Eduardo Habkost | 6210e37 | 2008-11-17 19:03:16 -0200 | [diff] [blame] | 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> |
Eduardo Habkost | 6210e37 | 2008-11-17 19:03:16 -0200 | [diff] [blame] | 19 | |
Eduardo Habkost | 1e99311 | 2008-11-17 19:03:17 -0200 | [diff] [blame] | 20 | #include <asm/vmx.h> |
Eduardo Habkost | 63d1142 | 2008-11-17 19:03:20 -0200 | [diff] [blame] | 21 | #include <asm/svm.h> |
Eduardo Habkost | 1e99311 | 2008-11-17 19:03:17 -0200 | [diff] [blame] | 22 | |
Eduardo Habkost | 6210e37 | 2008-11-17 19:03:16 -0200 | [diff] [blame] | 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 | |
Eduardo Habkost | 1e99311 | 2008-11-17 19:03:17 -0200 | [diff] [blame] | 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 | |
Eduardo Habkost | 6aa07a0 | 2008-11-17 19:03:19 -0200 | [diff] [blame] | 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 | |
Eduardo Habkost | 63d1142 | 2008-11-17 19:03:20 -0200 | [diff] [blame] | 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 | |
Eduardo Habkost | 2c8dcee | 2008-11-17 19:03:21 -0200 | [diff] [blame] | 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); |
Alexander Graf | 9962d03 | 2008-11-25 20:17:02 +0100 | [diff] [blame] | 120 | wrmsrl(MSR_EFER, efer & ~EFER_SVME); |
Eduardo Habkost | 2c8dcee | 2008-11-17 19:03:21 -0200 | [diff] [blame] | 121 | } |
| 122 | |
Eduardo Habkost | 0f3e9ee | 2008-11-17 19:03:22 -0200 | [diff] [blame] | 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 | |
Eduardo Habkost | 6210e37 | 2008-11-17 19:03:16 -0200 | [diff] [blame] | 131 | #endif /* _ASM_X86_VIRTEX_H */ |