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6210e37b EH |
1 | /* CPU virtualization extensions handling |
2 | * | |
3 | * This should carry the code for handling CPU virtualization extensions | |
4 | * that needs to live in the kernel core. | |
5 | * | |
6 | * Author: Eduardo Habkost <ehabkost@redhat.com> | |
7 | * | |
8 | * Copyright (C) 2008, Red Hat Inc. | |
9 | * | |
10 | * Contains code from KVM, Copyright (C) 2006 Qumranet, Inc. | |
11 | * | |
12 | * This work is licensed under the terms of the GNU GPL, version 2. See | |
13 | * the COPYING file in the top-level directory. | |
14 | */ | |
15 | #ifndef _ASM_X86_VIRTEX_H | |
16 | #define _ASM_X86_VIRTEX_H | |
17 | ||
18 | #include <asm/processor.h> | |
6210e37b | 19 | |
1e993114 | 20 | #include <asm/vmx.h> |
63d1142f | 21 | #include <asm/svm.h> |
1e993114 | 22 | |
6210e37b EH |
23 | /* |
24 | * VMX functions: | |
25 | */ | |
26 | ||
27 | static inline int cpu_has_vmx(void) | |
28 | { | |
29 | unsigned long ecx = cpuid_ecx(1); | |
30 | return test_bit(5, &ecx); /* CPUID.1:ECX.VMX[bit 5] -> VT */ | |
31 | } | |
32 | ||
1e993114 EH |
33 | |
34 | /** Disable VMX on the current CPU | |
35 | * | |
36 | * vmxoff causes a undefined-opcode exception if vmxon was not run | |
37 | * on the CPU previously. Only call this function if you know VMX | |
38 | * is enabled. | |
39 | */ | |
40 | static inline void cpu_vmxoff(void) | |
41 | { | |
42 | asm volatile (ASM_VMX_VMXOFF : : : "cc"); | |
43 | write_cr4(read_cr4() & ~X86_CR4_VMXE); | |
44 | } | |
45 | ||
6aa07a0d EH |
46 | static inline int cpu_vmx_enabled(void) |
47 | { | |
48 | return read_cr4() & X86_CR4_VMXE; | |
49 | } | |
50 | ||
51 | /** Disable VMX if it is enabled on the current CPU | |
52 | * | |
53 | * You shouldn't call this if cpu_has_vmx() returns 0. | |
54 | */ | |
55 | static inline void __cpu_emergency_vmxoff(void) | |
56 | { | |
57 | if (cpu_vmx_enabled()) | |
58 | cpu_vmxoff(); | |
59 | } | |
60 | ||
61 | /** Disable VMX if it is supported and enabled on the current CPU | |
62 | */ | |
63 | static inline void cpu_emergency_vmxoff(void) | |
64 | { | |
65 | if (cpu_has_vmx()) | |
66 | __cpu_emergency_vmxoff(); | |
67 | } | |
68 | ||
63d1142f EH |
69 | |
70 | ||
71 | ||
72 | /* | |
73 | * SVM functions: | |
74 | */ | |
75 | ||
76 | /** Check if the CPU has SVM support | |
77 | * | |
78 | * You can use the 'msg' arg to get a message describing the problem, | |
79 | * if the function returns zero. Simply pass NULL if you are not interested | |
80 | * on the messages; gcc should take care of not generating code for | |
81 | * the messages on this case. | |
82 | */ | |
83 | static inline int cpu_has_svm(const char **msg) | |
84 | { | |
85 | uint32_t eax, ebx, ecx, edx; | |
86 | ||
87 | if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) { | |
88 | if (msg) | |
89 | *msg = "not amd"; | |
90 | return 0; | |
91 | } | |
92 | ||
93 | cpuid(0x80000000, &eax, &ebx, &ecx, &edx); | |
94 | if (eax < SVM_CPUID_FUNC) { | |
95 | if (msg) | |
96 | *msg = "can't execute cpuid_8000000a"; | |
97 | return 0; | |
98 | } | |
99 | ||
100 | cpuid(0x80000001, &eax, &ebx, &ecx, &edx); | |
101 | if (!(ecx & (1 << SVM_CPUID_FEATURE_SHIFT))) { | |
102 | if (msg) | |
103 | *msg = "svm not available"; | |
104 | return 0; | |
105 | } | |
106 | return 1; | |
107 | } | |
108 | ||
2c8dceeb EH |
109 | |
110 | /** Disable SVM on the current CPU | |
111 | * | |
112 | * You should call this only if cpu_has_svm() returned true. | |
113 | */ | |
114 | static inline void cpu_svm_disable(void) | |
115 | { | |
116 | uint64_t efer; | |
117 | ||
118 | wrmsrl(MSR_VM_HSAVE_PA, 0); | |
119 | rdmsrl(MSR_EFER, efer); | |
9962d032 | 120 | wrmsrl(MSR_EFER, efer & ~EFER_SVME); |
2c8dceeb EH |
121 | } |
122 | ||
0f3e9eeb EH |
123 | /** Makes sure SVM is disabled, if it is supported on the CPU |
124 | */ | |
125 | static inline void cpu_emergency_svm_disable(void) | |
126 | { | |
127 | if (cpu_has_svm(NULL)) | |
128 | cpu_svm_disable(); | |
129 | } | |
130 | ||
6210e37b | 131 | #endif /* _ASM_X86_VIRTEX_H */ |