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 <[email protected]>
   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 #include <asm/sysreg.h>
  14
  15 #define ARM_EXIT_WITH_SERROR_BIT  31
  16 #define ARM_EXCEPTION_CODE(x)     ((x) & ~(1U << ARM_EXIT_WITH_SERROR_BIT))
  17 #define ARM_EXCEPTION_IS_TRAP(x)  (ARM_EXCEPTION_CODE((x)) == ARM_EXCEPTION_TRAP)
  18 #define ARM_SERROR_PENDING(x)     !!((x) & (1U << ARM_EXIT_WITH_SERROR_BIT))
  19
  20 #define ARM_EXCEPTION_IRQ         0
  21 #define ARM_EXCEPTION_EL1_SERROR  1
  22 #define ARM_EXCEPTION_TRAP        2
  23 #define ARM_EXCEPTION_IL          3
  24 /* The hyp-stub will return this for any kvm_call_hyp() call */
  25 #define ARM_EXCEPTION_HYP_GONE    HVC_STUB_ERR
  26
  27 #define kvm_arm_exception_type                                  \
  28         {ARM_EXCEPTION_IRQ,             "IRQ"           },      \
  29         {ARM_EXCEPTION_EL1_SERROR,      "SERROR"        },      \
  30         {ARM_EXCEPTION_TRAP,            "TRAP"          },      \
  31         {ARM_EXCEPTION_HYP_GONE,        "HYP_GONE"      }
  32
  33 /*
  34  * Size of the HYP vectors preamble. kvm_patch_vector_branch() generates code
  35  * that jumps over this.
  36  */
  37 #define KVM_VECTOR_PREAMBLE     (2 * AARCH64_INSN_SIZE)
  38
  39 #define KVM_HOST_SMCCC_ID(id)                                           \
  40         ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,                         \
  41                            ARM_SMCCC_SMC_64,                            \
  42                            ARM_SMCCC_OWNER_VENDOR_HYP,                  \
  43                            (id))
  44
  45 #define KVM_HOST_SMCCC_FUNC(name) KVM_HOST_SMCCC_ID(__KVM_HOST_SMCCC_FUNC_##name)
  46
  47 #define __KVM_HOST_SMCCC_FUNC___kvm_hyp_init                    0
  48
  49 #ifndef __ASSEMBLY__
  50
  51 #include <linux/mm.h>
  52
  53 enum __kvm_host_smccc_func {
  54         /* Hypercalls available only prior to pKVM finalisation */
  55         /* __KVM_HOST_SMCCC_FUNC___kvm_hyp_init */
  56         __KVM_HOST_SMCCC_FUNC___pkvm_init = __KVM_HOST_SMCCC_FUNC___kvm_hyp_init + 1,
  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___pkvm_host_share_guest,
  68         __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_guest,
  69         __KVM_HOST_SMCCC_FUNC___pkvm_host_relax_perms_guest,
  70         __KVM_HOST_SMCCC_FUNC___pkvm_host_wrprotect_guest,
  71         __KVM_HOST_SMCCC_FUNC___pkvm_host_test_clear_young_guest,
  72         __KVM_HOST_SMCCC_FUNC___pkvm_host_mkyoung_guest,
  73         __KVM_HOST_SMCCC_FUNC___kvm_adjust_pc,
  74         __KVM_HOST_SMCCC_FUNC___kvm_vcpu_run,
  75         __KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context,
  76         __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa,
  77         __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa_nsh,
  78         __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid,
  79         __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_range,
  80         __KVM_HOST_SMCCC_FUNC___kvm_flush_cpu_context,
  81         __KVM_HOST_SMCCC_FUNC___kvm_timer_set_cntvoff,
  82         __KVM_HOST_SMCCC_FUNC___vgic_v3_save_vmcr_aprs,
  83         __KVM_HOST_SMCCC_FUNC___vgic_v3_restore_vmcr_aprs,
  84         __KVM_HOST_SMCCC_FUNC___pkvm_init_vm,
  85         __KVM_HOST_SMCCC_FUNC___pkvm_init_vcpu,
  86         __KVM_HOST_SMCCC_FUNC___pkvm_teardown_vm,
  87         __KVM_HOST_SMCCC_FUNC___pkvm_vcpu_load,
  88         __KVM_HOST_SMCCC_FUNC___pkvm_vcpu_put,
  89         __KVM_HOST_SMCCC_FUNC___pkvm_tlb_flush_vmid,
  90 };
  91
  92 #define DECLARE_KVM_VHE_SYM(sym)        extern char sym[]
  93 #define DECLARE_KVM_NVHE_SYM(sym)       extern char kvm_nvhe_sym(sym)[]
  94
  95 /*
  96  * Define a pair of symbols sharing the same name but one defined in
  97  * VHE and the other in nVHE hyp implementations.
