Line data    Source code

       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