162784854SIngo Molnar /* 262784854SIngo Molnar * xsave/xrstor support. 362784854SIngo Molnar * 462784854SIngo Molnar * Author: Suresh Siddha <suresh.b.siddha@intel.com> 562784854SIngo Molnar */ 662784854SIngo Molnar #include <linux/compat.h> 762784854SIngo Molnar #include <linux/cpu.h> 8e8c24d3aSDave Hansen #include <linux/mman.h> 984594296SDave Hansen #include <linux/pkeys.h> 1059a36d16SIngo Molnar 1162784854SIngo Molnar #include <asm/fpu/api.h> 1262784854SIngo Molnar #include <asm/fpu/internal.h> 13fcbc99c4SIngo Molnar #include <asm/fpu/signal.h> 1459a36d16SIngo Molnar #include <asm/fpu/regset.h> 1591c3dba7SYu-cheng Yu #include <asm/fpu/xstate.h> 16b992c660SIngo Molnar 1762784854SIngo Molnar #include <asm/tlbflush.h> 1862784854SIngo Molnar 191f96b1efSDave Hansen /* 201f96b1efSDave Hansen * Although we spell it out in here, the Processor Trace 211f96b1efSDave Hansen * xfeature is completely unused. We use other mechanisms 221f96b1efSDave Hansen * to save/restore PT state in Linux. 231f96b1efSDave Hansen */ 245b073430SIngo Molnar static const char *xfeature_names[] = 255b073430SIngo Molnar { 265b073430SIngo Molnar "x87 floating point registers" , 275b073430SIngo Molnar "SSE registers" , 285b073430SIngo Molnar "AVX registers" , 295b073430SIngo Molnar "MPX bounds registers" , 305b073430SIngo Molnar "MPX CSR" , 315b073430SIngo Molnar "AVX-512 opmask" , 325b073430SIngo Molnar "AVX-512 Hi256" , 335b073430SIngo Molnar "AVX-512 ZMM_Hi256" , 341f96b1efSDave Hansen "Processor Trace (unused)" , 35c8df4009SDave Hansen "Protection Keys User registers", 365b073430SIngo Molnar "unknown xstate feature" , 375b073430SIngo Molnar }; 385b073430SIngo Molnar 3962784854SIngo Molnar /* 4062784854SIngo Molnar * Mask of xstate features supported by the CPU and the kernel: 4162784854SIngo Molnar */ 425b073430SIngo Molnar u64 xfeatures_mask __read_mostly; 4362784854SIngo Molnar 44dad8c4feSDave Hansen static unsigned int xstate_offsets[XFEATURE_MAX] = { [ 0 ... XFEATURE_MAX - 1] = -1}; 45dad8c4feSDave Hansen static unsigned int xstate_sizes[XFEATURE_MAX] = { [ 0 ... XFEATURE_MAX - 1] = -1}; 4662784854SIngo Molnar static unsigned int xstate_comp_offsets[sizeof(xfeatures_mask)*8]; 4762784854SIngo Molnar 4862784854SIngo Molnar /* 49a1141e0bSFenghua Yu * The XSAVE area of kernel can be in standard or compacted format; 50a1141e0bSFenghua Yu * it is always in standard format for user mode. This is the user 51a1141e0bSFenghua Yu * mode standard format size used for signal and ptrace frames. 52a1141e0bSFenghua Yu */ 53a1141e0bSFenghua Yu unsigned int fpu_user_xstate_size; 54a1141e0bSFenghua Yu 55a1141e0bSFenghua Yu /* 560a265375SDave Hansen * Clear all of the X86_FEATURE_* bits that are unavailable 570a265375SDave Hansen * when the CPU has no XSAVE support. 580a265375SDave Hansen */ 590a265375SDave Hansen void fpu__xstate_clear_all_cpu_caps(void) 600a265375SDave Hansen { 610a265375SDave Hansen setup_clear_cpu_cap(X86_FEATURE_XSAVE); 620a265375SDave Hansen setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT); 630a265375SDave Hansen setup_clear_cpu_cap(X86_FEATURE_XSAVEC); 640a265375SDave Hansen setup_clear_cpu_cap(X86_FEATURE_XSAVES); 650a265375SDave Hansen setup_clear_cpu_cap(X86_FEATURE_AVX); 660a265375SDave Hansen setup_clear_cpu_cap(X86_FEATURE_AVX2); 670a265375SDave Hansen setup_clear_cpu_cap(X86_FEATURE_AVX512F); 680a265375SDave Hansen setup_clear_cpu_cap(X86_FEATURE_AVX512PF); 690a265375SDave Hansen setup_clear_cpu_cap(X86_FEATURE_AVX512ER); 700a265375SDave Hansen setup_clear_cpu_cap(X86_FEATURE_AVX512CD); 71d0500494SFenghua Yu setup_clear_cpu_cap(X86_FEATURE_AVX512DQ); 72d0500494SFenghua Yu setup_clear_cpu_cap(X86_FEATURE_AVX512BW); 73d0500494SFenghua Yu setup_clear_cpu_cap(X86_FEATURE_AVX512VL); 740a265375SDave Hansen setup_clear_cpu_cap(X86_FEATURE_MPX); 75eb7c5f87Syu-cheng yu setup_clear_cpu_cap(X86_FEATURE_XGETBV1); 76c8df4009SDave Hansen setup_clear_cpu_cap(X86_FEATURE_PKU); 770a265375SDave Hansen } 780a265375SDave Hansen 790a265375SDave Hansen /* 805b073430SIngo Molnar * Return whether the system supports a given xfeature. 815b073430SIngo Molnar * 825b073430SIngo Molnar * Also return the name of the (most advanced) feature that the caller requested: 835b073430SIngo Molnar */ 845b073430SIngo Molnar int cpu_has_xfeatures(u64 xfeatures_needed, const char **feature_name) 855b073430SIngo Molnar { 865b073430SIngo Molnar u64 xfeatures_missing = xfeatures_needed & ~xfeatures_mask; 875b073430SIngo Molnar 885b073430SIngo Molnar if (unlikely(feature_name)) { 895b073430SIngo Molnar long xfeature_idx, max_idx; 905b073430SIngo Molnar u64 xfeatures_print; 915b073430SIngo Molnar /* 925b073430SIngo Molnar * So we use FLS here to be able to print the most advanced 935b073430SIngo Molnar * feature that was requested but is missing. So if a driver 94d91cab78SDave Hansen * asks about "XFEATURE_MASK_SSE | XFEATURE_MASK_YMM" we'll print the 955b073430SIngo Molnar * missing AVX feature - this is the most informative message 965b073430SIngo Molnar * to users: 975b073430SIngo Molnar */ 985b073430SIngo Molnar if (xfeatures_missing) 995b073430SIngo Molnar xfeatures_print = xfeatures_missing; 1005b073430SIngo Molnar else 1015b073430SIngo Molnar xfeatures_print = xfeatures_needed; 1025b073430SIngo Molnar 1035b073430SIngo Molnar xfeature_idx = fls64(xfeatures_print)-1; 1045b073430SIngo Molnar max_idx = ARRAY_SIZE(xfeature_names)-1; 1055b073430SIngo Molnar xfeature_idx = min(xfeature_idx, max_idx); 1065b073430SIngo Molnar 1075b073430SIngo Molnar *feature_name = xfeature_names[xfeature_idx]; 1085b073430SIngo Molnar } 1095b073430SIngo Molnar 1105b073430SIngo Molnar if (xfeatures_missing) 1115b073430SIngo Molnar return 0; 1125b073430SIngo Molnar 1135b073430SIngo Molnar return 1; 1145b073430SIngo Molnar } 1155b073430SIngo Molnar EXPORT_SYMBOL_GPL(cpu_has_xfeatures); 1165b073430SIngo Molnar 1171499ce2dSYu-cheng Yu static int xfeature_is_supervisor(int xfeature_nr) 1181499ce2dSYu-cheng Yu { 1191499ce2dSYu-cheng Yu /* 1201499ce2dSYu-cheng Yu * We currently do not support supervisor states, but if 1211499ce2dSYu-cheng Yu * we did, we could find out like this. 1221499ce2dSYu-cheng Yu * 1231499ce2dSYu-cheng Yu * SDM says: If state component 'i' is a user state component, 1241499ce2dSYu-cheng Yu * ECX[0] return 0; if state component i is a supervisor 1251499ce2dSYu-cheng Yu * state component, ECX[0] returns 1. 1261499ce2dSYu-cheng Yu */ 1271499ce2dSYu-cheng Yu u32 eax, ebx, ecx, edx; 1281499ce2dSYu-cheng Yu 1291499ce2dSYu-cheng Yu cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx); 1301499ce2dSYu-cheng Yu return !!