/* SPDX-License-Identifier: GPL-2.0-only */ /* * Copyright (C) 2015-2018 - ARM Ltd * Author: Marc Zyngier */ #include #include #include #include #include #include #include #include #include .text .pushsection .hyp.text, "ax" .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 #ifdef CONFIG_ARM64_SSBD alternative_cb arm64_enable_wa2_handling b wa2_end alternative_cb_end get_vcpu_ptr x2, x0 ldr x0, [x2, #VCPU_WORKAROUND_FLAGS] // Sanitize the argument and update the guest flags ldr x1, [sp, #8] // Guest's x1 clz w1, w1 // Murphy's device: lsr w1, w1, #5 // w1 = !!w1 without using eor w1, w1, #1 // the flags... bfi x0, x1, #VCPU_WORKAROUND_2_FLAG_SHIFT, #1 str x0, [x2, #VCPU_WORKAROUND_FLAGS] /* Check that we actually need to perform the call */ hyp_ldr_this_cpu x0, arm64_ssbd_callback_required, x2 cbz x0, wa2_end mov w0, #ARM_SMCCC_ARCH_WORKAROUND_2 smc #0 /* Don't leak data from the SMC call */ mov x3, xzr wa2_end: mov x2, xzr mov x1, xzr #endif 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, otherwise panic */ mrs x0, spsr_el2 /* if this was something else, then panic! */ tst x0, #PSR_IL_BIT b.eq __hyp_panic /* 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: ldp x0, x1, [sp], #16 /* * Only two possibilities: * 1) Either we come from the exit path, having just unmasked * PSTATE.A: change the return code to an EL2 fault, and * carry on, as we're already in a sane state to handle it. * 2) Or we come from anywhere else, and that's a bug: we panic. * * For (1), x0 contains the original return code and x1 doesn't * contain anything meaningful at that stage. We can reuse them * as temp registers. * For (2), who cares? */ mrs x0, elr_el2 adr x1, abort_guest_exit_start cmp x0, x1 adr x1, abort_guest_exit_end ccmp x0, x1, #4, ne b.ne __hyp_panic mov x0, #(1 << ARM_EXIT_WITH_SERROR_BIT) eret sb 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) 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) #ifdef CONFIG_KVM_INDIRECT_VECTORS .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) #endif