  98  */
  99 #define DECLARE_KVM_HYP_SYM(sym)                \
 100         DECLARE_KVM_VHE_SYM(sym);               \
 101         DECLARE_KVM_NVHE_SYM(sym)
 102
 103 #define DECLARE_KVM_VHE_PER_CPU(type, sym)      \
 104         DECLARE_PER_CPU(type, sym)
 105 #define DECLARE_KVM_NVHE_PER_CPU(type, sym)     \
 106         DECLARE_PER_CPU(type, kvm_nvhe_sym(sym))
 107
 108 #define DECLARE_KVM_HYP_PER_CPU(type, sym)      \
 109         DECLARE_KVM_VHE_PER_CPU(type, sym);     \
 110         DECLARE_KVM_NVHE_PER_CPU(type, sym)
 111
 112 /*
 113  * Compute pointer to a symbol defined in nVHE percpu region.
 114  * Returns NULL if percpu memory has not been allocated yet.
 115  */
 116 #define this_cpu_ptr_nvhe_sym(sym)      per_cpu_ptr_nvhe_sym(sym, smp_processor_id())
 117 #define per_cpu_ptr_nvhe_sym(sym, cpu)                                          \
 118         ({                                                                      \
 119                 unsigned long base, off;                                        \
 120                 base = kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu];              \
 121                 off = (unsigned long)&CHOOSE_NVHE_SYM(sym) -                    \
 122                       (unsigned long)&CHOOSE_NVHE_SYM(__per_cpu_start);         \
 123                 base ? (typeof(CHOOSE_NVHE_SYM(sym))*)(base + off) : NULL;      \
 124         })
 125
 126 #if defined(__KVM_NVHE_HYPERVISOR__)
 127
 128 #define CHOOSE_NVHE_SYM(sym)    sym
 129 #define CHOOSE_HYP_SYM(sym)     CHOOSE_NVHE_SYM(sym)
 130
 131 /* The nVHE hypervisor shouldn't even try to access VHE symbols */
 132 extern void *__nvhe_undefined_symbol;
 133 #define CHOOSE_VHE_SYM(sym)             __nvhe_undefined_symbol
 134 #define this_cpu_ptr_hyp_sym(sym)       (&__nvhe_undefined_symbol)
 135 #define per_cpu_ptr_hyp_sym(sym, cpu)   (&__nvhe_undefined_symbol)
 136
 137 #elif defined(__KVM_VHE_HYPERVISOR__)
 138
 139 #define CHOOSE_VHE_SYM(sym)     sym
 140 #define CHOOSE_HYP_SYM(sym)     CHOOSE_VHE_SYM(sym)
 141
 142 /* The VHE hypervisor shouldn't even try to access nVHE symbols */
 143 extern void *__vhe_undefined_symbol;
 144 #define CHOOSE_NVHE_SYM(sym)            __vhe_undefined_symbol
 145 #define this_cpu_ptr_hyp_sym(sym)       (&__vhe_undefined_symbol)
 146 #define per_cpu_ptr_hyp_sym(sym, cpu)   (&__vhe_undefined_symbol)
 147
 148 #else
 149
 150 /*
 151  * BIG FAT WARNINGS:
 152  *
 153  * - Don't be tempted to change the following is_kernel_in_hyp_mode()
 154  *   to has_vhe(). has_vhe() is implemented as a *final* capability,
 155  *   while this is used early at boot time, when the capabilities are
 156  *   not final yet....
