSH (19*32+ 2) /* "" VM Page Flush MSR is supported */ #define X86_FEATURE_SEV_ES (19*32+ 3) /* AMD Secure Encrypted Virtualization - Encrypted State */ +#define X86_FEATURE_SEV_SNP (19*32+ 4) /* AMD Secure Encrypted Virtualization - Secure Nested Paging */ #define X86_FEATURE_V_TSC_AUX (19*32+ 9) /* "" Virtual TSC_AUX */ #define X86_FEATURE_SME_COHERENT (19*32+10) /* "" AMD hardware-enforced cache coherency */ #define X86_FEATURE_DEBUG_SWAP (19*32+14) /* AMD SEV-ES full debug state swap support */ diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h index 702d93fdd10e..3332d2940020 100644 --- a/arch/x86/include/asm/disabled-features.h +++ b/arch/x86/include/asm/disabled-features.h @@ -117,6 +117,12 @@ #define DISABLE_IBT (1 << (X86_FEATURE_IBT & 31)) #endif +#ifdef CONFIG_KVM_AMD_SEV +#define DISABLE_SEV_SNP 0 +#else +#define DISABLE_SEV_SNP (1 << (X86_FEATURE_SEV_SNP & 31)) +#endif + /* * Make sure to add features to the correct mask */ @@ -141,7 +147,7 @@ DISABLE_ENQCMD) #define DISABLED_MASK17 0 #define DISABLED_MASK18 (DISABLE_IBT) -#define DISABLED_MASK19 0 +#define DISABLED_MASK19 (DISABLE_SEV_SNP) #define DISABLED_MASK20 0 #define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 21) diff --git a/arch/x86/include/asm/iommu.h b/arch/x86/include/asm/iommu.h index 2fd52b65deac..3be2451e7bc8 100644 --- a/arch/x86/include/asm/iommu.h +++ b/arch/x86/include/asm/iommu.h @@ -10,6 +10,7 @@ extern int force_iommu, no_iommu; extern int iommu_detected; extern int iommu_merge; extern int panic_on_overflow; +extern bool amd_iommu_snp_en; #ifdef CONFIG_SWIOTLB extern bool x86_swiotlb_enable; diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h index 378ed944b849..ab24ce207988 100644 --- a/arch/x86/include/asm/kvm-x86-ops.h +++ b/arch/x86/include/asm/kvm-x86-ops.h @@ -138,6 +138,7 @@ KVM_X86_OP(complete_emulated_msr) KVM_X86_OP(vcpu_deliver_sipi_vector) KVM_X86_OP_OPTIONAL_RET0(vcpu_get_apicv_inhibit_reasons); KVM_X86_OP_OPTIONAL(get_untagged_addr) +KVM_X86_OP_OPTIONAL(alloc_apic_backing_page) #undef KVM_X86_OP #undef KVM_X86_OP_OPTIONAL diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index d271ba20a0b2..18cbde14cf81 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1796,6 +1796,7 @@ struct kvm_x86_ops { unsigned long (*vcpu_get_apicv_inhibit_reasons)(struct kvm_vcpu *vcpu); gva_t (*get_untagged_addr)(struct kvm_vcpu *vcpu, gva_t gva, unsigned int flags); + void *(*alloc_apic_backing_page)(struct kvm_vcpu *vcpu); }; struct kvm_x86_nested_ops { diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h index 359ada486fa9..b31eb9fd5954 100644 --- a/arch/x86/include/asm/mem_encrypt.h +++ b/arch/x86/include/asm/mem_encrypt.h @@ -15,7 +15,8 @@ #include <linux/init.h> #include <linux/cc_platform.h> -#include <asm/bootparam.h> +#include <asm/asm.h> +struct boot_params; #ifdef CONFIG_X86_MEM_ENCRYPT void __init mem_encrypt_init(void); @@ -58,6 +59,11 @@ void __init mem_encrypt_free_decrypted_mem(void); void __init sev_es_init_vc_handling(void); +static inline u64 sme_get_me_mask(void) +{ + return RIP_REL_REF(sme_me_mask); +} + #define __bss_decrypted __section(".bss..decrypted") #else /* !CONFIG_AMD_MEM_ENCRYPT */ @@ -89,6 +95,8 @@ early_set_mem_enc_dec_hypercall(unsigned long vaddr, unsigned long size, bool en static inline void mem_encrypt_free_decrypted_mem(void) { } +static inline u64 sme_get_me_mask(void) { return 0; } + #define __bss_decrypted #endif /* CONFIG_AMD_MEM_ENCRYPT */ @@ -106,11 +114,6 @@ void add_encrypt_protection_map(void); extern char __start_bss_decrypted[], __end_bss_decrypted[], __start_bss_decrypted_unused[]; -static inline u64 sme_get_me_mask(void) -{ - return sme_me_mask; -} - #endif /* __ASSEMBLY__ */ #endif /* __X86_MEM_ENCRYPT_H__ */ diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index f1bd7b91b3c6..f482bc6a5ae7 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -599,6 +599,8 @@ #define MSR_AMD64_SEV_ENABLED BIT_ULL(MSR_AMD64_SEV_ENABLED_BIT) #define MSR_AMD64_SEV_ES_ENABLED BIT_ULL(MSR_AMD64_SEV_ES_ENABLED_BIT) #define MSR_AMD64_SEV_SNP_ENABLED BIT_ULL(MSR_AMD64_SEV_SNP_ENABLED_BIT) +#define MSR_AMD64_RMP_BASE 0xc0010132 +#define MSR_AMD64_RMP_END 0xc0010133 /* SNP feature bits enabled by the hypervisor */ #define MSR_AMD64_SNP_VTOM BIT_ULL(3) @@ -708,8 +710,15 @@ #define MSR_K8_TOP_MEM1 0xc001001a #define MSR_K8_TOP_MEM2 0xc001001d #define MSR_AMD64_SYSCFG 0xc0010010 -#define MSR_AMD64_SYSCFG_MEM_ENCRYPT_BIT 23 +#define MSR_AMD64_SYSCFG_MEM_ENCRYPT_BIT 23 #define MSR_AMD64_SYSCFG_MEM_ENCRYPT BIT_ULL(MSR_AMD64_SYSCFG_MEM_ENCRYPT_BIT) +#define MSR_AMD64_SYSCFG_SNP_EN_BIT 24 +#define MSR_AMD64_SYSCFG_SNP_EN BIT_ULL(MSR_AMD64_SYSCFG_SNP_EN_BIT) +#define MSR_AMD64_SYSCFG_SNP_VMPL_EN_BIT 25 +#define MSR_AMD64_SYSCFG_SNP_VMPL_EN BIT_ULL(MSR_AMD64_SYSCFG_SNP_VMPL_EN_BIT) +#define MSR_AMD64_SYSCFG_MFDM_BIT 19 +#define MSR_AMD64_SYSCFG_MFDM BIT_ULL(MSR_AMD64_SYSCFG_MFDM_BIT) + #define MSR_K8_INT_PENDING_MSG 0xc0010055 /* C1E active bits in int pending message */ #define K8_INTP_C1E_ACTIVE_MASK 0x18000000 diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h index 5b4a1ce3d368..bed95e1f4d52 100644 --- a/arch/x86/include/asm/sev.h +++ b/arch/x86/include/asm/sev.h @@ -87,9 +87,23 @@ extern