xref: /openbmc/linux/arch/x86/include/asm/kvm_para.h (revision 12cecbf9)
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 <linux/interrupt.h>
8 #include <uapi/asm/kvm_para.h>
9 
10 #include <asm/tdx.h>
11 
12 #ifdef CONFIG_KVM_GUEST
13 bool kvm_check_and_clear_guest_paused(void);
14 #else
15 static inline bool kvm_check_and_clear_guest_paused(void)
16 {
17 	return false;
18 }
19 #endif /* CONFIG_KVM_GUEST */
20 
21 #define KVM_HYPERCALL \
22         ALTERNATIVE("vmcall", "vmmcall", X86_FEATURE_VMMCALL)
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 
38 	if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST))
39 		return tdx_kvm_hypercall(nr, 0, 0, 0, 0);
40 
41 	asm volatile(KVM_HYPERCALL
42 		     : "=a"(ret)
43 		     : "a"(nr)
44 		     : "memory");
45 	return ret;
46 }
47 
48 static inline long kvm_hypercall1(unsigned int nr, unsigned long p1)
49 {
50 	long ret;
51 
52 	if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST))
53 		return tdx_kvm_hypercall(nr, p1, 0, 0, 0);
54 
55 	asm volatile(KVM_HYPERCALL
56 		     : "=a"(ret)
57 		     : "a"(nr), "b"(p1)
58 		     : "memory");
59 	return ret;
60 }
61 
62 static inline long kvm_hypercall2(unsigned int nr, unsigned long p1,
63 				  unsigned long p2)
64 {
65 	long ret;
66 
67 	if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST))
68 		return tdx_kvm_hypercall(nr, p1, p2, 0, 0);
69 
70 	asm volatile(KVM_HYPERCALL
71 		     : "=a"(ret)
72 		     : "a"(nr), "b"(p1), "c"(p2)
73 		     : "memory");
74 	return ret;
75 }
76 
77 static inline long kvm_hypercall3(unsigned int nr, unsigned long p1,
78 				  unsigned long p2, unsigned long p3)
79 {
80 	long ret;
81 
82 	if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST))
83 		return tdx_kvm_hypercall(nr, p1, p2, p3, 0);
84 
85 	asm volatile(KVM_HYPERCALL
86 		     : "=a"(ret)
87 		     : "a"(nr), "b"(p1), "c"(p2), "d"(p3)
88 		     : "memory");
89 	return ret;
90 }
91 
92 static inline long kvm_hypercall4(unsigned int nr, unsigned long p1,
93 				  unsigned long p2, unsigned long p3,
94 				  unsigned long p4)
95 {
96 	long ret;
97 
98 	if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST))
99 		return tdx_kvm_hypercall(nr, p1, p2, p3, p4);
100 
101 	asm volatile(KVM_HYPERCALL
102 		     : "=a"(ret)
103 		     : "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4)
104 		     : "memory");
105 	return ret;
106 }
107 
108 static inline long kvm_sev_hypercall3(unsigned int nr, unsigned long p1,
109 				      unsigned long p2, unsigned long p3)
110 {
111 	long ret;
112 
113 	asm volatile("vmmcall"
114 		     : "=a"(ret)
115 		     : "a"(nr), "b"(p1), "c"(p2), "d"(p3)
116 		     : "memory");
117 	return ret;
118 }
119 
120 #ifdef CONFIG_KVM_GUEST
121 void kvmclock_init(void);
122 void kvmclock_disable(void);
123 bool kvm_para_available(void);
124 unsigned int kvm_arch_para_features(void);
125 unsigned int kvm_arch_para_hints(void);
126 void kvm_async_pf_task_wait_schedule(u32 token);
127 void kvm_async_pf_task_wake(u32 token);
128 u32 kvm_read_and_reset_apf_flags(void);
129 bool __kvm_handle_async_pf(struct pt_regs *regs, u32 token);
130 
131 DECLARE_STATIC_KEY_FALSE(kvm_async_pf_enabled);
132 
133 static __always_inline bool kvm_handle_async_pf(struct pt_regs *regs, u32 token)
134 {
135 	if (static_branch_unlikely(&kvm_async_pf_enabled))
136 		return __kvm_handle_async_pf(regs, token);
137 	else
138 		return false;
139 }
140 
141 #ifdef CONFIG_PARAVIRT_SPINLOCKS
142 void __init kvm_spinlock_init(void);
143 #else /* !CONFIG_PARAVIRT_SPINLOCKS */
144 static inline void kvm_spinlock_init(void)
145 {
146 }
147 #endif /* CONFIG_PARAVIRT_SPINLOCKS */
148 
149 #else /* CONFIG_KVM_GUEST */
150 #define kvm_async_pf_task_wait_schedule(T) do {} while(0)
151 #define kvm_async_pf_task_wake(T) do {} while(0)
152 
153 static inline bool kvm_para_available(void)
154 {
155 	return false;
156 }
157 
158 static inline unsigned int kvm_arch_para_features(void)
159 {
160 	return 0;
161 }
162 
163 static inline unsigned int kvm_arch_para_hints(void)
164 {
165 	return 0;
166 }
167 
168 static inline u32 kvm_read_and_reset_apf_flags(void)
169 {
170 	return 0;
171 }
172 
173 static __always_inline bool kvm_handle_async_pf(struct pt_regs *regs, u32 token)
174 {
175 	return false;
176 }
177 #endif
178 
179 #endif /* _ASM_X86_KVM_PARA_H */
180