arch/arm64/include/asm/kvm_asm.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2012,2013 - ARM Ltd
   4  * Author: Marc Zyngier <marc.zyngier@arm.com>
   5  */
   6
   7 #ifndef __ARM_KVM_ASM_H__
   8 #define __ARM_KVM_ASM_H__
   9
  10 #include <asm/hyp_image.h>
  11 #include <asm/insn.h>
  12 #include <asm/virt.h>
  13
  14 #define ARM_EXIT_WITH_SERROR_BIT  31
  15 #define ARM_EXCEPTION_CODE(x)     ((x) & ~(1U << ARM_EXIT_WITH_SERROR_BIT))
  16 #define ARM_EXCEPTION_IS_TRAP(x)  (ARM_EXCEPTION_CODE((x)) == ARM_EXCEPTION_TRAP)
  17 #define ARM_SERROR_PENDING(x)     !!((x) & (1U << ARM_EXIT_WITH_SERROR_BIT))
  18
  19 #define ARM_EXCEPTION_IRQ         0
  20 #define ARM_EXCEPTION_EL1_SERROR  1
  21 #define ARM_EXCEPTION_TRAP        2
  22 #define ARM_EXCEPTION_IL          3
  23 /* The hyp-stub will return this for any kvm_call_hyp() call */
  24 #define ARM_EXCEPTION_HYP_GONE    HVC_STUB_ERR
  25
  26 #define kvm_arm_exception_type                                  \
  27         {ARM_EXCEPTION_IRQ,             "IRQ"           },      \
  28         {ARM_EXCEPTION_EL1_SERROR,      "SERROR"        },      \
  29         {ARM_EXCEPTION_TRAP,            "TRAP"          },      \
  30         {ARM_EXCEPTION_HYP_GONE,        "HYP_GONE"      }
  31
  32 /*
  33  * Size of the HYP vectors preamble. kvm_patch_vector_branch() generates code
  34  * that jumps over this.
  35  */
  36 #define KVM_VECTOR_PREAMBLE     (2 * AARCH64_INSN_SIZE)
  37
  38 #define KVM_HOST_SMCCC_ID(id)                                           \
  39         ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,                         \
  40                            ARM_SMCCC_SMC_64,                            \
  41                            ARM_SMCCC_OWNER_VENDOR_HYP,                  \
  42                            (id))
  43
  44 #define KVM_HOST_SMCCC_FUNC(name) KVM_HOST_SMCCC_ID(__KVM_HOST_SMCCC_FUNC_##name)
  45
  46 #define __KVM_HOST_SMCCC_FUNC___kvm_hyp_init                    0
  47
  48 #ifndef __ASSEMBLY__
  49
  50 #include <linux/mm.h>
  51
  52 enum __kvm_host_smccc_func {
  53         /* Hypercalls available only prior to pKVM finalisation */
  54         /* __KVM_HOST_SMCCC_FUNC___kvm_hyp_init */
  55         __KVM_HOST_SMCCC_FUNC___kvm_get_mdcr_el2 = __KVM_HOST_SMCCC_FUNC___kvm_hyp_init + 1,
  56         __KVM_HOST_SMCCC_FUNC___pkvm_init,
  57         __KVM_HOST_SMCCC_FUNC___pkvm_create_private_mapping,
  58         __KVM_HOST_SMCCC_FUNC___pkvm_cpu_set_vector,
  59         __KVM_HOST_SMCCC_FUNC___kvm_enable_ssbs,
  60         __KVM_HOST_SMCCC_FUNC___vgic_v3_init_lrs,
  61         __KVM_HOST_SMCCC_FUNC___vgic_v3_get_gic_config,
  62         __KVM_HOST_SMCCC_FUNC___pkvm_prot_finalize,
  63
  64         /* Hypercalls available after pKVM finalisation */
  65         __KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp,
  66         __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_hyp,
  67         __KVM_HOST_SMCCC_FUNC___kvm_adjust_pc,
  68         __KVM_HOST_SMCCC_FUNC___kvm_vcpu_run,
  69         __KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context,
  70         __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa,
  71         __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa_nsh,
  72         __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid,
  73         __KVM_HOST_SMCCC_FUNC___kvm_flush_cpu_context,
  74         __KVM_HOST_SMCCC_FUNC___kvm_timer_set_cntvoff,
