diff options
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/Makefile | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/head64.c | 29 | ||||
| -rw-r--r-- | arch/x86/kernel/head_64.S | 37 | ||||
| -rw-r--r-- | arch/x86/kernel/probe_roms.c | 13 | ||||
| -rw-r--r-- | arch/x86/kernel/sev-shared.c | 534 | ||||
| -rw-r--r-- | arch/x86/kernel/sev.c | 855 | ||||
| -rw-r--r-- | arch/x86/kernel/smpboot.c | 3 |
8 files changed, 1404 insertions, 73 deletions
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index c41ef42adbe8..1a2dc328cb5e 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -46,8 +46,6 @@ endif # non-deterministic coverage. KCOV_INSTRUMENT := n -CFLAGS_head$(BITS).o += -fno-stack-protector - CFLAGS_irq.o := -I $(srctree)/$(src)/../include/asm/trace obj-y := process_$(BITS).o signal.o diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index e342ae4db3c4..f0baf1b7522e 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -60,6 +60,7 @@ #include <asm/uv/uv.h> #include <asm/sigframe.h> #include <asm/traps.h> +#include <asm/sev.h> #include "cpu.h" @@ -2126,6 +2127,9 @@ void cpu_init_exception_handling(void) load_TR_desc(); + /* GHCB needs to be setup to handle #VC. */ + setup_ghcb(); + /* Finally load the IDT */ load_current_idt(); } diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 4f5ecbbaae77..c185f4831498 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -143,7 +143,20 @@ static unsigned long __head sme_postprocess_startup(struct boot_params *bp, pmdv if (sme_get_me_mask()) { vaddr = (unsigned long)__start_bss_decrypted; vaddr_end = (unsigned long)__end_bss_decrypted; + for (; vaddr < vaddr_end; vaddr += PMD_SIZE) { + /* + * On SNP, transition the page to shared in the RMP table so that + * it is consistent with the page table attribute change. + * + * __start_bss_decrypted has a virtual address in the high range + * mapping (kernel .text). PVALIDATE, by way of + * early_snp_set_memory_shared(), requires a valid virtual + * address but the kernel is currently running off of the identity + * mapping so use __pa() to get a *currently* valid virtual address. + */ + early_snp_set_memory_shared(__pa(vaddr), __pa(vaddr), PTRS_PER_PMD); + i = pmd_index(vaddr); pmd[i] -= sme_get_me_mask(); } @@ -192,9 +205,6 @@ unsigned long __head __startup_64(unsigned long physaddr, if (load_delta & ~PMD_PAGE_MASK) for (;;); - /* Activate Secure Memory Encryption (SME) if supported and enabled */ - sme_enable(bp); - /* Include the SME encryption mask in the fixup value */ load_delta += sme_get_me_mask(); @@ -308,15 +318,6 @@ unsigned long __head __startup_64(unsigned long physaddr, return sme_postprocess_startup(bp, pmd); } -unsigned long __startup_secondary_64(void) -{ - /* - * Return the SME encryption mask (if SME is active) to be used as a - * modifier for the initial pgdir entry programmed into CR3. - */ - return sme_get_me_mask(); -} - /* Wipe all early page tables except for the kernel symbol map */ static void __init reset_early_page_tables(void) { @@ -600,8 +601,10 @@ static void startup_64_load_idt(unsigned long physbase) void early_setup_idt(void) { /* VMM Communication Exception */ - if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) + if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) { + setup_ghcb(); set_bringup_idt_handler(bringup_idt_table, X86_TRAP_VC, vc_boot_ghcb); + } bringup_idt_descr.address = (unsigned long)bringup_idt_table; native_load_idt(&bringup_idt_descr); diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index b8e3019547a5..7bac9a4bdf7c 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -65,10 +65,39 @@ SYM_CODE_START_NOALIGN(startup_64) leaq (__end_init_task - FRAME_SIZE)(%rip), %rsp leaq _text(%rip), %rdi + + /* + * initial_gs points to initial fixed_percpu_data