 157  *
 158  * - Don't let the nVHE hypervisor have access to this, as it will
 159  *   pick the *wrong* symbol (yes, it runs at EL2...).
 160  */
 161 #define CHOOSE_HYP_SYM(sym)             (is_kernel_in_hyp_mode()        \
 162                                            ? CHOOSE_VHE_SYM(sym)        \
 163                                            : CHOOSE_NVHE_SYM(sym))
 164
 165 #define this_cpu_ptr_hyp_sym(sym)       (is_kernel_in_hyp_mode()        \
 166                                            ? this_cpu_ptr(&sym)         \
 167                                            : this_cpu_ptr_nvhe_sym(sym))
 168
 169 #define per_cpu_ptr_hyp_sym(sym, cpu)   (is_kernel_in_hyp_mode()        \
 170                                            ? per_cpu_ptr(&sym, cpu)     \
 171                                            : per_cpu_ptr_nvhe_sym(sym, cpu))
 172
 173 #define CHOOSE_VHE_SYM(sym)     sym
 174 #define CHOOSE_NVHE_SYM(sym)    kvm_nvhe_sym(sym)
 175
 176 #endif
 177
 178 struct kvm_nvhe_init_params {
 179         unsigned long mair_el2;
 180         unsigned long tcr_el2;
 181         unsigned long tpidr_el2;
 182         unsigned long stack_hyp_va;
 183         unsigned long stack_pa;
 184         phys_addr_t pgd_pa;
 185         unsigned long hcr_el2;
 186         unsigned long vttbr;
 187         unsigned long vtcr;
 188         unsigned long tmp;
 189 };
 190
 191 /*
 192  * Used by the host in EL1 to dump the nVHE hypervisor backtrace on
 193  * hyp_panic() in non-protected mode.
 194  *
 195  * @stack_base:                 hyp VA of the hyp_stack base.
 196  * @overflow_stack_base:        hyp VA of the hyp_overflow_stack base.
 197  * @fp:                         hyp FP where the backtrace begins.
 198  * @pc:                         hyp PC where the backtrace begins.
 199  */
 200 struct kvm_nvhe_stacktrace_info {
 201         unsigned long stack_base;
 202         unsigned long overflow_stack_base;
 203         unsigned long fp;
 204         unsigned long pc;
 205 };
 206
 207 /* Translate a kernel address @ptr into its equivalent linear mapping */
 208 #define kvm_ksym_ref(ptr)                                               \
 209         ({                                                              \
 210                 void *val = (ptr);                                      \
 211                 if (!is_kernel_in_hyp_mode())                           \
 212                         val = lm_alias((ptr));                          \
 213                 val;                                                    \
 214          })
 215 #define kvm_ksym_ref_nvhe(sym)  kvm_ksym_ref(kvm_nvhe_sym(sym))
 216
 217 struct kvm;
 218 struct kvm_vcpu;
 219 struct kvm_s2_mmu;
 220
 221 DECLARE_KVM_NVHE_SYM(__kvm_hyp_init);
 222 DECLARE_KVM_HYP_SYM(__kvm_hyp_vector);
 223 #define __kvm_hyp_init          CHOOSE_NVHE_SYM(__kvm_hyp_init)
 224 #define __kvm_hyp_vector        CHOOSE_HYP_SYM(__kvm_hyp_vector)
 225
 226 extern unsigned long kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[];
 227 DECLARE_KVM_NVHE_SYM(__per_cpu_start);
 228 DECLARE_KVM_NVHE_SYM(__per_cpu_end);
 229
 230 DECLARE_KVM_HYP_SYM(__bp_harden_hyp_vecs);
 231 #define __bp_harden_hyp_vecs    CHOOSE_HYP_SYM(__bp_harden_hyp_vecs)
 232
 233 extern void __kvm_flush_vm_context(void);
 234 extern void __kvm_flush_cpu_context(struct kvm_s2_mmu *mmu);
 235 extern void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa,
 236                                      int level);