(ecx & 1); 1311499ce2dSYu-cheng Yu } 1321499ce2dSYu-cheng Yu 1331499ce2dSYu-cheng Yu static int xfeature_is_user(int xfeature_nr) 1341499ce2dSYu-cheng Yu { 1351499ce2dSYu-cheng Yu return !xfeature_is_supervisor(xfeature_nr); 1361499ce2dSYu-cheng Yu } 1371499ce2dSYu-cheng Yu 1385b073430SIngo Molnar /* 139aeb997b9SIngo Molnar * When executing XSAVEOPT (or other optimized XSAVE instructions), if 140aeb997b9SIngo Molnar * a processor implementation detects that an FPU state component is still 141aeb997b9SIngo Molnar * (or is again) in its initialized state, it may clear the corresponding 142aeb997b9SIngo Molnar * bit in the header.xfeatures field, and can skip the writeout of registers 143aeb997b9SIngo Molnar * to the corresponding memory layout. 14462784854SIngo Molnar * 14562784854SIngo Molnar * This means that when the bit is zero, the state component might still contain 14662784854SIngo Molnar * some previous - non-initialized register state. 14762784854SIngo Molnar * 14862784854SIngo Molnar * Before writing xstate information to user-space we sanitize those components, 14962784854SIngo Molnar * to always ensure that the memory layout of a feature will be in the init state 15062784854SIngo Molnar * if the corresponding header bit is zero. This is to ensure that user-space doesn't 15162784854SIngo Molnar * see some stale state in the memory layout during signal handling, debugging etc. 15262784854SIngo Molnar */ 15336e49e7fSIngo Molnar void fpstate_sanitize_xstate(struct fpu *fpu) 15462784854SIngo Molnar { 155c47ada30SIngo Molnar struct fxregs_state *fx = &fpu->state.fxsave; 15662784854SIngo Molnar int feature_bit; 15762784854SIngo Molnar u64 xfeatures; 15862784854SIngo Molnar 1591ac91a76SIngo Molnar if (!use_xsaveopt()) 16062784854SIngo Molnar return; 16162784854SIngo Molnar 16236e49e7fSIngo Molnar xfeatures = fpu->state.xsave.header.xfeatures; 16362784854SIngo Molnar 16462784854SIngo Molnar /* 16562784854SIngo Molnar * None of the feature bits are in init state. So nothing else 16662784854SIngo Molnar * to do for us, as the memory layout is up to date. 16762784854SIngo Molnar */ 16862784854SIngo Molnar if ((xfeatures & xfeatures_mask) == xfeatures_mask) 16962784854SIngo Molnar return; 17062784854SIngo Molnar 17162784854SIngo Molnar /* 17262784854SIngo Molnar * FP is in init state 17362784854SIngo Molnar */ 174d91cab78SDave Hansen if (!(xfeatures & XFEATURE_MASK_FP)) { 17562784854SIngo Molnar fx->cwd = 0x37f; 17662784854SIngo Molnar fx->swd = 0; 17762784854SIngo Molnar fx->twd = 0; 17862784854SIngo Molnar fx->fop = 0; 17962784854SIngo Molnar fx->rip = 0; 18062784854SIngo Molnar fx->rdp = 0; 18162784854SIngo Molnar memset(&fx->st_space[0], 0, 128); 18262784854SIngo Molnar } 18362784854SIngo Molnar 18462784854SIngo Molnar /* 18562784854SIngo Molnar * SSE is in init state 18662784854SIngo Molnar */ 187d91cab78SDave Hansen if (!(xfeatures & XFEATURE_MASK_SSE)) 18862784854SIngo Molnar memset(&fx->xmm_space[0], 0, 256); 18962784854SIngo Molnar 19062784854SIngo Molnar /* 19162784854SIngo Molnar * First two features are FPU and SSE, which above we handled 19262784854SIngo Molnar * in a special way already: 19362784854SIngo Molnar */ 19462784854SIngo Molnar feature_bit = 0x2; 19562784854SIngo Molnar xfeatures = (xfeatures_mask & ~xfeatures) >> 2; 19662784854SIngo Molnar 19762784854SIngo Molnar /* 19862784854SIngo Molnar * Update all the remaining memory layouts according to their 19962784854SIngo Molnar * standard xstate layout, if their header bit is in the init 20062784854SIngo Molnar * state: 20162784854SIngo Molnar */ 20262784854SIngo Molnar while (xfeatures) { 20362784854SIngo Molnar if (xfeatures & 0x1) { 204a1141e0bSFenghua Yu int offset = xstate_comp_offsets[feature_bit]; 20562784854SIngo Molnar int size = xstate_sizes[feature_bit]; 20662784854SIngo Molnar 20762784854SIngo Molnar memcpy((void *)fx + offset, 2086f575023SIngo Molnar (void *)&init_fpstate.xsave + offset, 20962784854SIngo Molnar size); 21062784854SIngo Molnar } 21162784854SIngo Molnar 21262784854SIngo Molnar xfeatures >>= 1; 21362784854SIngo Molnar feature_bit++; 21462784854SIngo Molnar } 21562784854SIngo Molnar } 21662784854SIngo Molnar 21762784854SIngo Molnar /* 21862784854SIngo Molnar * Enable the extended processor state save/restore feature. 21962784854SIngo Molnar * Called once per CPU onlining. 22062784854SIngo Molnar */ 22162784854SIngo Molnar void fpu__init_cpu_xstate(void) 22262784854SIngo Molnar { 223d366bf7eSBorislav Petkov if (!boot_cpu_has(X86_FEATURE_XSAVE) || !xfeatures_mask) 22462784854SIngo Molnar return; 225b8be15d5SYu-cheng Yu /* 226b8be15d5SYu-cheng Yu * Make it clear that XSAVES supervisor states are not yet 227b8be15d5SYu-cheng Yu * implemented should anyone expect it to work by changing 228b8be15d5SYu-cheng Yu * bits in XFEATURE_MASK_* macros and XCR0. 229b8be15d5SYu-cheng Yu */ 230b8be15d5SYu-cheng Yu WARN_ONCE((xfeatures_mask & XFEATURE_MASK_SUPERVISOR), 231b8be15d5SYu-cheng Yu "x86/fpu: XSAVES supervisor states are not yet implemented.\n"); 232b8be15d5SYu-cheng Yu 233b8be15d5SYu-cheng Yu xfeatures_mask &= ~XFEATURE_MASK_SUPERVISOR; 23462784854SIngo Molnar 23562784854SIngo Molnar cr4_set_bits(X86_CR4_OSXSAVE); 23662784854SIngo Molnar xsetbv(XCR_XFEATURE_ENABLED_MASK, xfeatures_mask); 23762784854SIngo Molnar } 23862784854SIngo Molnar 23962784854SIngo Molnar /* 240e6e888f9SDave Hansen * Note that in the future we will likely need a pair of 241e6e888f9SDave Hansen * functions here: one for user xstates and the other for 242e6e888f9SDave Hansen * system xstates. For now, they are the same. 243e6e888f9SDave Hansen */ 244e6e888f9SDave Hansen static int xfeature_enabled(enum xfeature xfeature) 245e6e888f9SDave Hansen { 246e6e888f9SDave Hansen return !!(xfeatures_mask & (1UL << xfeature)); 247e6e888f9SDave Hansen } 248e6e888f9SDave Hansen 249e6e888f9SDave Hansen /* 25039f1acd2SIngo Molnar * Record the offsets and sizes of various xstates contained 25139f1acd2SIngo Molnar * in the XSAVE state memory layout. 25262784854SIngo Molnar */ 25362784854SIngo Molnar static void __init setup_xstate_features(void) 25462784854SIngo Molnar { 255ee9ae257SDave Hansen u32 eax, ebx, ecx, edx, i; 256e6e888f9SDave Hansen /* start at the beginnning of the "extended state" */ 257e6e888f9SDave Hansen unsigned int last_good_offset = offsetof(struct xregs_state, 258e6e888f9SDave Hansen extended_state_area); 259ac73b27aSYu-cheng Yu /* 260ac73b27aSYu-cheng Yu * The FP xstates and SSE xstates are legacy states. They are always 261ac73b27aSYu-cheng Yu * in the fixed offsets in the xsave area in either compacted form 262ac73b27aSYu-cheng Yu * or standard form. 263ac73b27aSYu-cheng Yu */ 264ac73b27aSYu-cheng Yu xstate_offsets[0] = 0; 265ac73b27aSYu-cheng Yu xstate_sizes[0] = offsetof(struct fxregs_state, xmm_space); 266ac73b27aSYu-cheng Yu xstate_offsets[1] = xstate_sizes[0]; 267ac73b27aSYu-cheng Yu xstate_sizes[1] = FIELD_SIZEOF(struct fxregs_state, xmm_space); 26862784854SIngo Molnar 269ee9ae257SDave Hansen for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) { 270e6e888f9SDave Hansen if (!xfeature_enabled(i)) 271e6e888f9SDave Hansen continue; 27262784854SIngo Molnar 273e6e888f9SDave Hansen cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx); 2741499ce2dSYu-cheng Yu 2751499ce2dSYu-cheng Yu /* 2761499ce2dSYu-cheng Yu * If an xfeature is supervisor state, the offset 2771499ce2dSYu-cheng Yu * in EBX is invalid. We leave it to -1. 