  75         __KVM_HOST_SMCCC_FUNC___vgic_v3_read_vmcr,
  76         __KVM_HOST_SMCCC_FUNC___vgic_v3_write_vmcr,
  77         __KVM_HOST_SMCCC_FUNC___vgic_v3_save_aprs,
  78         __KVM_HOST_SMCCC_FUNC___vgic_v3_restore_aprs,
  79         __KVM_HOST_SMCCC_FUNC___pkvm_vcpu_init_traps,
  80         __KVM_HOST_SMCCC_FUNC___pkvm_init_vm,
  81         __KVM_HOST_SMCCC_FUNC___pkvm_init_vcpu,
  82         __KVM_HOST_SMCCC_FUNC___pkvm_teardown_vm,
  83 };
  84
  85 #define DECLARE_KVM_VHE_SYM(sym)        extern char sym[]
  86 #define DECLARE_KVM_NVHE_SYM(sym)       extern char kvm_nvhe_sym(sym)[]
  87
  88 /*
  89  * Define a pair of symbols sharing the same name but one defined in
  90  * VHE and the other in nVHE hyp implementations.
  91  */
  92 #define DECLARE_KVM_HYP_SYM(sym)                \
  93         DECLARE_KVM_VHE_SYM(sym);               \
  94         DECLARE_KVM_NVHE_SYM(sym)
  95
  96 #define DECLARE_KVM_VHE_PER_CPU(type, sym)      \
  97         DECLARE_PER_CPU(type, sym)
  98 #define DECLARE_KVM_NVHE_PER_CPU(type, sym)     \
  99         DECLARE_PER_CPU(type, kvm_nvhe_sym(sym))
 100
 101 #define DECLARE_KVM_HYP_PER_CPU(type, sym)      \
 102         DECLARE_KVM_VHE_PER_CPU(type, sym);     \
 103         DECLARE_KVM_NVHE_PER_CPU(type, sym)
 104
 105 /*
 106  * Compute pointer to a symbol defined in nVHE percpu region.
 107  * Returns NULL if percpu memory has not been allocated yet.
 108  */
 109 #define this_cpu_ptr_nvhe_sym(sym)      per_cpu_ptr_nvhe_sym(sym, smp_processor_id())
 110 #define per_cpu_ptr_nvhe_sym(sym, cpu)                                          \
 111         ({                                                                      \
 112                 unsigned long base, off;                                        \
 113                 base = kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu];              \
 114                 off = (unsigned long)&CHOOSE_NVHE_SYM(sym) -                    \
 115                       (unsigned long)&CHOOSE_NVHE_SYM(__per_cpu_start);         \
 116                 base ? (typeof(CHOOSE_NVHE_SYM(sym))*)(base + off) : NULL;      \
 117         })
 118
 119 #if defined(__KVM_NVHE_HYPERVISOR__)
 120
 121 #define CHOOSE_NVHE_SYM(sym)    sym
 122 #define CHOOSE_HYP_SYM(sym)     CHOOSE_NVHE_SYM(sym)
 123
 124 /* The nVHE hypervisor shouldn't even try to access VHE symbols */
 125 extern void *__nvhe_undefined_symbol;
 126 #define CHOOSE_VHE_SYM(sym)             __nvhe_undefined_symbol
 127 #define this_cpu_ptr_hyp_sym(sym)       (&__nvhe_undefined_symbol)
 128 #define per_cpu_ptr_hyp_sym(sym, cpu)   (&__nvhe_undefined_symbol)
 129
 130 #elif defined(__KVM_VHE_HYPERVISOR__)
 131
 132 #define CHOOSE_VHE_SYM(sym)     sym
 133 #define CHOOSE_HYP_SYM(sym)     CHOOSE_VHE_SYM(sym)
 134
 135 /* The VHE hypervisor shouldn't even try to access nVHE symbols */
 136 extern void *__vhe_undefined_symbol;
 137 #define CHOOSE_NVHE_SYM(sym)            __vhe_undefined_symbol
 138 #define this_cpu_ptr_hyp_sym(sym)       (&__vhe_undefined_symbol)
 139 #define per_cpu_ptr_hyp_sym(sym, cpu)   (&__vhe_undefined_symbol)
 140
 141 #else
 142
 143 /*
 144  * BIG FAT WARNINGS:
 145  *
 146  * - Don't be tempted to change the following is_kernel_in_hyp_mode()
 147  *   to has_vhe(). has_vhe() is implemented as a *final* capability,
 148  *   while this is used early at boot time, when the capabilities are
 149  *   not final yet....