 237 extern void __kvm_tlb_flush_vmid_ipa_nsh(struct kvm_s2_mmu *mmu,
 238                                          phys_addr_t ipa,
 239                                          int level);
 240 extern void __kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
 241                                         phys_addr_t start, unsigned long pages);
 242 extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu);
 243
 244 extern int __kvm_tlbi_s1e2(struct kvm_s2_mmu *mmu, u64 va, u64 sys_encoding);
 245
 246 extern void __kvm_timer_set_cntvoff(u64 cntvoff);
 247 extern void __kvm_at_s1e01(struct kvm_vcpu *vcpu, u32 op, u64 vaddr);
 248 extern void __kvm_at_s1e2(struct kvm_vcpu *vcpu, u32 op, u64 vaddr);
 249 extern void __kvm_at_s12(struct kvm_vcpu *vcpu, u32 op, u64 vaddr);
 250
 251 extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
 252
 253 extern void __kvm_adjust_pc(struct kvm_vcpu *vcpu);
 254
 255 extern u64 __vgic_v3_get_gic_config(void);
 256 extern void __vgic_v3_init_lrs(void);
 257
 258 #define __KVM_EXTABLE(from, to)                                         \
 259         "       .pushsection    __kvm_ex_table, \"a\"\n"                \
 260         "       .align          3\n"                                    \
 261         "       .long           (" #from " - .), (" #to " - .)\n"       \
 262         "       .popsection\n"
 263
 264
 265 #define __kvm_at(at_op, addr)                                           \
 266 ( {                                                                     \
 267         int __kvm_at_err = 0;                                           \
 268         u64 spsr, elr;                                                  \
 269         asm volatile(                                                   \
 270         "       mrs     %1, spsr_el2\n"                                 \
 271         "       mrs     %2, elr_el2\n"                                  \
 272         "1:     " __msr_s(at_op, "%3") "\n"                             \
 273         "       isb\n"                                                  \
 274         "       b       9f\n"                                           \
 275         "2:     msr     spsr_el2, %1\n"                                 \
 276         "       msr     elr_el2, %2\n"                                  \
 277         "       mov     %w0, %4\n"                                      \
 278         "9:\n"                                                          \
 279         __KVM_EXTABLE(1b, 2b)                                           \
 280         : "+r" (__kvm_at_err), "=&r" (spsr), "=&r" (elr)                \
 281         : "r" (addr), "i" (-EFAULT));                                   \
 282         __kvm_at_err;                                                   \
 283 } )
 284
 285 void __noreturn hyp_panic(void);
 286 asmlinkage void kvm_unexpected_el2_exception(void);
 287 asmlinkage void __noreturn hyp_panic(void);
 288 asmlinkage void __noreturn hyp_panic_bad_stack(void);
 289 asmlinkage void kvm_unexpected_el2_exception(void);
 290 struct kvm_cpu_context;
 291 void handle_trap(struct kvm_cpu_context *host_ctxt);
 292 asmlinkage void __noreturn __kvm_host_psci_cpu_entry(bool is_cpu_on);
 293 void __noreturn __pkvm_init_finalise(void);
 294 void kvm_nvhe_prepare_backtrace(unsigned long fp, unsigned long pc);
 295 void kvm_patch_vector_branch(struct alt_instr *alt,
 296         __le32 *origptr, __le32 *updptr, int nr_inst);
 297 void kvm_get_kimage_voffset(struct alt_instr *alt,
