1 /*
2 * Copyright (C) 2012-2015 - ARM Ltd
3 * Author: Marc Zyngier <marc.zyngier@arm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
16 */
17
18 #include <linux/compiler.h>
19 #include <linux/kvm_host.h>
20
21 #include <asm/kvm_asm.h>
22 #include <asm/kvm_emulate.h>
23 #include <asm/kvm_hyp.h>
24
25 /*
26 * Non-VHE: Both host and guest must save everything.
27 *
28 * VHE: Host and guest must save mdscr_el1 and sp_el0 (and the PC and pstate,
29 * which are handled as part of the el2 return state) on every switch.
30 * tpidr_el0 and tpidrro_el0 only need to be switched when going
31 * to host userspace or a different VCPU. EL1 registers only need to be
32 * switched when potentially going to run a different VCPU. The latter two
33 * classes are handled as part of kvm_arch_vcpu_load and kvm_arch_vcpu_put.
34 */
35
__sysreg_save_common_state(struct kvm_cpu_context * ctxt)36 static void __hyp_text __sysreg_save_common_state(struct kvm_cpu_context *ctxt)
37 {
38 ctxt->sys_regs[MDSCR_EL1] = read_sysreg(mdscr_el1);
39
40 /*
41 * The host arm64 Linux uses sp_el0 to point to 'current' and it must
42 * therefore be saved/restored on every entry/exit to/from the guest.
43 */
44 ctxt->gp_regs.regs.sp = read_sysreg(sp_el0);
45 }
46
__sysreg_save_user_state(struct kvm_cpu_context * ctxt)47 static void __hyp_text __sysreg_save_user_state(struct kvm_cpu_context *ctxt)
48 {
49 ctxt->sys_regs[TPIDR_EL0] = read_sysreg(tpidr_el0);
50 ctxt->sys_regs[TPIDRRO_EL0] = read_sysreg(tpidrro_el0);
51 }
52
__sysreg_save_el1_state(struct kvm_cpu_context * ctxt)53 static void __hyp_text __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
54 {
55 ctxt->sys_regs[MPIDR_EL1] = read_sysreg(vmpidr_el2);
56 ctxt->sys_regs[CSSELR_EL1] = read_sysreg(csselr_el1);
57 ctxt->sys_regs[SCTLR_EL1] = read_sysreg_el1(sctlr);
58 ctxt->sys_regs[ACTLR_EL1] = read_sysreg(actlr_el1);
59 ctxt->sys_regs[CPACR_EL1] = read_sysreg_el1(cpacr);
60 ctxt->sys_regs[TTBR0_EL1] = read_sysreg_el1(ttbr0);
61 ctxt->sys_regs[TTBR1_EL1] = read_sysreg_el1(ttbr1);
62 ctxt->sys_regs[TCR_EL1] = read_sysreg_el1(tcr);
63 ctxt->sys_regs[ESR_EL1] = read_sysreg_el1(esr);
64 ctxt->sys_regs[AFSR0_EL1] = read_sysreg_el1(afsr0);
65 ctxt->sys_regs[AFSR1_EL1] = read_sysreg_el1(afsr1);
66 ctxt->sys_regs[FAR_EL1] = read_sysreg_el1(far);
67 ctxt->sys_regs[MAIR_EL1] = read_sysreg_el1(mair);
68 ctxt->sys_regs[VBAR_EL1] = read_sysreg_el1(vbar);
69 ctxt->sys_regs[CONTEXTIDR_EL1] = read_sysreg_el1(contextidr);
70 ctxt->sys_regs[AMAIR_EL1] = read_sysreg_el1(amair);
71 ctxt->sys_regs[CNTKCTL_EL1] = read_sysreg_el1(cntkctl);
72 ctxt->sys_regs[PAR_EL1] = read_sysreg(par_el1);
73 ctxt->sys_regs[TPIDR_EL1] = read_sysreg(tpidr_el1);