2781499ce2dSYu-cheng Yu */ 2791499ce2dSYu-cheng Yu if (xfeature_is_user(i)) 280ee9ae257SDave Hansen xstate_offsets[i] = ebx; 2811499ce2dSYu-cheng Yu 282ee9ae257SDave Hansen xstate_sizes[i] = eax; 283e6e888f9SDave Hansen /* 284e6e888f9SDave Hansen * In our xstate size checks, we assume that the 285e6e888f9SDave Hansen * highest-numbered xstate feature has the 286e6e888f9SDave Hansen * highest offset in the buffer. Ensure it does. 287e6e888f9SDave Hansen */ 288e6e888f9SDave Hansen WARN_ONCE(last_good_offset > xstate_offsets[i], 289e6e888f9SDave Hansen "x86/fpu: misordered xstate at %d\n", last_good_offset); 290e6e888f9SDave Hansen last_good_offset = xstate_offsets[i]; 29139f1acd2SIngo Molnar } 29262784854SIngo Molnar } 29362784854SIngo Molnar 29432231879SIngo Molnar static void __init print_xstate_feature(u64 xstate_mask) 29562784854SIngo Molnar { 29633588b52SIngo Molnar const char *feature_name; 29762784854SIngo Molnar 29833588b52SIngo Molnar if (cpu_has_xfeatures(xstate_mask, &feature_name)) 299c8df4009SDave Hansen pr_info("x86/fpu: Supporting XSAVE feature 0x%03Lx: '%s'\n", xstate_mask, feature_name); 30062784854SIngo Molnar } 30162784854SIngo Molnar 30262784854SIngo Molnar /* 30362784854SIngo Molnar * Print out all the supported xstate features: 30462784854SIngo Molnar */ 30532231879SIngo Molnar static void __init print_xstate_features(void) 30662784854SIngo Molnar { 307d91cab78SDave Hansen print_xstate_feature(XFEATURE_MASK_FP); 308d91cab78SDave Hansen print_xstate_feature(XFEATURE_MASK_SSE); 309d91cab78SDave Hansen print_xstate_feature(XFEATURE_MASK_YMM); 310d91cab78SDave Hansen print_xstate_feature(XFEATURE_MASK_BNDREGS); 311d91cab78SDave Hansen print_xstate_feature(XFEATURE_MASK_BNDCSR); 312d91cab78SDave Hansen print_xstate_feature(XFEATURE_MASK_OPMASK); 313d91cab78SDave Hansen print_xstate_feature(XFEATURE_MASK_ZMM_Hi256); 314d91cab78SDave Hansen print_xstate_feature(XFEATURE_MASK_Hi16_ZMM); 315c8df4009SDave Hansen print_xstate_feature(XFEATURE_MASK_PKRU); 31662784854SIngo Molnar } 31762784854SIngo Molnar 31862784854SIngo Molnar /* 31903482e08SYu-cheng Yu * This check is important because it is easy to get XSTATE_* 32003482e08SYu-cheng Yu * confused with XSTATE_BIT_*. 32103482e08SYu-cheng Yu */ 32203482e08SYu-cheng Yu #define CHECK_XFEATURE(nr) do { \ 32303482e08SYu-cheng Yu WARN_ON(nr < FIRST_EXTENDED_XFEATURE); \ 32403482e08SYu-cheng Yu WARN_ON(nr >= XFEATURE_MAX); \ 32503482e08SYu-cheng Yu } while (0) 32603482e08SYu-cheng Yu 32703482e08SYu-cheng Yu /* 32803482e08SYu-cheng Yu * We could cache this like xstate_size[], but we only use 32903482e08SYu-cheng Yu * it here, so it would be a waste of space. 33003482e08SYu-cheng Yu */ 33103482e08SYu-cheng Yu static int xfeature_is_aligned(int xfeature_nr) 33203482e08SYu-cheng Yu { 33303482e08SYu-cheng Yu u32 eax, ebx, ecx, edx; 33403482e08SYu-cheng Yu 33503482e08SYu-cheng Yu CHECK_XFEATURE(xfeature_nr); 33603482e08SYu-cheng Yu cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx); 33703482e08SYu-cheng Yu /* 33803482e08SYu-cheng Yu * The value returned by ECX[1] indicates the alignment 33903482e08SYu-cheng Yu * of state component 'i' when the compacted format 34003482e08SYu-cheng Yu * of the extended region of an XSAVE area is used: 34103482e08SYu-cheng Yu */ 34203482e08SYu-cheng Yu return !!(ecx & 2); 34303482e08SYu-cheng Yu } 34403482e08SYu-cheng Yu 34503482e08SYu-cheng Yu /* 34662784854SIngo Molnar * This function sets up offsets and sizes of all extended states in 34762784854SIngo Molnar * xsave area. This supports both standard format and compacted format 34862784854SIngo Molnar * of the xsave aread. 34962784854SIngo Molnar */ 35032231879SIngo Molnar static void __init setup_xstate_comp(void) 35162784854SIngo Molnar { 35262784854SIngo Molnar unsigned int xstate_comp_sizes[sizeof(xfeatures_mask)*8]; 35362784854SIngo Molnar int i; 35462784854SIngo Molnar 35562784854SIngo Molnar /* 35662784854SIngo Molnar * The FP xstates and SSE xstates are legacy states. They are always 35762784854SIngo Molnar * in the fixed offsets in the xsave area in either compacted form 35862784854SIngo Molnar * or standard form. 35962784854SIngo Molnar */ 36062784854SIngo Molnar xstate_comp_offsets[0] = 0; 361c47ada30SIngo Molnar xstate_comp_offsets[1] = offsetof(struct fxregs_state, xmm_space); 36262784854SIngo Molnar 363782511b0SBorislav Petkov if (!boot_cpu_has(X86_FEATURE_XSAVES)) { 364ee9ae257SDave Hansen for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) { 365633d54c4SDave Hansen if (xfeature_enabled(i)) { 36662784854SIngo Molnar xstate_comp_offsets[i] = xstate_offsets[i]; 36762784854SIngo Molnar xstate_comp_sizes[i] = xstate_sizes[i]; 36862784854SIngo Molnar } 36962784854SIngo Molnar } 37062784854SIngo Molnar return; 37162784854SIngo Molnar } 37262784854SIngo Molnar 3738a93c9e0SDave Hansen xstate_comp_offsets[FIRST_EXTENDED_XFEATURE] = 3748a93c9e0SDave Hansen FXSAVE_SIZE + XSAVE_HDR_SIZE; 37562784854SIngo Molnar 376ee9ae257SDave Hansen for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) { 377633d54c4SDave Hansen if (xfeature_enabled(i)) 37862784854SIngo Molnar xstate_comp_sizes[i] = xstate_sizes[i]; 37962784854SIngo Molnar else 38062784854SIngo Molnar xstate_comp_sizes[i] = 0; 38162784854SIngo Molnar 38203482e08SYu-cheng Yu if (i > FIRST_EXTENDED_XFEATURE) { 38362784854SIngo Molnar xstate_comp_offsets[i] = xstate_comp_offsets[i-1] 38462784854SIngo Molnar + xstate_comp_sizes[i-1]; 38562784854SIngo Molnar 38603482e08SYu-cheng Yu if (xfeature_is_aligned(i)) 38703482e08SYu-cheng Yu xstate_comp_offsets[i] = 38803482e08SYu-cheng Yu ALIGN(xstate_comp_offsets[i], 64); 38903482e08SYu-cheng Yu } 39062784854SIngo Molnar } 39162784854SIngo Molnar } 39262784854SIngo Molnar 39362784854SIngo Molnar /* 394996952e0SYu-cheng Yu * Print out xstate component offsets and sizes 395996952e0SYu-cheng Yu */ 396996952e0SYu-cheng Yu static void __init print_xstate_offset_size(void) 397996952e0SYu-cheng Yu { 398996952e0SYu-cheng Yu int i; 399996952e0SYu-cheng Yu 400996952e0SYu-cheng Yu for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) { 