 150  *
 151  * - Don't let the nVHE hypervisor have access to this, as it will
 152  *   pick the *wrong* symbol (yes, it runs at EL2...).
 153  */
 154 #define CHOOSE_HYP_SYM(sym)             (is_kernel_in_hyp_mode()        \
 155                                            ? CHOOSE_VHE_SYM(sym)        \
 156                                            : CHOOSE_NVHE_SYM(sym))
 157
 158 #define this_cpu_ptr_hyp_sym(sym)       (is_kernel_in_hyp_mode()        \
 159                                            ? this_cpu_ptr(&sym)         \
 160                                            : this_cpu_ptr_nvhe_sym(sym))
 161
 162 #define per_cpu_ptr_hyp_sym(sym, cpu)   (is_kernel_in_hyp_mode()        \
 163                                            ? per_cpu_ptr(&sym, cpu)     \
 164                                            : per_cpu_ptr_nvhe_sym(sym, cpu))
 165
 166 #define CHOOSE_VHE_SYM(sym)     sym
 167 #define CHOOSE_NVHE_SYM(sym)    kvm_nvhe_sym(sym)
 168
 169 #endif
 170
 171 struct kvm_nvhe_init_params {
 172         unsigned long mair_el2;
 173         unsigned long tcr_el2;
 174         unsigned long tpidr_el2;
 175         unsigned long stack_hyp_va;
 176         unsigned long stack_pa;
 177         phys_addr_t pgd_pa;
 178         unsigned long hcr_el2;
 179         unsigned long vttbr;
 180         unsigned long vtcr;
 181 };
 182
 183 /*
 184  * Used by the host in EL1 to dump the nVHE hypervisor backtrace on
 185  * hyp_panic() in non-protected mode.
 186  *
 187  * @stack_base:                 hyp VA of the hyp_stack base.
 188  * @overflow_stack_base:        hyp VA of the hyp_overflow_stack base.
 189  * @fp:                         hyp FP where the backtrace begins.
 190  * @pc:                         hyp PC where the backtrace begins.
