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/user.h> 10 11 /* Bit 63 of XCR0 is reserved for future expansion */ 12 #define XFEATURE_MASK_EXTEND (~(XFEATURE_MASK_FPSSE | (1ULL << 63))) 13 14 #define XSTATE_CPUID 0x0000000d 15 16 #define FXSAVE_SIZE 512 17 18 #define XSAVE_HDR_SIZE 64 19 #define XSAVE_HDR_OFFSET FXSAVE_SIZE 20 21 #define XSAVE_YMM_SIZE 256 22 #define XSAVE_YMM_OFFSET (XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET) 23 24 /* All currently supported user features */ 25 #define XFEATURE_MASK_USER_SUPPORTED (XFEATURE_MASK_FP | \ 26 XFEATURE_MASK_SSE | \ 27 XFEATURE_MASK_YMM | \ 28 XFEATURE_MASK_OPMASK | \ 29 XFEATURE_MASK_ZMM_Hi256 | \ 30 XFEATURE_MASK_Hi16_ZMM | \ 31 XFEATURE_MASK_PKRU | \ 32 XFEATURE_MASK_BNDREGS | \ 33 XFEATURE_MASK_BNDCSR) 34 35 /* All currently supported supervisor features */ 36 #define XFEATURE_MASK_SUPERVISOR_SUPPORTED (0) 37 38 /* 39 * A supervisor state component may not always contain valuable information, 40 * and its size may be huge. Saving/restoring such supervisor state components 41 * at each context switch can cause high CPU and space overhead, which should 42 * be avoided. Such supervisor state components should only be saved/restored 43 * on demand. The on-demand dynamic supervisor features are set in this mask. 44 * 45 * Unlike the existing supported supervisor features, a dynamic supervisor 46 * feature does not allocate a buffer in task->fpu, and the corresponding 47 * supervisor state component cannot be saved/restored at each context switch. 48 * 49 * To support a dynamic supervisor feature, a developer should follow the 50 * dos and don'ts as below: 51 * - Do dynamically allocate a buffer for the supervisor state component. 52 * - Do manually invoke the XSAVES/XRSTORS instruction to save/restore the 53 * state component to/from the buffer. 54 * - Don't set the bit corresponding to the dynamic supervisor feature in 55 * IA32_XSS at run time, since it has been set at boot time. 56 */ 57 #define XFEATURE_MASK_DYNAMIC (XFEATURE_MASK_LBR) 58 59 /* 60 * Unsupported supervisor features. When a supervisor feature in this mask is 61 * supported in the future, move it to the supported supervisor feature mask. 62 */ 63 #define XFEATURE_MASK_SUPERVISOR_UNSUPPORTED (XFEATURE_MASK_PT) 64 65 /* All supervisor states including supported and unsupported states. */ 66 #define XFEATURE_MASK_SUPERVISOR_ALL (XFEATURE_MASK_SUPERVISOR_SUPPORTED | \ 67 XFEATURE_MASK_DYNAMIC | \ 68 XFEATURE_MASK_SUPERVISOR_UNSUPPORTED) 69 70 #ifdef CONFIG_X86_64 71 #define REX_PREFIX "0x48, " 72 #else 73 #define REX_PREFIX 74 #endif 75 76 extern u64 xfeatures_mask_all; 77 78 static inline u64 xfeatures_mask_supervisor(void) 79 { 80 return xfeatures_mask_all & XFEATURE_MASK_SUPERVISOR_SUPPORTED; 81 } 82 83 static inline u64 xfeatures_mask_user(void) 84 { 85 return xfeatures_mask_all & XFEATURE_MASK_USER_SUPPORTED; 86 } 87 88 static inline u64 xfeatures_mask_dynamic(void) 89 { 90 if (!boot_cpu_has(X86_FEATURE_ARCH_LBR)) 91 return XFEATURE_MASK_DYNAMIC & ~XFEATURE_MASK_LBR; 92 93 return XFEATURE_MASK_DYNAMIC; 94 } 95 96 extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS]; 97 98 extern void __init update_regset_xstate_info(unsigned int size, 99 u64 xstate_mask); 100 101 void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr); 102 const void *get_xsave_field_ptr(int xfeature_nr); 103 int using_compacted_format(void); 104 int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int offset, unsigned int size); 105 int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned int offset, unsigned int size); 106 int copy_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf); 107 int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf); 108 void copy_supervisor_to_kernel(struct xregs_state *xsave); 109 void copy_dynamic_supervisor_to_kernel(struct xregs_state *xstate, u64 mask); 110 void copy_kernel_to_dynamic_supervisor(struct xregs_state *xstate, u64 mask); 111 112 113 /* Validate an xstate header supplied by userspace (ptrace or sigreturn) */ 114 int validate_user_xstate_header(const struct xstate_header *hdr); 115 116 #endif 117