1  /* SPDX-License-Identifier: GPL-2.0 */
2  #ifndef __LINUX_ENTRYKVM_H
3  #define __LINUX_ENTRYKVM_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_KVM_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_SIGPENDING | _TIF_NOTIFY_SIGNAL |	\
21  	 _TIF_NOTIFY_RESUME | ARCH_XFER_TO_GUEST_MODE_WORK)
22  
23  struct kvm_vcpu;
24  
25  /**
26   * arch_xfer_to_guest_mode_handle_work - Architecture specific xfer to guest
27   *					 mode work handling function.
28   * @vcpu:	Pointer to current's VCPU data
29   * @ti_work:	Cached TIF flags gathered in xfer_to_guest_mode_handle_work()
30   *
31   * Invoked from xfer_to_guest_mode_handle_work(). Defaults to NOOP. Can be
32   * replaced by architecture specific code.
33   */
34  static inline int arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu,
35  						      unsigned long ti_work);
36  
37  #ifndef arch_xfer_to_guest_mode_work
arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu * vcpu,unsigned long ti_work)38  static inline int arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu,
39  						      unsigned long ti_work)
40  {
41  	return 0;
42  }
43  #endif
44  
45  /**
46   * xfer_to_guest_mode_handle_work - Check and handle pending work which needs
47   *				    to be handled before going to guest mode
48   * @vcpu:	Pointer to current's VCPU data
49   *
50   * Returns: 0 or an error code
51   */
52  int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu);
53  
54  /**
55   * xfer_to_guest_mode_prepare - Perform last minute preparation work that
56   *				need to be handled while IRQs are disabled
57   *				upon entering to guest.
58   *
59   * Has to be invoked with interrupts disabled before the last call
60   * to xfer_to_guest_mode_work_pending().
61   */
xfer_to_guest_mode_prepare(void)62  static inline void xfer_to_guest_mode_prepare(void)
63  {
64  	lockdep_assert_irqs_disabled();
65  	tick_nohz_user_enter_prepare();
66  }
67  
68  /**
69   * __xfer_to_guest_mode_work_pending - Check if work is pending
70   *
71   * Returns: True if work pending, False otherwise.
72   *
73   * Bare variant of xfer_to_guest_mode_work_pending(). Can be called from
74   * interrupt enabled code for racy quick checks with care.
75   */
__xfer_to_guest_mode_work_pending(void)76  static inline bool __xfer_to_guest_mode_work_pending(void)
77  {
78  	unsigned long ti_work = read_thread_flags();
79  
80  	return !!(ti_work & XFER_TO_GUEST_MODE_WORK);
81  }
82  
83  /**
84   * xfer_to_guest_mode_work_pending - Check if work is pending which needs to be
85   *				     handled before returning to guest mode
86   *
87   * Returns: True if work pending, False otherwise.
88   *
89   * Has to be invoked with interrupts disabled before the transition to
90   * guest mode.
91   */
xfer_to_guest_mode_work_pending(void)92  static inline bool xfer_to_guest_mode_work_pending(void)
93  {
94  	lockdep_assert_irqs_disabled();
95  	return __xfer_to_guest_mode_work_pending();
96  }
97  #endif /* CONFIG_KVM_XFER_TO_GUEST_WORK */
98  
99  #endif
100