struct with storage for + * the stack protector canary. Global pointer fixups are needed at this + * stage, so apply them as is done in fixup_pointer(), and initialize %gs + * such that the canary can be accessed at %gs:40 for subsequent C calls. + */ + movl $MSR_GS_BASE, %ecx + movq initial_gs(%rip), %rax + movq $_text, %rdx + subq %rdx, %rax + addq %rdi, %rax + movq %rax, %rdx + shrq $32, %rdx + wrmsr + pushq %rsi call startup_64_setup_env popq %rsi +#ifdef CONFIG_AMD_MEM_ENCRYPT + /* + * Activate SEV/SME memory encryption if supported/enabled. This needs to + * be done now, since this also includes setup of the SEV-SNP CPUID table, + * which needs to be done before any CPUID instructions are executed in + * subsequent code. + */ + movq %rsi, %rdi + pushq %rsi + call sme_enable + popq %rsi +#endif + /* Now switch to __KERNEL_CS so IRET works reliably */ pushq $__KERNEL_CS leaq .Lon_kernel_cs(%rip), %rax @@ -134,9 +163,11 @@ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL) * Retrieve the modifier (SME encryption mask if SME is active) to be * added to the initial pgdir entry that will be programmed into CR3. */ - pushq %rsi - call __startup_secondary_64 - popq %rsi +#ifdef CONFIG_AMD_MEM_ENCRYPT + movq sme_me_mask, %rax +#else + xorq %rax, %rax +#endif /* Form the CR3 value being sure to include the CR3 modifier */ addq $(init_top_pgt - __START_KERNEL_map), %rax diff --git a/arch/x86/kernel/probe_roms.c b/arch/x86/kernel/probe_roms.c index 36e84d904260..319fef37d9dc 100644 --- a/arch/x86/kernel/probe_roms.c +++ b/arch/x86/kernel/probe_roms.c @@ -21,6 +21,7 @@ #include <asm/sections.h> #include <asm/io.h> #include <asm/setup_arch.h> +#include <asm/sev.h> static struct resource system_rom_resource = { .name = "System ROM", @@ -197,11 +198,21 @@ static int __init romchecksum(const unsigned char *rom, unsigned long length) void __init probe_roms(void) { - const unsigned char *rom; unsigned long start, length, upper; + const unsigned char *rom; unsigned char c; int i; + /* + * The ROM memory range is not part of the e820 table and is therefore not + * pre-validated by BIOS. The kernel page table maps the ROM region as encrypted + * memory, and SNP requires encrypted memory to be validated before access. + * Do that here. + */ + snp_prep_memory(video_rom_resource.start, + ((system_rom_resource.end + 1) - video_rom_resource.start), + SNP_PAGE_STATE_PRIVATE); + /* video rom */ upper = adapter_rom_resources[0].start; for (start = video_rom_resource.start; start < upper; start += 2048) { diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c index ce987688bbc0..b478edf43bec 100644 --- a/arch/x86/kernel/sev-shared.c +++ b/arch/x86/kernel/sev-shared.c @@ -14,6 +14,68 @@ #define has_cpuflag(f) boot_cpu_has(f) #endif +/* I/O parameters for CPUID-related helpers */ +struct cpuid_leaf { + u32 fn; + u32 subfn; + u32 eax; + u32 ebx; + u32 ecx; + u32 edx; +}; + +/* + * Individual entries of the SNP CPUID table, as defined by the SNP + * Firmware ABI, Revision 0.9, Section 7.1, Table 14. + */ +struct snp_cpuid_fn { + u32 eax_in; + u32 ecx_in; + u64 xcr0_in; + u64 xss_in; + u32 eax; + u32 ebx; + u32 ecx; + u32 edx; + u64 __reserved; +} __packed; + +/* + * SNP CPUID table, as defined by the SNP Firmware ABI, Revision 0.9, + * Section 8.14.2.6. Also noted there is the SNP firmware-enforced limit + * of 64 entries per CPUID table. + */ +#define SNP_CPUID_COUNT_MAX 64 + +struct snp_cpuid_table { + u32 count; + u32 __reserved1; + u64 __reserved2; + struct snp_cpuid_fn fn[SNP_CPUID_COUNT_MAX]; +} __packed; + +/* + * Since feature negotiation related variables are set early in the boot + * process they must reside in the .data section so as not to be zeroed + * out when the .bss section is later cleared. + * + * GHCB protocol version