arch/x86/kvm/kvm_cache_regs.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef ASM_KVM_CACHE_REGS_H
   3 #define ASM_KVM_CACHE_REGS_H
   4
   5 #include <linux/kvm_host.h>
   6
   7 #define KVM_POSSIBLE_CR0_GUEST_BITS     (X86_CR0_TS | X86_CR0_WP)
   8 #define KVM_POSSIBLE_CR4_GUEST_BITS                               \
   9         (X86_CR4_PVI | X86_CR4_DE | X86_CR4_PCE | X86_CR4_OSFXSR  \
  10          | X86_CR4_OSXMMEXCPT | X86_CR4_PGE | X86_CR4_TSD | X86_CR4_FSGSBASE)
  11
  12 #define X86_CR0_PDPTR_BITS    (X86_CR0_CD | X86_CR0_NW | X86_CR0_PG)
  13 #define X86_CR4_TLBFLUSH_BITS (X86_CR4_PGE | X86_CR4_PCIDE | X86_CR4_PAE | X86_CR4_SMEP)
  14 #define X86_CR4_PDPTR_BITS    (X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PAE | X86_CR4_SMEP)
  15
  16 static_assert(!(KVM_POSSIBLE_CR0_GUEST_BITS & X86_CR0_PDPTR_BITS));
  17
  18 #define BUILD_KVM_GPR_ACCESSORS(lname, uname)                                 \
  19 static __always_inline unsigned long kvm_##lname##_read(struct kvm_vcpu *vcpu)\
  20 {                                                                             \
  21         return vcpu->arch.regs[VCPU_REGS_##uname];                            \
  22 }                                                                             \
  23 static __always_inline void kvm_##lname##_write(struct kvm_vcpu *vcpu,        \
  24                                                 unsigned long val)            \
  25 {                                                                             \
  26         vcpu->arch.regs[VCPU_REGS_##uname] = val;                             \
  27 }
  28 BUILD_KVM_GPR_ACCESSORS(rax, RAX)
  29 BUILD_KVM_GPR_ACCESSORS(rbx, RBX)
  30 BUILD_KVM_GPR_ACCESSORS(rcx, RCX)
  31 BUILD_KVM_GPR_ACCESSORS(rdx, RDX)
  32 BUILD_KVM_GPR_ACCESSORS(rbp, RBP)
  33 BUILD_KVM_GPR_ACCESSORS(rsi, RSI)
  34 BUILD_KVM_GPR_ACCESSORS(rdi, RDI)
  35 #ifdef CONFIG_X86_64
  36 BUILD_KVM_GPR_ACCESSORS(r8,  R8)
  37 BUILD_KVM_GPR_ACCESSORS(r9,  R9)
  38 BUILD_KVM_GPR_ACCESSORS(r10, R10)
  39 BUILD_KVM_GPR_ACCESSORS(r11, R11)
  40 BUILD_KVM_GPR_ACCESSORS(r12, R12)
  41 BUILD_KVM_GPR_ACCESSORS(r13, R13)
  42 BUILD_KVM_GPR_ACCESSORS(r14, R14)
  43 BUILD_KVM_GPR_ACCESSORS(r15, R15)
  44 #endif
  45
  46 /*
  47  * avail  dirty
  48  * 0      0       register in VMCS/VMCB
  49  * 0      1       *INVALID*
  50  * 1      0       register in vcpu->arch
  51  * 1      1       register in vcpu->arch, needs to be stored back
  52  */
  53 static inline bool kvm_register_is_available(struct kvm_vcpu *vcpu,
  54                                              enum kvm_reg reg)
  55 {
  56         return test_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
  57 }
  58
  59 static inline bool kvm_register_is_dirty(struct kvm_vcpu *vcpu,
  60                                          enum kvm_reg reg)
  61 {
  62         return test_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty);
  63 }
  64
  65 static inline void kvm_register_mark_available(struct kvm_vcpu *vcpu,
  66                                                enum kvm_reg reg)
  67 {
  68         __set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
  69 }
  70
  71 static inline void kvm_register_mark_dirty(struct kvm_vcpu *vcpu,
  72                                            enum kvm_reg reg)
  73 {
  74         __set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
  75         __set_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty);
  76 }
  77
  78 /*
  79  * kvm_register_test_and_mark_available() is a special snowflake that uses an
  80  * arch bitop directly to avoid the explicit instrumentation that comes with
  81  * the generic bitops.  This allows code that cannot be instrumented (noinstr
  82  * functions), e.g. the low level VM-Enter/VM-Exit paths, to cache registers.
  83  */
  84 static __always_inline bool kvm_register_test_and_mark_available(struct kvm_vcpu *vcpu,
  85                                                                  enum kvm_reg reg)
  86 {
  87         return arch___test_and_set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
  88 }
  89
  90 /*
  91  * The "raw" register helpers are only for cases where the full 64 bits of a
  92  * register are read/written irrespective of current vCPU mode.  In other words,
  93  * odds are good you shouldn't be using the raw variants.
