1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __ASM_X86_XSAVE_H 3 #define __ASM_X86_XSAVE_H 4 5 #include <linux/uaccess.h> 6 #include <linux/types.h> 7 8 #include <asm/processor.h> 9 #include <asm/fpu/api.h> 10 #include <asm/user.h> 11 12 /* Bit 63 of XCR0 is reserved for future expansion */ 13 #define XFEATURE_MASK_EXTEND (~(XFEATURE_MASK_FPSSE | (1ULL << 63))) 14 15 #define XSTATE_CPUID 0x0000000d 16 17 #define FXSAVE_SIZE 512 18 19 #define XSAVE_HDR_SIZE 64 20 #define XSAVE_HDR_OFFSET FXSAVE_SIZE 21 22 #define XSAVE_YMM_SIZE 256 23 #define XSAVE_YMM_OFFSET (XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET) 24 25 #define XSAVE_ALIGNMENT 64 26 27 /* All currently supported user features */ 28 #define XFEATURE_MASK_USER_SUPPORTED (XFEATURE_MASK_FP | \ 29 XFEATURE_MASK_SSE | \ 30 XFEATURE_MASK_YMM | \ 31 XFEATURE_MASK_OPMASK | \ 32 XFEATURE_MASK_ZMM_Hi256 | \ 33 XFEATURE_MASK_Hi16_ZMM | \ 34 XFEATURE_MASK_PKRU | \ 35 XFEATURE_MASK_BNDREGS | \ 36 XFEATURE_MASK_BNDCSR) 37 38 /* 39 * Features which are restored when returning to user space. 40 * PKRU is not restored on return to user space because PKRU 41 * is switched eagerly in switch_to() and flush_thread() 42 */ 43 #define XFEATURE_MASK_USER_RESTORE \ 44 (XFEATURE_MASK_USER_SUPPORTED & ~XFEATURE_MASK_PKRU) 45 46 /* All currently supported supervisor features */ 47 #define XFEATURE_MASK_SUPERVISOR_SUPPORTED (XFEATURE_MASK_PASID) 48 49 /* 50 * A supervisor state component may not always contain valuable information, 51 * and its size may be huge. Saving/restoring such supervisor state components 52 * at each context switch can cause high CPU and space overhead, which should 53 * be avoided. Such supervisor state components should only be saved/restored 54 * on demand. The on-demand supervisor features are set in this mask. 55 * 56 * Unlike the existing supported supervisor features, an independent supervisor 57 * feature does not allocate a buffer in task->fpu, and the corresponding 58 * supervisor state component cannot be saved/restored at each context switch. 59 * 60 * To support an independent supervisor feature, a developer should follow the 61 * dos and don'ts as below: 62 * - Do dynamically allocate a buffer for the supervisor state component. 63 * - Do manually invoke the XSAVES/XRSTORS instruction to save/restore the 64 * state component to/from the buffer. 65 * - Don't set the bit corresponding to the independent supervisor feature in 66 * IA32_XSS at run time, since it has been set at boot time. 67 */ 68 #define XFEATURE_MASK_INDEPENDENT (XFEATURE_MASK_LBR) 69 70 /* 71 * Unsupported supervisor features. When a supervisor feature in this mask is 72 * supported in the future, move it to the supported supervisor feature mask. 73 */ 74 #define XFEATURE_MASK_SUPERVISOR_UNSUPPORTED (XFEATURE_MASK_PT) 75 76 /* All supervisor states including supported and unsupported states. */ 77 #define XFEATURE_MASK_SUPERVISOR_ALL (XFEATURE_MASK_SUPERVISOR_SUPPORTED | \ 78 XFEATURE_MASK_INDEPENDENT | \ 79 XFEATURE_MASK_SUPERVISOR_UNSUPPORTED) 80 81 #ifdef CONFIG_X86_64 82 #define REX_PREFIX "0x48, " 83 #else 84 #define REX_PREFIX 85 #endif 86 87 extern u64 xfeatures_mask_all; 88 89 static inline u64 xfeatures_mask_supervisor(void) 90 { 91 return xfeatures_mask_all & XFEATURE_MASK_SUPERVISOR_SUPPORTED; 92 } 93 94 /* 95 * The xfeatures which are enabled in XCR0 and expected to be in ptrace 96 * buffers and signal frames. 97 */ 98 static inline u64 xfeatures_mask_uabi(void) 99 { 100 return xfeatures_mask_all & XFEATURE_MASK_USER_SUPPORTED; 101 } 102 103 /* 104 * The xfeatures which are restored by the kernel when returning to user 105 * mode. This is not necessarily the same as xfeatures_mask_uabi() as the 106 * kernel does not manage all XCR0 enabled features via xsave/xrstor as 107 * some of them have to be switched eagerly on context switch and exec(). 108 */ 109 static inline u64 xfeatures_mask_restore_user(void) 110 { 111 return xfeatures_mask_all & XFEATURE_MASK_USER_RESTORE; 112 } 113 114 /* 115 * Like xfeatures_mask_restore_user() but additionally restors the 116 * supported supervisor states. 117 */ 118 static inline u64 xfeatures_mask_fpstate(void) 119 { 120 return xfeatures_mask_all & \ 121 (XFEATURE_MASK_USER_RESTORE | XFEATURE_MASK_SUPERVISOR_SUPPORTED); 122 } 123 124 static inline u64 xfeatures_mask_independent(void) 125 { 126 if (!boot_cpu_has(X86_FEATURE_ARCH_LBR)) 127 return XFEATURE_MASK_INDEPENDENT & ~XFEATURE_MASK_LBR; 128 129 return XFEATURE_MASK_INDEPENDENT; 130 } 131 132 extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS]; 133 134 extern void __init update_regset_xstate_info(unsigned int size, 135 u64 xstate_mask); 136 137 void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr); 138 int xfeature_size(int xfeature_nr); 139 int copy_uabi_from_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf); 140 int copy_sigframe_from_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf); 141 142 void xsaves(struct xregs_state *xsave, u64 mask); 143 void xrstors(struct xregs_state *xsave, u64 mask); 144 145 enum xstate_copy_mode { 146 XSTATE_COPY_FP, 147 XSTATE_COPY_FX, 148 XSTATE_COPY_XSAVE, 149 }; 150 151 struct membuf; 152 void copy_xstate_to_uabi_buf(struct membuf to, struct task_struct *tsk, 153 enum xstate_copy_mode mode); 154 155 #endif 156