74
75 ctxt->gp_regs.sp_el1 = read_sysreg(sp_el1);
76 ctxt->gp_regs.elr_el1 = read_sysreg_el1(elr);
77 ctxt->gp_regs.spsr[KVM_SPSR_EL1]= read_sysreg_el1(spsr);
78 }
79
__sysreg_save_el2_return_state(struct kvm_cpu_context * ctxt)80 static void __hyp_text __sysreg_save_el2_return_state(struct kvm_cpu_context *ctxt)
81 {
82 ctxt->gp_regs.regs.pc = read_sysreg_el2(elr);
83 ctxt->gp_regs.regs.pstate = read_sysreg_el2(spsr);
84
85 if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN))
86 ctxt->sys_regs[DISR_EL1] = read_sysreg_s(SYS_VDISR_EL2);
87 }
88
__sysreg_save_state_nvhe(struct kvm_cpu_context * ctxt)89 void __hyp_text __sysreg_save_state_nvhe(struct kvm_cpu_context *ctxt)
90 {
91 __sysreg_save_el1_state(ctxt);
92 __sysreg_save_common_state(ctxt);
93 __sysreg_save_user_state(ctxt);
94 __sysreg_save_el2_return_state(ctxt);
95 }
96
sysreg_save_host_state_vhe(struct kvm_cpu_context * ctxt)97 void sysreg_save_host_state_vhe(struct kvm_cpu_context *ctxt)
98 {
99 __sysreg_save_common_state(ctxt);
100 }
101
sysreg_save_guest_state_vhe(struct kvm_cpu_context * ctxt)102 void sysreg_save_guest_state_vhe(struct kvm_cpu_context *ctxt)
103 {
104 __sysreg_save_common_state(ctxt);
105 __sysreg_save_el2_return_state(ctxt);
106 }
107
__sysreg_restore_common_state(struct kvm_cpu_context * ctxt)108 static void __hyp_text __sysreg_restore_common_state(struct kvm_cpu_context *ctxt)
109 {
110 write_sysreg(ctxt->sys_regs[MDSCR_EL1], mdscr_el1);
111
112 /*
113 * The host arm64 Linux uses sp_el0 to point to 'current' and it must
114 * therefore be saved/restored on every entry/exit to/from the guest.
115 */
116 write_sysreg(ctxt->gp_regs.regs.sp, sp_el0);
117 }
118
__sysreg_restore_user_state(struct kvm_cpu_context * ctxt)119 static void __hyp_text __sysreg_restore_user_state(struct kvm_cpu_context *ctxt)
120 {
121 write_sysreg(ctxt->sys_regs[TPIDR_EL0], tpidr_el0);
122 write_sysreg(ctxt->sys_regs[TPIDRRO_EL0], tpidrro_el0);
123 }
124
__sysreg_restore_el1_state(struct kvm_cpu_context * ctxt)125 static void __hyp_text __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
126 {
127 write_sysreg(ctxt->sys_regs[MPIDR_EL1], vmpidr_el2);
128 write_sysreg(ctxt->sys_regs[CSSELR_EL1], csselr_el1);
129 write_sysreg_el1(ctxt->sys_regs[SCTLR_EL1], sctlr);
130 write_sysreg(ctxt->sys_regs[ACTLR_EL1], actlr_el1);
131 write_sysreg_el1(ctxt->sys_regs[CPACR_EL1], cpacr);
132 write_sysreg_el1(ctxt->sys_regs[TTBR0_EL1], ttbr0);
133 write_sysreg_el1(ctxt->sys_regs[TTBR1_EL1], ttbr1);
134 write_sysreg_el1(ctxt->sys_regs[TCR_EL1], tcr);
135 write_sysreg_el1(ctxt->sys_regs[ESR_EL1], esr);
136 write_sysreg_el1(ctxt->sys_regs[AFSR0_EL1], afsr0);
