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Diffstat (limited to 'kernel/arch/x86/include/asm/virtext.h')
-rw-r--r-- | kernel/arch/x86/include/asm/virtext.h | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/kernel/arch/x86/include/asm/virtext.h b/kernel/arch/x86/include/asm/virtext.h new file mode 100644 index 000000000..cce9ee68e --- /dev/null +++ b/kernel/arch/x86/include/asm/virtext.h @@ -0,0 +1,132 @@ +/* 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/vmx.h> +#include <asm/svm.h> +#include <asm/tlbflush.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"); + cr4_clear_bits(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 */ |