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_VHE_RESTART - Upgrade the CPU from EL1 to EL2, if possible 40 */ 41 #define HVC_VHE_RESTART 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 #ifndef __ASSEMBLY__ 53 54 #include <asm/ptrace.h> 55 #include <asm/sections.h> 56 #include <asm/sysreg.h> 57 #include <asm/cpufeature.h> 58 59 /* 60 * __boot_cpu_mode records what mode CPUs were booted in. 61 * A correctly-implemented bootloader must start all CPUs in the same mode: 62 * In this case, both 32bit halves of __boot_cpu_mode will contain the 63 * same value (either 0 if booted in EL1, BOOT_CPU_MODE_EL2 if booted in EL2). 64 * 65 * Should the bootloader fail to do this, the two values will be different. 66 * This allows the kernel to flag an error when the secondaries have come up. 67 */ 68 extern u32 __boot_cpu_mode[2]; 69 70 #define ARM64_VECTOR_TABLE_LEN SZ_2K 71 72 void __hyp_set_vectors(phys_addr_t phys_vector_base); 73 void __hyp_reset_vectors(void); 74 75 DECLARE_STATIC_KEY_FALSE(kvm_protected_mode_initialized); 76 77 /* Reports the availability of HYP mode */ 78 static inline bool is_hyp_mode_available(void) 79 { 80 /* 81 * If KVM protected mode is initialized, all CPUs must have been booted 82 * in EL2. Avoid checking __boot_cpu_mode as CPUs now come up in EL1. 83 */ 84 if (IS_ENABLED(CONFIG_KVM) && 85 static_branch_likely(&kvm_protected_mode_initialized)) 86 return true; 87 88 return (__boot_cpu_mode[0] == BOOT_CPU_MODE_EL2 && 89 __boot_cpu_mode[1] == BOOT_CPU_MODE_EL2); 90 } 91 92 /* Check if the bootloader has booted CPUs in different modes */ 93 static inline bool is_hyp_mode_mismatched(void) 94 { 95 /* 96 * If KVM protected mode is initialized, all CPUs must have been booted 97 * in EL2. Avoid checking __boot_cpu_mode as CPUs now come up in EL1. 98 */ 99 if (IS_ENABLED(CONFIG_KVM) && 100 static_branch_likely(&kvm_protected_mode_initialized)) 101 return false; 102 103 return __boot_cpu_mode[0] != __boot_cpu_mode[1]; 104 } 105 106 static inline bool is_kernel_in_hyp_mode(void) 107 { 108 return read_sysreg(CurrentEL) == CurrentEL_EL2; 109 } 110 111 static __always_inline bool has_vhe(void) 112 { 113 /* 114 * Code only run in VHE/NVHE hyp context can assume VHE is present or 115 * absent. Otherwise fall back to caps. 116 */ 117 if (is_vhe_hyp_code()) 118 return true; 119 else if (is_nvhe_hyp_code()) 120 return false; 121 else 122 return cpus_have_final_cap(ARM64_HAS_VIRT_HOST_EXTN); 123 } 124 125 static __always_inline bool is_protected_kvm_enabled(void) 126 { 127 if (is_vhe_hyp_code()) 128 return false; 129 else 130 return cpus_have_final_cap(ARM64_KVM_PROTECTED_MODE); 131 } 132 133 static inline bool is_hyp_nvhe(void) 134 { 135 return is_hyp_mode_available() && !is_kernel_in_hyp_mode(); 136 } 137 138 #endif /* __ASSEMBLY__ */ 139 140 #endif /* ! __ASM__VIRT_H */ 141