 298         __le32 *origptr, __le32 *updptr, int nr_inst);
 299 void kvm_compute_final_ctr_el0(struct alt_instr *alt,
 300         __le32 *origptr, __le32 *updptr, int nr_inst);
 301 void __noreturn __cold nvhe_hyp_panic_handler(u64 esr, u64 spsr, u64 elr_virt,
 302         u64 elr_phys, u64 par, uintptr_t vcpu, u64 far, u64 hpfar);
 303
 304 #else /* __ASSEMBLY__ */
 305
 306 .macro get_host_ctxt reg, tmp
 307         adr_this_cpu \reg, kvm_host_data, \tmp
 308         add     \reg, \reg, #HOST_DATA_CONTEXT
 309 .endm
 310
 311 .macro get_vcpu_ptr vcpu, ctxt
 312         get_host_ctxt \ctxt, \vcpu
 313         ldr     \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
 314 .endm
 315
 316 .macro get_loaded_vcpu vcpu, ctxt
 317         adr_this_cpu \ctxt, kvm_hyp_ctxt, \vcpu
 318         ldr     \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
 319 .endm
 320
 321 .macro set_loaded_vcpu vcpu, ctxt, tmp
 322         adr_this_cpu \ctxt, kvm_hyp_ctxt, \tmp
 323         str     \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
 324 .endm
 325
 326 /*
 327  * KVM extable for unexpected exceptions.
 328  * Create a struct kvm_exception_table_entry output to a section that can be
 329  * mapped by EL2. The table is not sorted.
 330  *
 331  * The caller must ensure:
 332  * x18 has the hypervisor value to allow any Shadow-Call-Stack instrumented
 333  * code to write to it, and that SPSR_EL2 and ELR_EL2 are restored by the fixup.
 334  */
 335 .macro  _kvm_extable, from, to
 336         .pushsection    __kvm_ex_table, "a"
 337         .align          3
 338         .long           (\from - .), (\to - .)
 339         .popsection
 340 .endm
 341
 342 #define CPU_XREG_OFFSET(x)      (CPU_USER_PT_REGS + 8*x)
 343 #define CPU_LR_OFFSET           CPU_XREG_OFFSET(30)
 344 #define CPU_SP_EL0_OFFSET       (CPU_LR_OFFSET + 8)
 345
 346 /*
 347  * We treat x18 as callee-saved as the host may use it as a platform
 348  * register (e.g. for shadow call stack).
 349  */
 350 .macro save_callee_saved_regs ctxt
 351         str     x18,      [\ctxt, #CPU_XREG_OFFSET(18)]
 352         stp     x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
 353         stp     x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
 354         stp     x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
 355         stp     x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
 356         stp     x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
 357         stp     x29, lr,  [\ctxt, #CPU_XREG_OFFSET(29)]
 358 .endm
 359
 360 .macro restore_callee_saved_regs ctxt
 361         // We require \ctxt is not x18-x28
 362         ldr     x18,      [\ctxt, #CPU_XREG_OFFSET(18)]
 363         ldp     x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
 364         ldp     x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
 365         ldp     x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
 366         ldp     x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
 367         ldp     x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
 368         ldp     x29, lr,  [\ctxt, #CPU_XREG_OFFSET(29)]
 369 .endm
 370
 371 .macro save_sp_el0 ctxt, tmp
 372         mrs     \tmp,   sp_el0
 373         str     \tmp,   [\ctxt, #CPU_SP_EL0_OFFSET]
 374 .endm
 375
 376 .macro restore_sp_el0 ctxt, tmp
 377         ldr     \tmp,     [\ctxt, #CPU_SP_EL0_OFFSET]
 378         msr     sp_el0, \tmp
 379 .endm
 380
 381 #endif
 382
 383 #endif /* __ARM_KVM_ASM_H__ */