KVM: x86: Move reverse CPUID helpers to separate header file

Split out the reverse CPUID machinery to a dedicated header file
so that KVM selftests can reuse the reverse CPUID definitions without
introducing any '#ifdef __KERNEL__' pollution.

Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
Message-Id: <20210422005626.564163-2-ricarkol@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
index 50c78dc..c99edff 100644 (file)
--- a/arch/x86/kvm/cpuid.h
+++ b/arch/x86/kvm/cpuid.h
@@ -3,28 +3,11 @@
 #define ARCH_X86_KVM_CPUID_H
 
 #include "x86.h"
+#include "reverse_cpuid.h"
 #include <asm/cpu.h>
 #include <asm/processor.h>
 #include <uapi/asm/kvm_para.h>
 
-/*
- * Hardware-defined CPUID leafs that are scattered in the kernel, but need to
- * be directly used by KVM.  Note, these word values conflict with the kernel's
- * "bug" caps, but KVM doesn't use those.
- */
-enum kvm_only_cpuid_leafs {
-       CPUID_12_EAX     = NCAPINTS,
-       NR_KVM_CPU_CAPS,
-
-       NKVMCAPINTS = NR_KVM_CPU_CAPS - NCAPINTS,
-};
-
-#define KVM_X86_FEATURE(w, f)          ((w)*32 + (f))
-
-/* Intel-defined SGX sub-features, CPUID level 0x12 (EAX). */
-#define KVM_X86_FEATURE_SGX1           KVM_X86_FEATURE(CPUID_12_EAX, 0)
-#define KVM_X86_FEATURE_SGX2           KVM_X86_FEATURE(CPUID_12_EAX, 1)
-
 extern u32 kvm_cpu_caps[NR_KVM_CPU_CAPS] __read_mostly;
 void kvm_set_cpu_caps(void);
 
@@ -76,164 +59,6 @@ static inline bool page_address_valid(struct kvm_vcpu *vcpu, gpa_t gpa)
        return kvm_vcpu_is_legal_aligned_gpa(vcpu, gpa, PAGE_SIZE);
 }
 
