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 #define __KVM_HOST_SMCCC_FUNC___kvm_vcpu_run                    1
  48 #define __KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context            2
  49 #define __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa          3
  50 #define __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid              4
  51 #define __KVM_HOST_SMCCC_FUNC___kvm_flush_cpu_context           5
  52 #define __KVM_HOST_SMCCC_FUNC___kvm_timer_set_cntvoff           6
  53 #define __KVM_HOST_SMCCC_FUNC___kvm_enable_ssbs                 7
  54 #define __KVM_HOST_SMCCC_FUNC___vgic_v3_get_gic_config          8
  55 #define __KVM_HOST_SMCCC_FUNC___vgic_v3_read_vmcr               9
  56 #define __KVM_HOST_SMCCC_FUNC___vgic_v3_write_vmcr              10
  57 #define __KVM_HOST_SMCCC_FUNC___vgic_v3_init_lrs                11
  58 #define __KVM_HOST_SMCCC_FUNC___kvm_get_mdcr_el2                12
  59 #define __KVM_HOST_SMCCC_FUNC___vgic_v3_save_aprs               13
  60 #define __KVM_HOST_SMCCC_FUNC___vgic_v3_restore_aprs            14
  61 #define __KVM_HOST_SMCCC_FUNC___pkvm_init                       15
  62 #define __KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp             16
  63 #define __KVM_HOST_SMCCC_FUNC___pkvm_create_private_mapping     17
  64 #define __KVM_HOST_SMCCC_FUNC___pkvm_cpu_set_vector             18
  65 #define __KVM_HOST_SMCCC_FUNC___pkvm_prot_finalize              19
  66 #define __KVM_HOST_SMCCC_FUNC___kvm_adjust_pc                   20
  67
  68 #ifndef __ASSEMBLY__
  69
  70 #include <linux/mm.h>
  71
  72 #define DECLARE_KVM_VHE_SYM(sym)        extern char sym[]
  73 #define DECLARE_KVM_NVHE_SYM(sym)       extern char kvm_nvhe_sym(sym)[]
  74
  75 /*
  76  * Define a pair of symbols sharing the same name but one defined in
  77  * VHE and the other in nVHE hyp implementations.
  78  */
  79 #define DECLARE_KVM_HYP_SYM(sym)                \
  80         DECLARE_KVM_VHE_SYM(sym);               \
  81         DECLARE_KVM_NVHE_SYM(sym)
  82
  83 #define DECLARE_KVM_VHE_PER_CPU(type, sym)      \
  84         DECLARE_PER_CPU(type, sym)
  85 #define DECLARE_KVM_NVHE_PER_CPU(type, sym)     \
  86         DECLARE_PER_CPU(type, kvm_nvhe_sym(sym))
  87
  88 #define DECLARE_KVM_HYP_PER_CPU(type, sym)      \
  89         DECLARE_KVM_VHE_PER_CPU(type, sym);     \
  90         DECLARE_KVM_NVHE_PER_CPU(type, sym)
  91
  92 /*
  93  * Compute pointer to a symbol defined in nVHE percpu region.
  94  * Returns NULL if percpu memory has not been allocated yet.
  95  */
  96 #define this_cpu_ptr_nvhe_sym(sym)      per_cpu_ptr_nvhe_sym(sym, smp_processor_id())
  97 #define per_cpu_ptr_nvhe_sym(sym, cpu)                                          \
  98         ({                                                                      \
  99                 unsigned long base, off;                                        \
 100                 base = kvm_arm_hyp_percpu_base[cpu];                            \
 101                 off = (unsigned long)&CHOOSE_NVHE_SYM(sym) -                    \
 102                       (unsigned long)&CHOOSE_NVHE_SYM(__per_cpu_start);         \
 103                 base ? (typeof(CHOOSE_NVHE_SYM(sym))*)(base + off) : NULL;      \
 104         })
 105
 106 #if defined(__KVM_NVHE_HYPERVISOR__)
 107
 108 #define CHOOSE_NVHE_SYM(sym)    sym
 109 #define CHOOSE_HYP_SYM(sym)     CHOOSE_NVHE_SYM(sym)
 110
 111 /* The nVHE hypervisor shouldn't even try to access VHE symbols */
 112 extern void *__nvhe_undefined_symbol;
 113 #define CHOOSE_VHE_SYM(sym)             __nvhe_undefined_symbol
 114 #define this_cpu_ptr_hyp_sym(sym)       (&__nvhe_undefined_symbol)
 115 #define per_cpu_ptr_hyp_sym(sym, cpu)   (&__nvhe_undefined_symbol)
 116
 117 #elif defined(__KVM_VHE_HYPERVISOR__)
 118
 119 #define CHOOSE_VHE_SYM(sym)     sym
 120 #define CHOOSE_HYP_SYM(sym)     CHOOSE_VHE_SYM(sym)
 121
 122 /* The VHE hypervisor shouldn't even try to access nVHE symbols */
 123 extern void *__vhe_undefined_symbol;
 124 #define CHOOSE_NVHE_SYM(sym)            __vhe_undefined_symbol
 125 #define this_cpu_ptr_hyp_sym(sym)       (&__vhe_undefined_symbol)
 126 #define per_cpu_ptr_hyp_sym(sym, cpu)   (&__vhe_undefined_symbol)
 127
 128 #else
 129
 130 /*
 131  * BIG FAT WARNINGS:
 132  *
 133  * - Don't be tempted to change the following is_kernel_in_hyp_mode()
 134  *   to has_vhe(). has_vhe() is implemented as a *final* capability,
 135  *   while this is used early at boot time, when the capabilities are
 136  *   not final yet....
