xref: /openbmc/linux/arch/x86/include/asm/kvm_para.h (revision f7018c21)
1 #ifndef _ASM_X86_KVM_PARA_H
2 #define _ASM_X86_KVM_PARA_H
3 
4 #include <asm/processor.h>
5 #include <uapi/asm/kvm_para.h>
6 
7 extern void kvmclock_init(void);
8 extern int kvm_register_clock(char *txt);
9 
10 #ifdef CONFIG_KVM_GUEST
11 bool kvm_check_and_clear_guest_paused(void);
12 #else
13 static inline bool kvm_check_and_clear_guest_paused(void)
14 {
15 	return false;
16 }
17 #endif /* CONFIG_KVM_GUEST */
18 
19 /* This instruction is vmcall.  On non-VT architectures, it will generate a
20  * trap that we will then rewrite to the appropriate instruction.
21  */
22 #define KVM_HYPERCALL ".byte 0x0f,0x01,0xc1"
23 
24 /* For KVM hypercalls, a three-byte sequence of either the vmcall or the vmmcall
25  * instruction.  The hypervisor may replace it with something else but only the
26  * instructions are guaranteed to be supported.
27  *
28  * Up to four arguments may be passed in rbx, rcx, rdx, and rsi respectively.
29  * The hypercall number should be placed in rax and the return value will be
30  * placed in rax.  No other registers will be clobbered unless explicitly
31  * noted by the particular hypercall.
32  */
33 
34 static inline long kvm_hypercall0(unsigned int nr)
35 {
36 	long ret;
37 	asm volatile(KVM_HYPERCALL
38 		     : "=a"(ret)
39 		     : "a"(nr)
40 		     : "memory");
41 	return ret;
42 }
43 
44 static inline long kvm_hypercall1(unsigned int nr, unsigned long p1)
45 {
46 	long ret;
47 	asm volatile(KVM_HYPERCALL
48 		     : "=a"(ret)
49 		     : "a"(nr), "b"(p1)
50 		     : "memory");
51 	return ret;
52 }
53 
54 static inline long kvm_hypercall2(unsigned int nr, unsigned long p1,
55 				  unsigned long p2)
56 {
57 	long ret;
58 	asm volatile(KVM_HYPERCALL
59 		     : "=a"(ret)
60 		     : "a"(nr), "b"(p1), "c"(p2)
61 		     : "memory");
62 	return ret;
63 }
64 
65 static inline long kvm_hypercall3(unsigned int nr, unsigned long p1,
66 				  unsigned long p2, unsigned long p3)
67 {
68 	long ret;
69 	asm volatile(KVM_HYPERCALL
70 		     : "=a"(ret)
71 		     : "a"(nr), "b"(p1), "c"(p2), "d"(p3)
72 		     : "memory");
73 	return ret;
74 }
75 
76 static inline long kvm_hypercall4(unsigned int nr, unsigned long p1,
77 				  unsigned long p2, unsigned long p3,
78 				  unsigned long p4)
79 {
80 	long ret;
81 	asm volatile(KVM_HYPERCALL
82 		     : "=a"(ret)
83 		     : "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4)
84 		     : "memory");
85 	return ret;
86 }
87 
88 #ifdef CONFIG_KVM_GUEST
89 bool kvm_para_available(void);
90 unsigned int kvm_arch_para_features(void);
91 void __init kvm_guest_init(void);
92 void kvm_async_pf_task_wait(u32 token);
93 void kvm_async_pf_task_wake(u32 token);
94 u32 kvm_read_and_reset_pf_reason(void);
95 extern void kvm_disable_steal_time(void);
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_guest_init() do {} while (0)
107 #define kvm_async_pf_task_wait(T) do {} while(0)
108 #define kvm_async_pf_task_wake(T) do {} while(0)
109 
110 static inline bool kvm_para_available(void)
111 {
112 	return 0;
113 }
114 
115 static inline unsigned int kvm_arch_para_features(void)
116 {
117 	return 0;
118 }
119 
120 static inline u32 kvm_read_and_reset_pf_reason(void)
121 {
122 	return 0;
123 }
124 
125 static inline void kvm_disable_steal_time(void)
126 {
127 	return;
128 }
129 #endif
130 
131 #endif /* _ASM_X86_KVM_PARA_H */
132