Line data    Source code

       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             : #define XSAVE_ALIGNMENT     64
      25             : 
      26             : /* All currently supported user features */
      27             : #define XFEATURE_MASK_USER_SUPPORTED (XFEATURE_MASK_FP | \
      28             :                                       XFEATURE_MASK_SSE | \
      29             :                                       XFEATURE_MASK_YMM | \
      30             :                                       XFEATURE_MASK_OPMASK | \
      31             :                                       XFEATURE_MASK_ZMM_Hi256 | \
      32             :                                       XFEATURE_MASK_Hi16_ZMM     | \
      33             :                                       XFEATURE_MASK_PKRU | \
      34             :                                       XFEATURE_MASK_BNDREGS | \
      35             :                                       XFEATURE_MASK_BNDCSR)
      36             : 
      37             : /* All currently supported supervisor features */
      38             : #define XFEATURE_MASK_SUPERVISOR_SUPPORTED (XFEATURE_MASK_PASID)
      39             : 
      40             : /*
      41             :  * A supervisor state component may not always contain valuable information,
      42             :  * and its size may be huge. Saving/restoring such supervisor state components
      43             :  * at each context switch can cause high CPU and space overhead, which should
      44             :  * be avoided. Such supervisor state components should only be saved/restored
      45             :  * on demand. The on-demand dynamic supervisor features are set in this mask.
      46             :  *
      47             :  * Unlike the existing supported supervisor features, a dynamic supervisor
      48             :  * feature does not allocate a buffer in task->fpu, and the corresponding
      49             :  * supervisor state component cannot be saved/restored at each context switch.
      50             :  *
      51             :  * To support a dynamic supervisor feature, a developer should follow the
      52             :  * dos and don'ts as below:
      53             :  * - Do dynamically allocate a buffer for the supervisor state component.
      54             :  * - Do manually invoke the XSAVES/XRSTORS instruction to save/restore the
      55             :  *   state component to/from the buffer.
      56             :  * - Don't set the bit corresponding to the dynamic supervisor feature in
      57             :  *   IA32_XSS at run time, since it has been set at boot time.
      58             :  */
      59             : #define XFEATURE_MASK_DYNAMIC (XFEATURE_MASK_LBR)
      60             : 
      61             : /*
      62             :  * Unsupported supervisor features. When a supervisor feature in this mask is
      63             :  * supported in the future, move it to the supported supervisor feature mask.
      64             :  */
      65             : #define XFEATURE_MASK_SUPERVISOR_UNSUPPORTED (XFEATURE_MASK_PT)
      66             : 
      67             : /* All supervisor states including supported and unsupported states. */
      68             : #define XFEATURE_MASK_SUPERVISOR_ALL (XFEATURE_MASK_SUPERVISOR_SUPPORTED | \
      69             :                                       XFEATURE_MASK_DYNAMIC | \
      70             :                                       XFEATURE_MASK_SUPERVISOR_UNSUPPORTED)
      71             : 
      72             : #ifdef CONFIG_X86_64
      73             : #define REX_PREFIX      "0x48, "
      74             : #else
      75             : #define REX_PREFIX
      76             : #endif
      77             : 
      78             : extern u64 xfeatures_mask_all;
      79             : 
      80           0 : static inline u64 xfeatures_mask_supervisor(void)
      81             : {
      82           0 :         return xfeatures_mask_all & XFEATURE_MASK_SUPERVISOR_SUPPORTED;
      83             : }
      84             : 
      85        4262 : static inline u64 xfeatures_mask_user(void)
      86             : {
      87        4261 :         return xfeatures_mask_all & XFEATURE_MASK_USER_SUPPORTED;
      88             : }
      89             : 
      90           0 : static inline u64 xfeatures_mask_dynamic(void)
      91             : {
      92           0 :         if (!boot_cpu_has(X86_FEATURE_ARCH_LBR))
      93           0 :                 return XFEATURE_MASK_DYNAMIC & ~XFEATURE_MASK_LBR;
      94             : 
      95             :         return XFEATURE_MASK_DYNAMIC;
      96             : }
      97             : 
      98             : extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
      99             : 
     100             : extern void __init update_regset_xstate_info(unsigned int size,
     101             :                                              u64 xstate_mask);
     102             : 
     103             : void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr);
     104             : const void *get_xsave_field_ptr(int xfeature_nr);
     105             : int using_compacted_format(void);
     106             : int xfeature_size(int xfeature_nr);
     107             : struct membuf;
     108             : void copy_xstate_to_kernel(struct membuf to, struct xregs_state *xsave);
     109             : int copy_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf);
     110             : int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf);
     111             : void copy_supervisor_to_kernel(struct xregs_state *xsave);
     112             : void copy_dynamic_supervisor_to_kernel(struct xregs_state *xstate, u64 mask);
     113             : void copy_kernel_to_dynamic_supervisor(struct xregs_state *xstate, u64 mask);
     114             : 
     115             : 
     116             : /* Validate an xstate header supplied by userspace (ptrace or sigreturn) */
     117             : int validate_user_xstate_header(const struct xstate_header *hdr);
     118             : 
     119             : #endif