xref: /linux-6.15/include/linux/entry-kvm.h (revision d3003d9e)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_ENTRYKVM_H
3 #define __LINUX_ENTRYKVM_H
4 
5 #include <linux/entry-common.h>
6 
7 /* Transfer to guest mode work */
8 #ifdef CONFIG_KVM_XFER_TO_GUEST_WORK
9 
10 #ifndef ARCH_XFER_TO_GUEST_MODE_WORK
11 # define ARCH_XFER_TO_GUEST_MODE_WORK	(0)
12 #endif
13 
14 #define XFER_TO_GUEST_MODE_WORK						\
15 	(_TIF_NEED_RESCHED | _TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL |	\
16 	 _TIF_NOTIFY_RESUME | ARCH_XFER_TO_GUEST_MODE_WORK)
17 
18 struct kvm_vcpu;
19 
20 /**
21  * arch_xfer_to_guest_mode_handle_work - Architecture specific xfer to guest
22  *					 mode work handling function.
23  * @vcpu:	Pointer to current's VCPU data
24  * @ti_work:	Cached TIF flags gathered in xfer_to_guest_mode_handle_work()
25  *
26  * Invoked from xfer_to_guest_mode_handle_work(). Defaults to NOOP. Can be
27  * replaced by architecture specific code.
28  */
29 static inline int arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu,
30 						      unsigned long ti_work);
31 
32 #ifndef arch_xfer_to_guest_mode_work
33 static inline int arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu,
34 						      unsigned long ti_work)
35 {
36 	return 0;
37 }
38 #endif
39 
40 /**
41  * xfer_to_guest_mode_handle_work - Check and handle pending work which needs
42  *				    to be handled before going to guest mode
43  * @vcpu:	Pointer to current's VCPU data
44  *
45  * Returns: 0 or an error code
46  */
47 int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu);
48 
49 /**
50  * xfer_to_guest_mode_prepare - Perform last minute preparation work that
51  *				need to be handled while IRQs are disabled
52  *				upon entering to guest.
53  *
54  * Has to be invoked with interrupts disabled before the last call
55  * to xfer_to_guest_mode_work_pending().
56  */
57 static inline void xfer_to_guest_mode_prepare(void)
58 {
59 	lockdep_assert_irqs_disabled();
60 	rcu_nocb_flush_deferred_wakeup();
61 }
62 
63 /**
64  * __xfer_to_guest_mode_work_pending - Check if work is pending
65  *
66  * Returns: True if work pending, False otherwise.
67  *
68  * Bare variant of xfer_to_guest_mode_work_pending(). Can be called from
69  * interrupt enabled code for racy quick checks with care.
70  */
71 static inline bool __xfer_to_guest_mode_work_pending(void)
72 {
73 	unsigned long ti_work = READ_ONCE(current_thread_info()->flags);
74 
75 	return !!(ti_work & XFER_TO_GUEST_MODE_WORK);
76 }
77 
78 /**
79  * xfer_to_guest_mode_work_pending - Check if work is pending which needs to be
80  *				     handled before returning to guest mode
81  *
82  * Returns: True if work pending, False otherwise.
83  *
84  * Has to be invoked with interrupts disabled before the transition to
85  * guest mode.
86  */
87 static inline bool xfer_to_guest_mode_work_pending(void)
88 {
89 	lockdep_assert_irqs_disabled();
90 	return __xfer_to_guest_mode_work_pending();
91 }
92 #endif /* CONFIG_KVM_XFER_TO_GUEST_WORK */
93 
94 #endif
95