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
  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,
  72         __KVM_HOST_SMCCC_FUNC___kvm_flush_cpu_context,
  73         __KVM_HOST_SMCCC_FUNC___kvm_timer_set_cntvoff,
  74         __KVM_HOST_SMCCC_FUNC___vgic_v3_read_vmcr,
  75         __KVM_HOST_SMCCC_FUNC___vgic_v3_write_vmcr,
  76         __KVM_HOST_SMCCC_FUNC___vgic_v3_save_aprs,
  77         __KVM_HOST_SMCCC_FUNC___vgic_v3_restore_aprs,
  78         __KVM_HOST_SMCCC_FUNC___pkvm_vcpu_init_traps,
  79         __KVM_HOST_SMCCC_FUNC___pkvm_init_vm,
  80         __KVM_HOST_SMCCC_FUNC___pkvm_init_vcpu,
  81         __KVM_HOST_SMCCC_FUNC___pkvm_teardown_vm,
  82 };
  83
  84 #define DECLARE_KVM_VHE_SYM(sym)        extern char sym[]
  85 #define DECLARE_KVM_NVHE_SYM(sym)       extern char kvm_nvhe_sym(sym)[]
  86
  87 /*
  88  * Define a pair of symbols sharing the same name but one defined in
  89  * VHE and the other in nVHE hyp implementations.
  90  */
  91 #define DECLARE_KVM_HYP_SYM(sym)                \
  92         DECLARE_KVM_VHE_SYM(sym);               \
  93         DECLARE_KVM_NVHE_SYM(sym)
  94
  95 #define DECLARE_KVM_VHE_PER_CPU(type, sym)      \
  96         DECLARE_PER_CPU(type, sym)
  97 #define DECLARE_KVM_NVHE_PER_CPU(type, sym)     \
  98         DECLARE_PER_CPU(type, kvm_nvhe_sym(sym))
  99
 100 #define DECLARE_KVM_HYP_PER_CPU(type, sym)      \
 101         DECLARE_KVM_VHE_PER_CPU(type, sym);     \
 102         DECLARE_KVM_NVHE_PER_CPU(type, sym)
 103
 104 /*
 105  * Compute pointer to a symbol defined in nVHE percpu region.
 106  * Returns NULL if percpu memory has not been allocated yet.
 107  */
 108 #define this_cpu_ptr_nvhe_sym(sym)      per_cpu_ptr_nvhe_sym(sym, smp_processor_id())
 109 #define per_cpu_ptr_nvhe_sym(sym, cpu)                                          \
 110         ({                                                                      \
 111                 unsigned long base, off;                                        \
 112                 base = kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu];              \
 113                 off = (unsigned long)&CHOOSE_NVHE_SYM(sym) -                    \
 114                       (unsigned long)&CHOOSE_NVHE_SYM(__per_cpu_start);         \
 115                 base ? (typeof(CHOOSE_NVHE_SYM(sym))*)(base + off) : NULL;      \
 116         })
 117
 118 #if defined(__KVM_NVHE_HYPERVISOR__)
 119
 120 #define CHOOSE_NVHE_SYM(sym)    sym
 121 #define CHOOSE_HYP_SYM(sym)     CHOOSE_NVHE_SYM(sym)
 122
 123 /* The nVHE hypervisor shouldn't even try to access VHE symbols */
 124 extern void *__nvhe_undefined_symbol;
 125 #define CHOOSE_VHE_SYM(sym)             __nvhe_undefined_symbol
 126 #define this_cpu_ptr_hyp_sym(sym)       (&__nvhe_undefined_symbol)
 127 #define per_cpu_ptr_hyp_sym(sym, cpu)   (&__nvhe_undefined_symbol)
 128
 129 #elif defined(__KVM_VHE_HYPERVISOR__)
 130
 131 #define CHOOSE_VHE_SYM(sym)     sym
 132 #define CHOOSE_HYP_SYM(sym)     CHOOSE_VHE_SYM(sym)
 133
 134 /* The VHE hypervisor shouldn't even try to access nVHE symbols */
 135 extern void *__vhe_undefined_symbol;
 136 #define CHOOSE_NVHE_SYM(sym)            __vhe_undefined_symbol
 137 #define this_cpu_ptr_hyp_sym(sym)       (&__vhe_undefined_symbol)
 138 #define per_cpu_ptr_hyp_sym(sym, cpu)   (&__vhe_undefined_symbol)
 139
 140 #else
 141
 142 /*
 143  * BIG FAT WARNINGS:
 144  *
 145  * - Don't be tempted to change the following is_kernel_in_hyp_mode()
 146  *   to has_vhe(). has_vhe() is implemented as a *final* capability,
 147  *   while this is used early at boot time, when the capabilities are
 148  *   not final yet....
