xref: /openbmc/linux/arch/x86/include/asm/kvm_para.h (revision f125e2d4)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_KVM_PARA_H
3 #define _ASM_X86_KVM_PARA_H
4 
5 #include <asm/processor.h>
6 #include <asm/alternative.h>
7 #include <uapi/asm/kvm_para.h>
8 
9 extern void kvmclock_init(void);
10 
11 #ifdef CONFIG_KVM_GUEST
12 bool kvm_check_and_clear_guest_paused(void);
13 #else
14 static inline bool kvm_check_and_clear_guest_paused(void)
15 {
16 	return false;
17 }
18 #endif /* CONFIG_KVM_GUEST */
19 
20 #define KVM_HYPERCALL \
21         ALTERNATIVE(".byte 0x0f,0x01,0xc1", ".byte 0x0f,0x01,0xd9", X86_FEATURE_VMMCALL)
22 
23 /* For KVM hypercalls, a three-byte sequence of either the vmcall or the vmmcall
24  * instruction.  The hypervisor may replace it with something else but only the
25  * instructions are guaranteed to be supported.
26  *
27  * Up to four arguments may be passed in rbx, rcx, rdx, and rsi respectively.
28  * The hypercall number should be placed in rax and the return value will be
29  * placed in rax.  No other registers will be clobbered unless explicitly
30  * noted by the particular hypercall.
31  */
32 
33 static inline long kvm_hypercall0(unsigned int nr)
34 {
35 	long ret;
36 	asm volatile(KVM_HYPERCALL
37 		     : "=a"(ret)
38 		     : "a"(nr)
39 		     : "memory");
40 	return ret;
41 }
42 
43 static inline long kvm_hypercall1(unsigned int nr, unsigned long p1)
44 {
45 	long ret;
46 	asm volatile(KVM_HYPERCALL
47 		     : "=a"(ret)
48 		     : "a"(nr), "b"(p1)
49 		     : "memory");
50 	return ret;
51 }
52 
53 static inline long kvm_hypercall2(unsigned int nr, unsigned long p1,
54 				  unsigned long p2)
55 {
56 	long ret;
57 	asm volatile(KVM_HYPERCALL
58 		     : "=a"(ret)
59 		     : "a"(nr), "b"(p1), "c"(p2)
60 		     : "memory");
61 	return ret;
62 }
63 
64 static inline long kvm_hypercall3(unsigned int nr, unsigned long p1,
65 				  unsigned long p2, unsigned long p3)
66 {
67 	long ret;
68 	asm volatile(KVM_HYPERCALL
69 		     : "=a"(ret)
70 		     : "a"(nr), "b"(p1), "c"(p2), "d"(p3)
71 		     : "memory");
72 	return ret;
73 }
74 
75 static inline long kvm_hypercall4(unsigned int nr, unsigned long p1,
76 				  unsigned long p2, unsigned long p3,
77 				  unsigned long p4)
78 {
79 	long ret;
80 	asm volatile(KVM_HYPERCALL
81 		     : "=a"(ret)
82 		     : "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4)
83 		     : "memory");
84 	return ret;
85 }
86 
87 #ifdef CONFIG_KVM_GUEST
88 bool kvm_para_available(void);
89 unsigned int kvm_arch_para_features(void);
90 unsigned int kvm_arch_para_hints(void);
91 void kvm_async_pf_task_wait(u32 token, int interrupt_kernel);
92 void kvm_async_pf_task_wake(u32 token);
93 u32 kvm_read_and_reset_pf_reason(void);
94 extern void kvm_disable_steal_time(void);
95 void do_async_page_fault(struct pt_regs *regs, unsigned long error_code, unsigned long address);
96 
97 #ifdef CONFIG_PARAVIRT_SPINLOCKS
98 void __init kvm_spinlock_init(void);
99 #else /* !CONFIG_PARAVIRT_SPINLOCKS */
100 static inline void kvm_spinlock_init(void)
101 {
102 }
103 #endif /* CONFIG_PARAVIRT_SPINLOCKS */
104 
105 #else /* CONFIG_KVM_GUEST */
106 #define kvm_async_pf_task_wait(T, I) do {} while(0)
107 #define kvm_async_pf_task_wake(T) do {} while(0)
108 
109 static inline bool kvm_para_available(void)
110 {
111 	return false;
112 }
113 
114 static inline unsigned int kvm_arch_para_features(void)
115 {
116 	return 0;
117 }
118 
119 static inline unsigned int kvm_arch_para_hints(void)
120 {
121 	return 0;
122 }
123 
124 static inline u32 kvm_read_and_reset_pf_reason(void)
125 {
126 	return 0;
127 }
128 
129 static inline void kvm_disable_steal_time(void)
130 {
131 	return;
132 }
133 #endif
134 
135 #endif /* _ASM_X86_KVM_PARA_H */
136