1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2020 - Google Inc 4 * Author: Andrew Scull <ascull@google.com> 5 */ 6 7 #include <linux/linkage.h> 8 9 #include <asm/assembler.h> 10 #include <asm/kvm_asm.h> 11 #include <asm/kvm_mmu.h> 12 13 .text 14 15 SYM_FUNC_START(__host_exit) 16 stp x0, x1, [sp, #-16]! 17 18 get_host_ctxt x0, x1 19 20 /* Store the host regs x2 and x3 */ 21 stp x2, x3, [x0, #CPU_XREG_OFFSET(2)] 22 23 /* Retrieve the host regs x0-x1 from the stack */ 24 ldp x2, x3, [sp], #16 // x0, x1 25 26 /* Store the host regs x0-x1 and x4-x17 */ 27 stp x2, x3, [x0, #CPU_XREG_OFFSET(0)] 28 stp x4, x5, [x0, #CPU_XREG_OFFSET(4)] 29 stp x6, x7, [x0, #CPU_XREG_OFFSET(6)] 30 stp x8, x9, [x0, #CPU_XREG_OFFSET(8)] 31 stp x10, x11, [x0, #CPU_XREG_OFFSET(10)] 32 stp x12, x13, [x0, #CPU_XREG_OFFSET(12)] 33 stp x14, x15, [x0, #CPU_XREG_OFFSET(14)] 34 stp x16, x17, [x0, #CPU_XREG_OFFSET(16)] 35 36 /* Store the host regs x18-x29, lr */ 37 save_callee_saved_regs x0 38 39 /* Save the host context pointer in x29 across the function call */ 40 mov x29, x0 41 bl handle_trap 42 43 /* Restore host regs x0-x17 */ 44 ldp x0, x1, [x29, #CPU_XREG_OFFSET(0)] 45 ldp x2, x3, [x29, #CPU_XREG_OFFSET(2)] 46 ldp x4, x5, [x29, #CPU_XREG_OFFSET(4)] 47 ldp x6, x7, [x29, #CPU_XREG_OFFSET(6)] 48 49 /* x0-7 are use for panic arguments */ 50 __host_enter_for_panic: 51 ldp x8, x9, [x29, #CPU_XREG_OFFSET(8)] 52 ldp x10, x11, [x29, #CPU_XREG_OFFSET(10)] 53 ldp x12, x13, [x29, #CPU_XREG_OFFSET(12)] 54 ldp x14, x15, [x29, #CPU_XREG_OFFSET(14)] 55 ldp x16, x17, [x29, #CPU_XREG_OFFSET(16)] 56 57 /* Restore host regs x18-x29, lr */ 58 restore_callee_saved_regs x29 59 60 /* Do not touch any register after this! */ 61 __host_enter_without_restoring: 62 eret 63 sb 64 SYM_FUNC_END(__host_exit) 65 66 /* 67 * void __noreturn __hyp_do_panic(struct kvm_cpu_context *host_ctxt, u64 spsr, 68 * u64 elr, u64 par); 69 */ 70 SYM_FUNC_START(__hyp_do_panic) 71 mov x29, x0 72 73 /* Load the format string into x0 and arguments into x1-7 */ 74 ldr x0, =__hyp_panic_string 75 76 mov x6, x3 77 get_vcpu_ptr x7, x3 78 79 mrs x3, esr_el2 80 mrs x4, far_el2 81 mrs x5, hpfar_el2 82 83 /* Prepare and exit to the host's panic funciton. */ 84 mov lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\ 85 PSR_MODE_EL1h) 86 msr spsr_el2, lr 87 ldr lr, =panic 88 msr elr_el2, lr 89 90 /* Enter the host, conditionally restoring the host context. */ 91 cbz x29, __host_enter_without_restoring 92 b __host_enter_for_panic 93 SYM_FUNC_END(__hyp_do_panic) 94 95 .macro host_el1_sync_vect 96 .align 7 97 .L__vect_start\@: 98 stp x0, x1, [sp, #-16]! 99 mrs x0, esr_el2 100 ubfx x0, x0, #ESR_ELx_EC_SHIFT, #ESR_ELx_EC_WIDTH 101 cmp x0, #ESR_ELx_EC_HVC64 102 ldp x0, x1, [sp], #16 103 b.ne __host_exit 104 105 /* Check for a stub HVC call */ 106 cmp x0, #HVC_STUB_HCALL_NR 107 b.hs __host_exit 108 109 /* 110 * Compute the idmap address of __kvm_handle_stub_hvc and 111 * jump there. Since we use kimage_voffset, do not use the 112 * HYP VA for __kvm_handle_stub_hvc, but the kernel VA instead 113 * (by loading it from the constant pool). 114 * 115 * Preserve x0-x4, which may contain stub parameters. 116 */ 117 ldr x5, =__kvm_handle_stub_hvc 118 ldr_l x6, kimage_voffset 119 120 /* x5 = __pa(x5) */ 121 sub x5, x5, x6 122 br x5 123 .L__vect_end\@: 124 .if ((.L__vect_end\@ - .L__vect_start\@) > 0x80) 125 .error "host_el1_sync_vect larger than vector entry" 126 .endif 127 .endm 128 129 .macro invalid_host_el2_vect 130 .align 7 131 /* If a guest is loaded, panic out of it. */ 132 stp x0, x1, [sp, #-16]! 133 get_loaded_vcpu x0, x1 134 cbnz x0, __guest_exit_panic 135 add sp, sp, #16 136 137 /* 138 * The panic may not be clean if the exception is taken before the host 139 * context has been saved by __host_exit or after the hyp context has 140 * been partially clobbered by __host_enter. 141 */ 142 b hyp_panic 143 .endm 144 145 .macro invalid_host_el1_vect 146 .align 7 147 mov x0, xzr /* host_ctxt = NULL */ 148 mrs x1, spsr_el2 149 mrs x2, elr_el2 150 mrs x3, par_el1 151 b __hyp_do_panic 152 .endm 153 154 /* 155 * The host vector does not use an ESB instruction in order to avoid consuming 156 * SErrors that should only be consumed by the host. Guest entry is deferred by 157 * __guest_enter if there are any pending asynchronous exceptions so hyp will 158 * always return to the host without having consumerd host SErrors. 159 * 160 * CONFIG_KVM_INDIRECT_VECTORS is not applied to the host vectors because the 161 * host knows about the EL2 vectors already, and there is no point in hiding 162 * them. 163 */ 164 .align 11 165 SYM_CODE_START(__kvm_hyp_host_vector) 166 invalid_host_el2_vect // Synchronous EL2t 167 invalid_host_el2_vect // IRQ EL2t 168 invalid_host_el2_vect // FIQ EL2t 169 invalid_host_el2_vect // Error EL2t 170 171 invalid_host_el2_vect // Synchronous EL2h 172 invalid_host_el2_vect // IRQ EL2h 173 invalid_host_el2_vect // FIQ EL2h 174 invalid_host_el2_vect // Error EL2h 175 176 host_el1_sync_vect // Synchronous 64-bit EL1 177 invalid_host_el1_vect // IRQ 64-bit EL1 178 invalid_host_el1_vect // FIQ 64-bit EL1 179 invalid_host_el1_vect // Error 64-bit EL1 180 181 invalid_host_el1_vect // Synchronous 32-bit EL1 182 invalid_host_el1_vect // IRQ 32-bit EL1 183 invalid_host_el1_vect // FIQ 32-bit EL1 184 invalid_host_el1_vect // Error 32-bit EL1 185 SYM_CODE_END(__kvm_hyp_host_vector) 186