LXR linux/arch/arm64/include/asm/kvm

   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_create_mappings            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___pkvm_mark_hyp                   20
  67#define __KVM_HOST_SMCCC_FUNC___kvm_adjust_pc                   21
  68
  69#ifndef __ASSEMBLY__
  70
  71#include <linux/mm.h>
  72
  73#define DECLARE_KVM_VHE_SYM(sym)        extern char sym[]
  74#define DECLARE_KVM_NVHE_SYM(sym)       extern char kvm_nvhe_sym(sym)[]
  75
  76/*
  77 * Define a pair of symbols sharing the same name but one defined in
  78 * VHE and the other in nVHE hyp implementations.
  79 */
  80#define DECLARE_KVM_HYP_SYM(sym)                \
  81        DECLARE_KVM_VHE_SYM(sym);               \
  82        DECLARE_KVM_NVHE_SYM(sym)
  83
  84#define DECLARE_KVM_VHE_PER_CPU(type, sym)      \
  85        DECLARE_PER_CPU(type, sym)
  86#define DECLARE_KVM_NVHE_PER_CPU(type, sym)     \
  87        DECLARE_PER_CPU(type, kvm_nvhe_sym(sym))
  88
  89#define DECLARE_KVM_HYP_PER_CPU(type, sym)      \
  90        DECLARE_KVM_VHE_PER_CPU(type, sym);     \
  91        DECLARE_KVM_NVHE_PER_CPU(type, sym)
  92
  93/*
  94 * Compute pointer to a symbol defined in nVHE percpu region.
  95 * Returns NULL if percpu memory has not been allocated yet.
  96 */
  97#define this_cpu_ptr_nvhe_sym(sym)      per_cpu_ptr_nvhe_sym(sym, smp_processor_id())
  98#define per_cpu_ptr_nvhe_sym(sym, cpu)                                          \
  99        ({                                                                      \
 100                unsigned long base, off;                                        \
 101                base = kvm_arm_hyp_percpu_base[cpu];                            \
 102                off = (unsigned long)&CHOOSE_NVHE_SYM(sym) -                    \
 103                      (unsigned long)&CHOOSE_NVHE_SYM(__per_cpu_start);         \
 104                base ? (typeof(CHOOSE_NVHE_SYM(sym))*)(base + off) : NULL;      \
 105        })
 106
 107#if defined(__KVM_NVHE_HYPERVISOR__)
 108
 109#define CHOOSE_NVHE_SYM(sym)    sym
 110#define CHOOSE_HYP_SYM(sym)     CHOOSE_NVHE_SYM(sym)
 111
 112/* The nVHE hypervisor shouldn't even try to access VHE symbols */
 113extern void *__nvhe_undefined_symbol;
 114#define CHOOSE_VHE_SYM(sym)             __nvhe_undefined_symbol
 115#define this_cpu_ptr_hyp_sym(sym)       (&__nvhe_undefined_symbol)
 116#define per_cpu_ptr_hyp_sym(sym, cpu)   (&__nvhe_undefined_symbol)
 117
 118#elif defined(__KVM_VHE_HYPERVISOR__)
 119
 120#define CHOOSE_VHE_SYM(sym)     sym
 121#define CHOOSE_HYP_SYM(sym)     CHOOSE_VHE_SYM(sym)
 122
 123/* The VHE hypervisor shouldn't even try to access nVHE symbols */
 124extern void *__vhe_undefined_symbol;
 125#define CHOOSE_NVHE_SYM(sym)            __vhe_undefined_symbol
 126#define this_cpu_ptr_hyp_sym(sym)       (&__vhe_undefined_symbol)
 127#define per_cpu_ptr_hyp_sym(sym, cpu)   (&__vhe_undefined_symbol)
 128
 129#else
 130
 131/*
 132 * BIG FAT WARNINGS:
 133 *
 134 * - Don't be tempted to change the following is_kernel_in_hyp_mode()
 135 *   to has_vhe(). has_vhe() is implemented as a *final* capability,
 136 *   while this is used early at boot time, when the capabilities are
 137 *   not final yet....