 191  */
 192 struct kvm_nvhe_stacktrace_info {
 193         unsigned long stack_base;
 194         unsigned long overflow_stack_base;
 195         unsigned long fp;
 196         unsigned long pc;
 197 };
 198
 199 /* Translate a kernel address @ptr into its equivalent linear mapping */
 200 #define kvm_ksym_ref(ptr)                                               \
 201         ({                                                              \
 202                 void *val = (ptr);                                      \
 203                 if (!is_kernel_in_hyp_mode())                           \
 204                         val = lm_alias((ptr));                          \
 205                 val;                                                    \
 206          })
 207 #define kvm_ksym_ref_nvhe(sym)  kvm_ksym_ref(kvm_nvhe_sym(sym))
 208
 209 struct kvm;
 210 struct kvm_vcpu;
 211 struct kvm_s2_mmu;
 212
 213 DECLARE_KVM_NVHE_SYM(__kvm_hyp_init);
 214 DECLARE_KVM_HYP_SYM(__kvm_hyp_vector);
 215 #define __kvm_hyp_init          CHOOSE_NVHE_SYM(__kvm_hyp_init)
 216 #define __kvm_hyp_vector        CHOOSE_HYP_SYM(__kvm_hyp_vector)
 217
 218 extern unsigned long kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[];
 219 DECLARE_KVM_NVHE_SYM(__per_cpu_start);
 220 DECLARE_KVM_NVHE_SYM(__per_cpu_end);
 221
 222 DECLARE_KVM_HYP_SYM(__bp_harden_hyp_vecs);
 223 #define __bp_harden_hyp_vecs    CHOOSE_HYP_SYM(__bp_harden_hyp_vecs)
 224
 225 extern void __kvm_flush_vm_context(void);
 226 extern void __kvm_flush_cpu_context(struct kvm_s2_mmu *mmu);
 227 extern void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa,
 228                                      int level);
 229 extern void __kvm_tlb_flush_vmid_ipa_nsh(struct kvm_s2_mmu *mmu,
 230                                          phys_addr_t ipa,
 231                                          int level);
 232 extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu);
 233
 234 extern void __kvm_timer_set_cntvoff(u64 cntvoff);
 235
 236 extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
 237
 238 extern void __kvm_adjust_pc(struct kvm_vcpu *vcpu);
 239
 240 extern u64 __vgic_v3_get_gic_config(void);
 241 extern u64 __vgic_v3_read_vmcr(void);
 242 extern void __vgic_v3_write_vmcr(u32 vmcr);
 243 extern void __vgic_v3_init_lrs(void);
 244
 245 extern u64 __kvm_get_mdcr_el2(void);
 246
 247 #define __KVM_EXTABLE(from, to)                                         \
 248         "       .pushsection    __kvm_ex_table, \"a\"\n"                \
 249         "       .align          3\n"                                    \
 250         "       .long           (" #from " - .), (" #to " - .)\n"       \
 251         "       .popsection\n"
 252
 253
 254 #define __kvm_at(at_op, addr)                                           \
 255 ( {                                                                     \
 256         int __kvm_at_err = 0;                                           \
 257         u64 spsr, elr;                                                  \
 258         asm volatile(                                                   \
 259         "       mrs     %1, spsr_el2\n"                                 \
 260         "       mrs     %2, elr_el2\n"                                  \
 261         "1:     at      "at_op", %3\n"                                  \
 262         "       isb\n"                                                  \
 263         "       b       9f\n"                                           \
 264         "2:     msr     spsr_el2, %1\n"                                 \
 265         "       msr     elr_el2, %2\n"                                  \
 266         "       mov     %w0, %4\n"                                      \
 267         "9:\n"                                                          \
 268         __KVM_EXTABLE(1b, 2b)                                           \
 269         : "+r" (__kvm_at_err), "=&r" (spsr), "=&r" (elr)                \
 270         : "r" (addr), "i" (-EFAULT));                                   \
 271         __kvm_at_err;                                                   \
 272 } )
 273
 274 void __noreturn hyp_panic(void);
