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1 #ifndef _ASM_X86_KVM_PARA_H
2 #define _ASM_X86_KVM_PARA_H
3 
4 /* This CPUID returns the signature 'KVMKVMKVM' in ebx, ecx, and edx.  It
5  * should be used to determine that a VM is running under KVM.
6  */
7 #define KVM_CPUID_SIGNATURE	0x40000000
8 
9 /* This CPUID returns a feature bitmap in eax.  Before enabling a particular
10  * paravirtualization, the appropriate feature bit should be checked.
11  */
12 #define KVM_CPUID_FEATURES	0x40000001
13 #define KVM_FEATURE_CLOCKSOURCE		0
14 #define KVM_FEATURE_NOP_IO_DELAY	1
15 #define KVM_FEATURE_MMU_OP		2
16 
17 #define MSR_KVM_WALL_CLOCK  0x11
18 #define MSR_KVM_SYSTEM_TIME 0x12
19 
20 #define KVM_MAX_MMU_OP_BATCH           32
21 
22 /* Operations for KVM_HC_MMU_OP */
23 #define KVM_MMU_OP_WRITE_PTE            1
24 #define KVM_MMU_OP_FLUSH_TLB	        2
25 #define KVM_MMU_OP_RELEASE_PT	        3
26 
27 /* Payload for KVM_HC_MMU_OP */
28 struct kvm_mmu_op_header {
29 	__u32 op;
30 	__u32 pad;
31 };
32 
33 struct kvm_mmu_op_write_pte {
34 	struct kvm_mmu_op_header header;
35 	__u64 pte_phys;
36 	__u64 pte_val;
37 };
38 
39 struct kvm_mmu_op_flush_tlb {
40 	struct kvm_mmu_op_header header;
41 };
42 
43 struct kvm_mmu_op_release_pt {
44 	struct kvm_mmu_op_header header;
45 	__u64 pt_phys;
46 };
47 
48 #ifdef __KERNEL__
49 #include <asm/processor.h>
50 
51 extern void kvmclock_init(void);
52 
53 
54 /* This instruction is vmcall.  On non-VT architectures, it will generate a
55  * trap that we will then rewrite to the appropriate instruction.
56  */
57 #define KVM_HYPERCALL ".byte 0x0f,0x01,0xc1"
58 
59 /* For KVM hypercalls, a three-byte sequence of either the vmrun or the vmmrun
60  * instruction.  The hypervisor may replace it with something else but only the
61  * instructions are guaranteed to be supported.
62  *
63  * Up to four arguments may be passed in rbx, rcx, rdx, and rsi respectively.
64  * The hypercall number should be placed in rax and the return value will be
65  * placed in rax.  No other registers will be clobbered unless explicited
66  * noted by the particular hypercall.
67  */
68 
kvm_hypercall0(unsigned int nr)69 static inline long kvm_hypercall0(unsigned int nr)
70 {
71 	long ret;
72 	asm volatile(KVM_HYPERCALL
73 		     : "=a"(ret)
74 		     : "a"(nr)
75 		     : "memory");
76 	return ret;
77 }
78 
kvm_hypercall1(unsigned int nr,unsigned long p1)79 static inline long kvm_hypercall1(unsigned int nr, unsigned long p1)
80 {
81 	long ret;
82 	asm volatile(KVM_HYPERCALL
83 		     : "=a"(ret)
84 		     : "a"(nr), "b"(p1)
85 		     : "memory");
86 	return ret;
87 }
88 
kvm_hypercall2(unsigned int nr,unsigned long p1,unsigned long p2)89 static inline long kvm_hypercall2(unsigned int nr, unsigned long p1,
90 				  unsigned long p2)
91 {
92 	long ret;
93 	asm volatile(KVM_HYPERCALL
94 		     : "=a"(ret)
95 		     : "a"(nr), "b"(p1), "c"(p2)
96 		     : "memory");
97 	return ret;
98 }
99 
kvm_hypercall3(unsigned int nr,unsigned long p1,unsigned long p2,unsigned long p3)100 static inline long kvm_hypercall3(unsigned int nr, unsigned long p1,
101 				  unsigned long p2, unsigned long p3)
102 {
103 	long ret;
104 	asm volatile(KVM_HYPERCALL
105 		     : "=a"(ret)
106 		     : "a"(nr), "b"(p1), "c"(p2), "d"(p3)
107 		     : "memory");
108 	return ret;
109 }
110 
kvm_hypercall4(unsigned int nr,unsigned long p1,unsigned long p2,unsigned long p3,unsigned long p4)111 static inline long kvm_hypercall4(unsigned int nr, unsigned long p1,
112 				  unsigned long p2, unsigned long p3,
113 				  unsigned long p4)
114 {
115 	long ret;
116 	asm volatile(KVM_HYPERCALL
117 		     : "=a"(ret)
118 		     : "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4)
119 		     : "memory");
120 	return ret;
121 }
122 
kvm_para_available(void)123 static inline int kvm_para_available(void)
124 {
125 	unsigned int eax, ebx, ecx, edx;
126 	char signature[13];
127 
128 	cpuid(KVM_CPUID_SIGNATURE, &eax, &ebx, &ecx, &edx);
129 	memcpy(signature + 0, &ebx, 4);
130 	memcpy(signature + 4, &ecx, 4);
131 	memcpy(signature + 8, &edx, 4);
132 	signature[12] = 0;
133 
134 	if (strcmp(signature, "KVMKVMKVM") == 0)
135 		return 1;
136 
137 	return 0;
138 }
139 
kvm_arch_para_features(void)140 static inline unsigned int kvm_arch_para_features(void)
141 {
142 	return cpuid_eax(KVM_CPUID_FEATURES);
143 }
144 
145 #endif
146 
147 #endif /* _ASM_X86_KVM_PARA_H */
148