 149  *
 150  * - Don't let the nVHE hypervisor have access to this, as it will
 151  *   pick the *wrong* symbol (yes, it runs at EL2...).
 152  */
 153 #define CHOOSE_HYP_SYM(sym)             (is_kernel_in_hyp_mode()        \
 154                                            ? CHOOSE_VHE_SYM(sym)        \
 155                                            : CHOOSE_NVHE_SYM(sym))
 156
 157 #define this_cpu_ptr_hyp_sym(sym)       (is_kernel_in_hyp_mode()        \
 158                                            ? this_cpu_ptr(&sym)         \
 159                                            : this_cpu_ptr_nvhe_sym(sym))
 160
 161 #define per_cpu_ptr_hyp_sym(sym, cpu)   (is_kernel_in_hyp_mode()        \
 162                                            ? per_cpu_ptr(&sym, cpu)     \
 163                                            : per_cpu_ptr_nvhe_sym(sym, cpu))
 164
 165 #define CHOOSE_VHE_SYM(sym)     sym
 166 #define CHOOSE_NVHE_SYM(sym)    kvm_nvhe_sym(sym)
 167
 168 #endif
 169
 170 struct kvm_nvhe_init_params {
 171         unsigned long mair_el2;
 172         unsigned long tcr_el2;
 173         unsigned long tpidr_el2;
 174         unsigned long stack_hyp_va;
 175         unsigned long stack_pa;
 176         phys_addr_t pgd_pa;
 177         unsigned long hcr_el2;
 178         unsigned long vttbr;
 179         unsigned long vtcr;
 180 };
 181
 182 /*
 183  * Used by the host in EL1 to dump the nVHE hypervisor backtrace on
 184  * hyp_panic() in non-protected mode.
 185  *
 186  * @stack_base:                 hyp VA of the hyp_stack base.
 187  * @overflow_stack_base:        hyp VA of the hyp_overflow_stack base.
 188  * @fp:                         hyp FP where the backtrace begins.
 189  * @pc:                         hyp PC where the backtrace begins.
 190  */
 191 struct kvm_nvhe_stacktrace_info {
 192         unsigned long stack_base;
 193         unsigned long overflow_stack_base;
 194         unsigned long fp;
 195         unsigned long pc;
 196 };
 197
 198 /* Translate a kernel address @ptr into its equivalent linear mapping */
 199 #define kvm_ksym_ref(ptr)                                               \
 200         ({                                                              \
 201                 void *val = (ptr);                                      \
 202                 if (!is_kernel_in_hyp_mode())                           \
 203                         val = lm_alias((ptr));                          \
 204                 val;                                                    \
 205          })
 206 #define kvm_ksym_ref_nvhe(sym)  kvm_ksym_ref(kvm_nvhe_sym(sym))
 207
 208 struct kvm;
 209 struct kvm_vcpu;
 210 struct kvm_s2_mmu;
 211
 212 DECLARE_KVM_NVHE_SYM(__kvm_hyp_init);
 213 DECLARE_KVM_HYP_SYM(__kvm_hyp_vector);
 214 #define __kvm_hyp_init          CHOOSE_NVHE_SYM(__kvm_hyp_init)
 215 #define __kvm_hyp_vector        CHOOSE_HYP_SYM(__kvm_hyp_vector)
 216
 217 extern unsigned long kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[];
 218 DECLARE_KVM_NVHE_SYM(__per_cpu_start);
 219 DECLARE_KVM_NVHE_SYM(__per_cpu_end);
 220
 221 DECLARE_KVM_HYP_SYM(__bp_harden_hyp_vecs);
 222 #define __bp_harden_hyp_vecs    CHOOSE_HYP_SYM(__bp_harden_hyp_vecs)
 223
 224 extern void __kvm_flush_vm_context(void);
 225 extern void __kvm_flush_cpu_context(struct kvm_s2_mmu *mmu);
 226 extern void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa,
 227                                      int level);
 228 extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu);
 229
 230 extern void __kvm_timer_set_cntvoff(u64 cntvoff);
 231
 232 extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
 233
 234 extern void __kvm_adjust_pc(struct kvm_vcpu *vcpu);
 235
 236 extern u64 __vgic_v3_get_gic_config(void);
 237 extern u64 __vgic_v3_read_vmcr(void);
 238 extern void __vgic_v3_write_vmcr(u32 vmcr);
 239 extern void __vgic_v3_init_lrs(void);
 240
 241 extern u64 __kvm_get_mdcr_el2(void);
 242
 243 #define __KVM_EXTABLE(from, to)                                         \
 244         "       .pushsection    __kvm_ex_table, \"a\"\n"                \
 245         "       .align          3\n"                                    \
 246         "       .long           (" #from " - .), (" #to " - .)\n"       \
 247         "       .popsection\n"
 248
 249
 250 #define __kvm_at(at_op, addr)                                           \
 251 ( {                                                                     \
