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