401996952e0SYu-cheng Yu if (!xfeature_enabled(i)) 402996952e0SYu-cheng Yu continue; 403996952e0SYu-cheng Yu pr_info("x86/fpu: xstate_offset[%d]: %4d, xstate_sizes[%d]: %4d\n", 404996952e0SYu-cheng Yu i, xstate_comp_offsets[i], i, xstate_sizes[i]); 405996952e0SYu-cheng Yu } 406996952e0SYu-cheng Yu } 407996952e0SYu-cheng Yu 408996952e0SYu-cheng Yu /* 40962784854SIngo Molnar * setup the xstate image representing the init state 41062784854SIngo Molnar */ 41132231879SIngo Molnar static void __init setup_init_fpu_buf(void) 41262784854SIngo Molnar { 413e49a449bSRasmus Villemoes static int on_boot_cpu __initdata = 1; 414e97131a8SIngo Molnar 415e97131a8SIngo Molnar WARN_ON_FPU(!on_boot_cpu); 416e97131a8SIngo Molnar on_boot_cpu = 0; 417e97131a8SIngo Molnar 418d366bf7eSBorislav Petkov if (!boot_cpu_has(X86_FEATURE_XSAVE)) 41962784854SIngo Molnar return; 42062784854SIngo Molnar 42162784854SIngo Molnar setup_xstate_features(); 42262784854SIngo Molnar print_xstate_features(); 42362784854SIngo Molnar 4247d937060SFenghua Yu if (boot_cpu_has(X86_FEATURE_XSAVES)) 4256f575023SIngo Molnar init_fpstate.xsave.header.xcomp_bv = (u64)1 << 63 | xfeatures_mask; 42662784854SIngo Molnar 42762784854SIngo Molnar /* 4287d937060SFenghua Yu * Init all the features state with header.xfeatures being 0x0 42962784854SIngo Molnar */ 430d65fcd60SIngo Molnar copy_kernel_to_xregs_booting(&init_fpstate.xsave); 43162784854SIngo Molnar 43262784854SIngo Molnar /* 43362784854SIngo Molnar * Dump the init state again. This is to identify the init state 43462784854SIngo Molnar * of any feature which is not represented by all zero's. 43562784854SIngo Molnar */ 436c6813144SIngo Molnar copy_xregs_to_kernel_booting(&init_fpstate.xsave); 43762784854SIngo Molnar } 43862784854SIngo Molnar 43965ac2e9bSDave Hansen static int xfeature_uncompacted_offset(int xfeature_nr) 44065ac2e9bSDave Hansen { 44165ac2e9bSDave Hansen u32 eax, ebx, ecx, edx; 44265ac2e9bSDave Hansen 4431499ce2dSYu-cheng Yu /* 4441499ce2dSYu-cheng Yu * Only XSAVES supports supervisor states and it uses compacted 4451499ce2dSYu-cheng Yu * format. Checking a supervisor state's uncompacted offset is 4461499ce2dSYu-cheng Yu * an error. 4471499ce2dSYu-cheng Yu */ 4481499ce2dSYu-cheng Yu if (XFEATURE_MASK_SUPERVISOR & (1 << xfeature_nr)) { 4491499ce2dSYu-cheng Yu WARN_ONCE(1, "No fixed offset for xstate %d\n", xfeature_nr); 4501499ce2dSYu-cheng Yu return -1; 4511499ce2dSYu-cheng Yu } 4521499ce2dSYu-cheng Yu 45365ac2e9bSDave Hansen CHECK_XFEATURE(xfeature_nr); 45465ac2e9bSDave Hansen cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx); 45565ac2e9bSDave Hansen return ebx; 45665ac2e9bSDave Hansen } 45765ac2e9bSDave Hansen 45865ac2e9bSDave Hansen static int xfeature_size(int xfeature_nr) 45965ac2e9bSDave Hansen { 46065ac2e9bSDave Hansen u32 eax, ebx, ecx, edx; 46165ac2e9bSDave Hansen 46265ac2e9bSDave Hansen CHECK_XFEATURE(xfeature_nr); 46365ac2e9bSDave Hansen cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx); 46465ac2e9bSDave Hansen return eax; 46565ac2e9bSDave Hansen } 46665ac2e9bSDave Hansen 46765ac2e9bSDave Hansen /* 46865ac2e9bSDave Hansen * 'XSAVES' implies two different things: 46965ac2e9bSDave Hansen * 1. saving of supervisor/system state 47065ac2e9bSDave Hansen * 2. using the compacted format 47165ac2e9bSDave Hansen * 47265ac2e9bSDave Hansen * Use this function when dealing with the compacted format so 47365ac2e9bSDave Hansen * that it is obvious which aspect of 'XSAVES' is being handled 47465ac2e9bSDave Hansen * by the calling code. 47565ac2e9bSDave Hansen */ 47699aa22d0SYu-cheng Yu int using_compacted_format(void) 47765ac2e9bSDave Hansen { 478782511b0SBorislav Petkov return boot_cpu_has(X86_FEATURE_XSAVES); 47965ac2e9bSDave Hansen } 48065ac2e9bSDave Hansen 48165ac2e9bSDave Hansen static void __xstate_dump_leaves(void) 48265ac2e9bSDave Hansen { 48365ac2e9bSDave Hansen int i; 48465ac2e9bSDave Hansen u32 eax, ebx, ecx, edx; 48565ac2e9bSDave Hansen static int should_dump = 1; 48665ac2e9bSDave Hansen 48765ac2e9bSDave Hansen if (!should_dump) 48865ac2e9bSDave Hansen return; 48965ac2e9bSDave Hansen should_dump = 0; 49065ac2e9bSDave Hansen /* 49165ac2e9bSDave Hansen * Dump out a few leaves past the ones that we support 49265ac2e9bSDave Hansen * just in case there are some goodies up there 49365ac2e9bSDave Hansen */ 49465ac2e9bSDave Hansen for (i = 0; i < XFEATURE_MAX + 10; i++) { 49565ac2e9bSDave Hansen cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx); 49665ac2e9bSDave Hansen pr_warn("CPUID[%02x, %02x]: eax=%08x ebx=%08x ecx=%08x edx=%08x\n", 49765ac2e9bSDave Hansen XSTATE_CPUID, i, eax, ebx, ecx, edx); 49865ac2e9bSDave Hansen } 49965ac2e9bSDave Hansen } 50065ac2e9bSDave Hansen 50165ac2e9bSDave Hansen #define XSTATE_WARN_ON(x) do { \ 50265ac2e9bSDave Hansen if (WARN_ONCE(x, "XSAVE consistency problem, dumping leaves")) { \ 50365ac2e9bSDave Hansen __xstate_dump_leaves(); \ 50465ac2e9bSDave Hansen } \ 50565ac2e9bSDave Hansen } while (0) 50665ac2e9bSDave Hansen 507ef78f2a4SDave Hansen #define XCHECK_SZ(sz, nr, nr_macro, __struct) do { \ 508ef78f2a4SDave Hansen if ((nr == nr_macro) && \ 509ef78f2a4SDave Hansen WARN_ONCE(sz != sizeof(__struct), \ 510ef78f2a4SDave Hansen "%s: struct is %zu bytes, cpu state %d bytes\n", \ 511ef78f2a4SDave Hansen __stringify(nr_macro), sizeof(__struct), sz)) { \ 512ef78f2a4SDave Hansen __xstate_dump_leaves(); \ 513ef78f2a4SDave Hansen } \ 514ef78f2a4SDave Hansen } while (0) 515ef78f2a4SDave Hansen 516ef78f2a4SDave Hansen /* 517ef78f2a4SDave Hansen * We have a C struct for each 'xstate'. We need to ensure 518ef78f2a4SDave Hansen * that our software representation matches what the CPU 519ef78f2a4SDave Hansen * tells us about the state's size. 520ef78f2a4SDave Hansen */ 521ef78f2a4SDave Hansen static void check_xstate_against_struct(int nr) 522ef78f2a4SDave Hansen { 523ef78f2a4SDave Hansen /* 524ef78f2a4SDave Hansen * Ask the CPU for the size of the state. 525ef78f2a4SDave Hansen */ 526ef78f2a4SDave Hansen int sz = xfeature_size(nr); 527ef78f2a4SDave Hansen /* 528ef78f2a4SDave Hansen * Match each CPU state with the corresponding software 529ef78f2a4SDave Hansen * structure. 530ef78f2a4SDave Hansen */ 531ef78f2a4SDave Hansen XCHECK_SZ(sz, nr, XFEATURE_YMM, struct ymmh_struct); 532ef78f2a4SDave Hansen XCHECK_SZ(sz, nr, XFEATURE_BNDREGS, struct mpx_bndreg_state); 533ef78f2a4SDave Hansen XCHECK_SZ(sz, nr, XFEATURE_BNDCSR, struct mpx_bndcsr_state); 534ef78f2a4SDave Hansen XCHECK_SZ(sz, nr, XFEATURE_OPMASK, struct avx_512_opmask_state); 535ef78f2a4SDave Hansen XCHECK_SZ(sz, nr, XFEATURE_ZMM_Hi256, struct avx_512_zmm_uppers_state); 536ef78f2a4SDave Hansen XCHECK_SZ(sz, nr, XFEATURE_Hi16_ZMM, struct avx_512_hi16_state); 537c8df4009SDave Hansen XCHECK_SZ(sz, nr, XFEATURE_PKRU, struct pkru_state); 538ef78f2a4SDave Hansen 539ef78f2a4SDave Hansen /* 540ef78f2a4SDave Hansen * Make *SURE* to add any feature numbers in below if 541ef78f2a4SDave Hansen * there are "holes" in the xsave state component 542ef78f2a4SDave Hansen * numbers. 