bool handle_vc_boot_ghcb(struct pt_regs *regs); /* Software defined (when rFlags.CF = 1) */ #define PVALIDATE_FAIL_NOUPDATE 255 +/* RMUPDATE detected 4K page and 2MB page overlap. */ +#define RMPUPDATE_FAIL_OVERLAP 4 + /* RMP page size */ #define RMP_PG_SIZE_4K 0 #define RMP_PG_SIZE_2M 1 +#define RMP_TO_PG_LEVEL(level) (((level) == RMP_PG_SIZE_4K) ? PG_LEVEL_4K : PG_LEVEL_2M) +#define PG_LEVEL_TO_RMP(level) (((level) == PG_LEVEL_4K) ? RMP_PG_SIZE_4K : RMP_PG_SIZE_2M) + +struct rmp_state { + u64 gpa; + u8 assigned; + u8 pagesize; + u8 immutable; + u8 rsvd; + u32 asid; +} __packed; #define RMPADJUST_VMSA_PAGE_BIT BIT(16) @@ -213,6 +227,7 @@ 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); #else static inline void sev_es_ist_enter(struct pt_regs *regs) { } static inline void sev_es_ist_exit(void) { } @@ -241,6 +256,29 @@ 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) { } +#endif + +#ifdef CONFIG_KVM_AMD_SEV +bool snp_probe_rmptable_info(void); +int snp_lookup_rmpentry(u64 pfn, bool *assigned, int *level); +void snp_dump_hva_rmpentry(unsigned long address); +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); +#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; } +static inline void snp_dump_hva_rmpentry(unsigned long address) {} +static inline int psmash(u64 pfn) { return -ENODEV; } +static inline int rmp_make_private(u64 pfn, u64 gpa, enum pg_level level, u32 asid, + bool immutable) +{ + return -ENODEV; +} +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) {} #endif #endif diff --git a/arch/x86/include/asm/trap_pf.h b/arch/x86/include/asm/trap_pf.h index afa524325e55..a23a7b707b64 100644 --- a/arch/x86/include/asm/trap_pf.h +++ b/arch/x86/include/asm/trap_pf.h @@ -2,6 +2,8 @@ #ifndef _ASM_X86_TRAP_PF_H #define _ASM_X86_TRAP_PF_H +#include <linux/bits.h> + /* * Page fault error code bits: * @@ -13,16 +15,18 @@ * bit 5 == 1: protection keys block access * bit 6 == 1: shadow stack access fault * bit 15 == 1: SGX MMU page-fault + * bit 31 == 1: fault was due to RMP violation */ enum x86_pf_error_code { - X86_PF_PROT = 1 << 0, - X86_PF_WRITE = 1 << 1, - X86_PF_USER = 1 << 2, - X86_PF_RSVD = 1 << 3, - X86_PF_INSTR = 1 << 4, - X86_PF_PK = 1 << 5, - X86_PF_SHSTK = 1 << 6, - X86_PF_SGX = 1 << 15, + X86_PF_PROT = BIT(0), + X86_PF_WRITE = BIT(1), + X86_PF_USER = BIT(2), + X86_PF_RSVD = BIT(3), + X86_PF_INSTR = BIT(4), + X86_PF_PK = BIT(5), + X86_PF_SHSTK = BIT(6), + X86_PF_SGX = BIT(15), + X86_PF_RMP = BIT(31), }; #endif /* _ASM_X86_TRAP_PF_H */ diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index f3abca334199..ce89281640a9 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -20,6 +20,7 @@ #include <asm/delay.h> #include <asm/debugreg.h> #include <asm/resctrl.h> +#include <asm/sev.h> #ifdef CONFIG_X86_64 # include <asm/mmconfig.h> @@ -587,6 +588,21 @@ 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); + } + return; warn: @@ -605,8 +621,8 @@ static void early_detect_mem_encrypt(struct cpuinfo_x86 *c) * SME feature (set in scattered.c). * If the kernel has not enabled SME via any means then * don't advertise the SME feature. - * For SEV: If BIOS has not enabled SEV then don't advertise the - * SEV and SEV_ES feature (set in scattered.c). + * For SEV: If BIOS has not enabled SEV then don't advertise SEV and + * any additional functionality based on it. * * In all cases, since support for SME and SEV requires long mode, * don't advertise the feature under CONFIG_X86_32. @@ -641,6 +657,7 @@ clear_all: clear_sev: setup_clear_cpu_cap(X86_FEATURE_SEV); setup_clear_cpu_cap(X86_FEATURE_SEV_ES); + setup_clear_cpu_cap(X86_FEATURE_SEV_SNP); } } diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 0b97bcde70c6..9e35e276c55a 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1355,8 +1355,13 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c) /* * AMD's AutoIBRS is equivalent to Intel's eIBRS - use the Intel feature * flag and protect from vendor-specific bugs via the whitelist. + * + * Don't use AutoIBRS when SNP is enabled because it degrades host + * userspace indirect branch performance. */ - if ((ia32_cap & ARCH_CAP_IBRS_ALL) || cpu_has(c, X86_FEATURE_AUTOIBRS)) { + if ((ia32_cap & ARCH_CAP_IBRS_ALL) || + (cpu_has(c, X86_FEATURE_AUTOIBRS) && + !cpu_feature_enabled(X86_FEATURE_SEV_SNP))) { setup_force_cpu_cap(X86_FEATURE_IBRS_ENHANCED); if (!cpu_matches(cpu_vuln_whitelist, NO_EIBRS_PBRSB) && !(ia32_cap & ARCH_CAP_PBRSB_NO)) diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c index d3524778a545..422a4ddc2ab7 100644 --- a/arch/x86/kernel/cpu/mtrr/generic.c +++ b/arch/x86/kernel/cpu/mtrr/generic.c @@ -108,6 +108,9 @@ static inline void k8_check_syscfg_dram_mod_en(void) (boot_cpu_data.x86 >= 0x0f))) return; + if (cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + return; + rdmsr(MSR_AMD64_SYSCFG, lo, hi); if (lo & K8_MTRRFIXRANGE_DRAM_MODIFY) { pr_err(FW_WARN "MTRR: CPU %u: SYSCFG[MtrrFixDramModEn]" diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index b6b044356f1b..d184c29398db 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -40,6 +40,7 @@ #include <asm/intel_pt.h> #include <asm/crash.h> #include <asm/cmdline.h> +#include <asm/sev.h> /* Used while preparing memory map entries for second kernel */ struct crash_memmap_data { @@ -59,6 +60,8 @@ static void kdump_nmi_callback(int cpu, struct pt_regs *regs) */ cpu_emergency_stop_pt(); + kdump_sev_callback(); + disable_local_APIC(); } diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c index 1d24ec679915..ae79f9505298 100644 --- a/arch/x86/kernel/sev-shared.c +++ b/arch/x86/kernel/sev-shared.c @@ -10,11 +10,15 @@ */ #ifndef __BOOT_COMPRESSED -#define error(v) pr_err(v) -#define has_cpuflag(f) boot_cpu_has(f) +#define error(v) pr_err(v) +#define has_cpuflag(f) boot_cpu_has(f) +#define sev_printk(fmt, ...) printk(fmt, ##__VA_ARGS__) +#define sev_printk_rtl(fmt, ...) printk_ratelimited(fmt, ##__VA_ARGS__) #else #undef WARN #define WARN(condition, format...) (!!