-struct cpuid_reg {
-       u32 function;
-       u32 index;
-       int reg;
-};
-
-static const struct cpuid_reg reverse_cpuid[] = {
-       [CPUID_1_EDX]         = {         1, 0, CPUID_EDX},
-       [CPUID_8000_0001_EDX] = {0x80000001, 0, CPUID_EDX},
-       [CPUID_8086_0001_EDX] = {0x80860001, 0, CPUID_EDX},
-       [CPUID_1_ECX]         = {         1, 0, CPUID_ECX},
-       [CPUID_C000_0001_EDX] = {0xc0000001, 0, CPUID_EDX},
-       [CPUID_8000_0001_ECX] = {0x80000001, 0, CPUID_ECX},
-       [CPUID_7_0_EBX]       = {         7, 0, CPUID_EBX},
-       [CPUID_D_1_EAX]       = {       0xd, 1, CPUID_EAX},
-       [CPUID_8000_0008_EBX] = {0x80000008, 0, CPUID_EBX},
-       [CPUID_6_EAX]         = {         6, 0, CPUID_EAX},
-       [CPUID_8000_000A_EDX] = {0x8000000a, 0, CPUID_EDX},
-       [CPUID_7_ECX]         = {         7, 0, CPUID_ECX},
-       [CPUID_8000_0007_EBX] = {0x80000007, 0, CPUID_EBX},
-       [CPUID_7_EDX]         = {         7, 0, CPUID_EDX},
-       [CPUID_7_1_EAX]       = {         7, 1, CPUID_EAX},
-       [CPUID_12_EAX]        = {0x00000012, 0, CPUID_EAX},
-};
-
-/*
- * Reverse CPUID and its derivatives can only be used for hardware-defined
- * feature words, i.e. words whose bits directly correspond to a CPUID leaf.
- * Retrieving a feature bit or masking guest CPUID from a Linux-defined word
- * is nonsensical as the bit number/mask is an arbitrary software-defined value
- * and can't be used by KVM to query/control guest capabilities.  And obviously
- * the leaf being queried must have an entry in the lookup table.
- */
-static __always_inline void reverse_cpuid_check(unsigned int x86_leaf)
-{
-       BUILD_BUG_ON(x86_leaf == CPUID_LNX_1);
-       BUILD_BUG_ON(x86_leaf == CPUID_LNX_2);
-       BUILD_BUG_ON(x86_leaf == CPUID_LNX_3);
-       BUILD_BUG_ON(x86_leaf == CPUID_LNX_4);
-       BUILD_BUG_ON(x86_leaf >= ARRAY_SIZE(reverse_cpuid));
-       BUILD_BUG_ON(reverse_cpuid[x86_leaf].function == 0);
-}
-
-/*
- * Translate feature bits that are scattered in the kernel's cpufeatures word
- * into KVM feature words that align with hardware's definitions.
- */
-static __always_inline u32 __feature_translate(int x86_feature)
-{
-       if (x86_feature == X86_FEATURE_SGX1)
-               return KVM_X86_FEATURE_SGX1;
-       else if (x86_feature == X86_FEATURE_SGX2)
-               return KVM_X86_FEATURE_SGX2;
-
-       return x86_feature;
-}
-
-static __always_inline u32 __feature_leaf(int x86_feature)
-{
-       return __feature_translate(x86_feature) / 32;
-}
-
-/*
- * Retrieve the bit mask from an X86_FEATURE_* definition.  Features contain
- * the hardware defined bit number (stored in bits 4:0) and a software defined
- * "word" (stored in bits 31:5).  The word is used to index into arrays of
- * bit masks that hold the per-cpu feature capabilities, e.g. this_cpu_has().
- */
-static __always_inline u32 __feature_bit(int x86_feature)
-{
-       x86_feature = __feature_translate(x86_feature);
-
-       reverse_cpuid_check(x86_feature / 32);
-       return 1 << (x86_feature & 31);
-}
-
-#define feature_bit(name)  __feature_bit(X86_FEATURE_##name)
-
-static __always_inline struct cpuid_reg x86_feature_cpuid(unsigned int x86_feature)
-{
-       unsigned int x86_leaf = __feature_leaf(x86_feature);
-
-       reverse_cpuid_check(x86_leaf);
-       return reverse_cpuid[x86_leaf];
-}
-
-static __always_inline u32 *__cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry,
-                                                 u32 reg)
-{
-       switch (reg) {
-       case CPUID_EAX:
-               return &entry->eax;
-       case CPUID_EBX:
-               return &entry->ebx;
-       case CPUID_ECX:
-               return &entry->ecx;
-       case CPUID_EDX:
-               return &entry->edx;
-       default:
-               BUILD_BUG();
-               return NULL;
-       }
-}
-
-static __always_inline u32 *cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry,
-                                               unsigned int x86_feature)
-{
-       const struct cpuid_reg cpuid = x86_feature_cpuid(x86_feature);
-
-       return __cpuid_entry_get_reg(entry, cpuid.reg);
-}
-
-static __always_inline u32 cpuid_entry_get(struct kvm_cpuid_entry2 *entry,
-                                          unsigned int x86_feature)
-{
-       u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
-
-       return *reg & __feature_bit(x86_feature);
-}
-
-static __always_inline bool cpuid_entry_has(struct kvm_cpuid_entry2 *entry,
-                                           unsigned int x86_feature)
-{
-       return cpuid_entry_get(entry, x86_feature);
-}
-
-static __always_inline void cpuid_entry_clear(struct kvm_cpuid_entry2 *entry,
-                                             unsigned int x86_feature)
-{
-       u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
-
-       *reg &= ~__feature_bit(x86_feature);
-}
-
-static __always_inline void cpuid_entry_set(struct kvm_cpuid_entry2 *entry,
-                                           unsigned int x86_feature)
-{
-       u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
-
-       *reg |= __feature_bit(x86_feature);
-}
-
-static __always_inline void cpuid_entry_change(struct kvm_cpuid_entry2 *entry,
-                                              unsigned int x86_feature,
-                                              bool set)
-{
-       u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
-
-       /*
-        * Open coded instead of using cpuid_entry_{clear,set}() to coerce the
-        * compiler into using CMOV instead of Jcc when possible.
-        */
-       if (set)
-               *reg |= __feature_bit(x86_feature);
-       else
-               *reg &= ~__feature_bit(x86_feature);
-}
-
 static __always_inline void cpuid_entry_override(struct kvm_cpuid_entry2 *entry,
                                                 unsigned int leaf)
 {