543ef78f2a4SDave Hansen */ 544ef78f2a4SDave Hansen if ((nr < XFEATURE_YMM) || 5451f96b1efSDave Hansen (nr >= XFEATURE_MAX) || 5461f96b1efSDave Hansen (nr == XFEATURE_PT_UNIMPLEMENTED_SO_FAR)) { 547ef78f2a4SDave Hansen WARN_ONCE(1, "no structure for xstate: %d\n", nr); 548ef78f2a4SDave Hansen XSTATE_WARN_ON(1); 549ef78f2a4SDave Hansen } 550ef78f2a4SDave Hansen } 551ef78f2a4SDave Hansen 55265ac2e9bSDave Hansen /* 55365ac2e9bSDave Hansen * This essentially double-checks what the cpu told us about 55465ac2e9bSDave Hansen * how large the XSAVE buffer needs to be. We are recalculating 55565ac2e9bSDave Hansen * it to be safe. 55665ac2e9bSDave Hansen */ 55765ac2e9bSDave Hansen static void do_extra_xstate_size_checks(void) 55865ac2e9bSDave Hansen { 55965ac2e9bSDave Hansen int paranoid_xstate_size = FXSAVE_SIZE + XSAVE_HDR_SIZE; 56065ac2e9bSDave Hansen int i; 56165ac2e9bSDave Hansen 56265ac2e9bSDave Hansen for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) { 56365ac2e9bSDave Hansen if (!xfeature_enabled(i)) 56465ac2e9bSDave Hansen continue; 565ef78f2a4SDave Hansen 566ef78f2a4SDave Hansen check_xstate_against_struct(i); 56765ac2e9bSDave Hansen /* 56865ac2e9bSDave Hansen * Supervisor state components can be managed only by 56965ac2e9bSDave Hansen * XSAVES, which is compacted-format only. 57065ac2e9bSDave Hansen */ 57165ac2e9bSDave Hansen if (!using_compacted_format()) 57265ac2e9bSDave Hansen XSTATE_WARN_ON(xfeature_is_supervisor(i)); 57365ac2e9bSDave Hansen 57465ac2e9bSDave Hansen /* Align from the end of the previous feature */ 57565ac2e9bSDave Hansen if (xfeature_is_aligned(i)) 57665ac2e9bSDave Hansen paranoid_xstate_size = ALIGN(paranoid_xstate_size, 64); 57765ac2e9bSDave Hansen /* 57865ac2e9bSDave Hansen * The offset of a given state in the non-compacted 57965ac2e9bSDave Hansen * format is given to us in a CPUID leaf. We check 58065ac2e9bSDave Hansen * them for being ordered (increasing offsets) in 58165ac2e9bSDave Hansen * setup_xstate_features(). 58265ac2e9bSDave Hansen */ 58365ac2e9bSDave Hansen if (!using_compacted_format()) 58465ac2e9bSDave Hansen paranoid_xstate_size = xfeature_uncompacted_offset(i); 58565ac2e9bSDave Hansen /* 58665ac2e9bSDave Hansen * The compacted-format offset always depends on where 58765ac2e9bSDave Hansen * the previous state ended. 58865ac2e9bSDave Hansen */ 58965ac2e9bSDave Hansen paranoid_xstate_size += xfeature_size(i); 59065ac2e9bSDave Hansen } 591bf15a8cfSFenghua Yu XSTATE_WARN_ON(paranoid_xstate_size != fpu_kernel_xstate_size); 59265ac2e9bSDave Hansen } 59365ac2e9bSDave Hansen 594a1141e0bSFenghua Yu 59562784854SIngo Molnar /* 596a1141e0bSFenghua Yu * Get total size of enabled xstates in XCR0/xfeatures_mask. 59765ac2e9bSDave Hansen * 59865ac2e9bSDave Hansen * Note the SDM's wording here. "sub-function 0" only enumerates 59965ac2e9bSDave Hansen * the size of the *user* states. If we use it to size a buffer 60065ac2e9bSDave Hansen * that we use 'XSAVES' on, we could potentially overflow the 60165ac2e9bSDave Hansen * buffer because 'XSAVES' saves system states too. 60265ac2e9bSDave Hansen * 60365ac2e9bSDave Hansen * Note that we do not currently set any bits on IA32_XSS so 60465ac2e9bSDave Hansen * 'XCR0 | IA32_XSS == XCR0' for now. 60562784854SIngo Molnar */ 606a1141e0bSFenghua Yu static unsigned int __init get_xsaves_size(void) 60762784854SIngo Molnar { 60862784854SIngo Molnar unsigned int eax, ebx, ecx, edx; 60965ac2e9bSDave Hansen /* 61065ac2e9bSDave Hansen * - CPUID function 0DH, sub-function 1: 61165ac2e9bSDave Hansen * EBX enumerates the size (in bytes) required by 61265ac2e9bSDave Hansen * the XSAVES instruction for an XSAVE area 61365ac2e9bSDave Hansen * containing all the state components 61465ac2e9bSDave Hansen * corresponding to bits currently set in 61565ac2e9bSDave Hansen * XCR0 | IA32_XSS. 61665ac2e9bSDave Hansen */ 61765ac2e9bSDave Hansen cpuid_count(XSTATE_CPUID, 1, &eax, &ebx, &ecx, &edx); 618a1141e0bSFenghua Yu return ebx; 61962784854SIngo Molnar } 620a1141e0bSFenghua Yu 621a1141e0bSFenghua Yu static unsigned int __init get_xsave_size(void) 622a1141e0bSFenghua Yu { 623a1141e0bSFenghua Yu unsigned int eax, ebx, ecx, edx; 624a1141e0bSFenghua Yu /* 625a1141e0bSFenghua Yu * - CPUID function 0DH, sub-function 0: 626a1141e0bSFenghua Yu * EBX enumerates the size (in bytes) required by 627a1141e0bSFenghua Yu * the XSAVE instruction for an XSAVE area 628a1141e0bSFenghua Yu * containing all the *user* state components 629a1141e0bSFenghua Yu * corresponding to bits currently set in XCR0. 630a1141e0bSFenghua Yu */ 631a1141e0bSFenghua Yu cpuid_count(XSTATE_CPUID, 0, &eax, &ebx, &ecx, &edx); 632a1141e0bSFenghua Yu return ebx; 6334109ca06SDave Hansen } 6344109ca06SDave Hansen 6354109ca06SDave Hansen /* 6364109ca06SDave Hansen * Will the runtime-enumerated 'xstate_size' fit in the init 6374109ca06SDave Hansen * task's statically-allocated buffer? 6384109ca06SDave Hansen */ 6394109ca06SDave Hansen static bool is_supported_xstate_size(unsigned int test_xstate_size) 6404109ca06SDave Hansen { 6414109ca06SDave Hansen if (test_xstate_size <= sizeof(union fpregs_state)) 6424109ca06SDave Hansen return true; 6434109ca06SDave Hansen 6444109ca06SDave Hansen pr_warn("x86/fpu: xstate buffer too small (%zu < %d), disabling xsave\n", 6454109ca06SDave Hansen sizeof(union fpregs_state), test_xstate_size); 6464109ca06SDave Hansen return false; 6474109ca06SDave Hansen } 6484109ca06SDave Hansen 6494109ca06SDave Hansen static int init_xstate_size(void) 6504109ca06SDave Hansen { 6514109ca06SDave Hansen /* Recompute the context size for enabled features: */ 652a1141e0bSFenghua Yu unsigned int possible_xstate_size; 653a1141e0bSFenghua Yu unsigned int xsave_size; 654a1141e0bSFenghua Yu 655a1141e0bSFenghua Yu xsave_size = get_xsave_size(); 656a1141e0bSFenghua Yu 657a1141e0bSFenghua Yu if (boot_cpu_has(X86_FEATURE_XSAVES)) 658a1141e0bSFenghua Yu possible_xstate_size = get_xsaves_size(); 659a1141e0bSFenghua Yu else 660a1141e0bSFenghua Yu possible_xstate_size = xsave_size; 6614109ca06SDave Hansen 6624109ca06SDave Hansen /* Ensure we have the space to store all enabled: */ 6634109ca06SDave Hansen if (!is_supported_xstate_size(possible_xstate_size)) 6644109ca06SDave Hansen return -EINVAL; 6654109ca06SDave Hansen 6664109ca06SDave Hansen /* 6674109ca06SDave Hansen * The size is OK, we are definitely going to use xsave, 6684109ca06SDave Hansen * make it known to the world that we need more space. 