(condition)) +#define sev_printk(fmt, ...) +#define sev_printk_rtl(fmt, ...) #endif /* I/O parameters for CPUID-related helpers */ @@ -556,9 +560,9 @@ static int snp_cpuid(struct ghcb *ghcb, struct es_em_ctxt *ctxt, struct cpuid_le leaf->eax = leaf->ebx = leaf->ecx = leaf->edx = 0; /* Skip post-processing for out-of-range zero leafs. */ - if (!(leaf->fn <= cpuid_std_range_max || - (leaf->fn >= 0x40000000 && leaf->fn <= cpuid_hyp_range_max) || - (leaf->fn >= 0x80000000 && leaf->fn <= cpuid_ext_range_max))) + if (!(leaf->fn <= RIP_REL_REF(cpuid_std_range_max) || + (leaf->fn >= 0x40000000 && leaf->fn <= RIP_REL_REF(cpuid_hyp_range_max)) || + (leaf->fn >= 0x80000000 && leaf->fn <= RIP_REL_REF(cpuid_ext_range_max)))) return 0; } @@ -574,6 +578,7 @@ void __init do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code) { unsigned int subfn = lower_bits(regs->cx, 32); unsigned int fn = lower_bits(regs->ax, 32); + u16 opcode = *(unsigned short *)regs->ip; struct cpuid_leaf leaf; int ret; @@ -581,6 +586,10 @@ void __init do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code) if (exit_code != SVM_EXIT_CPUID) goto fail; + /* Is it really a CPUID insn? */ + if (opcode != 0xa20f) + goto fail; + leaf.fn = fn; leaf.subfn = subfn; @@ -1063,11 +1072,11 @@ static void __init setup_cpuid_table(const struct cc_blob_sev_info *cc_info) const struct snp_cpuid_fn *fn = &cpuid_table->fn[i]; if (fn->eax_in == 0x0) - cpuid_std_range_max = fn->eax; + RIP_REL_REF(cpuid_std_range_max) = fn->eax; else if (fn->eax_in == 0x40000000) - cpuid_hyp_range_max = fn->eax; + RIP_REL_REF(cpuid_hyp_range_max) = fn->eax; else if (fn->eax_in == 0x80000000) - cpuid_ext_range_max = fn->eax; + RIP_REL_REF(cpuid_ext_range_max) = fn->eax; } } @@ -1170,3 +1179,92 @@ static int vmgexit_psc(struct ghcb *ghcb, struct snp_psc_desc *desc) out: return ret; } + +static enum es_result vc_check_opcode_bytes(struct es_em_ctxt *ctxt, + unsigned long exit_code) +{ + unsigned int opcode = (unsigned int)ctxt->insn.opcode.value; + u8 modrm = ctxt->insn.modrm.value; + + switch (exit_code) { + + case SVM_EXIT_IOIO: + case SVM_EXIT_NPF: + /* handled separately */ + return ES_OK; + + case SVM_EXIT_CPUID: + if (opcode == 0xa20f) + return ES_OK; + break; + + case SVM_EXIT_INVD: + if (opcode == 0x080f) + return ES_OK; + break; + + case SVM_EXIT_MONITOR: + if (opcode == 0x010f && modrm == 0xc8) + return ES_OK; + break; + + case SVM_EXIT_MWAIT: + if (opcode == 0x010f && modrm == 0xc9) + return ES_OK; + break; + + case SVM_EXIT_MSR: + /* RDMSR */ + if (opcode == 0x320f || + /* WRMSR */ + opcode == 0x300f) + return ES_OK; + break; + + case SVM_EXIT_RDPMC: + if (opcode == 0x330f) + return ES_OK; + break; + + case SVM_EXIT_RDTSC: + if (opcode == 0x310f) + return ES_OK; + break; + + case SVM_EXIT_RDTSCP: + if (opcode == 0x010f && modrm == 0xf9) + return ES_OK; + break; + + case SVM_EXIT_READ_DR7: + if (opcode == 0x210f && + X86_MODRM_REG(ctxt->insn.modrm.value) == 7) + return ES_OK; + break; + + case SVM_EXIT_VMMCALL: + if (opcode == 0x010f && modrm == 0xd9) + return ES_OK; + + break; + + case SVM_EXIT_WRITE_DR7: + if (opcode == 0x230f && + X86_MODRM_REG(ctxt->insn.modrm.value) == 7) + return ES_OK; + break; + + case SVM_EXIT_WBINVD: + if (opcode == 0x90f) + return ES_OK; + break; + + default: + break; + } + + sev_printk(KERN_ERR "Wrong/unhandled opcode bytes: 0x%x, exit_code: 0x%lx, rIP: 0x%lx\n", + opcode, exit_code, ctxt->regs->ip); + + return ES_UNSUPPORTED; +} diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index c67285824e82..1ef7ae806a01 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -748,7 +748,7 @@ void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long padd * This eliminates worries about jump tables or checking boot_cpu_data * in the cc_platform_has() function. */ - if (!(sev_status & MSR_AMD64_SEV_SNP_ENABLED)) + if (!(RIP_REL_REF(sev_status) & MSR_AMD64_SEV_SNP_ENABLED)) return; /* @@ -767,7 +767,7 @@ void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr * This eliminates worries about jump tables or checking boot_cpu_data * in the cc_platform_has() function. */ - if (!(sev_status & MSR_AMD64_SEV_SNP_ENABLED)) + if (!