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       1                 :            : /* SPDX-License-Identifier: GPL-2.0 */
       2                 :            : #ifndef _ASM_X86_SPECCTRL_H_
       3                 :            : #define _ASM_X86_SPECCTRL_H_
       4                 :            : 
       5                 :            : #include <linux/thread_info.h>
       6                 :            : #include <asm/nospec-branch.h>
       7                 :            : 
       8                 :            : /*
       9                 :            :  * On VMENTER we must preserve whatever view of the SPEC_CTRL MSR
      10                 :            :  * the guest has, while on VMEXIT we restore the host view. This
      11                 :            :  * would be easier if SPEC_CTRL were architecturally maskable or
      12                 :            :  * shadowable for guests but this is not (currently) the case.
      13                 :            :  * Takes the guest view of SPEC_CTRL MSR as a parameter and also
      14                 :            :  * the guest's version of VIRT_SPEC_CTRL, if emulated.
      15                 :            :  */
      16                 :            : extern void x86_virt_spec_ctrl(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl, bool guest);
      17                 :            : 
      18                 :            : /**
      19                 :            :  * x86_spec_ctrl_set_guest - Set speculation control registers for the guest
      20                 :            :  * @guest_spec_ctrl:            The guest content of MSR_SPEC_CTRL
      21                 :            :  * @guest_virt_spec_ctrl:       The guest controlled bits of MSR_VIRT_SPEC_CTRL
      22                 :            :  *                              (may get translated to MSR_AMD64_LS_CFG bits)
      23                 :            :  *
      24                 :            :  * Avoids writing to the MSR if the content/bits are the same
      25                 :            :  */
      26                 :            : static inline
      27                 :            : void x86_spec_ctrl_set_guest(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl)
      28                 :            : {
      29                 :            :         x86_virt_spec_ctrl(guest_spec_ctrl, guest_virt_spec_ctrl, true);
      30                 :            : }
      31                 :            : 
      32                 :            : /**
      33                 :            :  * x86_spec_ctrl_restore_host - Restore host speculation control registers
      34                 :            :  * @guest_spec_ctrl:            The guest content of MSR_SPEC_CTRL
      35                 :            :  * @guest_virt_spec_ctrl:       The guest controlled bits of MSR_VIRT_SPEC_CTRL
      36                 :            :  *                              (may get translated to MSR_AMD64_LS_CFG bits)
      37                 :            :  *
      38                 :            :  * Avoids writing to the MSR if the content/bits are the same
      39                 :            :  */
      40                 :            : static inline
      41                 :            : void x86_spec_ctrl_restore_host(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl)
      42                 :            : {
      43                 :            :         x86_virt_spec_ctrl(guest_spec_ctrl, guest_virt_spec_ctrl, false);
      44                 :            : }
      45                 :            : 
      46                 :            : /* AMD specific Speculative Store Bypass MSR data */
      47                 :            : extern u64 x86_amd_ls_cfg_base;
      48                 :            : extern u64 x86_amd_ls_cfg_ssbd_mask;
      49                 :            : 
      50                 :          0 : static inline u64 ssbd_tif_to_spec_ctrl(u64 tifn)
      51                 :            : {
      52                 :          0 :         BUILD_BUG_ON(TIF_SSBD < SPEC_CTRL_SSBD_SHIFT);
      53                 :          0 :         return (tifn & _TIF_SSBD) >> (TIF_SSBD - SPEC_CTRL_SSBD_SHIFT);
      54                 :            : }
      55                 :            : 
      56                 :          0 : static inline u64 stibp_tif_to_spec_ctrl(u64 tifn)
      57                 :            : {
      58                 :          0 :         BUILD_BUG_ON(TIF_SPEC_IB < SPEC_CTRL_STIBP_SHIFT);
      59                 :          0 :         return (tifn & _TIF_SPEC_IB) >> (TIF_SPEC_IB - SPEC_CTRL_STIBP_SHIFT);
      60                 :            : }
      61                 :            : 
      62                 :          0 : static inline unsigned long ssbd_spec_ctrl_to_tif(u64 spec_ctrl)
      63                 :            : {
      64                 :          0 :         BUILD_BUG_ON(TIF_SSBD < SPEC_CTRL_SSBD_SHIFT);
      65                 :          0 :         return (spec_ctrl & SPEC_CTRL_SSBD) << (TIF_SSBD - SPEC_CTRL_SSBD_SHIFT);
      66                 :            : }
      67                 :            : 
      68                 :            : static inline unsigned long stibp_spec_ctrl_to_tif(u64 spec_ctrl)
      69                 :            : {
      70                 :            :         BUILD_BUG_ON(TIF_SPEC_IB < SPEC_CTRL_STIBP_SHIFT);
      71                 :            :         return (spec_ctrl & SPEC_CTRL_STIBP) << (TIF_SPEC_IB - SPEC_CTRL_STIBP_SHIFT);
      72                 :            : }
      73                 :            : 
      74                 :          0 : static inline u64 ssbd_tif_to_amd_ls_cfg(u64 tifn)
      75                 :            : {
      76   [ -  -  -  -  :          0 :         return (tifn & _TIF_SSBD) ? x86_amd_ls_cfg_ssbd_mask : 0ULL;
                   -  - ]
      77                 :            : }
      78                 :            : 
      79                 :            : #ifdef CONFIG_SMP
      80                 :            : extern void speculative_store_bypass_ht_init(void);
      81                 :            : #else
      82                 :            : static inline void speculative_store_bypass_ht_init(void) { }
      83                 :            : #endif
      84                 :            : 
      85                 :            : extern void speculation_ctrl_update(unsigned long tif);
      86                 :            : extern void speculation_ctrl_update_current(void);
      87                 :            : 
      88                 :            : #endif