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 /* Max number of HYP stub hypercalls */
  39 #define HVC_STUB_HCALL_NR 3
  40
  41 /* Error returned when an invalid stub number is passed into x0 */
  42 #define HVC_STUB_ERR    0xbadca11
  43
  44 #define BOOT_CPU_MODE_EL1       (0xe11)
  45 #define BOOT_CPU_MODE_EL2       (0xe12)
  46
  47 #ifndef __ASSEMBLY__
  48
  49 #include <asm/ptrace.h>
  50 #include <asm/sections.h>
  51 #include <asm/sysreg.h>
  52 #include <asm/cpufeature.h>
  53
  54 /*
  55  * __boot_cpu_mode records what mode CPUs were booted in.
  56  * A correctly-implemented bootloader must start all CPUs in the same mode:
  57  * In this case, both 32bit halves of __boot_cpu_mode will contain the
  58  * same value (either 0 if booted in EL1, BOOT_CPU_MODE_EL2 if booted in EL2).
  59  *
  60  * Should the bootloader fail to do this, the two values will be different.
  61  * This allows the kernel to flag an error when the secondaries have come up.
  62  */
  63 extern u32 __boot_cpu_mode[2];
  64
  65 void __hyp_set_vectors(phys_addr_t phys_vector_base);
  66 void __hyp_reset_vectors(void);
  67
  68 DECLARE_STATIC_KEY_FALSE(kvm_protected_mode_initialized);
  69
  70 /* Reports the availability of HYP mode */
  71 static inline bool is_hyp_mode_available(void)
  72 {
  73         /*
  74          * If KVM protected mode is initialized, all CPUs must have been booted
  75          * in EL2. Avoid checking __boot_cpu_mode as CPUs now come up in EL1.
  76          */
  77         if (IS_ENABLED(CONFIG_KVM) &&
  78             static_branch_likely(&kvm_protected_mode_initialized))
  79                 return true;
  80
  81         return (__boot_cpu_mode[0] == BOOT_CPU_MODE_EL2 &&
  82                 __boot_cpu_mode[1] == BOOT_CPU_MODE_EL2);
  83 }
  84
  85 /* Check if the bootloader has booted CPUs in different modes */
  86 static inline bool is_hyp_mode_mismatched(void)
  87 {
  88         /*
  89          * If KVM protected mode is initialized, all CPUs must have been booted
  90          * in EL2. Avoid checking __boot_cpu_mode as CPUs now come up in EL1.
  91          */
  92         if (IS_ENABLED(CONFIG_KVM) &&
  93             static_branch_likely(&kvm_protected_mode_initialized))
  94                 return false;
  95
  96         return __boot_cpu_mode[0] != __boot_cpu_mode[1];
  97 }
  98
  99 static inline bool is_kernel_in_hyp_mode(void)
 100 {
 101         return read_sysreg(CurrentEL) == CurrentEL_EL2;
 102 }
 103
 104 static __always_inline bool has_vhe(void)
 105 {
 106         /*
 107          * Code only run in VHE/NVHE hyp context can assume VHE is present or
 108          * absent. Otherwise fall back to caps.
 109          */
 110         if (is_vhe_hyp_code())
 111                 return true;
 112         else if (is_nvhe_hyp_code())
 113                 return false;
 114         else
 115                 return cpus_have_final_cap(ARM64_HAS_VIRT_HOST_EXTN);
 116 }
 117
 118 static __always_inline bool is_protected_kvm_enabled(void)
 119 {
 120         if (is_vhe_hyp_code())
 121                 return false;
 122         else
 123                 return cpus_have_final_cap(ARM64_KVM_PROTECTED_MODE);
 124 }
 125
 126 #endif /* __ASSEMBLY__ */
 127
 128 #endif /* ! __ASM__VIRT_H */