| /* SPDX-License-Identifier: GPL-2.0-only */ |
| /* |
| * Copyright (C) 2015-2018 - ARM Ltd |
| * Author: Marc Zyngier <marc.zyngier@arm.com> |
| */ |
| |
| #include <linux/arm-smccc.h> |
| #include <linux/linkage.h> |
| |
| #include <asm/alternative.h> |
| #include <asm/assembler.h> |
| #include <asm/cpufeature.h> |
| #include <asm/kvm_arm.h> |
| #include <asm/kvm_asm.h> |
| #include <asm/kvm_mmu.h> |
| #include <asm/mmu.h> |
| |
| .macro save_caller_saved_regs_vect |
| /* x0 and x1 were saved in the vector entry */ |
| stp x2, x3, [sp, #-16]! |
| stp x4, x5, [sp, #-16]! |
| stp x6, x7, [sp, #-16]! |
| stp x8, x9, [sp, #-16]! |
| stp x10, x11, [sp, #-16]! |
| stp x12, x13, [sp, #-16]! |
| stp x14, x15, [sp, #-16]! |
| stp x16, x17, [sp, #-16]! |
| .endm |
| |
| .macro restore_caller_saved_regs_vect |
| ldp x16, x17, [sp], #16 |
| ldp x14, x15, [sp], #16 |
| ldp x12, x13, [sp], #16 |
| ldp x10, x11, [sp], #16 |
| ldp x8, x9, [sp], #16 |
| ldp x6, x7, [sp], #16 |
| ldp x4, x5, [sp], #16 |
| ldp x2, x3, [sp], #16 |
| ldp x0, x1, [sp], #16 |
| .endm |
| |
| .text |
| |
| .macro do_el2_call |
| /* |
| * Shuffle the parameters before calling the function |
| * pointed to in x0. Assumes parameters in x[1,2,3]. |
| */ |
| str lr, [sp, #-16]! |
| mov lr, x0 |
| mov x0, x1 |
| mov x1, x2 |
| mov x2, x3 |
| blr lr |
| ldr lr, [sp], #16 |
| .endm |
| |
| el1_sync: // Guest trapped into EL2 |
| |
| mrs x0, esr_el2 |
| lsr x0, x0, #ESR_ELx_EC_SHIFT |
| cmp x0, #ESR_ELx_EC_HVC64 |
| ccmp x0, #ESR_ELx_EC_HVC32, #4, ne |
| b.ne el1_trap |
| |
| #ifdef __KVM_NVHE_HYPERVISOR__ |
| mrs x1, vttbr_el2 // If vttbr is valid, the guest |
| cbnz x1, el1_hvc_guest // called HVC |
| |
| /* Here, we're pretty sure the host called HVC. */ |
| ldp x0, x1, [sp], #16 |
| |
| /* Check for a stub HVC call */ |
| cmp x0, #HVC_STUB_HCALL_NR |
| b.hs 1f |
| |
| /* |
| * Compute the idmap address of __kvm_handle_stub_hvc and |
| * jump there. Since we use kimage_voffset, do not use the |
| * HYP VA for __kvm_handle_stub_hvc, but the kernel VA instead |
| * (by loading it from the constant pool). |
| * |
| * Preserve x0-x4, which may contain stub parameters. |
| */ |
| ldr x5, =__kvm_handle_stub_hvc |
| ldr_l x6, kimage_voffset |
| |
| /* x5 = __pa(x5) */ |
| sub x5, x5, x6 |
| br x5 |
| |
| 1: |
| /* |
| * Perform the EL2 call |
| */ |
| kern_hyp_va x0 |
| do_el2_call |
| |
| eret |
| sb |
| #endif /* __KVM_NVHE_HYPERVISOR__ */ |
| |
| el1_hvc_guest: |
| /* |
| * Fastest possible path for ARM_SMCCC_ARCH_WORKAROUND_1. |
| * The workaround has already been applied on the host, |
| * so let's quickly get back to the guest. We don't bother |
| * restoring x1, as it can be clobbered anyway. |
| */ |
| ldr x1, [sp] // Guest's x0 |
| eor w1, w1, #ARM_SMCCC_ARCH_WORKAROUND_1 |
| cbz w1, wa_epilogue |
| |
| /* ARM_SMCCC_ARCH_WORKAROUND_2 handling */ |
| eor w1, w1, #(ARM_SMCCC_ARCH_WORKAROUND_1 ^ \ |
| ARM_SMCCC_ARCH_WORKAROUND_2) |
| cbnz w1, el1_trap |
| |
| wa_epilogue: |
| mov x0, xzr |
| add sp, sp, #16 |
| eret |
| sb |
| |
| el1_trap: |
| get_vcpu_ptr x1, x0 |
| mov x0, #ARM_EXCEPTION_TRAP |
| b __guest_exit |
| |
| el1_irq: |
| get_vcpu_ptr x1, x0 |
| mov x0, #ARM_EXCEPTION_IRQ |
| b __guest_exit |
| |
| el1_error: |
| get_vcpu_ptr x1, x0 |
| mov x0, #ARM_EXCEPTION_EL1_SERROR |
| b __guest_exit |
| |
| el2_sync: |
| /* Check for illegal exception return */ |
| mrs x0, spsr_el2 |
| tbnz x0, #20, 1f |
| |
| save_caller_saved_regs_vect |
| stp x29, x30, [sp, #-16]! |
| bl kvm_unexpected_el2_exception |
| ldp x29, x30, [sp], #16 |
| restore_caller_saved_regs_vect |
| |
| eret |
| |
| 1: |
| /* Let's attempt a recovery from the illegal exception return */ |
| get_vcpu_ptr x1, x0 |
| mov x0, #ARM_EXCEPTION_IL |
| b __guest_exit |
| |
| |
| el2_error: |