(RIP_REL_REF(sev_status) & MSR_AMD64_SEV_SNP_ENABLED)) return; /* Ask hypervisor to mark the memory pages shared in the RMP table. */ @@ -1752,7 +1752,10 @@ static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt, struct ghcb *ghcb, unsigned long exit_code) { - enum es_result result; + enum es_result result = vc_check_opcode_bytes(ctxt, exit_code); + + if (result != ES_OK) + return result; switch (exit_code) { case SVM_EXIT_READ_DR7: @@ -2262,3 +2265,13 @@ static int __init snp_init_platform_device(void) return 0; } 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(); +} diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 3242f3da2457..1edf93ee3395 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2815,7 +2815,10 @@ int kvm_create_lapic(struct kvm_vcpu *vcpu, int timer_advance_ns) vcpu->arch.apic = apic; - apic->regs = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); + if (kvm_x86_ops.alloc_apic_backing_page) + apic->regs = static_call(kvm_x86_alloc_apic_backing_page)(vcpu); + else + apic->regs = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); if (!apic->regs) { printk(KERN_ERR "malloc apic regs error for vcpu %x\n", vcpu->vcpu_id); diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index dee62362a360..55b9a6d96bcf 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -1181,7 +1181,7 @@ int svm_allocate_nested(struct vcpu_svm *svm) if (svm->nested.initialized) return 0; - vmcb02_page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO); + vmcb02_page = snp_safe_alloc_page(&svm->vcpu); if (!vmcb02_page) return -ENOMEM; svm->nested.vmcb02.ptr = page_address(vmcb02_page); diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index f760106c31f8..f99435b6648f 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -246,6 +246,7 @@ static void sev_unbind_asid(struct kvm *kvm, unsigned int handle) static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp) { struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct sev_platform_init_args init_args = {0}; int asid, ret; if (kvm->created_vcpus) @@ -262,7 +263,8 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp) goto e_no_asid; sev->asid = asid; - ret = sev_platform_init(&argp->error); + init_args.probe = false; + ret = sev_platform_init(&init_args); if (ret) goto e_free; @@ -274,6 +276,7 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp) return 0; e_free: + argp->error = init_args.error; sev_asid_free(sev); sev->asid = 0; e_no_asid: @@ -3160,3 +3163,35 @@ void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector) ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, 1); } + +struct page *snp_safe_alloc_page(struct kvm_vcpu *vcpu) +{ + unsigned long pfn; + struct page *p; + + if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + return alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO); + + /* + * Allocate an SNP-safe page to workaround the SNP erratum where + * the CPU will incorrectly signal an RMP violation #PF if a + * hugepage (2MB or 1GB) collides with the RMP entry of a + * 2MB-aligned VMCB, VMSA, or AVIC backing page. + * + * Allocate one extra page, choose a page which is not + * 2MB-aligned, and free the other. + */ + p = alloc_pages(GFP_KERNEL_ACCOUNT | __GFP_ZERO, 1); + if (!p) + return NULL; + + split_page(p, 1); + + pfn = page_to_pfn(p); + if (IS_ALIGNED(pfn, PTRS_PER_PMD)) + __free_page(p++); + else + __free_page(p + 1); + + return p; +} diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index e90b429c84f1..8284105bf704 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -703,7 +703,7 @@ static int svm_cpu_init(int cpu) int ret = -ENOMEM; memset(sd, 0, sizeof(struct svm_cpu_data)); - sd->save_area = alloc_page(GFP_KERNEL | __GFP_ZERO); + sd->save_area = snp_safe_alloc_page(NULL); if (!sd->save_area) return ret; @@ -1421,7 +1421,7 @@ static int svm_vcpu_create(struct kvm_vcpu *vcpu) svm = to_svm(vcpu); err = -ENOMEM; - vmcb01_page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO); + vmcb01_page = snp_safe_alloc_page(vcpu); if (!vmcb01_page) goto out; @@ -1430,7 +1430,7 @@ static int svm_vcpu_create(struct kvm_vcpu *vcpu) * SEV-ES guests require a separate VMSA page used to contain * the encrypted register state of the guest. */ - vmsa_page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO); + vmsa_page = snp_safe_alloc_page(vcpu); if (!vmsa_page) goto error_free_vmcb_page; @@ -4900,6 +4900,16 @@ static int svm_vm_init(struct kvm *kvm) return 0; } +static void *svm_alloc_apic_backing_page(struct kvm_vcpu *vcpu) +{ + struct page *page = snp_safe_alloc_page(vcpu); + + if (!page) + return NULL; + + return page_address(page); +} + static struct kvm_x86_ops svm_x86_ops __initdata = { .name = KBUILD_MODNAME, @@ -5031,6 +5041,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = { .vcpu_deliver_sipi_vector = svm_vcpu_deliver_sipi_vector, .vcpu_get_apicv_inhibit_reasons = avic_vcpu_get_apicv_inhibit_reasons, + .alloc_apic_backing_page = svm_alloc_apic_backing_page, }; /* diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 8ef95139cd24..7f1fbd874c45 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -694,6 +694,7 @@ void sev_es_vcpu_reset(struct vcpu_svm *svm); void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector); void sev_es_prepare_switch_to_guest(struct sev_es_save_area *hostsa); void sev_es_unmap_ghcb(struct vcpu_svm *svm); +struct page *snp_safe_alloc_page(struct kvm_vcpu *vcpu); /* vmenter.S */ diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index d6375b3c633b..8224567abdb6 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -34,6 +34,7 @@ #include <asm/kvm_para.h> /* kvm_handle_async_pf */ #include <asm/vdso.h> /* fixup_vdso_exception() */ #include <asm/irq_stack.h> +#include <asm/sev.h> /* snp_dump_hva_rmpentry() */ #define CREATE_TRACE_POINTS #include <asm/trace/exceptions.h> @@ -547,6 +548,7 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code, unsigned long ad !