LXR linux/arch/x86/include/asm/spec-ctrl.h

   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 */
  16extern 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 */
  26static inline
  27void 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 */
  40static inline
  41void 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 */
  47extern u64 x86_amd_ls_cfg_base;
  48extern u64 x86_amd_ls_cfg_ssbd_mask;
  49
  50static inline u64 ssbd_tif_to_spec_ctrl(u64 tifn)
  51{
  52        BUILD_BUG_ON(TIF_SSBD < SPEC_CTRL_SSBD_SHIFT);
  53        return (tifn & _TIF_SSBD) >> (TIF_SSBD - SPEC_CTRL_SSBD_SHIFT);
  54}
  55
  56static inline u64 stibp_tif_to_spec_ctrl(u64 tifn)
  57{
  58        BUILD_BUG_ON(TIF_SPEC_IB < SPEC_CTRL_STIBP_SHIFT);
  59        return (tifn & _TIF_SPEC_IB) >> (TIF_SPEC_IB - SPEC_CTRL_STIBP_SHIFT);
  60}
  61
  62static inline unsigned long ssbd_spec_ctrl_to_tif(u64 spec_ctrl)
  63{
  64        BUILD_BUG_ON(TIF_SSBD < SPEC_CTRL_SSBD_SHIFT);
  65        return (spec_ctrl & SPEC_CTRL_SSBD) << (TIF_SSBD - SPEC_CTRL_SSBD_SHIFT);
  66}
  67
  68static 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
  74static inline u64 ssbd_tif_to_amd_ls_cfg(u64 tifn)
  75{
  76        return (tifn & _TIF_SSBD) ? x86_amd_ls_cfg_ssbd_mask : 0ULL;
  77}
  78
  79#ifdef CONFIG_SMP
  80extern void speculative_store_bypass_ht_init(void);
  81#else
  82static inline void speculative_store_bypass_ht_init(void) { }
  83#endif
  84
  85extern void speculation_ctrl_update(unsigned long tif);
  86extern void speculation_ctrl_update_current(void);
  87
  88#endif
  89