  94  */
  95 static inline unsigned long kvm_register_read_raw(struct kvm_vcpu *vcpu, int reg)
  96 {
  97         if (WARN_ON_ONCE((unsigned int)reg >= NR_VCPU_REGS))
  98                 return 0;
  99
 100         if (!kvm_register_is_available(vcpu, reg))
 101                 static_call(kvm_x86_cache_reg)(vcpu, reg);
 102
 103         return vcpu->arch.regs[reg];
 104 }
 105
 106 static inline void kvm_register_write_raw(struct kvm_vcpu *vcpu, int reg,
 107                                           unsigned long val)
 108 {
 109         if (WARN_ON_ONCE((unsigned int)reg >= NR_VCPU_REGS))
 110                 return;
 111
 112         vcpu->arch.regs[reg] = val;
 113         kvm_register_mark_dirty(vcpu, reg);
 114 }
 115
 116 static inline unsigned long kvm_rip_read(struct kvm_vcpu *vcpu)
 117 {
 118         return kvm_register_read_raw(vcpu, VCPU_REGS_RIP);
 119 }
 120
 121 static inline void kvm_rip_write(struct kvm_vcpu *vcpu, unsigned long val)
 122 {
 123         kvm_register_write_raw(vcpu, VCPU_REGS_RIP, val);
 124 }
 125
 126 static inline unsigned long kvm_rsp_read(struct kvm_vcpu *vcpu)
 127 {
 128         return kvm_register_read_raw(vcpu, VCPU_REGS_RSP);
 129 }
 130
 131 static inline void kvm_rsp_write(struct kvm_vcpu *vcpu, unsigned long val)
 132 {
 133         kvm_register_write_raw(vcpu, VCPU_REGS_RSP, val);
 134 }
 135
 136 static inline u64 kvm_pdptr_read(struct kvm_vcpu *vcpu, int index)
 137 {
 138         might_sleep();  /* on svm */
 139
 140         if (!kvm_register_is_available(vcpu, VCPU_EXREG_PDPTR))
 141                 static_call(kvm_x86_cache_reg)(vcpu, VCPU_EXREG_PDPTR);
 142
 143         return vcpu->arch.walk_mmu->pdptrs[index];
 144 }
 145
 146 static inline void kvm_pdptr_write(struct kvm_vcpu *vcpu, int index, u64 value)
 147 {
 148         vcpu->arch.walk_mmu->pdptrs[index] = value;
 149 }
 150
 151 static inline ulong kvm_read_cr0_bits(struct kvm_vcpu *vcpu, ulong mask)
 152 {
 153         ulong tmask = mask & KVM_POSSIBLE_CR0_GUEST_BITS;
 154         if ((tmask & vcpu->arch.cr0_guest_owned_bits) &&
 155             !kvm_register_is_available(vcpu, VCPU_EXREG_CR0))
 156                 static_call(kvm_x86_cache_reg)(vcpu, VCPU_EXREG_CR0);
 157         return vcpu->arch.cr0 & mask;
 158 }
 159
 160 static __always_inline bool kvm_is_cr0_bit_set(struct kvm_vcpu *vcpu,
 161                                                unsigned long cr0_bit)
 162 {
 163         BUILD_BUG_ON(!is_power_of_2(cr0_bit));
 164
 165         return !!kvm_read_cr0_bits(vcpu, cr0_bit);
 166 }
 167
 168 static inline ulong kvm_read_cr0(struct kvm_vcpu *vcpu)
 169 {
 170         return kvm_read_cr0_bits(vcpu, ~0UL);
 171 }
 172
 173 static inline ulong kvm_read_cr4_bits(struct kvm_vcpu *vcpu, ulong mask)
 174 {
 175         ulong tmask = mask & KVM_POSSIBLE_CR4_GUEST_BITS;
 176         if ((tmask & vcpu->arch.cr4_guest_owned_bits) &&
 177             !kvm_register_is_available(vcpu, VCPU_EXREG_CR4))
 178                 static_call(kvm_x86_cache_reg)(vcpu, VCPU_EXREG_CR4);
 179         return vcpu->arch.cr4 & mask;
 180 }
 181
 182 static __always_inline bool kvm_is_cr4_bit_set(struct kvm_vcpu *vcpu,
 183                                                unsigned long cr4_bit)
 184 {
 185         BUILD_BUG_ON(!is_power_of_2(cr4_bit));
 186
 187         return !!kvm_read_cr4_bits(vcpu, cr4_bit);
 188 }
 189
 190 static inline ulong kvm_read_cr3(struct kvm_vcpu *vcpu)
 191 {
 192         if (!kvm_register_is_available(vcpu, VCPU_EXREG_CR3))
 193                 static_call(kvm_x86_cache_reg)(vcpu, VCPU_EXREG_CR3);
 194         return vcpu->arch.cr3;
 195 }
 196
 197 static inline ulong kvm_read_cr4(struct kvm_vcpu *vcpu)
 198 {
 199         return kvm_read_cr4_bits(vcpu, ~0UL);
 200 }
 201
 202 static inline u64 kvm_read_edx_eax(struct kvm_vcpu *vcpu)
 203 {
 204         return (kvm_rax_read(vcpu) & -1u)
 205                 | ((u64)(kvm_rdx_read(vcpu) & -1u) << 32);
 206 }
 207
 208 static inline void enter_guest_mode(struct kvm_vcpu *vcpu)
 209 {
 210         vcpu->arch.hflags |= HF_GUEST_MASK;
 211         vcpu->stat.guest_mode = 1;
 212 }
 213
 214 static inline void leave_guest_mode(struct kvm_vcpu *vcpu)
 215 {
 216         vcpu->arch.hflags &= ~HF_GUEST_MASK;
 217
 218         if (vcpu->arch.load_eoi_exitmap_pending) {
 219                 vcpu->arch.load_eoi_exitmap_pending = false;
 220                 kvm_make_request(KVM_REQ_LOAD_EOI_EXITMAP, vcpu);
 221         }
 222
 223         vcpu->stat.guest_mode = 0;
 224 }
 225
 226 static inline bool is_guest_mode(struct kvm_vcpu *vcpu)
 227 {
 228         return vcpu->arch.hflags & HF_GUEST_MASK;
 229 }
 230
 231 #endif