 138 *
 139 * - Don't let the nVHE hypervisor have access to this, as it will
 140 *   pick the *wrong* symbol (yes, it runs at EL2...).
 141 */
 142#define CHOOSE_HYP_SYM(sym)             (is_kernel_in_hyp_mode()        \
 143                                           ? CHOOSE_VHE_SYM(sym)        \
 144                                           : CHOOSE_NVHE_SYM(sym))
 145
 146#define this_cpu_ptr_hyp_sym(sym)       (is_kernel_in_hyp_mode()        \
 147                                           ? this_cpu_ptr(&sym)         \
 148                                           : this_cpu_ptr_nvhe_sym(sym))
 149
 150#define per_cpu_ptr_hyp_sym(sym, cpu)   (is_kernel_in_hyp_mode()        \
 151                                           ? per_cpu_ptr(&sym, cpu)     \
 152                                           : per_cpu_ptr_nvhe_sym(sym, cpu))
 153
 154#define CHOOSE_VHE_SYM(sym)     sym
 155#define CHOOSE_NVHE_SYM(sym)    kvm_nvhe_sym(sym)
 156
 157#endif
 158
 159struct kvm_nvhe_init_params {
 160        unsigned long mair_el2;
 161        unsigned long tcr_el2;
 162        unsigned long tpidr_el2;
 163        unsigned long stack_hyp_va;
 164        phys_addr_t pgd_pa;
 165        unsigned long hcr_el2;
 166        unsigned long vttbr;
 167        unsigned long vtcr;
 168};
 169
 170/* Translate a kernel address @ptr into its equivalent linear mapping */
 171#define kvm_ksym_ref(ptr)                                               \
 172        ({                                                              \
 173                void *val = (ptr);                                      \
 174                if (!is_kernel_in_hyp_mode())                           \
 175                        val = lm_alias((ptr));                          \
 176                val;                                                    \
 177         })
 178#define kvm_ksym_ref_nvhe(sym)  kvm_ksym_ref(kvm_nvhe_sym(sym))
 179
 180struct kvm;
 181struct kvm_vcpu;
 182struct kvm_s2_mmu;
 183
 184DECLARE_KVM_NVHE_SYM(__kvm_hyp_init);
 185DECLARE_KVM_HYP_SYM(__kvm_hyp_vector);
 186#define __kvm_hyp_init          CHOOSE_NVHE_SYM(__kvm_hyp_init)
 187#define __kvm_hyp_vector        CHOOSE_HYP_SYM(__kvm_hyp_vector)
 188
 189extern unsigned long kvm_arm_hyp_percpu_base[NR_CPUS];
 190DECLARE_KVM_NVHE_SYM(__per_cpu_start);
 191DECLARE_KVM_NVHE_SYM(__per_cpu_end);
 192
 193DECLARE_KVM_HYP_SYM(__bp_harden_hyp_vecs);
 194#define __bp_harden_hyp_vecs    CHOOSE_HYP_SYM(__bp_harden_hyp_vecs)
 195
 196extern void __kvm_flush_vm_context(void);
 197extern void __kvm_flush_cpu_context(struct kvm_s2_mmu *mmu);
 198extern void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa,
 199                                     int level);
 200extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu);
 201
 202extern void __kvm_timer_set_cntvoff(u64 cntvoff);
 203
 204extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
 205
 206extern void __kvm_adjust_pc(struct kvm_vcpu *vcpu);
 207
 208extern u64 __vgic_v3_get_gic_config(void);
 209extern u64 __vgic_v3_read_vmcr(void);
 210extern void __vgic_v3_write_vmcr(u32 vmcr);
 211extern void __vgic_v3_init_lrs(void);
 212
 213extern u32 __kvm_get_mdcr_el2(void);
 214
 215#define __KVM_EXTABLE(from, to)                                         \
 216        "       .pushsection    __kvm_ex_table, \"a\"\n"                \
 217        "       .align          3\n"                                    \
 218        "       .long           (" #from " - .), (" #to " - .)\n"       \
 219        "       .popsection\n"
 220
 221
 222#define __kvm_at(at_op, addr)                                           \
 223( {                                                                     \
 224        int __kvm_at_err = 0;                                           \
 225        u64 spsr, elr;                                                  \
 226        asm volatile(                                                   \
 227        "       mrs     %1, spsr_el2\n"                                 \
