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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /arch/x86/include/asm/virtext.h | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/include/asm/virtext.h')
-rw-r--r-- | arch/x86/include/asm/virtext.h | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/arch/x86/include/asm/virtext.h b/arch/x86/include/asm/virtext.h new file mode 100644 index 000000000..331474296 --- /dev/null +++ b/arch/x86/include/asm/virtext.h @@ -0,0 +1,142 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* 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. + */ +#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 */ +} + + +/** + * cpu_vmxoff() - Disable VMX on the current CPU + * + * Disable VMX and clear CR4.VMXE (even if VMXOFF faults) + * + * Note, VMXOFF causes a #UD if the CPU is !post-VMXON, but it's impossible to + * atomically track post-VMXON state, e.g. this may be called in NMI context. + * Eat all faults as all other faults on VMXOFF faults are mode related, i.e. + * faults are guaranteed to be due to the !post-VMXON check unless the CPU is + * magically in RM, VM86, compat mode, or at CPL>0. + */ +static inline void cpu_vmxoff(void) +{ + asm_volatile_goto("1: vmxoff\n\t" + _ASM_EXTABLE(1b, %l[fault]) :::: fault); +fault: + 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) +{ + if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD && + boot_cpu_data.x86_vendor != X86_VENDOR_HYGON) { + if (msg) + *msg = "not amd or hygon"; + return 0; + } + + if (!boot_cpu_has(X86_FEATURE_SVM)) { + 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); + if (efer & EFER_SVME) { + /* + * Force GIF=1 prior to disabling SVM to ensure INIT and NMI + * aren't blocked, e.g. if a fatal error occurred between CLGI + * and STGI. Note, STGI may #UD if SVM is disabled from NMI + * context between reading EFER and executing STGI. In that + * case, GIF must already be set, otherwise the NMI would have + * been blocked, so just eat the fault. + */ + asm_volatile_goto("1: stgi\n\t" + _ASM_EXTABLE(1b, %l[fault]) + ::: "memory" : fault); +fault: + 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 */ |