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_NEED_RESCHED_LAZY | _TIF_SIGPENDING | \
21 	 _TIF_NOTIFY_SIGNAL | _TIF_NOTIFY_RESUME |			\
22 	 ARCH_XFER_TO_GUEST_MODE_WORK)
23 
24 struct kvm_vcpu;
25 
26 /**
27  * arch_xfer_to_guest_mode_handle_work - Architecture specific xfer to guest
28  *					 mode work handling function.
29  * @vcpu:	Pointer to current's VCPU data
30  * @ti_work:	Cached TIF flags gathered in xfer_to_guest_mode_handle_work()
31  *
32  * Invoked from xfer_to_guest_mode_handle_work(). Defaults to NOOP. Can be
33  * replaced by architecture specific code.
34  */
35 static inline int arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu,
36 						      unsigned long ti_work);
37 
38 #ifndef arch_xfer_to_guest_mode_work
arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu * vcpu,unsigned long ti_work)39 static inline int arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu,
40 						      unsigned long ti_work)
41 {
42 	return 0;
43 }
44 #endif
45 
46 /**
47  * xfer_to_guest_mode_handle_work - Check and handle pending work which needs
48  *				    to be handled before going to guest mode
49  * @vcpu:	Pointer to current's VCPU data
50  *
51  * Returns: 0 or an error code
52  */
53 int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu);
54 
55 /**
56  * xfer_to_guest_mode_prepare - Perform last minute preparation work that
57  *				need to be handled while IRQs are disabled
58  *				upon entering to guest.
59  *
60  * Has to be invoked with interrupts disabled before the last call
61  * to xfer_to_guest_mode_work_pending().
62  */
xfer_to_guest_mode_prepare(void)63 static inline void xfer_to_guest_mode_prepare(void)
64 {
65 	lockdep_assert_irqs_disabled();
66 	tick_nohz_user_enter_prepare();
67 }
68 
69 /**
70  * __xfer_to_guest_mode_work_pending - Check if work is pending
71  *
72  * Returns: True if work pending, False otherwise.
73  *
74  * Bare variant of xfer_to_guest_mode_work_pending(). Can be called from
75  * interrupt enabled code for racy quick checks with care.
76  */
__xfer_to_guest_mode_work_pending(void)77 static inline bool __xfer_to_guest_mode_work_pending(void)
78 {
79 	unsigned long ti_work = read_thread_flags();
80 
81 	return !!(ti_work & XFER_TO_GUEST_MODE_WORK);
82 }
83 
84 /**
85  * xfer_to_guest_mode_work_pending - Check if work is pending which needs to be
86  *				     handled before returning to guest mode
87  *
88  * Returns: True if work pending, False otherwise.
89  *
90  * Has to be invoked with interrupts disabled before the transition to
91  * guest mode.
92  */
xfer_to_guest_mode_work_pending(void)93 static inline bool xfer_to_guest_mode_work_pending(void)
94 {
95 	lockdep_assert_irqs_disabled();
96 	return __xfer_to_guest_mode_work_pending();
97 }
98 #endif /* CONFIG_KVM_XFER_TO_GUEST_WORK */
99 
100 #endif
101