| save_caller_saved_regs_vect |
| stp x29, x30, [sp, #-16]! |
| |
| bl kvm_unexpected_el2_exception |
| |
| ldp x29, x30, [sp], #16 |
| restore_caller_saved_regs_vect |
| |
| eret |
| sb |
| |
| #ifdef __KVM_NVHE_HYPERVISOR__ |
| SYM_FUNC_START(__hyp_do_panic) |
| mov lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\ |
| PSR_MODE_EL1h) |
| msr spsr_el2, lr |
| ldr lr, =panic |
| msr elr_el2, lr |
| eret |
| sb |
| SYM_FUNC_END(__hyp_do_panic) |
| #endif |
| |
| SYM_CODE_START(__hyp_panic) |
| get_host_ctxt x0, x1 |
| b hyp_panic |
| SYM_CODE_END(__hyp_panic) |
| |
| .macro invalid_vector label, target = __hyp_panic |
| .align 2 |
| SYM_CODE_START(\label) |
| b \target |
| SYM_CODE_END(\label) |
| .endm |
| |
| /* None of these should ever happen */ |
| invalid_vector el2t_sync_invalid |
| invalid_vector el2t_irq_invalid |
| invalid_vector el2t_fiq_invalid |
| invalid_vector el2t_error_invalid |
| invalid_vector el2h_sync_invalid |
| invalid_vector el2h_irq_invalid |
| invalid_vector el2h_fiq_invalid |
| invalid_vector el1_fiq_invalid |
| |
| .ltorg |
| |
| .align 11 |
| |
| .macro check_preamble_length start, end |
| /* kvm_patch_vector_branch() generates code that jumps over the preamble. */ |
| .if ((\end-\start) != KVM_VECTOR_PREAMBLE) |
| .error "KVM vector preamble length mismatch" |
| .endif |
| .endm |
| |
| .macro valid_vect target |
| .align 7 |
| 661: |
| esb |
| stp x0, x1, [sp, #-16]! |
| 662: |
| b \target |
| |
| check_preamble_length 661b, 662b |
| .endm |
| |
| .macro invalid_vect target |
| .align 7 |
| 661: |
| b \target |
| nop |
| 662: |
| ldp x0, x1, [sp], #16 |
| b \target |
| |
| check_preamble_length 661b, 662b |
| .endm |
| |
| SYM_CODE_START(__kvm_hyp_vector) |
| invalid_vect el2t_sync_invalid // Synchronous EL2t |
| invalid_vect el2t_irq_invalid // IRQ EL2t |
| invalid_vect el2t_fiq_invalid // FIQ EL2t |
| invalid_vect el2t_error_invalid // Error EL2t |
| |
| valid_vect el2_sync // Synchronous EL2h |
| invalid_vect el2h_irq_invalid // IRQ EL2h |
| invalid_vect el2h_fiq_invalid // FIQ EL2h |
| valid_vect el2_error // Error EL2h |
| |
| valid_vect el1_sync // Synchronous 64-bit EL1 |
| valid_vect el1_irq // IRQ 64-bit EL1 |
| invalid_vect el1_fiq_invalid // FIQ 64-bit EL1 |
| valid_vect el1_error // Error 64-bit EL1 |
| |
| valid_vect el1_sync // Synchronous 32-bit EL1 |
| valid_vect el1_irq // IRQ 32-bit EL1 |
| invalid_vect el1_fiq_invalid // FIQ 32-bit EL1 |
| valid_vect el1_error // Error 32-bit EL1 |
| SYM_CODE_END(__kvm_hyp_vector) |
| |
| .macro hyp_ventry |
| .align 7 |
| 1: esb |
| .rept 26 |
| nop |
| .endr |
| /* |
| * The default sequence is to directly branch to the KVM vectors, |
| * using the computed offset. This applies for VHE as well as |
| * !ARM64_HARDEN_EL2_VECTORS. The first vector must always run the preamble. |
| * |
| * For ARM64_HARDEN_EL2_VECTORS configurations, this gets replaced |
| * with: |
| * |
| * stp x0, x1, [sp, #-16]! |
| * movz x0, #(addr & 0xffff) |
| * movk x0, #((addr >> 16) & 0xffff), lsl #16 |
| * movk x0, #((addr >> 32) & 0xffff), lsl #32 |
| * br x0 |
| * |
| * Where: |
| * addr = kern_hyp_va(__kvm_hyp_vector) + vector-offset + KVM_VECTOR_PREAMBLE. |
| * See kvm_patch_vector_branch for details. |
| */ |
| alternative_cb kvm_patch_vector_branch |
| stp x0, x1, [sp, #-16]! |
| b __kvm_hyp_vector + (1b - 0b + KVM_VECTOR_PREAMBLE) |
| nop |
| nop |
| nop |
| alternative_cb_end |
| .endm |
| |
| .macro generate_vectors |
| 0: |
| .rept 16 |
| hyp_ventry |
| .endr |
| .org 0b + SZ_2K // Safety measure |
| .endm |
| |
| .align 11 |
| SYM_CODE_START(__bp_harden_hyp_vecs) |
| .rept BP_HARDEN_EL2_SLOTS |
| generate_vectors |
| .endr |
| 1: .org __bp_harden_hyp_vecs + __BP_HARDEN_HYP_VECS_SZ |
| .org 1b |
| SYM_CODE_END(__bp_harden_hyp_vecs) |