(error_code & X86_PF_PROT) ? "not-present page" : (error_code & X86_PF_RSVD) ? "reserved bit violation" : (error_code & X86_PF_PK) ? "protection keys violation" : + (error_code & X86_PF_RMP) ? "RMP violation" : "permissions violation"); if (!(error_code & X86_PF_USER) && user_mode(regs)) { @@ -579,6 +581,9 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code, unsigned long ad } dump_pagetable(address); + + if (error_code & X86_PF_RMP) + snp_dump_hva_rmpentry(address); } static noinline void diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c index c290c55b632b..d035bce3a2b0 100644 --- a/arch/x86/mm/mem_encrypt.c +++ b/arch/x86/mm/mem_encrypt.c @@ -42,38 +42,42 @@ bool force_dma_unencrypted(struct device *dev) static void print_mem_encrypt_feature_info(void) { - pr_info("Memory Encryption Features active:"); + pr_info("Memory Encryption Features active: "); - if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) { - pr_cont(" Intel TDX\n"); - return; - } - - pr_cont(" AMD"); + switch (cc_vendor) { + case CC_VENDOR_INTEL: + pr_cont("Intel TDX\n"); + break; + case CC_VENDOR_AMD: + pr_cont("AMD"); - /* Secure Memory Encryption */ - if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) { + /* Secure Memory Encryption */ + if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) { /* * SME is mutually exclusive with any of the SEV * features below. - */ - pr_cont(" SME\n"); - return; + */ + pr_cont(" SME\n"); + return; + } + + /* Secure Encrypted Virtualization */ + if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) + pr_cont(" SEV"); + + /* Encrypted Register State */ + if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT)) + pr_cont(" SEV-ES"); + + /* Secure Nested Paging */ + if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) + pr_cont(" SEV-SNP"); + + pr_cont("\n"); + break; + default: + pr_cont("Unknown\n"); } - - /* Secure Encrypted Virtualization */ - if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) - pr_cont(" SEV"); - - /* Encrypted Register State */ - if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT)) - pr_cont(" SEV-ES"); - - /* Secure Nested Paging */ - if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) - pr_cont(" SEV-SNP"); - - pr_cont("\n"); } /* Architecture __weak replacement functions */ diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c index d73aeb16417f..0166ab1780cc 100644 --- a/arch/x86/mm/mem_encrypt_identity.c +++ b/arch/x86/mm/mem_encrypt_identity.c @@ -97,7 +97,6 @@ static char sme_workarea[2 * PMD_SIZE] __section(".init.scratch"); static char sme_cmdline_arg[] __initdata = "mem_encrypt"; static char sme_cmdline_on[] __initdata = "on"; -static char sme_cmdline_off[] __initdata = "off"; static void __init sme_clear_pgd(struct sme_populate_pgd_data *ppd) { @@ -305,7 +304,8 @@ void __init sme_encrypt_kernel(struct boot_params *bp) * instrumentation or checking boot_cpu_data in the cc_platform_has() * function. */ - if (!sme_get_me_mask() || sev_status & MSR_AMD64_SEV_ENABLED) + if (!sme_get_me_mask() || + RIP_REL_REF(sev_status) & MSR_AMD64_SEV_ENABLED) return; /* @@ -504,10 +504,9 @@ void __init sme_encrypt_kernel(struct boot_params *bp) void __init sme_enable(struct boot_params *bp) { - const char *cmdline_ptr, *cmdline_arg, *cmdline_on, *cmdline_off; + const char *cmdline_ptr, *cmdline_arg, *cmdline_on; unsigned int eax, ebx, ecx, edx; unsigned long feature_mask; - bool active_by_default; unsigned long me_mask; char buffer[16]; bool snp; @@ -543,11 +542,11 @@ void __init sme_enable(struct boot_params *bp) me_mask = 1UL << (ebx & 0x3f); /* Check the SEV MSR whether SEV or SME is enabled */ - sev_status = __rdmsr(MSR_AMD64_SEV); - feature_mask = (sev_status & MSR_AMD64_SEV_ENABLED) ? AMD_SEV_BIT : AMD_SME_BIT; + RIP_REL_REF(sev_status) = msr = __rdmsr(MSR_AMD64_SEV); + feature_mask = (msr & MSR_AMD64_SEV_ENABLED) ? AMD_SEV_BIT : AMD_SME_BIT; /* The SEV-SNP CC blob should never be present unless SEV-SNP is enabled. */ - if (snp && !(sev_status & MSR_AMD64_SEV_SNP_ENABLED)) + if (snp && !(msr & MSR_AMD64_SEV_SNP_ENABLED)) snp_abort(); /* Check if memory encryption is enabled */ @@ -573,7 +572,6 @@ void __init sme_enable(struct boot_params *bp) return; } else { /* SEV state cannot be controlled by a command line option */ - sme_me_mask = me_mask; goto out; } @@ -588,31 +586,17 @@ void __init sme_enable(struct boot_params *bp) asm ("lea sme_cmdline_on(%%rip), %0" : "=r" (cmdline_on) : "p" (sme_cmdline_on)); - asm ("lea sme_cmdline_off(%%rip), %0" - : "=r" (cmdline_off) - : "p" (sme_cmdline_off)); - - if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT)) - active_by_default = true; - else - active_by_default = false; cmdline_ptr = (const char *)((u64)bp->hdr.cmd_line_ptr | ((u64)bp->ext_cmd_line_ptr << 32)); - if (cmdline_find_option(cmdline_ptr, cmdline_arg, buffer, sizeof(buffer)) < 