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 #include <hyp/adjust_pc.h>
8 #include <hyp/switch.h>
9
10 #include <linux/arm-smccc.h>
11 #include <linux/kvm_host.h>
12 #include <linux/types.h>
13 #include <linux/jump_label.h>
14 #include <uapi/linux/psci.h>
15
16 #include <kvm/arm_psci.h>
17
18 #include <asm/barrier.h>
19 #include <asm/cpufeature.h>
20 #include <asm/kprobes.h>
21 #include <asm/kvm_asm.h>
22 #include <asm/kvm_emulate.h>
23 #include <asm/kvm_hyp.h>
24 #include <asm/kvm_mmu.h>
25 #include <asm/fpsimd.h>
26 #include <asm/debug-monitors.h>
27 #include <asm/processor.h>
28 #include <asm/thread_info.h>
29
30 /* VHE specific context */
31 DEFINE_PER_CPU(struct kvm_host_data, kvm_host_data);
32 DEFINE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt);
33 DEFINE_PER_CPU(unsigned long, kvm_hyp_vector);
34
__activate_traps(struct kvm_vcpu * vcpu)35 static void __activate_traps(struct kvm_vcpu *vcpu)
36 {
37 u64 val;
38
39 ___activate_traps(vcpu);
40
41 val = read_sysreg(cpacr_el1);
42 val |= CPACR_EL1_TTA;
43 val &= ~CPACR_EL1_ZEN;
44
45 /*
46 * With VHE (HCR.E2H == 1), accesses to CPACR_EL1 are routed to
47 * CPTR_EL2. In general, CPACR_EL1 has the same layout as CPTR_EL2,
48 * except for some missing controls, such as TAM.
49 * In this case, CPTR_EL2.TAM has the same position with or without
50 * VHE (HCR.E2H == 1) which allows us to use here the CPTR_EL2.TAM
51 * shift value for trapping the AMU accesses.
52 */
53
54 val |= CPTR_EL2_TAM;
55
56 if (update_fp_enabled(vcpu)) {
57 if (vcpu_has_sve(vcpu))
58 val |= CPACR_EL1_ZEN;
59 } else {
60 val &= ~CPACR_EL1_FPEN;
61 __activate_traps_fpsimd32(vcpu);
62 }
63
64 write_sysreg(val, cpacr_el1);
65
66 write_sysreg(__this_cpu_read(kvm_hyp_vector), vbar_el1);
67 }
68 NOKPROBE_SYMBOL(__activate_traps);
69
__deactivate_traps(struct kvm_vcpu * vcpu)70 static void __deactivate_traps(struct kvm_vcpu *vcpu)
71 {
72 extern char vectors[]; /* kernel exception vectors */
73
74 ___deactivate_traps(vcpu);
75
76 write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2);
77
78 /*
79 * ARM errata 1165522 and 1530923 require the actual execution of the
80 * above before we can switch to the EL2/EL0 translation regime used by
81 * the host.
82 */
83 asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_SPECULATIVE_AT));
84
85 write_sysreg(CPACR_EL1_DEFAULT, cpacr_el1);
86 write_sysreg(vectors, vbar_el1);
87 }
88 NOKPROBE_SYMBOL(__deactivate_traps);
89
activate_traps_vhe_load(struct kvm_vcpu * vcpu)90 void activate_traps_vhe_load(struct kvm_vcpu *vcpu)
91 {
92 __activate_traps_common(vcpu);
93 }
94
deactivate_traps_vhe_put(void)95 void deactivate_traps_vhe_put(void)
96 {
97 u64 mdcr_el2 = read_sysreg(mdcr_el2);
98
99 mdcr_el2 &= MDCR_EL2_HPMN_MASK |
100 MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT |
101 MDCR_EL2_TPMS;
102
103 write_sysreg(mdcr_el2, mdcr_el2);
104
105 __deactivate_traps_common();
106 }
107
108 /* Switch to the guest for VHE systems running in EL2 */
__kvm_vcpu_run_vhe(struct kvm_vcpu * vcpu)109 static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
110 {
111 struct kvm_cpu_context *host_ctxt;
112 struct kvm_cpu_context *guest_ctxt;
113 u64 exit_code;
114
115 host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
116 host_ctxt->__hyp_running_vcpu = vcpu;
117 guest_ctxt = &vcpu->arch.ctxt;
118
119 sysreg_save_host_state_vhe(host_ctxt);
120
121 /*
122 * ARM erratum 1165522 requires us to configure both stage 1 and
123 * stage 2 translation for the guest context before we clear
124 * HCR_EL2.TGE.