negotiated with the hypervisor. + */ +static u16 ghcb_version __ro_after_init; + +/* Copy of the SNP firmware's CPUID page. */ +static struct snp_cpuid_table cpuid_table_copy __ro_after_init; + +/* + * These will be initialized based on CPUID table so that non-present + * all-zero leaves (for sparse tables) can be differentiated from + * invalid/out-of-range leaves. This is needed since all-zero leaves + * still need to be post-processed. + */ +static u32 cpuid_std_range_max __ro_after_init; +static u32 cpuid_hyp_range_max __ro_after_init; +static u32 cpuid_ext_range_max __ro_after_init; + static bool __init sev_es_check_cpu_features(void) { if (!has_cpuflag(X86_FEATURE_RDRAND)) { @@ -24,15 +86,12 @@ static bool __init sev_es_check_cpu_features(void) return true; } -static void __noreturn sev_es_terminate(unsigned int reason) +static void __noreturn sev_es_terminate(unsigned int set, unsigned int reason) { u64 val = GHCB_MSR_TERM_REQ; - /* - * Tell the hypervisor what went wrong - only reason-set 0 is - * currently supported. - */ - val |= GHCB_SEV_TERM_REASON(0, reason); + /* Tell the hypervisor what went wrong. */ + val |= GHCB_SEV_TERM_REASON(set, reason); /* Request Guest Termination from Hypvervisor */ sev_es_wr_ghcb_msr(val); @@ -42,6 +101,42 @@ static void __noreturn sev_es_terminate(unsigned int reason) asm volatile("hlt\n" : : : "memory"); } +/* + * The hypervisor features are available from GHCB version 2 onward. + */ +static u64 get_hv_features(void) +{ + u64 val; + + if (ghcb_version < 2) + return 0; + + sev_es_wr_ghcb_msr(GHCB_MSR_HV_FT_REQ); + VMGEXIT(); + + val = sev_es_rd_ghcb_msr(); + if (GHCB_RESP_CODE(val) != GHCB_MSR_HV_FT_RESP) + return 0; + + return GHCB_MSR_HV_FT_RESP_VAL(val); +} + +static void snp_register_ghcb_early(unsigned long paddr) +{ + unsigned long pfn = paddr >> PAGE_SHIFT; + u64 val; + + sev_es_wr_ghcb_msr(GHCB_MSR_REG_GPA_REQ_VAL(pfn)); + VMGEXIT(); + + val = sev_es_rd_ghcb_msr(); + + /* If the response GPA is not ours then abort the guest */ + if ((GHCB_RESP_CODE(val) != GHCB_MSR_REG_GPA_RESP) || + (GHCB_MSR_REG_GPA_RESP_VAL(val) != pfn)) + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_REGISTER); +} + static bool sev_es_negotiate_protocol(void) { u64 val; @@ -54,10 +149,12 @@ static bool sev_es_negotiate_protocol(void) if (GHCB_MSR_INFO(val) != GHCB_MSR_SEV_INFO_RESP) return false; - if (GHCB_MSR_PROTO_MAX(val) < GHCB_PROTO_OUR || - GHCB_MSR_PROTO_MIN(val) > GHCB_PROTO_OUR) + if (GHCB_MSR_PROTO_MAX(val) < GHCB_PROTOCOL_MIN || + GHCB_MSR_PROTO_MIN(val) > GHCB_PROTOCOL_MAX) return false; + ghcb_version = min_t(size_t, GHCB_MSR_PROTO_MAX(val), GHCB_PROTOCOL_MAX); + return true; } @@ -104,10 +201,7 @@ static enum es_result verify_exception_info(struct ghcb *ghcb, struct es_em_ctxt if (ret == 1) { u64 info = ghcb->save.sw_exit_info_2; - unsigned long v; - - info = ghcb->save.sw_exit_info_2; - v = info & SVM_EVTINJ_VEC_MASK; + unsigned long v = info & SVM_EVTINJ_VEC_MASK; /* Check if exception information from hypervisor is sane. */ if ((info & SVM_EVTINJ_VALID) && @@ -130,7 +224,7 @@ enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb, bool set_ghcb_msr, u64 exit_info_1, u64 exit_info_2) { /* Fill in protocol and format specifiers */ - ghcb->protocol_version = GHCB_PROTOCOL_MAX; + ghcb->protocol_version = ghcb_version; ghcb->ghcb_usage = GHCB_DEFAULT_USAGE; ghcb_set_sw_exit_code(ghcb, exit_code); @@ -150,6 +244,290 @@ enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb, bool set_ghcb_msr, return verify_exception_info(ghcb, ctxt); } +static int __sev_cpuid_hv(u32 fn, int reg_idx, u32 *reg) +{ + u64 val; + + sev_es_wr_ghcb_msr(GHCB_CPUID_REQ(fn, reg_idx)); + VMGEXIT(); + val = sev_es_rd_ghcb_msr(); + if (GHCB_RESP_CODE(val) != GHCB_MSR_CPUID_RESP) + return -EIO; + + *reg = (val >> 32); + + return 0; +} + +static int sev_cpuid_hv(struct cpuid_leaf *leaf) +{ + int ret; + + /* + * MSR protocol does not support fetching non-zero subfunctions, but is + * sufficient to handle current early-boot cases. Should that change, + * make sure to report an error rather than ignoring the index and + * grabbing random values. If this issue arises in the future, handling + * can be added here to use GHCB-page protocol for cases that occur late + * enough in boot that GHCB page is available. + */ + if (cpuid_function_is_indexed(leaf->fn) && leaf->subfn) + return -EINVAL; + + ret = __sev_cpuid_hv(leaf->fn, GHCB_CPUID_REQ_EAX, &leaf->eax); + ret = ret ? : __sev_cpuid_hv(leaf->fn, GHCB_CPUID_REQ_EBX, &leaf->ebx); + ret = ret ? : __sev_cpuid_hv(leaf->fn, GHCB_CPUID_REQ_ECX, &leaf->ecx); + ret = ret ? : __sev_cpuid_hv(leaf->fn, GHCB_CPUID_REQ_EDX, &leaf->edx); + + return ret; +} + +/* + * This may be called early while still running on the initial identity + * mapping. Use RIP-relative addressing to obtain the correct address + * while running with the initial identity mapping as well as the + * switch-over to kernel virtual addresses later. + */ +static const struct snp_cpuid_table *snp_cpuid_get_table(void) +{ + void *ptr; + + asm ("lea cpuid_table_copy(%%rip), %0" + : "=r" (ptr) + : "p" (&cpuid_table_copy)); + + return ptr; +} + +/* + * The SNP Firmware ABI, Revision 0.9, Section 7.1, details the use of + * XCR0_IN and XSS_IN to encode multiple versions of 0xD subfunctions 0 + * and 1 based on the corresponding features enabled by a particular + * combination of XCR0 and XSS registers so that a guest can look up the + * version corresponding to the features currently enabled in its XCR0/XSS + * registers. The only values that differ between these versions/table + * entries is the enabled XSAVE area size advertised via EBX. + * + * While hypervisors may choose to make use of this support, it is more + * robust/secure for a guest to simply find the entry corresponding to the + * base/legacy XSAVE area size (XCR0=1 or XCR0=3), and then calculate the + * XSAVE area size using subfunctions 2 through 64, as documented in APM + * Volume 3, Rev 3.31, Appendix E.3.8, which is what is done here. + * + * Since base/legacy XSAVE area size is documented as 0x240, use that value + * directly rather than relying on the base size in the CPUID table. + * + * Return: XSAVE area size on success, 0 otherwise. + */ +static u32 snp_cpuid_calc_xsave_size(u64 xfeatures_en, bool compacted) +{ + const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table(); + u64 xfeatures_found = 0; + u32 xsave_size = 0x240; + int i; + + for (i = 0; i < cpuid_table->count; i++) { + const struct snp_cpuid_fn *e = &cpuid_table->fn[i]; + + if (!(e->eax_in == 0xD && e->ecx_in > 1 && e->ecx_in < 64)) + continue; + if (!(xfeatures_en & (BIT_ULL(e->ecx_in)))) + continue; + if (xfeatures_found & (BIT_ULL(e->ecx_in))) + continue; + + xfeatures_found |= (BIT_ULL(e->ecx_in)); + + if (compacted) + xsave_size += e->eax; + else + xsave_size = max(xsave_size, e->eax + e->ebx); + } + + /* + * Either the guest set unsupported XCR0/XSS bits, or the corresponding + * entries in the CPUID table were not present. This is not a valid + * state to be in. + */ + if (xfeatures_found != (xfeatures_en & GENMASK_ULL(63, 2))) + return 0; + + return xsave_size; +} + +static bool +snp_cpuid_get_validated_func(struct cpuid_leaf *leaf) +{ + const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table(); + int i; + + for (i = 0; i < cpuid_table->count; i++) { + const struct snp_cpuid_fn *e = &cpuid_table->fn[i]; + + if (e->eax_in != leaf->fn) + continue; + + if (cpuid_function_is_indexed(leaf->fn) && e->ecx_in != leaf->subfn) + continue; + + /* + * For 0xD subfunctions 0 and 1, only use the entry corresponding + * to the base/legacy XSAVE area size (XCR0=1 or XCR0=3, XSS=0). + * See the comments above snp_cpuid_calc_xsave_size() for more + * details. + */ + if (e->eax_in == 0xD && (e->ecx_in == 0 || e->ecx_in == 1)) + if (!