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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/x86/include/asm/virtext.h
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
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.h148
1 files changed, 148 insertions, 0 deletions
diff --git a/arch/x86/include/asm/virtext.h b/arch/x86/include/asm/virtext.h
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+++ b/arch/x86/include/asm/virtext.h
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+/* 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 int cpu_vmxoff(void)
+{
+ asm_volatile_goto("1: vmxoff\n\t"
+ _ASM_EXTABLE(1b, %l[fault])
+ ::: "cc", "memory" : fault);
+
+ cr4_clear_bits(X86_CR4_VMXE);
+ return 0;
+
+fault:
+ cr4_clear_bits(X86_CR4_VMXE);
+ return -EIO;
+}
+
+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 */