 252         int __kvm_at_err = 0;                                           \
 253         u64 spsr, elr;                                                  \
 254         asm volatile(                                                   \
 255         "       mrs     %1, spsr_el2\n"                                 \
 256         "       mrs     %2, elr_el2\n"                                  \
 257         "1:     at      "at_op", %3\n"                                  \
 258         "       isb\n"                                                  \
 259         "       b       9f\n"                                           \
 260         "2:     msr     spsr_el2, %1\n"                                 \
 261         "       msr     elr_el2, %2\n"                                  \
 262         "       mov     %w0, %4\n"                                      \
 263         "9:\n"                                                          \
 264         __KVM_EXTABLE(1b, 2b)                                           \
 265         : "+r" (__kvm_at_err), "=&r" (spsr), "=&r" (elr)                \
 266         : "r" (addr), "i" (-EFAULT));                                   \
 267         __kvm_at_err;                                                   \
 268 } )
 269
 270
 271 #else /* __ASSEMBLY__ */
 272
 273 .macro get_host_ctxt reg, tmp
 274         adr_this_cpu \reg, kvm_host_data, \tmp
 275         add     \reg, \reg, #HOST_DATA_CONTEXT
 276 .endm
 277
 278 .macro get_vcpu_ptr vcpu, ctxt
 279         get_host_ctxt \ctxt, \vcpu
 280         ldr     \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
 281 .endm
 282
 283 .macro get_loaded_vcpu vcpu, ctxt
 284         adr_this_cpu \ctxt, kvm_hyp_ctxt, \vcpu
 285         ldr     \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
 286 .endm
 287
 288 .macro set_loaded_vcpu vcpu, ctxt, tmp
 289         adr_this_cpu \ctxt, kvm_hyp_ctxt, \tmp
 290         str     \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
 291 .endm
 292
 293 /*
 294  * KVM extable for unexpected exceptions.
 295  * Create a struct kvm_exception_table_entry output to a section that can be
 296  * mapped by EL2. The table is not sorted.
 297  *
 298  * The caller must ensure:
 299  * x18 has the hypervisor value to allow any Shadow-Call-Stack instrumented
 300  * code to write to it, and that SPSR_EL2 and ELR_EL2 are restored by the fixup.
 301  */
 302 .macro  _kvm_extable, from, to
 303         .pushsection    __kvm_ex_table, "a"
 304         .align          3
 305         .long           (\from - .), (\to - .)
 306         .popsection
 307 .endm
 308
 309 #define CPU_XREG_OFFSET(x)      (CPU_USER_PT_REGS + 8*x)
 310 #define CPU_LR_OFFSET           CPU_XREG_OFFSET(30)
 311 #define CPU_SP_EL0_OFFSET       (CPU_LR_OFFSET + 8)
 312
 313 /*
 314  * We treat x18 as callee-saved as the host may use it as a platform
 315  * register (e.g. for shadow call stack).
 316  */
 317 .macro save_callee_saved_regs ctxt
 318         str     x18,      [\ctxt, #CPU_XREG_OFFSET(18)]
 319         stp     x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
 320         stp     x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
 321         stp     x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
 322         stp     x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
 323         stp     x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
 324         stp     x29, lr,  [\ctxt, #CPU_XREG_OFFSET(29)]
 325 .endm
 326
 327 .macro restore_callee_saved_regs ctxt
 328         // We require \ctxt is not x18-x28
 329         ldr     x18,      [\ctxt, #CPU_XREG_OFFSET(18)]
 330         ldp     x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
 331         ldp     x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
 332         ldp     x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
 333         ldp     x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
 334         ldp     x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
 335         ldp     x29, lr,  [\ctxt, #CPU_XREG_OFFSET(29)]
 336 .endm
 337
 338 .macro save_sp_el0 ctxt, tmp
 339         mrs     \tmp,   sp_el0
 340         str     \tmp,   [\ctxt, #CPU_SP_EL0_OFFSET]
 341 .endm
 342
 343 .macro restore_sp_el0 ctxt, tmp
 344         ldr     \tmp,     [\ctxt, #CPU_SP_EL0_OFFSET]
 345         msr     sp_el0, \tmp
 346 .endm
 347
 348 #endif
 349
 350 #endif /* __ARM_KVM_ASM_H__ */