diff --git a/arch/x86/kvm/reverse_cpuid.h b/arch/x86/kvm/reverse_cpuid.h
new file mode 100644 (file)
index 0000000..8e0756d
--- /dev/null
+++ b/arch/x86/kvm/reverse_cpuid.h
@@ -0,0 +1,185 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef ARCH_X86_KVM_REVERSE_CPUID_H
+#define ARCH_X86_KVM_REVERSE_CPUID_H
+
+#include <uapi/asm/kvm.h>
+#include <asm/cpufeature.h>
+#include <asm/cpufeatures.h>
+
+/*
+ * Hardware-defined CPUID leafs that are scattered in the kernel, but need to
+ * be directly used by KVM.  Note, these word values conflict with the kernel's
+ * "bug" caps, but KVM doesn't use those.
+ */
+enum kvm_only_cpuid_leafs {
+       CPUID_12_EAX     = NCAPINTS,
+       NR_KVM_CPU_CAPS,
+
+       NKVMCAPINTS = NR_KVM_CPU_CAPS - NCAPINTS,
+};
+
+#define KVM_X86_FEATURE(w, f)          ((w)*32 + (f))
+
+/* Intel-defined SGX sub-features, CPUID level 0x12 (EAX). */
+#define KVM_X86_FEATURE_SGX1           KVM_X86_FEATURE(CPUID_12_EAX, 0)
+#define KVM_X86_FEATURE_SGX2           KVM_X86_FEATURE(CPUID_12_EAX, 1)
+
+struct cpuid_reg {
+       u32 function;
+       u32 index;
+       int reg;
+};
+
+static const struct cpuid_reg reverse_cpuid[] = {
+       [CPUID_1_EDX]         = {         1, 0, CPUID_EDX},
+       [CPUID_8000_0001_EDX] = {0x80000001, 0, CPUID_EDX},
+       [CPUID_8086_0001_EDX] = {0x80860001, 0, CPUID_EDX},
+       [CPUID_1_ECX]         = {         1, 0, CPUID_ECX},
+       [CPUID_C000_0001_EDX] = {0xc0000001, 0, CPUID_EDX},
+       [CPUID_8000_0001_ECX] = {0x80000001, 0, CPUID_ECX},
+       [CPUID_7_0_EBX]       = {         7, 0, CPUID_EBX},
+       [CPUID_D_1_EAX]       = {       0xd, 1, CPUID_EAX},
+       [CPUID_8000_0008_EBX] = {0x80000008, 0, CPUID_EBX},
+       [CPUID_6_EAX]         = {         6, 0, CPUID_EAX},
+       [CPUID_8000_000A_EDX] = {0x8000000a, 0, CPUID_EDX},
+       [CPUID_7_ECX]         = {         7, 0, CPUID_ECX},
+       [CPUID_8000_0007_EBX] = {0x80000007, 0, CPUID_EBX},
+       [CPUID_7_EDX]         = {         7, 0, CPUID_EDX},
+       [CPUID_7_1_EAX]       = {         7, 1, CPUID_EAX},
+       [CPUID_12_EAX]        = {0x00000012, 0, CPUID_EAX},
+};
+
+/*
+ * Reverse CPUID and its derivatives can only be used for hardware-defined
+ * feature words, i.e. words whose bits directly correspond to a CPUID leaf.
+ * Retrieving a feature bit or masking guest CPUID from a Linux-defined word
+ * is nonsensical as the bit number/mask is an arbitrary software-defined value
+ * and can't be used by KVM to query/control guest capabilities.  And obviously
+ * the leaf being queried must have an entry in the lookup table.
+ */
+static __always_inline void reverse_cpuid_check(unsigned int x86_leaf)
+{
+       BUILD_BUG_ON(x86_leaf == CPUID_LNX_1);
+       BUILD_BUG_ON(x86_leaf == CPUID_LNX_2);
+       BUILD_BUG_ON(x86_leaf == CPUID_LNX_3);
+       BUILD_BUG_ON(x86_leaf == CPUID_LNX_4);
+       BUILD_BUG_ON(x86_leaf >= ARRAY_SIZE(reverse_cpuid));
+       BUILD_BUG_ON(reverse_cpuid[x86_leaf].function == 0);
+}
+
+/*
+ * Translate feature bits that are scattered in the kernel's cpufeatures word
+ * into KVM feature words that align with hardware's definitions.
+ */
+static __always_inline u32 __feature_translate(int x86_feature)
+{
+       if (x86_feature == X86_FEATURE_SGX1)
+               return KVM_X86_FEATURE_SGX1;
+       else if (x86_feature == X86_FEATURE_SGX2)
+               return KVM_X86_FEATURE_SGX2;
+