 275 asmlinkage void kvm_unexpected_el2_exception(void);
 276 asmlinkage void __noreturn hyp_panic(void);
 277 asmlinkage void __noreturn hyp_panic_bad_stack(void);
 278 asmlinkage void kvm_unexpected_el2_exception(void);
 279 struct kvm_cpu_context;
 280 void handle_trap(struct kvm_cpu_context *host_ctxt);
 281 asmlinkage void __noreturn kvm_host_psci_cpu_entry(bool is_cpu_on);
 282 void __noreturn __pkvm_init_finalise(void);
 283 void kvm_nvhe_prepare_backtrace(unsigned long fp, unsigned long pc);
 284 void kvm_patch_vector_branch(struct alt_instr *alt,
 285         __le32 *origptr, __le32 *updptr, int nr_inst);
 286 void kvm_get_kimage_voffset(struct alt_instr *alt,
 287         __le32 *origptr, __le32 *updptr, int nr_inst);
 288 void kvm_compute_final_ctr_el0(struct alt_instr *alt,
 289         __le32 *origptr, __le32 *updptr, int nr_inst);
 290 void __noreturn __cold nvhe_hyp_panic_handler(u64 esr, u64 spsr, u64 elr_virt,
 291         u64 elr_phys, u64 par, uintptr_t vcpu, u64 far, u64 hpfar);
 292
 293 #else /* __ASSEMBLY__ */
 294
 295 .macro get_host_ctxt reg, tmp
 296         adr_this_cpu \reg, kvm_host_data, \tmp
 297         add     \reg, \reg, #HOST_DATA_CONTEXT
 298 .endm
 299
 300 .macro get_vcpu_ptr vcpu, ctxt
 301         get_host_ctxt \ctxt, \vcpu
 302         ldr     \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
 303 .endm
 304
 305 .macro get_loaded_vcpu vcpu, ctxt
 306         adr_this_cpu \ctxt, kvm_hyp_ctxt, \vcpu
 307         ldr     \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
 308 .endm
 309
 310 .macro set_loaded_vcpu vcpu, ctxt, tmp
 311         adr_this_cpu \ctxt, kvm_hyp_ctxt, \tmp
 312         str     \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
 313 .endm
 314
 315 /*
 316  * KVM extable for unexpected exceptions.
 317  * Create a struct kvm_exception_table_entry output to a section that can be
 318  * mapped by EL2. The table is not sorted.
 319  *
 320  * The caller must ensure:
 321  * x18 has the hypervisor value to allow any Shadow-Call-Stack instrumented
 322  * code to write to it, and that SPSR_EL2 and ELR_EL2 are restored by the fixup.
 323  */
 324 .macro  _kvm_extable, from, to
 325         .pushsection    __kvm_ex_table, "a"
 326         .align          3
 327         .long           (\from - .), (\to - .)
 328         .popsection
 329 .endm
 330
 331 #define CPU_XREG_OFFSET(x)      (CPU_USER_PT_REGS + 8*x)
 332 #define CPU_LR_OFFSET           CPU_XREG_OFFSET(30)
 333 #define CPU_SP_EL0_OFFSET       (CPU_LR_OFFSET + 8)
 334
 335 /*
 336  * We treat x18 as callee-saved as the host may use it as a platform
 337  * register (e.g. for shadow call stack).
 338  */
 339 .macro save_callee_saved_regs ctxt
 340         str     x18,      [\ctxt, #CPU_XREG_OFFSET(18)]
 341         stp     x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
 342         stp     x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
 343         stp     x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
 344         stp     x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
 345         stp     x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
 346         stp     x29, lr,  [\ctxt, #CPU_XREG_OFFSET(29)]
 347 .endm
 348
 349 .macro restore_callee_saved_regs ctxt
 350         // We require \ctxt is not x18-x28
 351         ldr     x18,      [\ctxt, #CPU_XREG_OFFSET(18)]
 352         ldp     x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
 353         ldp     x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
 354         ldp     x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
 355         ldp     x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
 356         ldp     x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
 357         ldp     x29, lr,  [\ctxt, #CPU_XREG_OFFSET(29)]
 358 .endm
 359
 360 .macro save_sp_el0 ctxt, tmp
 361         mrs     \tmp,   sp_el0
 362         str     \tmp,   [\ctxt, #CPU_SP_EL0_OFFSET]
 363 .endm
 364
 365 .macro restore_sp_el0 ctxt, tmp
 366         ldr     \tmp,     [\ctxt, #CPU_SP_EL0_OFFSET]
 367         msr     sp_el0, \tmp
 368 .endm
 369
 370 #endif
 371
 372 #endif /* __ARM_KVM_ASM_H__ */