6694109ca06SDave Hansen */ 670bf15a8cfSFenghua Yu fpu_kernel_xstate_size = possible_xstate_size; 67165ac2e9bSDave Hansen do_extra_xstate_size_checks(); 672a1141e0bSFenghua Yu 673a1141e0bSFenghua Yu /* 674a1141e0bSFenghua Yu * User space is always in standard format. 675a1141e0bSFenghua Yu */ 676a1141e0bSFenghua Yu fpu_user_xstate_size = xsave_size; 6774109ca06SDave Hansen return 0; 6784109ca06SDave Hansen } 6794109ca06SDave Hansen 680d91cab78SDave Hansen /* 681d91cab78SDave Hansen * We enabled the XSAVE hardware, but something went wrong and 682d91cab78SDave Hansen * we can not use it. Disable it. 683d91cab78SDave Hansen */ 684d91cab78SDave Hansen static void fpu__init_disable_system_xstate(void) 6854109ca06SDave Hansen { 6864109ca06SDave Hansen xfeatures_mask = 0; 6874109ca06SDave Hansen cr4_clear_bits(X86_CR4_OSXSAVE); 6884109ca06SDave Hansen fpu__xstate_clear_all_cpu_caps(); 68962784854SIngo Molnar } 69062784854SIngo Molnar 69162784854SIngo Molnar /* 69262784854SIngo Molnar * Enable and initialize the xsave feature. 69362784854SIngo Molnar * Called once per system bootup. 69462784854SIngo Molnar */ 69532231879SIngo Molnar void __init fpu__init_system_xstate(void) 69662784854SIngo Molnar { 69762784854SIngo Molnar unsigned int eax, ebx, ecx, edx; 698e49a449bSRasmus Villemoes static int on_boot_cpu __initdata = 1; 6994109ca06SDave Hansen int err; 700e97131a8SIngo Molnar 701e97131a8SIngo Molnar WARN_ON_FPU(!on_boot_cpu); 702e97131a8SIngo Molnar on_boot_cpu = 0; 70362784854SIngo Molnar 704d366bf7eSBorislav Petkov if (!boot_cpu_has(X86_FEATURE_XSAVE)) { 70562784854SIngo Molnar pr_info("x86/fpu: Legacy x87 FPU detected.\n"); 70662784854SIngo Molnar return; 70762784854SIngo Molnar } 70862784854SIngo Molnar 70962784854SIngo Molnar if (boot_cpu_data.cpuid_level < XSTATE_CPUID) { 710e97131a8SIngo Molnar WARN_ON_FPU(1); 71162784854SIngo Molnar return; 71262784854SIngo Molnar } 71362784854SIngo Molnar 71462784854SIngo Molnar cpuid_count(XSTATE_CPUID, 0, &eax, &ebx, &ecx, &edx); 71562784854SIngo Molnar xfeatures_mask = eax + ((u64)edx << 32); 71662784854SIngo Molnar 717d91cab78SDave Hansen if ((xfeatures_mask & XFEATURE_MASK_FPSSE) != XFEATURE_MASK_FPSSE) { 718ec3ed4a2SDave Hansen /* 719ec3ed4a2SDave Hansen * This indicates that something really unexpected happened 720ec3ed4a2SDave Hansen * with the enumeration. Disable XSAVE and try to continue 721ec3ed4a2SDave Hansen * booting without it. This is too early to BUG(). 722ec3ed4a2SDave Hansen */ 72362784854SIngo Molnar pr_err("x86/fpu: FP/SSE not present amongst the CPU's xstate features: 0x%llx.\n", xfeatures_mask); 724ec3ed4a2SDave Hansen goto out_disable; 72562784854SIngo Molnar } 72662784854SIngo Molnar 727a5fe93a5Syu-cheng yu xfeatures_mask &= fpu__get_supported_xfeatures_mask(); 72862784854SIngo Molnar 72962784854SIngo Molnar /* Enable xstate instructions to be able to continue with initialization: */ 73062784854SIngo Molnar fpu__init_cpu_xstate(); 7314109ca06SDave Hansen err = init_xstate_size(); 732ec3ed4a2SDave Hansen if (err) 733ec3ed4a2SDave Hansen goto out_disable; 73462784854SIngo Molnar 73591c3dba7SYu-cheng Yu /* 73691c3dba7SYu-cheng Yu * Update info used for ptrace frames; use standard-format size and no 73791c3dba7SYu-cheng Yu * supervisor xstates: 73891c3dba7SYu-cheng Yu */ 73991c3dba7SYu-cheng Yu update_regset_xstate_info(fpu_user_xstate_size, xfeatures_mask & ~XFEATURE_MASK_SUPERVISOR); 74091c3dba7SYu-cheng Yu 741b992c660SIngo Molnar fpu__init_prepare_fx_sw_frame(); 74262784854SIngo Molnar setup_init_fpu_buf(); 7435fd402dfSIngo Molnar setup_xstate_comp(); 744996952e0SYu-cheng Yu print_xstate_offset_size(); 74562784854SIngo Molnar 746b0815359SDave Hansen pr_info("x86/fpu: Enabled xstate features 0x%llx, context size is %d bytes, using '%s' format.\n", 74762784854SIngo Molnar xfeatures_mask, 748bf15a8cfSFenghua Yu fpu_kernel_xstate_size, 749782511b0SBorislav Petkov boot_cpu_has(X86_FEATURE_XSAVES) ? "compacted" : "standard"); 750ec3ed4a2SDave Hansen return; 751ec3ed4a2SDave Hansen 752ec3ed4a2SDave Hansen out_disable: 753ec3ed4a2SDave Hansen /* something went wrong, try to boot without any XSAVE support */ 754ec3ed4a2SDave Hansen fpu__init_disable_system_xstate(); 75562784854SIngo Molnar } 75662784854SIngo Molnar 75762784854SIngo Molnar /* 75862784854SIngo Molnar * Restore minimal FPU state after suspend: 75962784854SIngo Molnar */ 76062784854SIngo Molnar void fpu__resume_cpu(void) 76162784854SIngo Molnar { 76262784854SIngo Molnar /* 76362784854SIngo Molnar * Restore XCR0 on xsave capable CPUs: 76462784854SIngo Molnar */ 765d366bf7eSBorislav Petkov if (boot_cpu_has(X86_FEATURE_XSAVE)) 76662784854SIngo Molnar xsetbv(XCR_XFEATURE_ENABLED_MASK, xfeatures_mask); 76762784854SIngo Molnar } 76862784854SIngo Molnar 76962784854SIngo Molnar /* 770b8b9b6baSDave Hansen * Given an xstate feature mask, calculate where in the xsave 771b8b9b6baSDave Hansen * buffer the state is. Callers should ensure that the buffer 772b8b9b6baSDave Hansen * is valid. 773b8b9b6baSDave Hansen * 774b8b9b6baSDave Hansen * Note: does not work for compacted buffers. 775b8b9b6baSDave Hansen */ 776b8b9b6baSDave Hansen void *__raw_xsave_addr(struct xregs_state *xsave, int xstate_feature_mask) 777b8b9b6baSDave Hansen { 778b8b9b6baSDave Hansen int feature_nr = fls64(xstate_feature_mask) - 1; 779b8b9b6baSDave Hansen 7805060b915SYu-cheng Yu if (!xfeature_enabled(feature_nr)) { 7815060b915SYu-cheng Yu WARN_ON_FPU(1); 7825060b915SYu-cheng Yu return NULL; 7835060b915SYu-cheng Yu } 7845060b915SYu-cheng Yu 785b8b9b6baSDave Hansen return (void *)xsave + xstate_comp_offsets[feature_nr]; 786b8b9b6baSDave Hansen } 787b8b9b6baSDave Hansen /* 78862784854SIngo Molnar * Given the xsave area and a state inside, this function returns the 78962784854SIngo Molnar * address of the state. 79062784854SIngo Molnar * 79162784854SIngo Molnar * This is the API that is called to get xstate address in either 79262784854SIngo Molnar * standard format or compacted format of xsave area. 79362784854SIngo Molnar * 7940c4109beSDave Hansen * Note that if there is no data for the field in the xsave buffer 7950c4109beSDave Hansen * this will return NULL. 7960c4109beSDave Hansen * 79762784854SIngo Molnar * Inputs: 7980c4109beSDave Hansen * xstate: the thread's storage area for all FPU data 7990c4109beSDave Hansen * xstate_feature: state which is defined in xsave.h (e.g. 800d91cab78SDave Hansen * XFEATURE_MASK_FP, XFEATURE_MASK_SSE, etc...) 80162784854SIngo Molnar * Output: 8020c4109beSDave Hansen * address of the state in the xsave area, or NULL if the 8030c4109beSDave Hansen * field is not present in the xsave buffer. 