 137  *
 138  * - Don't let the nVHE hypervisor have access to this, as it will
 139  *   pick the *wrong* symbol (yes, it runs at EL2...).
 140  */
 141 #define CHOOSE_HYP_SYM(sym)             (is_kernel_in_hyp_mode()        \
 142                                            ? CHOOSE_VHE_SYM(sym)        \
 143                                            : CHOOSE_NVHE_SYM(sym))
 144
 145 #define this_cpu_ptr_hyp_sym(sym)       (is_kernel_in_hyp_mode()        \
 146                                            ? this_cpu_ptr(&sym)         \
 147                                            : this_cpu_ptr_nvhe_sym(sym))
 148
 149 #define per_cpu_ptr_hyp_sym(sym, cpu)   (is_kernel_in_hyp_mode()        \
 150                                            ? per_cpu_ptr(&sym, cpu)     \
 151                                            : per_cpu_ptr_nvhe_sym(sym, cpu))
 152
 153 #define CHOOSE_VHE_SYM(sym)     sym
 154 #define CHOOSE_NVHE_SYM(sym)    kvm_nvhe_sym(sym)
 155
 156 #endif
 157
 158 struct kvm_nvhe_init_params {
 159         unsigned long mair_el2;
 160         unsigned long tcr_el2;
 161         unsigned long tpidr_el2;
 162         unsigned long stack_hyp_va;
 163         phys_addr_t pgd_pa;
 164         unsigned long hcr_el2;
 165         unsigned long vttbr;
 166         unsigned long vtcr;
 167 };
 168
 169 /* Translate a kernel address @ptr into its equivalent linear mapping */
 170 #define kvm_ksym_ref(ptr)                                               \
 171         ({                                                              \
 172                 void *val = (ptr);                                      \
 173                 if (!is_kernel_in_hyp_mode())                           \
 174                         val = lm_alias((ptr));                          \
 175                 val;                                                    \
 176          })
 177 #define kvm_ksym_ref_nvhe(sym)  kvm_ksym_ref(kvm_nvhe_sym(sym))
 178
 179 struct kvm;
 180 struct kvm_vcpu;
 181 struct kvm_s2_mmu;
 182
 183 DECLARE_KVM_NVHE_SYM(__kvm_hyp_init);
 184 DECLARE_KVM_HYP_SYM(__kvm_hyp_vector);
 185 #define __kvm_hyp_init          CHOOSE_NVHE_SYM(__kvm_hyp_init)
 186 #define __kvm_hyp_vector        CHOOSE_HYP_SYM(__kvm_hyp_vector)
 187
 188 extern unsigned long kvm_arm_hyp_percpu_base[NR_CPUS];
 189 DECLARE_KVM_NVHE_SYM(__per_cpu_start);
 190 DECLARE_KVM_NVHE_SYM(__per_cpu_end);
 191
 192 DECLARE_KVM_HYP_SYM(__bp_harden_hyp_vecs);
 193 #define __bp_harden_hyp_vecs    CHOOSE_HYP_SYM(__bp_harden_hyp_vecs)
 194
 195 extern void __kvm_flush_vm_context(void);
 196 extern void __kvm_flush_cpu_context(struct kvm_s2_mmu *mmu);
 197 extern void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa,
 198                                      int level);
 199 extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu);
 200
 201 extern void __kvm_timer_set_cntvoff(u64 cntvoff);
 202
 203 extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
 204
 205 extern void __kvm_adjust_pc(struct kvm_vcpu *vcpu);
 206
 207 extern u64 __vgic_v3_get_gic_config(void);
 208 extern u64 __vgic_v3_read_vmcr(void);
 209 extern void __vgic_v3_write_vmcr(u32 vmcr);
 210 extern void __vgic_v3_init_lrs(void);
 211
 212 extern u64 __kvm_get_mdcr_el2(void);
 213
 214 #define __KVM_EXTABLE(from, to)                                         \
 215         "       .pushsection    __kvm_ex_table, \"a\"\n"                \
 216         "       .align          3\n"                                    \
 217         "       .long           (" #from " - .), (" #to " - .)\n"       \
 218         "       .popsection\n"
 219
 220
 221 #define __kvm_at(at_op, addr)                                           \
 222 ( {                                                                     \
 223         int __kvm_at_err = 0;                                           \
 224         u64 spsr, elr;                                                  \
 225         asm volatile(                                                   \
 226         "       mrs     %1, spsr_el2\n"                                 \