+       return x86_feature;
+}
+
+static __always_inline u32 __feature_leaf(int x86_feature)
+{
+       return __feature_translate(x86_feature) / 32;
+}
+
+/*
+ * Retrieve the bit mask from an X86_FEATURE_* definition.  Features contain
+ * the hardware defined bit number (stored in bits 4:0) and a software defined
+ * "word" (stored in bits 31:5).  The word is used to index into arrays of
+ * bit masks that hold the per-cpu feature capabilities, e.g. this_cpu_has().
+ */
+static __always_inline u32 __feature_bit(int x86_feature)
+{
+       x86_feature = __feature_translate(x86_feature);
+
+       reverse_cpuid_check(x86_feature / 32);
+       return 1 << (x86_feature & 31);
+}
+
+#define feature_bit(name)  __feature_bit(X86_FEATURE_##name)
+
+static __always_inline struct cpuid_reg x86_feature_cpuid(unsigned int x86_feature)
+{
+       unsigned int x86_leaf = __feature_leaf(x86_feature);
+
+       reverse_cpuid_check(x86_leaf);
+       return reverse_cpuid[x86_leaf];
+}
+
+static __always_inline u32 *__cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry,
+                                                 u32 reg)
+{
+       switch (reg) {
+       case CPUID_EAX:
+               return &entry->eax;
+       case CPUID_EBX:
+               return &entry->ebx;
+       case CPUID_ECX:
+               return &entry->ecx;
+       case CPUID_EDX:
+               return &entry->edx;
+       default:
+               BUILD_BUG();
+               return NULL;
+       }
+}
+
+static __always_inline u32 *cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry,
+                                               unsigned int x86_feature)
+{
+       const struct cpuid_reg cpuid = x86_feature_cpuid(x86_feature);
+
+       return __cpuid_entry_get_reg(entry, cpuid.reg);
+}
+
+static __always_inline u32 cpuid_entry_get(struct kvm_cpuid_entry2 *entry,
+                                          unsigned int x86_feature)
+{
+       u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
+
+       return *reg & __feature_bit(x86_feature);
+}
+
+static __always_inline bool cpuid_entry_has(struct kvm_cpuid_entry2 *entry,
+                                           unsigned int x86_feature)
+{
+       return cpuid_entry_get(entry, x86_feature);
+}
+
+static __always_inline void cpuid_entry_clear(struct kvm_cpuid_entry2 *entry,
+                                             unsigned int x86_feature)
+{
+       u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
+
+       *reg &= ~__feature_bit(x86_feature);
+}
+
+static __always_inline void cpuid_entry_set(struct kvm_cpuid_entry2 *entry,
+                                           unsigned int x86_feature)
+{
+       u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
+
+       *reg |= __feature_bit(x86_feature);
+}
+
+static __always_inline void cpuid_entry_change(struct kvm_cpuid_entry2 *entry,
+                                              unsigned int x86_feature,
+                                              bool set)
+{
+       u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
+
+       /*
+        * Open coded instead of using cpuid_entry_{clear,set}() to coerce the
+        * compiler into using CMOV instead of Jcc when possible.
+        */
+       if (set)
+               *reg |= __feature_bit(x86_feature);
+       else
+               *reg &= ~__feature_bit(x86_feature);
+}
+
+#endif /* ARCH_X86_KVM_REVERSE_CPUID_H */