80462784854SIngo Molnar */ 8050c4109beSDave Hansen void *get_xsave_addr(struct xregs_state *xsave, int xstate_feature) 80662784854SIngo Molnar { 8070c4109beSDave Hansen /* 8080c4109beSDave Hansen * Do we even *have* xsave state? 8090c4109beSDave Hansen */ 8100c4109beSDave Hansen if (!boot_cpu_has(X86_FEATURE_XSAVE)) 81162784854SIngo Molnar return NULL; 81262784854SIngo Molnar 8130c4109beSDave Hansen /* 8140c4109beSDave Hansen * We should not ever be requesting features that we 8150c4109beSDave Hansen * have not enabled. Remember that pcntxt_mask is 8160c4109beSDave Hansen * what we write to the XCR0 register. 8170c4109beSDave Hansen */ 8180c4109beSDave Hansen WARN_ONCE(!(xfeatures_mask & xstate_feature), 8190c4109beSDave Hansen "get of unsupported state"); 8200c4109beSDave Hansen /* 8210c4109beSDave Hansen * This assumes the last 'xsave*' instruction to 8220c4109beSDave Hansen * have requested that 'xstate_feature' be saved. 8230c4109beSDave Hansen * If it did not, we might be seeing and old value 8240c4109beSDave Hansen * of the field in the buffer. 8250c4109beSDave Hansen * 8260c4109beSDave Hansen * This can happen because the last 'xsave' did not 8270c4109beSDave Hansen * request that this feature be saved (unlikely) 8280c4109beSDave Hansen * or because the "init optimization" caused it 8290c4109beSDave Hansen * to not be saved. 8300c4109beSDave Hansen */ 8310c4109beSDave Hansen if (!(xsave->header.xfeatures & xstate_feature)) 8320c4109beSDave Hansen return NULL; 8330c4109beSDave Hansen 834b8b9b6baSDave Hansen return __raw_xsave_addr(xsave, xstate_feature); 83562784854SIngo Molnar } 83662784854SIngo Molnar EXPORT_SYMBOL_GPL(get_xsave_addr); 83704cd027bSDave Hansen 83804cd027bSDave Hansen /* 83904cd027bSDave Hansen * This wraps up the common operations that need to occur when retrieving 84004cd027bSDave Hansen * data from xsave state. It first ensures that the current task was 84104cd027bSDave Hansen * using the FPU and retrieves the data in to a buffer. It then calculates 84204cd027bSDave Hansen * the offset of the requested field in the buffer. 84304cd027bSDave Hansen * 84404cd027bSDave Hansen * This function is safe to call whether the FPU is in use or not. 84504cd027bSDave Hansen * 84604cd027bSDave Hansen * Note that this only works on the current task. 84704cd027bSDave Hansen * 84804cd027bSDave Hansen * Inputs: 849d91cab78SDave Hansen * @xsave_state: state which is defined in xsave.h (e.g. XFEATURE_MASK_FP, 850d91cab78SDave Hansen * XFEATURE_MASK_SSE, etc...) 85104cd027bSDave Hansen * Output: 85204cd027bSDave Hansen * address of the state in the xsave area or NULL if the state 85304cd027bSDave Hansen * is not present or is in its 'init state'. 85404cd027bSDave Hansen */ 85504cd027bSDave Hansen const void *get_xsave_field_ptr(int xsave_state) 85604cd027bSDave Hansen { 85704cd027bSDave Hansen struct fpu *fpu = ¤t->thread.fpu; 85804cd027bSDave Hansen 85904cd027bSDave Hansen if (!fpu->fpstate_active) 86004cd027bSDave Hansen return NULL; 86104cd027bSDave Hansen /* 86204cd027bSDave Hansen * fpu__save() takes the CPU's xstate registers 86304cd027bSDave Hansen * and saves them off to the 'fpu memory buffer. 86404cd027bSDave Hansen */ 86504cd027bSDave Hansen fpu__save(fpu); 86604cd027bSDave Hansen 86704cd027bSDave Hansen return get_xsave_addr(&fpu->state.xsave, xsave_state); 86804cd027bSDave Hansen } 869b8b9b6baSDave Hansen 870e8c24d3aSDave Hansen #ifdef CONFIG_ARCH_HAS_PKEYS 871e8c24d3aSDave Hansen 87284594296SDave Hansen #define NR_VALID_PKRU_BITS (CONFIG_NR_PROTECTION_KEYS * 2) 87384594296SDave Hansen #define PKRU_VALID_MASK (NR_VALID_PKRU_BITS - 1) 87484594296SDave Hansen /* 875b79daf85SDave Hansen * This will go out and modify PKRU register to set the access 876b79daf85SDave Hansen * rights for @pkey to @init_val. 87784594296SDave Hansen */ 87884594296SDave Hansen int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, 87984594296SDave Hansen unsigned long init_val) 88084594296SDave Hansen { 881b79daf85SDave Hansen u32 old_pkru; 88284594296SDave Hansen int pkey_shift = (pkey * PKRU_BITS_PER_PKEY); 88384594296SDave Hansen u32 new_pkru_bits = 0; 88484594296SDave Hansen 88584594296SDave Hansen /* 88684594296SDave Hansen * This check implies XSAVE support. OSPKE only gets 88784594296SDave Hansen * set if we enable XSAVE and we enable PKU in XCR0. 88884594296SDave Hansen */ 88984594296SDave Hansen if (!boot_cpu_has(X86_FEATURE_OSPKE)) 89084594296SDave Hansen return -EINVAL; 891b79daf85SDave Hansen /* 892b79daf85SDave Hansen * For most XSAVE components, this would be an arduous task: 893b79daf85SDave Hansen * brining fpstate up to date with fpregs, updating fpstate, 894b79daf85SDave Hansen * then re-populating fpregs. But, for components that are 895b79daf85SDave Hansen * never lazily managed, we can just access the fpregs 896b79daf85SDave Hansen * directly. PKRU is never managed lazily, so we can just 897b79daf85SDave Hansen * manipulate it directly. Make sure it stays that way. 898b79daf85SDave Hansen */ 899b79daf85SDave Hansen WARN_ON_ONCE(!use_eager_fpu()); 90084594296SDave Hansen 90191c3dba7SYu-cheng Yu /* Set the bits we need in PKRU: */ 90284594296SDave Hansen if (init_val & PKEY_DISABLE_ACCESS) 90384594296SDave Hansen new_pkru_bits |= PKRU_AD_BIT; 90484594296SDave Hansen if (init_val & PKEY_DISABLE_WRITE) 90584594296SDave Hansen new_pkru_bits |= PKRU_WD_BIT; 90684594296SDave Hansen 90791c3dba7SYu-cheng Yu /* Shift the bits in to the correct place in PKRU for pkey: */ 90884594296SDave Hansen new_pkru_bits <<= pkey_shift; 90984594296SDave Hansen 910b79daf85SDave Hansen /* Get old PKRU and mask off any old bits in place: */ 911b79daf85SDave Hansen old_pkru = read_pkru(); 912b79daf85SDave Hansen old_pkru &= ~((PKRU_AD_BIT|PKRU_WD_BIT) << pkey_shift); 91384594296SDave Hansen 914b79daf85SDave Hansen /* Write old part along with new part: */ 915b79daf85SDave Hansen write_pkru(old_pkru | new_pkru_bits); 91691c3dba7SYu-cheng Yu 91791c3dba7SYu-cheng Yu return 0; 91891c3dba7SYu-cheng Yu } 919e8c24d3aSDave Hansen #endif /* ! CONFIG_ARCH_HAS_PKEYS */ 92091c3dba7SYu-cheng Yu 92191c3dba7SYu-cheng Yu /* 92291c3dba7SYu-cheng Yu * This is similar to user_regset_copyout(), but will not add offset to 92391c3dba7SYu-cheng Yu * the source data pointer or increment pos, count, kbuf, and ubuf. 92491c3dba7SYu-cheng Yu */ 92591c3dba7SYu-cheng Yu static inline int xstate_copyout(unsigned int pos, unsigned int count, 92691c3dba7SYu-cheng Yu void *kbuf, void __user *ubuf, 92791c3dba7SYu-cheng Yu const void *data, const int start_pos, 92891c3dba7SYu-cheng Yu const int end_pos) 92991c3dba7SYu-cheng Yu { 93091c3dba7SYu-cheng Yu if ((count == 0) || (pos < start_pos)) 93191c3dba7SYu-cheng Yu return 0; 93291c3dba7SYu-cheng Yu 93391c3dba7SYu-cheng Yu if (end_pos < 0 || pos < end_pos) { 93491c3dba7SYu-cheng Yu unsigned int copy = (end_pos < 0 ? count : min(count, end_pos - pos)); 93591c3dba7SYu-cheng Yu 93691c3dba7SYu-cheng Yu if (kbuf) { 93791c3dba7SYu-cheng Yu memcpy(kbuf + pos, data, copy); 93891c3dba7SYu-cheng Yu } else { 93991c3dba7SYu-cheng Yu if (__copy_to_user(ubuf + pos, data, copy)) 94091c3dba7SYu-cheng Yu return -EFAULT; 94191c3dba7SYu-cheng Yu } 94291c3dba7SYu-cheng Yu } 94391c3dba7SYu-cheng Yu return 0; 94491c3dba7SYu-cheng Yu } 94591c3dba7SYu-cheng Yu 94691c3dba7SYu-cheng Yu /* 94791c3dba7SYu-cheng Yu * Convert from kernel XSAVES compacted format to standard format and copy 94891c3dba7SYu-cheng Yu * to a ptrace buffer. It supports partial copy but pos always starts from 94991c3dba7SYu-cheng Yu * zero. This is called from xstateregs_get() and there we check the CPU 95091c3dba7SYu-cheng Yu * has XSAVES. 