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_fsc_is_permission_fault(esr))) {
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
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.