0) + if (cmdline_find_option(cmdline_ptr, cmdline_arg, buffer, sizeof(buffer)) < 0 || + strncmp(buffer, cmdline_on, sizeof(buffer))) return; - if (!strncmp(buffer, cmdline_on, sizeof(buffer))) - sme_me_mask = me_mask; - else if (!strncmp(buffer, cmdline_off, sizeof(buffer))) - sme_me_mask = 0; - else - sme_me_mask = active_by_default ? me_mask : 0; out: - if (sme_me_mask) { - physical_mask &= ~sme_me_mask; - cc_vendor = CC_VENDOR_AMD; - cc_set_mask(sme_me_mask); - } + RIP_REL_REF(sme_me_mask) = me_mask; + physical_mask &= ~me_mask; + cc_vendor = CC_VENDOR_AMD; + cc_set_mask(me_mask); } diff --git a/arch/x86/virt/svm/Makefile b/arch/x86/virt/svm/Makefile new file mode 100644 index 000000000000..ef2a31bdcc70 --- /dev/null +++ b/arch/x86/virt/svm/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0 + +obj-$(CONFIG_KVM_AMD_SEV) += sev.o diff --git a/arch/x86/virt/svm/sev.c b/arch/x86/virt/svm/sev.c new file mode 100644 index 000000000000..cffe1157a90a --- /dev/null +++ b/arch/x86/virt/svm/sev.c @@ -0,0 +1,560 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AMD SVM-SEV Host Support. + * + * Copyright (C) 2023 Advanced Micro Devices, Inc. + * + * Author: Ashish Kalra <ashish.kalra@amd.com> + * + */ + +#include <linux/cc_platform.h> +#include <linux/printk.h> +#include <linux/mm_types.h> +#include <linux/set_memory.h> +#include <linux/memblock.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/cpumask.h> +#include <linux/iommu.h> +#include <linux/amd-iommu.h> + +#include <asm/sev.h> +#include <asm/processor.h> +#include <asm/setup.h> +#include <asm/svm.h> +#include <asm/smp.h> +#include <asm/cpu.h> +#include <asm/apic.h> +#include <asm/cpuid.h> +#include <asm/cmdline.h> +#include <asm/iommu.h> + +/* + * The RMP entry format is not architectural. The format is defined in PPR + * Family 19h Model 01h, Rev B1 processor. + */ +struct rmpentry { + union { + struct { + u64 assigned : 1, + pagesize : 1, + immutable : 1, + rsvd1 : 9, + gpa : 39, + asid : 10, + vmsa : 1, + validated : 1, + rsvd2 : 1; + }; + u64 lo; + }; + u64 hi; +} __packed; + +/* + * The first 16KB from the RMP_BASE is used by the processor for the + * bookkeeping, the range needs to be added during the RMP entry lookup. + */ +#define RMPTABLE_CPU_BOOKKEEPING_SZ 0x4000 + +/* Mask to apply to a PFN to get the first PFN of a 2MB page */ +#define PFN_PMD_MASK GENMASK_ULL(63, PMD_SHIFT - PAGE_SHIFT) + +static u64 probed_rmp_base, probed_rmp_size; +static struct rmpentry *rmptable __ro_after_init; +static u64 rmptable_max_pfn __ro_after_init; + +static LIST_HEAD(snp_leaked_pages_list); +static DEFINE_SPINLOCK(snp_leaked_pages_list_lock); + +static unsigned long snp_nr_leaked_pages; + +#undef pr_fmt +#define pr_fmt(fmt) "SEV-SNP: " fmt + +static int __mfd_enable(unsigned int cpu) +{ + u64 val; + + if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + return 0; + + rdmsrl(MSR_AMD64_SYSCFG, val); + + val |= MSR_AMD64_SYSCFG_MFDM; + + wrmsrl(MSR_AMD64_SYSCFG, val); + + return 0; +} + +static __init void mfd_enable(void *arg) +{ + __mfd_enable(smp_processor_id()); +} + +static int __snp_enable(unsigned int cpu) +{ + u64 val; + + if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + return 0; + + rdmsrl(MSR_AMD64_SYSCFG, val); + + val |= MSR_AMD64_SYSCFG_SNP_EN; + val |= MSR_AMD64_SYSCFG_SNP_VMPL_EN; + + wrmsrl(MSR_AMD64_SYSCFG, val); + + return 0; +} + +static __init void snp_enable(void *arg) +{ + __snp_enable(smp_processor_id()); +} + +#define RMP_ADDR_MASK GENMASK_ULL(51, 13) + +bool snp_probe_rmptable_info(void) +{ + u64 max_rmp_pfn, calc_rmp_sz, rmp_sz, rmp_base, rmp_end; + + rdmsrl(MSR_AMD64_RMP_BASE, rmp_base); + rdmsrl(MSR_AMD64_RMP_END, rmp_end); + + if (!(rmp_base & RMP_ADDR_MASK) || !(rmp_end & RMP_ADDR_MASK)) { + pr_err("Memory for the RMP table has not been reserved by BIOS\n"); + return false; + } + + if (rmp_base > rmp_end) { + pr_err("RMP configuration not valid: base=%#llx, end=%#llx\n", rmp_base, rmp_end); + return false; + } + + rmp_sz = rmp_end - rmp_base + 1; + + /* + * Calculate the amount the memory that must be reserved by the BIOS to + * address the whole RAM, including the bookkeeping area. The RMP itself + * must also be covered. + */ + max_rmp_pfn = max_pfn; + if (PHYS_PFN(rmp_end) > max_pfn) + max_rmp_pfn = PHYS_PFN(rmp_end); + + calc_rmp_sz = (max_rmp_pfn << 4) + RMPTABLE_CPU_BOOKKEEPING_SZ; + + if (calc_rmp_sz > rmp_sz) { + pr_err("Memory reserved for the RMP table does not cover full system RAM (expected 0x%llx got 0x%llx)\n", + calc_rmp_sz, rmp_sz); + return false; + } + + probed_rmp_base = rmp_base; + probed_rmp_size = rmp_sz; + + pr_info("RMP table physical range [0x%016llx - 0x%016llx]\n", + probed_rmp_base, probed_rmp_base + probed_rmp_size - 1); + + return true; +} + +/* + * Do the necessary preparations which are verified by the firmware as + * described in the SNP_INIT_EX firmware command description in the SNP + * firmware ABI spec. + */ +static int __init snp_rmptable_init(void) +{ + void *rmptable_start; + u64 rmptable_size; + u64 val; + + if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + return 0; + + if (!amd_iommu_snp_en) + return 0; + + if (!probed_rmp_size) + goto nosnp; + + rmptable_start = memremap(probed_rmp_base, probed_rmp_size, MEMREMAP_WB); + if (!rmptable_start) { + pr_err("Failed to map RMP table\n"); + return 1; + } + + /* + * Check if SEV-SNP is already enabled, this can happen in case of + * kexec boot. + */ + rdmsrl(MSR_AMD64_SYSCFG, val); + if (val & MSR_AMD64_SYSCFG_SNP_EN) + goto skip_enable; + + memset(rmptable_start, 0, probed_rmp_size); + + /* Flush the caches to ensure that data is written before SNP is enabled. */ + wbinvd_on_all_cpus(); + + /* MtrrFixDramModEn must be enabled on all the CPUs prior to enabling SNP. */ + on_each_cpu(mfd_enable, NULL, 1); + + on_each_cpu(snp_enable, NULL, 1); + +skip_enable: + rmptable_start += RMPTABLE_CPU_BOOKKEEPING_SZ; + rmptable_size = probed_rmp_size - RMPTABLE_CPU_BOOKKEEPING_SZ; + + rmptable = (struct rmpentry *)rmptable_start; + rmptable_max_pfn = rmptable_size / sizeof(struct rmpentry) - 1; + + cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/rmptable_init:online", __snp_enable, NULL); + + /* + * Setting crash_kexec_post_notifiers to 'true' to ensure that SNP panic + * notifier is invoked to do SNP IOMMU shutdown before kdump. + */ + crash_kexec_post_notifiers = true; + + return 0; + +nosnp: + setup_clear_cpu_cap(X86_FEATURE_SEV_SNP); + return -ENOSYS; +} + +/* + * This must be called after the IOMMU has been initialized. + */ +device_initcall(snp_rmptable_init); + +static struct rmpentry *get_rmpentry(u64 pfn) +{ + if (WARN_ON_ONCE(pfn > rmptable_max_pfn)) + return ERR_PTR(-EFAULT); + + return &rmptable[pfn]; +} + +static struct rmpentry *__snp_lookup_rmpentry(u64 pfn, int *level) +{ + struct rmpentry *large_entry, *entry; + + if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + return ERR_PTR(-ENODEV); + + entry = get_rmpentry(pfn); + if (IS_ERR(entry)) + return entry; + + /* + * Find the authoritative RMP entry for a PFN. This can be either a 4K + * RMP entry or a special large RMP entry that is authoritative for a + * whole 2M area. + */ + large_entry = get_rmpentry(pfn & PFN_PMD_MASK); + if (IS_ERR(large_entry)) + return large_entry; + + *level = RMP_TO_PG_LEVEL(large_entry->pagesize); + + return entry; +} + +int snp_lookup_rmpentry(u64 pfn, bool *assigned, int *level) +{ + struct rmpentry *e; + + e = __snp_lookup_rmpentry(pfn, level); + if (IS_ERR(e)) + return PTR_ERR(e); + + *assigned = !!e->assigned; + return 0; +} +EXPORT_SYMBOL_GPL(snp_lookup_rmpentry); + +/* + * Dump the raw RMP entry for a particular PFN. These bits are documented in the + * PPR for a particular CPU model and provide useful information about how a + * particular PFN is being utilized by the kernel/firmware at the time certain + * unexpected events occur, such as RMP faults. + */ +static void dump_rmpentry(u64 pfn) +{ + u64 pfn_i, pfn_end; + struct rmpentry *e; + int level; + + e = __snp_lookup_rmpentry(pfn, &level); + if (IS_ERR(e)) { + pr_err("Failed to read RMP entry for PFN 0x%llx, error %ld\n", + pfn, PTR_ERR(e)); + return; + } + + if (e->assigned) { + pr_info("PFN 0x%llx, RMP entry: [0x%016llx - 0x%016llx]\n", + pfn, e->lo, e->hi); + return; + } + + /* + * If the RMP entry for a particular PFN is not in an assigned state, + * then it is sometimes useful to get an idea of whether or not any RMP + * entries for other PFNs within the same 2MB region are assigned, since + * those too can affect the ability to access a particular PFN in + * certain situations, such as when the PFN is being accessed via a 2MB + * mapping in the host page table. + */ + pfn_i = ALIGN_DOWN(pfn, PTRS_PER_PMD); + pfn_end = pfn_i + PTRS_PER_PMD; + + pr_info("PFN 0x%llx unassigned, dumping non-zero entries in 2M PFN region: [0x%llx - 0x%llx]\n", + pfn, pfn_i, pfn_end); + + while (pfn_i < pfn_end) { + e = __snp_lookup_rmpentry(pfn_i, &level); + if (IS_ERR(e)) { + pr_err("Error %ld reading RMP entry for PFN 0x%llx\n", + PTR_ERR(e), pfn_i); + pfn_i++; + continue; + } + + if (e->lo || e->hi) + pr_info("PFN: 0x%llx, [0x%016llx - 0x%016llx]\n", pfn_i, e->lo, e->hi); + pfn_i++; + } +} + +void snp_dump_hva_rmpentry(unsigned long hva) +{ + unsigned long paddr; + unsigned int level; + pgd_t *pgd; + pte_t *pte; + + pgd = __va(read_cr3_pa()); + pgd += pgd_index(hva); + pte = lookup_address_in_pgd(pgd, hva, &level); + + if (!pte) { + pr_err("Can't dump RMP entry for HVA %lx: no PTE/PFN found\n", hva); + return; + } + + paddr = PFN_PHYS(pte_pfn(*pte)) | (hva & ~page_level_mask(level)); + dump_rmpentry(PHYS_PFN(paddr)); +} + +/* + * PSMASH a 2MB aligned page into 4K pages in the RMP table while preserving the + * Validated bit. + */ +int psmash(u64 pfn) +{ + unsigned long paddr = pfn << PAGE_SHIFT; + int ret; + + if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + return -ENODEV; + + if (!pfn_valid(pfn)) + return -EINVAL; + + /* Binutils version 2.36 supports the PSMASH mnemonic. */ + asm volatile(".byte 0xF3, 0x0F, 0x01, 0xFF" + : "=a" (ret) + : "a" (paddr) + : "memory", "cc"); + + return ret; +} +EXPORT_SYMBOL_GPL(psmash); + +/* + * If the kernel uses a 2MB or larger directmap mapping to write to an address, + * and that mapping contains any 4KB pages that are set to private in the RMP + * table, an RMP #PF will trigger and cause a host crash. Hypervisor code that + * owns the PFNs being transitioned