(e->xcr0_in == 1 || e->xcr0_in == 3) || e->xss_in) + continue; + + leaf->eax = e->eax; + leaf->ebx = e->ebx; + leaf->ecx = e->ecx; + leaf->edx = e->edx; + + return true; + } + + return false; +} + +static void snp_cpuid_hv(struct cpuid_leaf *leaf) +{ + if (sev_cpuid_hv(leaf)) + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_CPUID_HV); +} + +static int snp_cpuid_postprocess(struct cpuid_leaf *leaf) +{ + struct cpuid_leaf leaf_hv = *leaf; + + switch (leaf->fn) { + case 0x1: + snp_cpuid_hv(&leaf_hv); + + /* initial APIC ID */ + leaf->ebx = (leaf_hv.ebx & GENMASK(31, 24)) | (leaf->ebx & GENMASK(23, 0)); + /* APIC enabled bit */ + leaf->edx = (leaf_hv.edx & BIT(9)) | (leaf->edx & ~BIT(9)); + + /* OSXSAVE enabled bit */ + if (native_read_cr4() & X86_CR4_OSXSAVE) + leaf->ecx |= BIT(27); + break; + case 0x7: + /* OSPKE enabled bit */ + leaf->ecx &= ~BIT(4); + if (native_read_cr4() & X86_CR4_PKE) + leaf->ecx |= BIT(4); + break; + case 0xB: + leaf_hv.subfn = 0; + snp_cpuid_hv(&leaf_hv); + + /* extended APIC ID */ + leaf->edx = leaf_hv.edx; + break; + case 0xD: { + bool compacted = false; + u64 xcr0 = 1, xss = 0; + u32 xsave_size; + + if (leaf->subfn != 0 && leaf->subfn != 1) + return 0; + + if (native_read_cr4() & X86_CR4_OSXSAVE) + xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK); + if (leaf->subfn == 1) { + /* Get XSS value if XSAVES is enabled. */ + if (leaf->eax & BIT(3)) { + unsigned long lo, hi; + + asm volatile("rdmsr" : "=a" (lo), "=d" (hi) + : "c" (MSR_IA32_XSS)); + xss = (hi << 32) | lo; + } + + /* + * The PPR and APM aren't clear on what size should be + * encoded in 0xD:0x1:EBX when compaction is not enabled + * by either XSAVEC (feature bit 1) or XSAVES (feature + * bit 3) since SNP-capable hardware has these feature + * bits fixed as 1. KVM sets it to 0 in this case, but + * to avoid this becoming an issue it's safer to simply + * treat this as unsupported for SNP guests. + */ + if (!(leaf->eax & (BIT(1) | BIT(3)))) + return -EINVAL; + + compacted = true; + } + + xsave_size = snp_cpuid_calc_xsave_size(xcr0 | xss, compacted); + if (!xsave_size) + return -EINVAL; + + leaf->ebx = xsave_size; + } + break; + case 0x8000001E: + snp_cpuid_hv(&leaf_hv); + + /* extended APIC ID */ + leaf->eax = leaf_hv.eax; + /* compute ID */ + leaf->ebx = (leaf->ebx & GENMASK(31, 8)) | (leaf_hv.ebx & GENMASK(7, 0)); + /* node ID */ + leaf->ecx = (leaf->ecx & GENMASK(31, 8)) | (leaf_hv.ecx & GENMASK(7, 0)); + break; + default: + /* No fix-ups needed, use values as-is. */ + break; + } + + return 0; +} + +/* + * Returns -EOPNOTSUPP if feature not enabled. Any other non-zero return value + * should be treated as fatal by caller. + */ +static int snp_cpuid(struct cpuid_leaf *leaf) +{ + const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table(); + + if (!cpuid_table->count) + return -EOPNOTSUPP; + + if (!snp_cpuid_get_validated_func(leaf)) { + /* + * Some hypervisors will avoid keeping track of CPUID entries + * where all values are zero, since they can be handled the + * same as out-of-range values (all-zero). This is useful here + * as well as it allows virtually all guest configurations to + * work using a single SNP CPUID table. + * + * To allow for this, there is a need to distinguish between + * out-of-range entries and in-range zero entries, since the + * CPUID table entries are only a template that may need to be + * augmented with additional values for things like + * CPU-specific information during post-processing. So if it's + * not in the table, set the values