 228        "       mrs     %2, elr_el2\n"                                  \
 229        "1:     at      "at_op", %3\n"                                  \
 230        "       isb\n"                                                  \
 231        "       b       9f\n"                                           \
 232        "2:     msr     spsr_el2, %1\n"                                 \
 233        "       msr     elr_el2, %2\n"                                  \
 234        "       mov     %w0, %4\n"                                      \
 235        "9:\n"                                                          \
 236        __KVM_EXTABLE(1b, 2b)                                           \
 237        : "+r" (__kvm_at_err), "=&r" (spsr), "=&r" (elr)                \
 238        : "r" (addr), "i" (-EFAULT));                                   \
 239        __kvm_at_err;                                                   \
 240} )
 241
 242
 243#else /* __ASSEMBLY__ */
 244
 245.macro get_host_ctxt reg, tmp
 246        adr_this_cpu \reg, kvm_host_data, \tmp
 247        add     \reg, \reg, #HOST_DATA_CONTEXT
 248.endm
 249
 250.macro get_vcpu_ptr vcpu, ctxt
 251        get_host_ctxt \ctxt, \vcpu
 252        ldr     \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
 253.endm
 254
 255.macro get_loaded_vcpu vcpu, ctxt
 256        adr_this_cpu \ctxt, kvm_hyp_ctxt, \vcpu
 257        ldr     \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
 258.endm
 259
 260.macro set_loaded_vcpu vcpu, ctxt, tmp
 261        adr_this_cpu \ctxt, kvm_hyp_ctxt, \tmp
 262        str     \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
 263.endm
 264
 265/*
 266 * KVM extable for unexpected exceptions.
 267 * In the same format _asm_extable, but output to a different section so that
 268 * it can be mapped to EL2. The KVM version is not sorted. The caller must
 269 * ensure:
 270 * x18 has the hypervisor value to allow any Shadow-Call-Stack instrumented
 271 * code to write to it, and that SPSR_EL2 and ELR_EL2 are restored by the fixup.
 272 */
 273.macro  _kvm_extable, from, to
 274        .pushsection    __kvm_ex_table, "a"
 275        .align          3
 276        .long           (\from - .), (\to - .)
 277        .popsection
 278.endm
 279
 280#define CPU_XREG_OFFSET(x)      (CPU_USER_PT_REGS + 8*x)
 281#define CPU_LR_OFFSET           CPU_XREG_OFFSET(30)
 282#define CPU_SP_EL0_OFFSET       (CPU_LR_OFFSET + 8)
 283
 284/*
 285 * We treat x18 as callee-saved as the host may use it as a platform
 286 * register (e.g. for shadow call stack).
 287 */
 288.macro save_callee_saved_regs ctxt
 289        str     x18,      [\ctxt, #CPU_XREG_OFFSET(18)]
 290        stp     x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
 291        stp     x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
 292        stp     x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
 293        stp     x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
 294        stp     x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
 295        stp     x29, lr,  [\ctxt, #CPU_XREG_OFFSET(29)]
 296.endm
 297
 298.macro restore_callee_saved_regs ctxt
 299        // We require \ctxt is not x18-x28
 300        ldr     x18,      [\ctxt, #CPU_XREG_OFFSET(18)]
 301        ldp     x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
 302        ldp     x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
 303        ldp     x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
 304        ldp     x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
 305        ldp     x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
 306        ldp     x29, lr,  [\ctxt, #CPU_XREG_OFFSET(29)]
 307.endm
 308
 309.macro save_sp_el0 ctxt, tmp
 310        mrs     \tmp,   sp_el0
 311        str     \tmp,   [\ctxt, #CPU_SP_EL0_OFFSET]
 312.endm
 313
 314.macro restore_sp_el0 ctxt, tmp
 315        ldr     \tmp,     [\ctxt, #CPU_SP_EL0_OFFSET]
 316        msr     sp_el0, \tmp
 317.endm
 318
 319#endif
 320
 321#endif /* __ARM_KVM_ASM_H__ */
 322