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