summaryrefslogtreecommitdiff
path: root/include/asm-x86/kvm_para.h
blob: 76f392146daa46304adfb404874164a7a628010d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
#ifndef __X86_KVM_PARA_H
#define __X86_KVM_PARA_H

/* This CPUID returns the signature 'KVMKVMKVM' in ebx, ecx, and edx.  It
 * should be used to determine that a VM is running under KVM.
 */
#define KVM_CPUID_SIGNATURE	0x40000000

/* This CPUID returns a feature bitmap in eax.  Before enabling a particular
 * paravirtualization, the appropriate feature bit should be checked.
 */
#define KVM_CPUID_FEATURES	0x40000001
#define KVM_FEATURE_CLOCKSOURCE		0
#define KVM_FEATURE_NOP_IO_DELAY	1
#define KVM_FEATURE_MMU_OP		2

#define MSR_KVM_WALL_CLOCK  0x11
#define MSR_KVM_SYSTEM_TIME 0x12

#define KVM_MAX_MMU_OP_BATCH           32

/* Operations for KVM_HC_MMU_OP */
#define KVM_MMU_OP_WRITE_PTE            1
#define KVM_MMU_OP_FLUSH_TLB	        2
#define KVM_MMU_OP_RELEASE_PT	        3

/* Payload for KVM_HC_MMU_OP */
struct kvm_mmu_op_header {
	__u32 op;
	__u32 pad;
};

struct kvm_mmu_op_write_pte {
	struct kvm_mmu_op_header header;
	__u64 pte_phys;
	__u64 pte_val;
};

struct kvm_mmu_op_flush_tlb {
	struct kvm_mmu_op_header header;
};

struct kvm_mmu_op_release_pt {
	struct kvm_mmu_op_header header;
	__u64 pt_phys;
};

#ifdef __KERNEL__
#include <asm/processor.h>

extern void kvmclock_init(void);


/* This instruction is vmcall.  On non-VT architectures, it will generate a
 * trap that we will then rewrite to the appropriate instruction.
 */
#define KVM_HYPERCALL ".byte 0x0f,0x01,0xc1"

/* For KVM hypercalls, a three-byte sequence of either the vmrun or the vmmrun
 * instruction.  The hypervisor may replace it with something else but only the
 * instructions are guaranteed to be supported.
 *
 * Up to four arguments may be passed in rbx, rcx, rdx, and rsi respectively.
 * The hypercall number should be placed in rax and the return value will be
 * placed in rax.  No other registers will be clobbered unless explicited
 * noted by the particular hypercall.
 */

static inline long kvm_hypercall0(unsigned int nr)
{
	long ret;
	asm volatile(KVM_HYPERCALL
		     : "=a"(ret)
		     : "a"(nr)
		     : "memory");
	return ret;
}

static inline long kvm_hypercall1(unsigned int nr, unsigned long p1)
{
	long ret;
	asm volatile(KVM_HYPERCALL
		     : "=a"(ret)
		     : "a"(nr), "b"(p1)
		     : "memory");
	return ret;
}

static inline long kvm_hypercall2(unsigned int nr, unsigned long p1,
				  unsigned long p2)
{
	long ret;
	asm volatile(KVM_HYPERCALL
		     : "=a"(ret)
		     : "a"(nr), "b"(p1), "c"(p2)
		     : "memory");
	return ret;
}

static inline long kvm_hypercall3(unsigned int nr, unsigned long p1,
				  unsigned long p2, unsigned long p3)
{
	long ret;
	asm volatile(KVM_HYPERCALL
		     : "=a"(ret)
		     : "a"(nr), "b"(p1), "c"(p2), "d"(p3)
		     : "memory");
	return ret;
}

static inline long kvm_hypercall4(unsigned int nr, unsigned long p1,
				  unsigned long p2, unsigned long p3,
				  unsigned long p4)
{
	long ret;
	asm volatile(KVM_HYPERCALL
		     : "=a"(ret)
		     : "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4)
		     : "memory");
	return ret;
}

static inline int kvm_para_available(void)
{
	unsigned int eax, ebx, ecx, edx;
	char signature[13];

	cpuid(KVM_CPUID_SIGNATURE, &eax, &ebx, &ecx, &edx);
	memcpy(signature + 0, &ebx, 4);
	memcpy(signature + 4, &ecx, 4);
	memcpy(signature + 8, &edx, 4);
	signature[12] = 0;

	if (strcmp(signature, "KVMKVMKVM") == 0)
		return 1;

	return 0;
}

static inline unsigned int kvm_arch_para_features(void)
{
	return cpuid_eax(KVM_CPUID_FEATURES);
}

#endif

#endif