/* CPU virtualization extensions handling * * This should carry the code for handling CPU virtualization extensions * that needs to live in the kernel core. * * Author: Eduardo Habkost <ehabkost@redhat.com> * * Copyright (C) 2008, Red Hat Inc. * * Contains code from KVM, Copyright (C) 2006 Qumranet, Inc. * * This work is licensed under the terms of the GNU GPL, version 2. See * the COPYING file in the top-level directory. */ #ifndef _ASM_X86_VIRTEX_H #define _ASM_X86_VIRTEX_H #include <asm/processor.h> #include <asm/system.h> #include <asm/vmx.h> #include <asm/svm.h> /* * VMX functions: */ static inline int cpu_has_vmx(void) { unsigned long ecx = cpuid_ecx(1); return test_bit(5, &ecx); /* CPUID.1:ECX.VMX[bit 5] -> VT */ } /** Disable VMX on the current CPU * * vmxoff causes a undefined-opcode exception if vmxon was not run * on the CPU previously. Only call this function if you know VMX * is enabled. */ static inline void cpu_vmxoff(void) { asm volatile (ASM_VMX_VMXOFF : : : "cc"); write_cr4(read_cr4() & ~X86_CR4_VMXE); } static inline int cpu_vmx_enabled(void) { return read_cr4() & X86_CR4_VMXE; } /** Disable VMX if it is enabled on the current CPU * * You shouldn't call this if cpu_has_vmx() returns 0. */ static inline void __cpu_emergency_vmxoff(void) { if (cpu_vmx_enabled()) cpu_vmxoff(); } /** Disable VMX if it is supported and enabled on the current CPU */ static inline void cpu_emergency_vmxoff(void) { if (cpu_has_vmx()) __cpu_emergency_vmxoff(); } /* * SVM functions: */ /** Check if the CPU has SVM support * * You can use the 'msg' arg to get a message describing the problem, * if the function returns zero. Simply pass NULL if you are not interested * on the messages; gcc should take care of not generating code for * the messages on this case. */ static inline int cpu_has_svm(const char **msg) { uint32_t eax, ebx, ecx, edx; if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) { if (msg) *msg = "not amd"; return 0; } cpuid(0x80000000, &eax, &ebx, &ecx, &edx); if (eax < SVM_CPUID_FUNC) { if (msg) *msg = "can't execute cpuid_8000000a"; return 0; } cpuid(0x80000001, &eax, &ebx, &ecx, &edx); if (!(ecx & (1 << SVM_CPUID_FEATURE_SHIFT))) { if (msg) *msg = "svm not available"; return 0; } return 1; } /** Disable SVM on the current CPU * * You should call this only if cpu_has_svm() returned true. */ static inline void cpu_svm_disable(void) { uint64_t efer; wrmsrl(MSR_VM_HSAVE_PA, 0); rdmsrl(MSR_EFER, efer); wrmsrl(MSR_EFER, efer & ~EFER_SVME); } /** Makes sure SVM is disabled, if it is supported on the CPU */ static inline void cpu_emergency_svm_disable(void) { if (cpu_has_svm(NULL)) cpu_svm_disable(); } #endif /* _ASM_X86_VIRTEX_H */