 227         "       mrs     %2, elr_el2\n"                                  \
 228         "1:     at      "at_op", %3\n"                                  \
 229         "       isb\n"                                                  \
 230         "       b       9f\n"                                           \
 231         "2:     msr     spsr_el2, %1\n"                                 \
 232         "       msr     elr_el2, %2\n"                                  \
 233         "       mov     %w0, %4\n"                                      \
 234         "9:\n"                                                          \
 235         __KVM_EXTABLE(1b, 2b)                                           \
 236         : "+r" (__kvm_at_err), "=&r" (spsr), "=&r" (elr)                \
 237         : "r" (addr), "i" (-EFAULT));                                   \
 238         __kvm_at_err;                                                   \
 239 } )
 240
 241
 242 #else /* __ASSEMBLY__ */
 243
 244 .macro get_host_ctxt reg, tmp
 245         adr_this_cpu \reg, kvm_host_data, \tmp
 246         add     \reg, \reg, #HOST_DATA_CONTEXT
 247 .endm
 248
 249 .macro get_vcpu_ptr vcpu, ctxt
 250         get_host_ctxt \ctxt, \vcpu
 251         ldr     \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
 252 .endm
 253
 254 .macro get_loaded_vcpu vcpu, ctxt
 255         adr_this_cpu \ctxt, kvm_hyp_ctxt, \vcpu
 256         ldr     \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
 257 .endm
 258
 259 .macro set_loaded_vcpu vcpu, ctxt, tmp
 260         adr_this_cpu \ctxt, kvm_hyp_ctxt, \tmp
 261         str     \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
 262 .endm
 263
 264 /*
 265  * KVM extable for unexpected exceptions.
 266  * In the same format _asm_extable, but output to a different section so that
 267  * it can be mapped to EL2. The KVM version is not sorted. The caller must
 268  * ensure:
 269  * x18 has the hypervisor value to allow any Shadow-Call-Stack instrumented
 270  * code to write to it, and that SPSR_EL2 and ELR_EL2 are restored by the fixup.
 271  */
 272 .macro  _kvm_extable, from, to
 273         .pushsection    __kvm_ex_table, "a"
 274         .align          3
 275         .long           (\from - .), (\to - .)
 276         .popsection
 277 .endm
 278
 279 #define CPU_XREG_OFFSET(x)      (CPU_USER_PT_REGS + 8*x)
 280 #define CPU_LR_OFFSET           CPU_XREG_OFFSET(30)
 281 #define CPU_SP_EL0_OFFSET       (CPU_LR_OFFSET + 8)
 282
 283 /*
 284  * We treat x18 as callee-saved as the host may use it as a platform
 285  * register (e.g. for shadow call stack).
 286  */
 287 .macro save_callee_saved_regs ctxt
 288         str     x18,      [\ctxt, #CPU_XREG_OFFSET(18)]
 289         stp     x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
 290         stp     x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
 291         stp     x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
 292         stp     x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
 293         stp     x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
 294         stp     x29, lr,  [\ctxt, #CPU_XREG_OFFSET(29)]
 295 .endm
 296
 297 .macro restore_callee_saved_regs ctxt
 298         // We require \ctxt is not x18-x28
 299         ldr     x18,      [\ctxt, #CPU_XREG_OFFSET(18)]
 300         ldp     x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
 301         ldp     x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
 302         ldp     x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
 303         ldp     x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
 304         ldp     x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
 305         ldp     x29, lr,  [\ctxt, #CPU_XREG_OFFSET(29)]
 306 .endm
 307
 308 .macro save_sp_el0 ctxt, tmp
 309         mrs     \tmp,   sp_el0
 310         str     \tmp,   [\ctxt, #CPU_SP_EL0_OFFSET]
 311 .endm
 312
 313 .macro restore_sp_el0 ctxt, tmp
 314         ldr     \tmp,     [\ctxt, #CPU_SP_EL0_OFFSET]
 315         msr     sp_el0, \tmp
 316 .endm
 317
 318 #endif
 319
 320 #endif /* __ARM_KVM_ASM_H__ */