1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2015 - ARM Ltd 4 * Author: Marc Zyngier <marc.zyngier@arm.com> 5 */ 6 7 #ifndef __ARM64_KVM_HYP_FAULT_H__ 8 #define __ARM64_KVM_HYP_FAULT_H__ 9 10 #include <asm/kvm_asm.h> 11 #include <asm/kvm_emulate.h> 12 #include <asm/kvm_hyp.h> 13 #include <asm/kvm_mmu.h> 14 15 static inline bool __translate_far_to_hpfar(u64 far, u64 *hpfar) 16 { 17 u64 par, tmp; 18 19 /* 20 * Resolve the IPA the hard way using the guest VA. 21 * 22 * Stage-1 translation already validated the memory access 23 * rights. As such, we can use the EL1 translation regime, and 24 * don't have to distinguish between EL0 and EL1 access. 25 * 26 * We do need to save/restore PAR_EL1 though, as we haven't 27 * saved the guest context yet, and we may return early... 28 */ 29 par = read_sysreg_par(); 30 if (!__kvm_at("s1e1r", far)) 31 tmp = read_sysreg_par(); 32 else 33 tmp = SYS_PAR_EL1_F; /* back to the guest */ 34 write_sysreg(par, par_el1); 35 36 if (unlikely(tmp & SYS_PAR_EL1_F)) 37 return false; /* Translation failed, back to guest */ 38 39 /* Convert PAR to HPFAR format */ 40 *hpfar = PAR_TO_HPFAR(tmp); 41 return true; 42 } 43 44 static inline bool __get_fault_info(u64 esr, struct kvm_vcpu_fault_info *fault) 45 { 46 u64 hpfar, far; 47 48 far = read_sysreg_el2(SYS_FAR); 49 50 /* 51 * The HPFAR can be invalid if the stage 2 fault did not 52 * happen during a stage 1 page table walk (the ESR_EL2.S1PTW 53 * bit is clear) and one of the two following cases are true: 54 * 1. The fault was due to a permission fault 55 * 2. The processor carries errata 834220 56 * 57 * Therefore, for all non S1PTW faults where we either have a 58 * permission fault or the errata workaround is enabled, we 59 * resolve the IPA using the AT instruction. 60 */ 61 if (!(esr & ESR_ELx_S1PTW) && 62 (cpus_have_final_cap(ARM64_WORKAROUND_834220) || 63 (esr & ESR_ELx_FSC_TYPE) == FSC_PERM)) { 64 if (!__translate_far_to_hpfar(far, &hpfar)) 65 return false; 66 } else { 67 hpfar = read_sysreg(hpfar_el2); 68 } 69 70 fault->far_el2 = far; 71 fault->hpfar_el2 = hpfar; 72 return true; 73 } 74 75 #endif 76