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> 19#include <asm/system.h> 20 21#include <asm/vmx.h> 22#include <asm/svm.h> 23 24/* 25 * VMX functions: 26 */ 27 28static inline int cpu_has_vmx(void) 29{ 30 unsigned long ecx = cpuid_ecx(1); 31 return test_bit(5, &ecx); /* CPUID.1:ECX.VMX[bit 5] -> VT */ 32} 33 34 35/** Disable VMX on the current CPU 36 * 37 * vmxoff causes a undefined-opcode exception if vmxon was not run 38 * on the CPU previously. Only call this function if you know VMX 39 * is enabled. 40 */ 41static inline void cpu_vmxoff(void) 42{ 43 asm volatile (ASM_VMX_VMXOFF : : : "cc"); 44 write_cr4(read_cr4() & ~X86_CR4_VMXE); 45} 46 47static inline int cpu_vmx_enabled(void) 48{ 49 return read_cr4() & X86_CR4_VMXE; 50} 51 52/** Disable VMX if it is enabled on the current CPU 53 * 54 * You shouldn't call this if cpu_has_vmx() returns 0. 55 */ 56static inline void __cpu_emergency_vmxoff(void) 57{ 58 if (cpu_vmx_enabled()) 59 cpu_vmxoff(); 60} 61 62/** Disable VMX if it is supported and enabled on the current CPU 63 */ 64static inline void cpu_emergency_vmxoff(void) 65{ 66 if (cpu_has_vmx()) 67 __cpu_emergency_vmxoff(); 68} 69 70 71 72 73/* 74 * SVM functions: 75 */ 76 77/** Check if the CPU has SVM support 78 * 79 * You can use the 'msg' arg to get a message describing the problem, 80 * if the function returns zero. Simply pass NULL if you are not interested 81 * on the messages; gcc should take care of not generating code for 82 * the messages on this case. 83 */ 84static inline int cpu_has_svm(const char **msg) 85{ 86 uint32_t eax, ebx, ecx, edx; 87 88 if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) { 89 if (msg) 90 *msg = "not amd"; 91 return 0; 92 } 93 94 cpuid(0x80000000, &eax, &ebx, &ecx, &edx); 95 if (eax < SVM_CPUID_FUNC) { 96 if (msg) 97 *msg = "can't execute cpuid_8000000a"; 98 return 0; 99 } 100 101 cpuid(0x80000001, &eax, &ebx, &ecx, &edx); 102 if (!(ecx & (1 << SVM_CPUID_FEATURE_SHIFT))) { 103 if (msg) 104 *msg = "svm not available"; 105 return 0; 106 } 107 return 1; 108} 109 110 111/** Disable SVM on the current CPU 112 * 113 * You should call this only if cpu_has_svm() returned true. 114 */ 115static inline void cpu_svm_disable(void) 116{ 117 uint64_t efer; 118 119 wrmsrl(MSR_VM_HSAVE_PA, 0); 120 rdmsrl(MSR_EFER, efer); 121 wrmsrl(MSR_EFER, efer & ~EFER_SVME); 122} 123 124/** Makes sure SVM is disabled, if it is supported on the CPU 125 */ 126static inline void cpu_emergency_svm_disable(void) 127{ 128 if (cpu_has_svm(NULL)) 129 cpu_svm_disable(); 130} 131 132#endif /* _ASM_X86_VIRTEX_H */ 133