to zero. Then, if they are + * within a valid CPUID range, proceed with post-processing + * using zeros as the initial values. Otherwise, skip + * post-processing and just return zeros immediately. + */ + 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))) + return 0; + } + + return snp_cpuid_postprocess(leaf); +} + /* * Boot VC Handler - This is the first VC handler during boot, there is no GHCB * page yet, so it only supports the MSR based communication with the @@ -157,40 +535,33 @@ enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb, bool set_ghcb_msr, */ 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); - unsigned long val; + struct cpuid_leaf leaf; + int ret; /* Only CPUID is supported via MSR protocol */ if (exit_code != SVM_EXIT_CPUID) goto fail; - sev_es_wr_ghcb_msr(GHCB_CPUID_REQ(fn, GHCB_CPUID_REQ_EAX)); - VMGEXIT(); - val = sev_es_rd_ghcb_msr(); - if (GHCB_RESP_CODE(val) != GHCB_MSR_CPUID_RESP) - goto fail; - regs->ax = val >> 32; + leaf.fn = fn; + leaf.subfn = subfn; - sev_es_wr_ghcb_msr(GHCB_CPUID_REQ(fn, GHCB_CPUID_REQ_EBX)); - VMGEXIT(); - val = sev_es_rd_ghcb_msr(); - if (GHCB_RESP_CODE(val) != GHCB_MSR_CPUID_RESP) - goto fail; - regs->bx = val >> 32; + ret = snp_cpuid(&leaf); + if (!ret) + goto cpuid_done; - sev_es_wr_ghcb_msr(GHCB_CPUID_REQ(fn, GHCB_CPUID_REQ_ECX)); - VMGEXIT(); - val = sev_es_rd_ghcb_msr(); - if (GHCB_RESP_CODE(val) != GHCB_MSR_CPUID_RESP) + if (ret != -EOPNOTSUPP) goto fail; - regs->cx = val >> 32; - sev_es_wr_ghcb_msr(GHCB_CPUID_REQ(fn, GHCB_CPUID_REQ_EDX)); - VMGEXIT(); - val = sev_es_rd_ghcb_msr(); - if (GHCB_RESP_CODE(val) != GHCB_MSR_CPUID_RESP) + if (sev_cpuid_hv(&leaf)) goto fail; - regs->dx = val >> 32; + +cpuid_done: + regs->ax = leaf.eax; + regs->bx = leaf.ebx; + regs->cx = leaf.ecx; + regs->dx = leaf.edx; /* * This is a VC handler and the #VC is only raised when SEV-ES is @@ -221,7 +592,7 @@ void __init do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code) fail: /* Terminate the guest */ - sev_es_terminate(GHCB_SEV_ES_GEN_REQ); + sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ); } static enum es_result vc_insn_string_read(struct es_em_ctxt *ctxt, @@ -481,12 +852,37 @@ static enum es_result vc_handle_ioio(struct ghcb *ghcb, struct es_em_ctxt *ctxt) return ret; } +static int vc_handle_cpuid_snp(struct pt_regs *regs) +{ + struct cpuid_leaf leaf; + int ret; + + leaf.fn = regs->ax; + leaf.subfn = regs->cx; + ret = snp_cpuid(&leaf); + if (!ret) { + regs->ax = leaf.eax; + regs->bx = leaf.ebx; + regs->cx = leaf.ecx; + regs->dx = leaf.edx; + } + + return ret; +} + static enum es_result vc_handle_cpuid(struct ghcb *ghcb, struct es_em_ctxt *ctxt) { struct pt_regs *regs = ctxt->regs; u32 cr4 = native_read_cr4(); enum es_result ret; + int snp_cpuid_ret; + + snp_cpuid_ret = vc_handle_cpuid_snp(regs); + if (!snp_cpuid_ret) + return ES_OK; + if (snp_cpuid_ret != -EOPNOTSUPP) + return ES_VMM_ERROR; ghcb_set_rax(ghcb, regs->ax); ghcb_set_rcx(ghcb, regs->cx); @@ -538,3 +934,67 @@ static enum es_result vc_handle_rdtsc(struct ghcb *ghcb, return ES_OK; } + +struct cc_setup_data { + struct setup_data header; + u32 cc_blob_address; +}; + +/* + * Search for a Confidential Computing blob passed in as a setup_data entry + * via the Linux Boot Protocol. + */ +static struct cc_blob_sev_info *find_cc_blob_setup_data(struct boot_params *bp) +{ + struct cc_setup_data *sd = NULL; + struct setup_data *hdr; + + hdr = (struct setup_data *)bp->hdr.setup_data; + + while (hdr) { + if (hdr->type == SETUP_CC_BLOB) { + sd = (struct cc_setup_data *)hdr; + return (struct cc_blob_sev_info *)(unsigned long)sd->cc_blob_address; + } + hdr = (struct setup_data *)hdr->next; + } + + return NULL; +} + +/* + * Initialize the kernel's copy of the SNP CPUID table, and set up the + * pointer