95191c3dba7SYu-cheng Yu */ 95291c3dba7SYu-cheng Yu int copyout_from_xsaves(unsigned int pos, unsigned int count, void *kbuf, 95391c3dba7SYu-cheng Yu void __user *ubuf, struct xregs_state *xsave) 95491c3dba7SYu-cheng Yu { 95591c3dba7SYu-cheng Yu unsigned int offset, size; 95691c3dba7SYu-cheng Yu int ret, i; 95791c3dba7SYu-cheng Yu struct xstate_header header; 95891c3dba7SYu-cheng Yu 95991c3dba7SYu-cheng Yu /* 96091c3dba7SYu-cheng Yu * Currently copy_regset_to_user() starts from pos 0: 96191c3dba7SYu-cheng Yu */ 96291c3dba7SYu-cheng Yu if (unlikely(pos != 0)) 96391c3dba7SYu-cheng Yu return -EFAULT; 96491c3dba7SYu-cheng Yu 96591c3dba7SYu-cheng Yu /* 96691c3dba7SYu-cheng Yu * The destination is a ptrace buffer; we put in only user xstates: 96791c3dba7SYu-cheng Yu */ 96891c3dba7SYu-cheng Yu memset(&header, 0, sizeof(header)); 96991c3dba7SYu-cheng Yu header.xfeatures = xsave->header.xfeatures; 97091c3dba7SYu-cheng Yu header.xfeatures &= ~XFEATURE_MASK_SUPERVISOR; 97191c3dba7SYu-cheng Yu 97291c3dba7SYu-cheng Yu /* 97391c3dba7SYu-cheng Yu * Copy xregs_state->header: 97491c3dba7SYu-cheng Yu */ 97591c3dba7SYu-cheng Yu offset = offsetof(struct xregs_state, header); 97691c3dba7SYu-cheng Yu size = sizeof(header); 97791c3dba7SYu-cheng Yu 97891c3dba7SYu-cheng Yu ret = xstate_copyout(offset, size, kbuf, ubuf, &header, 0, count); 97991c3dba7SYu-cheng Yu 98091c3dba7SYu-cheng Yu if (ret) 98191c3dba7SYu-cheng Yu return ret; 98291c3dba7SYu-cheng Yu 98391c3dba7SYu-cheng Yu for (i = 0; i < XFEATURE_MAX; i++) { 98491c3dba7SYu-cheng Yu /* 98591c3dba7SYu-cheng Yu * Copy only in-use xstates: 98691c3dba7SYu-cheng Yu */ 98791c3dba7SYu-cheng Yu if ((header.xfeatures >> i) & 1) { 98891c3dba7SYu-cheng Yu void *src = __raw_xsave_addr(xsave, 1 << i); 98991c3dba7SYu-cheng Yu 99091c3dba7SYu-cheng Yu offset = xstate_offsets[i]; 99191c3dba7SYu-cheng Yu size = xstate_sizes[i]; 99291c3dba7SYu-cheng Yu 99391c3dba7SYu-cheng Yu ret = xstate_copyout(offset, size, kbuf, ubuf, src, 0, count); 99491c3dba7SYu-cheng Yu 99591c3dba7SYu-cheng Yu if (ret) 99691c3dba7SYu-cheng Yu return ret; 99791c3dba7SYu-cheng Yu 99891c3dba7SYu-cheng Yu if (offset + size >= count) 99991c3dba7SYu-cheng Yu break; 100091c3dba7SYu-cheng Yu } 100191c3dba7SYu-cheng Yu 100291c3dba7SYu-cheng Yu } 100391c3dba7SYu-cheng Yu 100491c3dba7SYu-cheng Yu /* 100591c3dba7SYu-cheng Yu * Fill xsave->i387.sw_reserved value for ptrace frame: 100691c3dba7SYu-cheng Yu */ 100791c3dba7SYu-cheng Yu offset = offsetof(struct fxregs_state, sw_reserved); 100891c3dba7SYu-cheng Yu size = sizeof(xstate_fx_sw_bytes); 100991c3dba7SYu-cheng Yu 101091c3dba7SYu-cheng Yu ret = xstate_copyout(offset, size, kbuf, ubuf, xstate_fx_sw_bytes, 0, count); 101191c3dba7SYu-cheng Yu 101291c3dba7SYu-cheng Yu if (ret) 101391c3dba7SYu-cheng Yu return ret; 101491c3dba7SYu-cheng Yu 101591c3dba7SYu-cheng Yu return 0; 101691c3dba7SYu-cheng Yu } 101791c3dba7SYu-cheng Yu 101891c3dba7SYu-cheng Yu /* 101991c3dba7SYu-cheng Yu * Convert from a ptrace standard-format buffer to kernel XSAVES format 102091c3dba7SYu-cheng Yu * and copy to the target thread. This is called from xstateregs_set() and 102191c3dba7SYu-cheng Yu * there we check the CPU has XSAVES and a whole standard-sized buffer 102291c3dba7SYu-cheng Yu * exists. 102391c3dba7SYu-cheng Yu */ 102491c3dba7SYu-cheng Yu int copyin_to_xsaves(const void *kbuf, const void __user *ubuf, 102591c3dba7SYu-cheng Yu struct xregs_state *xsave) 102691c3dba7SYu-cheng Yu { 102791c3dba7SYu-cheng Yu unsigned int offset, size; 102891c3dba7SYu-cheng Yu int i; 102991c3dba7SYu-cheng Yu u64 xfeatures; 103091c3dba7SYu-cheng Yu u64 allowed_features; 103191c3dba7SYu-cheng Yu 103291c3dba7SYu-cheng Yu offset = offsetof(struct xregs_state, header); 103391c3dba7SYu-cheng Yu size = sizeof(xfeatures); 103491c3dba7SYu-cheng Yu 103591c3dba7SYu-cheng Yu if (kbuf) { 103691c3dba7SYu-cheng Yu memcpy(&xfeatures, kbuf + offset, size); 103791c3dba7SYu-cheng Yu } else { 103891c3dba7SYu-cheng Yu if (__copy_from_user(&xfeatures, ubuf + offset, size)) 103991c3dba7SYu-cheng Yu return -EFAULT; 104091c3dba7SYu-cheng Yu } 104191c3dba7SYu-cheng Yu 104291c3dba7SYu-cheng Yu /* 104391c3dba7SYu-cheng Yu * Reject if the user sets any disabled or supervisor features: 104491c3dba7SYu-cheng Yu */ 104591c3dba7SYu-cheng Yu allowed_features = xfeatures_mask & ~XFEATURE_MASK_SUPERVISOR; 104691c3dba7SYu-cheng Yu 104791c3dba7SYu-cheng Yu if (xfeatures & ~allowed_features) 104891c3dba7SYu-cheng Yu return -EINVAL; 104991c3dba7SYu-cheng Yu 105091c3dba7SYu-cheng Yu for (i = 0; i < XFEATURE_MAX; i++) { 105191c3dba7SYu-cheng Yu u64 mask = ((u64)1 << i); 105291c3dba7SYu-cheng Yu 105391c3dba7SYu-cheng Yu if (xfeatures & mask) { 105491c3dba7SYu-cheng Yu void *dst = __raw_xsave_addr(xsave, 1 << i); 105591c3dba7SYu-cheng Yu 105691c3dba7SYu-cheng Yu offset = xstate_offsets[i]; 105791c3dba7SYu-cheng Yu size = xstate_sizes[i]; 105891c3dba7SYu-cheng Yu 105991c3dba7SYu-cheng Yu if (kbuf) { 106091c3dba7SYu-cheng Yu memcpy(dst, kbuf + offset, size); 106191c3dba7SYu-cheng Yu } else { 106291c3dba7SYu-cheng Yu if (__copy_from_user(dst, ubuf + offset, size)) 106391c3dba7SYu-cheng Yu return -EFAULT; 106491c3dba7SYu-cheng Yu } 106591c3dba7SYu-cheng Yu } 106691c3dba7SYu-cheng Yu } 106791c3dba7SYu-cheng Yu 106891c3dba7SYu-cheng Yu /* 106991c3dba7SYu-cheng Yu * The state that came in from userspace was user-state only. 107091c3dba7SYu-cheng Yu * Mask all the user states out of 'xfeatures': 107191c3dba7SYu-cheng Yu */ 107291c3dba7SYu-cheng Yu xsave->header.xfeatures &= XFEATURE_MASK_SUPERVISOR; 107391c3dba7SYu-cheng Yu 107491c3dba7SYu-cheng Yu /* 107591c3dba7SYu-cheng Yu * Add back in the features that came in from userspace: 107691c3dba7SYu-cheng Yu */ 107791c3dba7SYu-cheng Yu xsave->header.xfeatures |= xfeatures; 107884594296SDave Hansen 107984594296SDave Hansen return 0; 108084594296SDave Hansen } 1081