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