that will be used to access it. + * + * Maintaining a direct mapping of the SNP CPUID table used by firmware would + * be possible as an alternative, but the approach is brittle since the + * mapping needs to be updated in sync with all the changes to virtual memory + * layout and related mapping facilities throughout the boot process. + */ +static void __init setup_cpuid_table(const struct cc_blob_sev_info *cc_info) +{ + const struct snp_cpuid_table *cpuid_table_fw, *cpuid_table; + int i; + + if (!cc_info || !cc_info->cpuid_phys || cc_info->cpuid_len < PAGE_SIZE) + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_CPUID); + + cpuid_table_fw = (const struct snp_cpuid_table *)cc_info->cpuid_phys; + if (!cpuid_table_fw->count || cpuid_table_fw->count > SNP_CPUID_COUNT_MAX) + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_CPUID); + + cpuid_table = snp_cpuid_get_table(); + memcpy((void *)cpuid_table, cpuid_table_fw, sizeof(*cpuid_table)); + + /* Initialize CPUID ranges for range-checking. */ + for (i = 0; i < cpuid_table->count; i++) { + const struct snp_cpuid_fn *fn = &cpuid_table->fn[i]; + + if (fn->eax_in == 0x0) + cpuid_std_range_max = fn->eax; + else if (fn->eax_in == 0x40000000) + cpuid_hyp_range_max = fn->eax; + else if (fn->eax_in == 0x80000000) + cpuid_ext_range_max = fn->eax; + } +} diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index e6d316a01fdd..c05f0124c410 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -18,6 +18,10 @@ #include <linux/memblock.h> #include <linux/kernel.h> #include <linux/mm.h> +#include <linux/cpumask.h> +#include <linux/efi.h> +#include <linux/platform_device.h> +#include <linux/io.h> #include <asm/cpu_entry_area.h> #include <asm/stacktrace.h> @@ -31,9 +35,28 @@ #include <asm/svm.h> #include <asm/smp.h> #include <asm/cpu.h> +#include <asm/apic.h> +#include <asm/cpuid.h> +#include <asm/cmdline.h> #define DR7_RESET_VALUE 0x400 +/* AP INIT values as documented in the APM2 section "Processor Initialization State" */ +#define AP_INIT_CS_LIMIT 0xffff +#define AP_INIT_DS_LIMIT 0xffff +#define AP_INIT_LDTR_LIMIT 0xffff +#define AP_INIT_GDTR_LIMIT 0xffff +#define AP_INIT_IDTR_LIMIT 0xffff +#define AP_INIT_TR_LIMIT 0xffff +#define AP_INIT_RFLAGS_DEFAULT 0x2 +#define AP_INIT_DR6_DEFAULT 0xffff0ff0 +#define AP_INIT_GPAT_DEFAULT 0x0007040600070406ULL +#define AP_INIT_XCR0_DEFAULT 0x1 +#define AP_INIT_X87_FTW_DEFAULT 0x5555 +#define AP_INIT_X87_FCW_DEFAULT 0x0040 +#define AP_INIT_CR0_DEFAULT 0x60000010 +#define AP_INIT_MXCSR_DEFAULT 0x1f80 + /* For early boot hypervisor communication in SEV-ES enabled guests */ static struct ghcb boot_ghcb_page __bss_decrypted __aligned(PAGE_SIZE); @@ -41,7 +64,10 @@ static struct ghcb boot_ghcb_page __bss_decrypted __aligned(PAGE_SIZE); * Needs to be in the .data section because we need it NULL before bss is * cleared */ -static struct ghcb __initdata *boot_ghcb; +static struct ghcb *boot_ghcb __section(".data"); + +/* Bitmap of SEV features supported by the hypervisor */ +static u64 sev_hv_features __ro_after_init; /* #VC handler runtime per-CPU data */ struct sev_es_runtime_data { @@ -87,6 +113,15 @@ struct ghcb_state { static DEFINE_PER_CPU(struct sev_es_runtime_data*, runtime_data); DEFINE_STATIC_KEY_FALSE(sev_es_enable_key); +static DEFINE_PER_CPU(struct sev_es_save_area *, sev_vmsa); + +struct sev_config { + __u64 debug : 1, + __reserved : 63; +}; + +static struct sev_config sev_cfg __read_mostly; + static __always_inline bool on_vc_stack(struct pt_regs *regs) { unsigned long sp = regs->sp; @@ -523,13 +558,68 @@ void noinstr __sev_es_nmi_complete(void) __sev_put_ghcb(&state); } -static u64 get_jump_table_addr(void) +static u64 __init get_secrets_page(void) +{ + u64 pa_data = boot_params.cc_blob_address; + struct cc_blob_sev_info info; + void *map; + + /* + * The CC blob contains the address of the secrets page, check if the + * blob is present. + */ + if (!pa_data) + return 0; + + map = early_memremap(pa_data, sizeof(info)); + if (!map) { + pr_err("Unable to locate SNP secrets page: failed to map the Confidential Computing blob.