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/virt.h>
  11
  12 #define VCPU_WORKAROUND_2_FLAG_SHIFT    0
  13 #define VCPU_WORKAROUND_2_FLAG          (_AC(1, UL) << VCPU_WORKAROUND_2_FLAG_SHIFT)
  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 #ifndef __ASSEMBLY__
  40
  41 #include <linux/mm.h>
  42
  43 /* Translate a kernel address of @sym into its equivalent linear mapping */
  44 #define kvm_ksym_ref(sym)                                               \
  45         ({                                                              \
  46                 void *val = &sym;                                       \
  47                 if (!is_kernel_in_hyp_mode())                           \
  48                         val = lm_alias(&sym);                           \
  49                 val;                                                    \
  50          })
  51
  52 struct kvm;
  53 struct kvm_vcpu;
  54
  55 extern char __kvm_hyp_init[];
  56 extern char __kvm_hyp_init_end[];
  57
  58 extern char __kvm_hyp_vector[];
  59
  60 extern void __kvm_flush_vm_context(void);
  61 extern void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa);
  62 extern void __kvm_tlb_flush_vmid(struct kvm *kvm);
  63 extern void __kvm_flush_cpu_context(struct kvm_vcpu *vcpu);
  64
  65 extern void __kvm_timer_set_cntvoff(u32 cntvoff_low, u32 cntvoff_high);
  66
  67 extern int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu);
  68
  69 extern int __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu);
  70
  71 extern u64 __vgic_v3_get_ich_vtr_el2(void);
  72 extern u64 __vgic_v3_read_vmcr(void);
  73 extern void __vgic_v3_write_vmcr(u32 vmcr);
  74 extern void __vgic_v3_init_lrs(void);
  75
  76 extern u32 __kvm_get_mdcr_el2(void);
  77
  78 /* Home-grown __this_cpu_{ptr,read} variants that always work at HYP */
  79 #define __hyp_this_cpu_ptr(sym)                                         \
  80         ({                                                              \
  81                 void *__ptr = hyp_symbol_addr(sym);                     \
  82                 __ptr += read_sysreg(tpidr_el2);                        \
  83                 (typeof(&sym))__ptr;                                    \
  84          })
  85
  86 #define __hyp_this_cpu_read(sym)                                        \
  87         ({                                                              \
  88                 *__hyp_this_cpu_ptr(sym);                               \
  89          })
  90
  91 #define __KVM_EXTABLE(from, to)                                         \
  92         "       .pushsection    __kvm_ex_table, \"a\"\n"                \
  93         "       .align          3\n"                                    \
  94         "       .long           (" #from " - .), (" #to " - .)\n"       \
  95         "       .popsection\n"
  96
  97
  98 #define __kvm_at(at_op, addr)                                           \
  99 ( {                                                                     \
 100         int __kvm_at_err = 0;                                           \
 101         u64 spsr, elr;                                                  \
 102         asm volatile(                                                   \
 103         "       mrs     %1, spsr_el2\n"                                 \
 104         "       mrs     %2, elr_el2\n"                                  \
 105         "1:     at      "at_op", %3\n"                                  \
 106         "       isb\n"                                                  \
 107         "       b       9f\n"                                           \
 108         "2:     msr     spsr_el2, %1\n"                                 \
 109         "       msr     elr_el2, %2\n"                                  \
 110         "       mov     %w0, %4\n"                                      \
 111         "9:\n"                                                          \
 112         __KVM_EXTABLE(1b, 2b)                                           \
 113         : "+r" (__kvm_at_err), "=&r" (spsr), "=&r" (elr)                \
 114         : "r" (addr), "i" (-EFAULT));                                   \
 115         __kvm_at_err;                                                   \
 116 } )
 117
 118
 119 #else /* __ASSEMBLY__ */
 120
 121 .macro hyp_adr_this_cpu reg, sym, tmp
 122         adr_l   \reg, \sym
 123         mrs     \tmp, tpidr_el2
 124         add     \reg, \reg, \tmp
 125 .endm
 126
 127 .macro hyp_ldr_this_cpu reg, sym, tmp
 128         adr_l   \reg, \sym
 129         mrs     \tmp, tpidr_el2
 130         ldr     \reg,  [\reg, \tmp]
 131 .endm
 132
 133 .macro get_host_ctxt reg, tmp
 134         hyp_adr_this_cpu \reg, kvm_host_data, \tmp
 135         add     \reg, \reg, #HOST_DATA_CONTEXT
 136 .endm
 137
 138 .macro get_vcpu_ptr vcpu, ctxt
 139         get_host_ctxt \ctxt, \vcpu
 140         ldr     \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
 141         kern_hyp_va     \vcpu
 142 .endm
 143
 144 /*
 145  * KVM extable for unexpected exceptions.
 146  * In the same format _asm_extable, but output to a different section so that
 147  * it can be mapped to EL2. The KVM version is not sorted. The caller must
 148  * ensure:
 149  * x18 has the hypervisor value to allow any Shadow-Call-Stack instrumented
 150  * code to write to it, and that SPSR_EL2 and ELR_EL2 are restored by the fixup.
 151  */
 152 .macro  _kvm_extable, from, to
 153         .pushsection    __kvm_ex_table, "a"
 154         .align          3
 155         .long           (\from - .), (\to - .)
 156         .popsection
 157 .endm
 158
 159 #endif
 160
 161 #endif /* __ARM_KVM_ASM_H__ */