arch/arm64/include/asm/kvm_asm.h

   1 /*
   2  * Copyright (C) 2012,2013 - ARM Ltd
   3  * Author: Marc Zyngier <marc.zyngier@arm.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #ifndef __ARM_KVM_ASM_H__
  19 #define __ARM_KVM_ASM_H__
  20
  21 #include <asm/virt.h>
  22
  23 #define ARM_EXIT_WITH_SERROR_BIT  31
  24 #define ARM_EXCEPTION_CODE(x)     ((x) & ~(1U << ARM_EXIT_WITH_SERROR_BIT))
  25 #define ARM_SERROR_PENDING(x)     !!((x) & (1U << ARM_EXIT_WITH_SERROR_BIT))
  26
  27 #define ARM_EXCEPTION_IRQ         0
  28 #define ARM_EXCEPTION_EL1_SERROR  1
  29 #define ARM_EXCEPTION_TRAP        2
  30 /* The hyp-stub will return this for any kvm_call_hyp() call */
  31 #define ARM_EXCEPTION_HYP_GONE    3
  32
  33 #define KVM_ARM64_DEBUG_DIRTY_SHIFT     0
  34 #define KVM_ARM64_DEBUG_DIRTY           (1 << KVM_ARM64_DEBUG_DIRTY_SHIFT)
  35
  36 #define VCPU_WORKAROUND_2_FLAG_SHIFT    0
  37 #define VCPU_WORKAROUND_2_FLAG          (_AC(1, UL) << VCPU_WORKAROUND_2_FLAG_SHIFT)
  38
  39 /* Translate a kernel address of @sym into its equivalent linear mapping */
  40 #define kvm_ksym_ref(sym)                                               \
  41         ({                                                              \
  42                 void *val = &sym;                                       \
  43                 if (!is_kernel_in_hyp_mode())                           \
  44                         val = phys_to_virt((u64)&sym - kimage_voffset); \
  45                 val;                                                    \
  46          })
  47
  48 #ifndef __ASSEMBLY__
  49 struct kvm;
  50 struct kvm_vcpu;
  51
  52 extern char __kvm_hyp_init[];
  53 extern char __kvm_hyp_init_end[];
  54 extern char __kvm_hyp_reset[];
  55
  56 extern char __kvm_hyp_vector[];
  57
  58 extern void __kvm_flush_vm_context(void);
  59 extern void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa);
  60 extern void __kvm_tlb_flush_vmid(struct kvm *kvm);
  61 extern void __kvm_tlb_flush_local_vmid(struct kvm_vcpu *vcpu);
  62
  63 extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
  64
  65 extern u64 __vgic_v3_get_ich_vtr_el2(void);
  66 extern void __vgic_v3_init_lrs(void);
  67
  68 extern u32 __kvm_get_mdcr_el2(void);
  69
  70 extern u32 __init_stage2_translation(void);
  71
  72 /* Home-grown __this_cpu_{ptr,read} variants that always work at HYP */
  73 #define __hyp_this_cpu_ptr(sym)                                         \
  74         ({                                                              \
  75                 void *__ptr = hyp_symbol_addr(sym);                     \
  76                 __ptr += read_sysreg(tpidr_el2);                        \
  77                 (typeof(&sym))__ptr;                                    \
  78          })
  79
  80 #define __hyp_this_cpu_read(sym)                                        \
  81         ({                                                              \
  82                 *__hyp_this_cpu_ptr(sym);                               \
  83          })
  84
  85 #define __KVM_EXTABLE(from, to)                                         \
  86         "       .pushsection    __kvm_ex_table, \"a\"\n"                \
  87         "       .align          3\n"                                    \
  88         "       .long           (" #from " - .), (" #to " - .)\n"       \
  89         "       .popsection\n"
  90
  91
  92 #define __kvm_at(at_op, addr)                                           \
  93 ( {                                                                     \
  94         int __kvm_at_err = 0;                                           \
  95         u64 spsr, elr;                                                  \
  96         asm volatile(                                                   \
  97         "       mrs     %1, spsr_el2\n"                                 \
  98         "       mrs     %2, elr_el2\n"                                  \
  99         "1:     at      "at_op", %3\n"                                  \
 100         "       isb\n"                                                  \
 101         "       b       9f\n"                                           \
 102         "2:     msr     spsr_el2, %1\n"                                 \
 103         "       msr     elr_el2, %2\n"                                  \
 104         "       mov     %w0, %4\n"                                      \
 105         "9:\n"                                                          \
 106         __KVM_EXTABLE(1b, 2b)                                           \
 107         : "+r" (__kvm_at_err), "=&r" (spsr), "=&r" (elr)                \
 108         : "r" (addr), "i" (-EFAULT));                                   \
 109         __kvm_at_err;                                                   \
 110 } )
 111
 112
 113 #else /* __ASSEMBLY__ */
 114
 115 .macro hyp_adr_this_cpu reg, sym, tmp
 116         adr_l   \reg, \sym
 117         mrs     \tmp, tpidr_el2
 118         add     \reg, \reg, \tmp
 119 .endm
 120
 121 .macro hyp_ldr_this_cpu reg, sym, tmp
 122         adr_l   \reg, \sym
 123         mrs     \tmp, tpidr_el2
 124         ldr     \reg,  [\reg, \tmp]
 125 .endm
 126
 127 .macro get_host_ctxt reg, tmp
 128         hyp_adr_this_cpu \reg, kvm_host_cpu_state, \tmp
 129 .endm
 130
 131 .macro get_vcpu_ptr vcpu, ctxt
 132         get_host_ctxt \ctxt, \vcpu
 133         ldr     \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
 134         kern_hyp_va     \vcpu
 135 .endm
 136
 137 /*
 138  * KVM extable for unexpected exceptions.
 139  * In the same format _asm_extable, but output to a different section so that
 140  * it can be mapped to EL2. The KVM version is not sorted. The caller must
 141  * ensure:
 142  * x18 has the hypervisor value to allow any Shadow-Call-Stack instrumented
 143  * code to write to it, and that SPSR_EL2 and ELR_EL2 are restored by the fixup.
 144  */
 145 .macro  _kvm_extable, from, to
 146         .pushsection    __kvm_ex_table, "a"
 147         .align          3
 148         .long           (\from - .), (\to - .)
 149         .popsection
 150 .endm
 151
 152 #endif
 153
 154 #endif /* __ARM_KVM_ASM_H__ */