125 *
126 * We have already configured the guest's stage 1 translation in
127 * kvm_vcpu_load_sysregs_vhe above. We must now call
128 * __load_guest_stage2 before __activate_traps, because
129 * __load_guest_stage2 configures stage 2 translation, and
130 * __activate_traps clear HCR_EL2.TGE (among other things).
131 */
132 __load_guest_stage2(vcpu->arch.hw_mmu);
133 __activate_traps(vcpu);
134
135 __adjust_pc(vcpu);
136
137 sysreg_restore_guest_state_vhe(guest_ctxt);
138 __debug_switch_to_guest(vcpu);
139
140 do {
141 /* Jump in the fire! */
142 exit_code = __guest_enter(vcpu);
143
144 /* And we're baaack! */
145 } while (fixup_guest_exit(vcpu, &exit_code));
146
147 sysreg_save_guest_state_vhe(guest_ctxt);
148
149 __deactivate_traps(vcpu);
150
151 sysreg_restore_host_state_vhe(host_ctxt);
152
153 if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED)
154 __fpsimd_save_fpexc32(vcpu);
155
156 __debug_switch_to_host(vcpu);
157
158 return exit_code;
159 }
160 NOKPROBE_SYMBOL(__kvm_vcpu_run_vhe);
161
__kvm_vcpu_run(struct kvm_vcpu * vcpu)162 int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
163 {
164 int ret;
165
166 local_daif_mask();
167
168 /*
169 * Having IRQs masked via PMR when entering the guest means the GIC
170 * will not signal the CPU of interrupts of lower priority, and the
171 * only way to get out will be via guest exceptions.
172 * Naturally, we want to avoid this.
173 *
174 * local_daif_mask() already sets GIC_PRIO_PSR_I_SET, we just need a
175 * dsb to ensure the redistributor is forwards EL2 IRQs to the CPU.
176 */
177 pmr_sync();
178
179 ret = __kvm_vcpu_run_vhe(vcpu);
180
181 /*
182 * local_daif_restore() takes care to properly restore PSTATE.DAIF
183 * and the GIC PMR if the host is using IRQ priorities.
184 */
185 local_daif_restore(DAIF_PROCCTX_NOIRQ);
186
187 /*
188 * When we exit from the guest we change a number of CPU configuration
189 * parameters, such as traps. Make sure these changes take effect
190 * before running the host or additional guests.
191 */
192 isb();
193
194 return ret;
195 }
196
__hyp_call_panic(u64 spsr,u64 elr,u64 par)197 static void __hyp_call_panic(u64 spsr, u64 elr, u64 par)
198 {
199 struct kvm_cpu_context *host_ctxt;
200 struct kvm_vcpu *vcpu;
201
202 host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
203 vcpu = host_ctxt->__hyp_running_vcpu;
204
205 __deactivate_traps(vcpu);
206 sysreg_restore_host_state_vhe(host_ctxt);
207
208 panic("HYP panic:\nPS:%08llx PC:%016llx ESR:%08llx\nFAR:%016llx HPFAR:%016llx PAR:%016llx\nVCPU:%p\n",
209 spsr, elr,
210 read_sysreg_el2(SYS_ESR), read_sysreg_el2(SYS_FAR),
211 read_sysreg(hpfar_el2), par, vcpu);
212 }
213 NOKPROBE_SYMBOL(__hyp_call_panic);
214
hyp_panic(void)215 void __noreturn hyp_panic(void)
216 {
217 u64 spsr = read_sysreg_el2(SYS_SPSR);
218 u64 elr = read_sysreg_el2(SYS_ELR);
219 u64 par = read_sysreg_par();
220
221 __hyp_call_panic(spsr, elr, par);
222 unreachable();
223 }
224
kvm_unexpected_el2_exception(void)225 asmlinkage void kvm_unexpected_el2_exception(void)
226 {
227 return __kvm_unexpected_el2_exception();
228 }
229