\n"); + return 0; + } + memcpy(&info, map, sizeof(info)); + early_memunmap(map, sizeof(info)); + + /* smoke-test the secrets page passed */ + if (!info.secrets_phys || info.secrets_len != PAGE_SIZE) + return 0; + + return info.secrets_phys; +} + +static u64 __init get_snp_jump_table_addr(void) +{ + struct snp_secrets_page_layout *layout; + void __iomem *mem; + u64 pa, addr; + + pa = get_secrets_page(); + if (!pa) + return 0; + + mem = ioremap_encrypted(pa, PAGE_SIZE); + if (!mem) { + pr_err("Unable to locate AP jump table address: failed to map the SNP secrets page.\n"); + return 0; + } + + layout = (__force struct snp_secrets_page_layout *)mem; + + addr = layout->os_area.ap_jump_table_pa; + iounmap(mem); + + return addr; +} + +static u64 __init get_jump_table_addr(void) { struct ghcb_state state; unsigned long flags; struct ghcb *ghcb; u64 ret = 0; + if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) + return get_snp_jump_table_addr(); + local_irq_save(flags); ghcb = __sev_get_ghcb(&state); @@ -553,7 +643,496 @@ static u64 get_jump_table_addr(void) return ret; } -int sev_es_setup_ap_jump_table(struct real_mode_header *rmh) +static void pvalidate_pages(unsigned long vaddr, unsigned int npages, bool validate) +{ + unsigned long vaddr_end; + int rc; + + vaddr = vaddr & PAGE_MASK; + vaddr_end = vaddr + (npages << PAGE_SHIFT); + + while (vaddr < vaddr_end) { + rc = pvalidate(vaddr, RMP_PG_SIZE_4K, validate); + if (WARN(rc, "Failed to validate address 0x%lx ret %d", vaddr, rc)) + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PVALIDATE); + + vaddr = vaddr + PAGE_SIZE; + } +} + +static void __init early_set_pages_state(unsigned long paddr, unsigned int npages, enum psc_op op) +{ + unsigned long paddr_end; + u64 val; + + paddr = paddr & PAGE_MASK; + paddr_end = paddr + (npages << PAGE_SHIFT); + + while (paddr < paddr_end) { + /* + * Use the MSR protocol because this function can be called before + * the GHCB is established. + */ + sev_es_wr_ghcb_msr(GHCB_MSR_PSC_REQ_GFN(paddr >> PAGE_SHIFT, op)); + VMGEXIT(); + + val = sev_es_rd_ghcb_msr(); + + if (WARN(GHCB_RESP_CODE(val) != GHCB_MSR_PSC_RESP, + "Wrong PSC response code: 0x%x\n", + (unsigned int)GHCB_RESP_CODE(val))) + goto e_term; + + if (WARN(GHCB_MSR_PSC_RESP_VAL(val), + "Failed to change page state to '%s' paddr 0x%lx error 0x%llx\n", + op == SNP_PAGE_STATE_PRIVATE ? "private" : "shared", + paddr, GHCB_MSR_PSC_RESP_VAL(val))) + goto e_term; + + paddr = paddr + PAGE_SIZE; + } + + return; + +e_term: + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC); +} + +void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, + unsigned int npages) +{ + if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) + return; + + /* + * Ask the hypervisor to mark the memory pages as private in the RMP + * table. + */ + early_set_pages_state(paddr, npages, SNP_PAGE_STATE_PRIVATE); + + /* Validate the memory pages after they've been added in the RMP table. */ + pvalidate_pages(vaddr, npages, true); +} + +void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr, + unsigned int npages) +{ + if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) + return; + + /* Invalidate the memory pages before they are marked shared in the RMP table. */ + pvalidate_pages(vaddr, npages, false); + + /* Ask hypervisor to mark the memory pages shared in the RMP table. */ + early_set_pages_state(paddr, npages, SNP_PAGE_STATE_SHARED); +} + +void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op) +{< |