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 */ 166