entry-virt.h

 1/* SPDX-License-Identifier: GPL-2.0 */
 2#ifndef __LINUX_ENTRYVIRT_H
 3#define __LINUX_ENTRYVIRT_H
 4
 5#include <linux/static_call_types.h>
 6#include <linux/resume_user_mode.h>
 7#include <linux/syscalls.h>
 8#include <linux/seccomp.h>
 9#include <linux/sched.h>
10#include <linux/tick.h>
11
12/* Transfer to guest mode work */
13#ifdef CONFIG_VIRT_XFER_TO_GUEST_WORK
14
15#ifndef ARCH_XFER_TO_GUEST_MODE_WORK
16# define ARCH_XFER_TO_GUEST_MODE_WORK	(0)
17#endif
18
19#define XFER_TO_GUEST_MODE_WORK						\
20	(_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY | _TIF_SIGPENDING | \
21	 _TIF_NOTIFY_SIGNAL | _TIF_NOTIFY_RESUME |			\
22	 ARCH_XFER_TO_GUEST_MODE_WORK)
23
24/**
25 * arch_xfer_to_guest_mode_handle_work - Architecture specific xfer to guest
26 *					 mode work handling function.
27 * @vcpu:	Pointer to current's VCPU data
28 * @ti_work:	Cached TIF flags gathered in xfer_to_guest_mode_handle_work()
29 *
30 * Invoked from xfer_to_guest_mode_handle_work(). Defaults to NOOP. Can be
31 * replaced by architecture specific code.
32 */
33static inline int arch_xfer_to_guest_mode_handle_work(unsigned long ti_work);
34
35#ifndef arch_xfer_to_guest_mode_handle_work
36static inline int arch_xfer_to_guest_mode_handle_work(unsigned long ti_work)
37{
38	return 0;
39}
40#endif
41
42/**
43 * xfer_to_guest_mode_handle_work - Check and handle pending work which needs
44 *				    to be handled before going to guest mode
45 *
46 * Returns: 0 or an error code
47 */
48int xfer_to_guest_mode_handle_work(void);
49
50/**
51 * xfer_to_guest_mode_prepare - Perform last minute preparation work that
52 *				need to be handled while IRQs are disabled
53 *				upon entering to guest.
54 *
55 * Has to be invoked with interrupts disabled before the last call
56 * to xfer_to_guest_mode_work_pending().
57 */
58static inline void xfer_to_guest_mode_prepare(void)
59{
60	lockdep_assert_irqs_disabled();
61	tick_nohz_user_enter_prepare();
62}
63
64/**
65 * __xfer_to_guest_mode_work_pending - Check if work is pending
66 *
67 * Returns: True if work pending, False otherwise.
68 *
69 * Bare variant of xfer_to_guest_mode_work_pending(). Can be called from
70 * interrupt enabled code for racy quick checks with care.
71 */
72static inline bool __xfer_to_guest_mode_work_pending(void)
73{
74	unsigned long ti_work = read_thread_flags();
75
76	return !!(ti_work & XFER_TO_GUEST_MODE_WORK);
77}
78
79/**
80 * xfer_to_guest_mode_work_pending - Check if work is pending which needs to be
81 *				     handled before returning to guest mode
82 *
83 * Returns: True if work pending, False otherwise.
84 *
85 * Has to be invoked with interrupts disabled before the transition to
86 * guest mode.
87 */
88static inline bool xfer_to_guest_mode_work_pending(void)
89{
90	lockdep_assert_irqs_disabled();
91	return __xfer_to_guest_mode_work_pending();
92}
93#endif /* CONFIG_VIRT_XFER_TO_GUEST_WORK */
94
95#endif