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 int ret;
18 u64 par, tmp;
19
20 /*
21 * Resolve the IPA the hard way using the guest VA.
22 *
23 * Stage-1 translation already validated the memory access
24 * rights. As such, we can use the EL1 translation regime, and
25 * don't have to distinguish between EL0 and EL1 access.
26 *
27 * We do need to save/restore PAR_EL1 though, as we haven't
28 * saved the guest context yet, and we may return early...
29 */
30 par = read_sysreg_par();
31 ret = system_supports_poe() ? __kvm_at(OP_AT_S1E1A, far) :
32 __kvm_at(OP_AT_S1E1R, far);
33 if (!ret)
34 tmp = read_sysreg_par();
35 else
36 tmp = SYS_PAR_EL1_F; /* back to the guest */
37 write_sysreg(par, par_el1);
38
39 if (unlikely(tmp & SYS_PAR_EL1_F))
40 return false; /* Translation failed, back to guest */
41
42 /* Convert PAR to HPFAR format */
43 *hpfar = PAR_TO_HPFAR(tmp);
44 return true;
45 }
46
47 static inline bool __get_fault_info(u64 esr, struct kvm_vcpu_fault_info *fault)
48 {
49 u64 hpfar, far;
50
51 far = read_sysreg_el2(SYS_FAR);
52
53 /*
54 * The HPFAR can be invalid if the stage 2 fault did not
55 * happen during a stage 1 page table walk (the ESR_EL2.S1PTW
56 * bit is clear) and one of the two following cases are true:
57 * 1. The fault was due to a permission fault
58 * 2. The processor carries errata 834220
59 *
60 * Therefore, for all non S1PTW faults where we either have a
61 * permission fault or the errata workaround is enabled, we
62 * resolve the IPA using the AT instruction.
63 */
64 if (!(esr & ESR_ELx_S1PTW) &&
65 (cpus_have_final_cap(ARM64_WORKAROUND_834220) ||
66 esr_fsc_is_permission_fault(esr))) {
67 if (!__translate_far_to_hpfar(far, &hpfar))
68 return false;
69 } else {
70 hpfar = read_sysreg(hpfar_el2);
71 }
72
73 fault->far_el2 = far;
74 fault->hpfar_el2 = hpfar;
75 return true;
76 }
77
78 #endif
79
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