arch/arm64/include/asm/virt.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2012 ARM Ltd.
   4  * Author: Marc Zyngier <marc.zyngier@arm.com>
   5  */
   6
   7 #ifndef __ASM__VIRT_H
   8 #define __ASM__VIRT_H
   9
  10 /*
  11  * The arm64 hcall implementation uses x0 to specify the hcall
  12  * number. A value less than HVC_STUB_HCALL_NR indicates a special
  13  * hcall, such as set vector. Any other value is handled in a
  14  * hypervisor specific way.
  15  *
  16  * The hypercall is allowed to clobber any of the caller-saved
  17  * registers (x0-x18), so it is advisable to use it through the
  18  * indirection of a function call (as implemented in hyp-stub.S).
  19  */
  20
  21 /*
  22  * HVC_SET_VECTORS - Set the value of the vbar_el2 register.
  23  *
  24  * @x1: Physical address of the new vector table.
  25  */
  26 #define HVC_SET_VECTORS 0
  27
  28 /*
  29  * HVC_SOFT_RESTART - CPU soft reset, used by the cpu_soft_restart routine.
  30  */
  31 #define HVC_SOFT_RESTART 1
  32
  33 /*
  34  * HVC_RESET_VECTORS - Restore the vectors to the original HYP stubs
  35  */
  36 #define HVC_RESET_VECTORS 2
  37
  38 /*
  39  * HVC_FINALISE_EL2 - Upgrade the CPU from EL1 to EL2, if possible
  40  */
  41 #define HVC_FINALISE_EL2        3
  42
  43 /* Max number of HYP stub hypercalls */
  44 #define HVC_STUB_HCALL_NR 4
  45
  46 /* Error returned when an invalid stub number is passed into x0 */
  47 #define HVC_STUB_ERR    0xbadca11
  48
  49 #define BOOT_CPU_MODE_EL1       (0xe11)
  50 #define BOOT_CPU_MODE_EL2       (0xe12)
  51
  52 /*
  53  * Flags returned together with the boot mode, but not preserved in
  54  * __boot_cpu_mode. Used by the idreg override code to work out the
  55  * boot state.
  56  */
  57 #define BOOT_CPU_FLAG_E2H       BIT_ULL(32)
  58
  59 #ifndef __ASSEMBLY__
  60
  61 #include <asm/ptrace.h>
  62 #include <asm/sections.h>
  63 #include <asm/sysreg.h>
  64 #include <asm/cpufeature.h>
  65
  66 /*
  67  * __boot_cpu_mode records what mode CPUs were booted in.
  68  * A correctly-implemented bootloader must start all CPUs in the same mode:
  69  * In this case, both 32bit halves of __boot_cpu_mode will contain the
  70  * same value (either 0 if booted in EL1, BOOT_CPU_MODE_EL2 if booted in EL2).
  71  *
  72  * Should the bootloader fail to do this, the two values will be different.
  73  * This allows the kernel to flag an error when the secondaries have come up.
  74  */
  75 extern u32 __boot_cpu_mode[2];
  76
  77 #define ARM64_VECTOR_TABLE_LEN  SZ_2K
  78
  79 void __hyp_set_vectors(phys_addr_t phys_vector_base);
  80 void __hyp_reset_vectors(void);
  81 bool is_kvm_arm_initialised(void);
  82
  83 DECLARE_STATIC_KEY_FALSE(kvm_protected_mode_initialized);
  84
  85 static inline bool is_pkvm_initialized(void)
  86 {
  87         return IS_ENABLED(CONFIG_KVM) &&
  88                static_branch_likely(&kvm_protected_mode_initialized);
  89 }
  90
  91 /* Reports the availability of HYP mode */
  92 static inline bool is_hyp_mode_available(void)
  93 {
  94         /*
  95          * If KVM protected mode is initialized, all CPUs must have been booted
  96          * in EL2. Avoid checking __boot_cpu_mode as CPUs now come up in EL1.
  97          */
  98         if (is_pkvm_initialized())
  99                 return true;
 100
 101         return (__boot_cpu_mode[0] == BOOT_CPU_MODE_EL2 &&
 102                 __boot_cpu_mode[1] == BOOT_CPU_MODE_EL2);
 103 }
 104
 105 /* Check if the bootloader has booted CPUs in different modes */
 106 static inline bool is_hyp_mode_mismatched(void)
 107 {
 108         /*
 109          * If KVM protected mode is initialized, all CPUs must have been booted
 110          * in EL2. Avoid checking __boot_cpu_mode as CPUs now come up in EL1.
 111          */
 112         if (is_pkvm_initialized())
 113                 return false;
 114
 115         return __boot_cpu_mode[0] != __boot_cpu_mode[1];
 116 }
 117
 118 static __always_inline bool is_kernel_in_hyp_mode(void)
 119 {
 120         BUILD_BUG_ON(__is_defined(__KVM_NVHE_HYPERVISOR__) ||
 121                      __is_defined(__KVM_VHE_HYPERVISOR__));
 122         return read_sysreg(CurrentEL) == CurrentEL_EL2;
 123 }
 124
 125 static __always_inline bool has_vhe(void)
 126 {
 127         /*
 128          * Code only run in VHE/NVHE hyp context can assume VHE is present or
 129          * absent. Otherwise fall back to caps.
 130          * This allows the compiler to discard VHE-specific code from the
 131          * nVHE object, reducing the number of external symbol references
 132          * needed to link.
 133          */
 134         if (is_vhe_hyp_code())
 135                 return true;
 136         else if (is_nvhe_hyp_code())
 137                 return false;
 138         else
 139                 return cpus_have_final_cap(ARM64_HAS_VIRT_HOST_EXTN);
 140 }
 141
 142 static __always_inline bool is_protected_kvm_enabled(void)
 143 {
 144         if (is_vhe_hyp_code())
 145                 return false;
 146         else
 147                 return cpus_have_final_cap(ARM64_KVM_PROTECTED_MODE);
 148 }
 149
 150 static __always_inline bool has_hvhe(void)
 151 {
 152         if (is_vhe_hyp_code())
 153                 return false;
 154
 155         return cpus_have_final_cap(ARM64_KVM_HVHE);
 156 }
 157
 158 static inline bool is_hyp_nvhe(void)
 159 {
 160         return is_hyp_mode_available() && !is_kernel_in_hyp_mode();
 161 }
 162
 163 #endif /* __ASSEMBLY__ */
 164
 165 #endif /* ! __ASM__VIRT_H */