will never attempt such a write, but other + * kernel tasks writing to other PFNs in the range may trigger these checks + * inadvertently due a large directmap mapping that happens to overlap such a + * PFN. + * + * Prevent this by splitting any 2MB+ mappings that might end up containing a + * mix of private/shared PFNs as a result of a subsequent RMPUPDATE for the + * PFN/rmp_level passed in. + * + * Note that there is no attempt here to scan all the RMP entries for the 2MB + * physical range, since it would only be worthwhile in determining if a + * subsequent RMPUPDATE for a 4KB PFN would result in all the entries being of + * the same shared/private state, thus avoiding the need to split the mapping. + * But that would mean the entries are currently in a mixed state, and so the + * mapping would have already been split as a result of prior transitions. + * And since the 4K split is only done if the mapping is 2MB+, and there isn't + * currently a mechanism in place to restore 2MB+ mappings, such a check would + * not provide any usable benefit. + * + * More specifics on how these checks are carried out can be found in APM + * Volume 2, "RMP and VMPL Access Checks". + */ +static int adjust_direct_map(u64 pfn, int rmp_level) +{ + unsigned long vaddr; + unsigned int level; + int npages, ret; + pte_t *pte; + + /* + * pfn_to_kaddr() will return a vaddr only within the direct + * map range. + */ + vaddr = (unsigned long)pfn_to_kaddr(pfn); + + /* Only 4KB/2MB RMP entries are supported by current hardware. */ + if (WARN_ON_ONCE(rmp_level > PG_LEVEL_2M)) + return -EINVAL; + + if (!pfn_valid(pfn)) + return -EINVAL; + + if (rmp_level == PG_LEVEL_2M && + (!IS_ALIGNED(pfn, PTRS_PER_PMD) || !pfn_valid(pfn + PTRS_PER_PMD - 1))) + return -EINVAL; + + /* + * If an entire 2MB physical range is being transitioned, then there is + * no risk of RMP #PFs due to write accesses from overlapping mappings, + * since even accesses from 1GB mappings will be treated as 2MB accesses + * as far as RMP table checks are concerned. + */ + if (rmp_level == PG_LEVEL_2M) + return 0; + + pte = lookup_address(vaddr, &level); + if (!pte || pte_none(*pte)) + return 0; + + if (level == PG_LEVEL_4K) + return 0; + + npages = page_level_size(rmp_level) / PAGE_SIZE; + ret = set_memory_4k(vaddr, npages); + if (ret) + pr_warn("Failed to split direct map for PFN 0x%llx, ret: %d\n", + pfn, ret); + + return ret; +} + +/* + * It is expected that those operations are seldom enough so that no mutual + * exclusion of updaters is needed and thus the overlap error condition below + * should happen very rarely and would get resolved relatively quickly by + * the firmware. + * + * If not, one could consider introducing a mutex or so here to sync concurrent + * RMP updates and thus diminish the amount of cases where firmware needs to + * lock 2M ranges to protect against concurrent updates. + * + * The optimal solution would be range locking to avoid locking disjoint + * regions unnecessarily but there's no support for that yet. + */ +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)) + return -ENODEV; + + level = RMP_TO_PG_LEVEL(state->pagesize); + + if (adjust_direct_map(pfn, level)) + return -EFAULT; + + do { + /* Binutils version 2.36 supports the RMPUPDATE mnemonic. */ + asm volatile(".byte 0xF2, 0x0F, 0x01, 0xFE" + : "=a" (ret) + : "a" (paddr), "c" ((unsigned long)state) + : "memory", "cc"); + } while (ret == RMPUPDATE_FAIL_OVERLAP); + + if (ret) { + pr_err("RMPUPDATE failed for PFN %llx, pg_level: %d, ret: %d\n", + pfn, level, ret); + dump_rmpentry(pfn); + dump_stack(); + return -EFAULT; + } + + return 0; +} + +/* Transition a page to guest-owned/private state in the RMP table. */ +int rmp_make_private(u64 pfn, u64 gpa, enum pg_level level, u32 asid, bool immutable) +{ + struct rmp_state state; + + memset(&state, 0, sizeof(state)); + state.assigned = 1; + state.asid = asid; + state.immutable = immutable; + state.gpa = gpa; + state.pagesize = PG_LEVEL_TO_RMP(level); + + return rmpupdate(pfn, &state); +} +EXPORT_SYMBOL_GPL(rmp_make_private); + +/* Transition a page to hypervisor-owned/shared state in the RMP table. */ +int rmp_make_shared(u64 pfn, enum pg_level level) +{ + struct rmp_state state; + + memset(&state, 0, sizeof(state)); + state.pagesize = PG_LEVEL_TO_RMP(level); + + return rmpupdate(pfn, &state); +} +EXPORT_SYMBOL_GPL(rmp_make_shared); + +void snp_leak_pages(u64 pfn, unsigned int npages) +{ + struct page *page = pfn_to_page(pfn); + + pr_warn("Leaking PFN range 0x%llx-0x%llx\n", pfn, pfn + npages); + + spin_lock(&snp_leaked_pages_list_lock); + while (npages--) { + + /* + * Reuse the page's buddy list for chaining into the leaked + * pages list. This page should not be on a free list currently + * and is also unsafe to be added to a free list. + */ + if (likely(!PageCompound(page)) || + + /* + * Skip inserting tail pages of compound page as + * page->buddy_list of tail pages is not usable. + */ + (PageHead(page) && compound_nr(page) <= npages)) + list_add_tail(&page->buddy_list, &snp_leaked_pages_list); + + dump_rmpentry(pfn); + snp_nr_leaked_pages++; + pfn++; + page++; + } + spin_unlock(&snp_leaked_pages_list_lock); +} +EXPORT_SYMBOL_GPL(snp_leak_pages); |