137 write_sysreg_el1(ctxt->sys_regs[AFSR1_EL1], afsr1);
138 write_sysreg_el1(ctxt->sys_regs[FAR_EL1], far);
139 write_sysreg_el1(ctxt->sys_regs[MAIR_EL1], mair);
140 write_sysreg_el1(ctxt->sys_regs[VBAR_EL1], vbar);
141 write_sysreg_el1(ctxt->sys_regs[CONTEXTIDR_EL1],contextidr);
142 write_sysreg_el1(ctxt->sys_regs[AMAIR_EL1], amair);
143 write_sysreg_el1(ctxt->sys_regs[CNTKCTL_EL1], cntkctl);
144 write_sysreg(ctxt->sys_regs[PAR_EL1], par_el1);
145 write_sysreg(ctxt->sys_regs[TPIDR_EL1], tpidr_el1);
146
147 write_sysreg(ctxt->gp_regs.sp_el1, sp_el1);
148 write_sysreg_el1(ctxt->gp_regs.elr_el1, elr);
149 write_sysreg_el1(ctxt->gp_regs.spsr[KVM_SPSR_EL1],spsr);
150 }
151
152 static void __hyp_text
__sysreg_restore_el2_return_state(struct kvm_cpu_context * ctxt)153 __sysreg_restore_el2_return_state(struct kvm_cpu_context *ctxt)
154 {
155 write_sysreg_el2(ctxt->gp_regs.regs.pc, elr);
156 write_sysreg_el2(ctxt->gp_regs.regs.pstate, spsr);
157
158 if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN))
159 write_sysreg_s(ctxt->sys_regs[DISR_EL1], SYS_VDISR_EL2);
160 }
161
__sysreg_restore_state_nvhe(struct kvm_cpu_context * ctxt)162 void __hyp_text __sysreg_restore_state_nvhe(struct kvm_cpu_context *ctxt)
163 {
164 __sysreg_restore_el1_state(ctxt);
165 __sysreg_restore_common_state(ctxt);
166 __sysreg_restore_user_state(ctxt);
167 __sysreg_restore_el2_return_state(ctxt);
168 }
169
sysreg_restore_host_state_vhe(struct kvm_cpu_context * ctxt)170 void sysreg_restore_host_state_vhe(struct kvm_cpu_context *ctxt)
171 {
172 __sysreg_restore_common_state(ctxt);
173 }
174
sysreg_restore_guest_state_vhe(struct kvm_cpu_context * ctxt)175 void sysreg_restore_guest_state_vhe(struct kvm_cpu_context *ctxt)
176 {
177 __sysreg_restore_common_state(ctxt);
178 __sysreg_restore_el2_return_state(ctxt);
179 }
180
__sysreg32_save_state(struct kvm_vcpu * vcpu)181 void __hyp_text __sysreg32_save_state(struct kvm_vcpu *vcpu)
182 {
183 u64 *spsr, *sysreg;
184
185 if (!vcpu_el1_is_32bit(vcpu))
186 return;
187
188 spsr = vcpu->arch.ctxt.gp_regs.spsr;
189 sysreg = vcpu->arch.ctxt.sys_regs;
190
191 spsr[KVM_SPSR_ABT] = read_sysreg(spsr_abt);
192 spsr[KVM_SPSR_UND] = read_sysreg(spsr_und);
193 spsr[KVM_SPSR_IRQ] = read_sysreg(spsr_irq);
194 spsr[KVM_SPSR_FIQ] = read_sysreg(spsr_fiq);
195
196 sysreg[DACR32_EL2] = read_sysreg(dacr32_el2);
197 sysreg[IFSR32_EL2] = read_sysreg(ifsr32_el2);
198
199 if (has_vhe() || vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY)
200 sysreg[DBGVCR32_EL2] = read_sysreg(dbgvcr32_el2);
201 }
202
__sysreg32_restore_state(struct kvm_vcpu * vcpu)203 void __hyp_text __sysreg32_restore_state(struct kvm_vcpu *vcpu)
204 {
205 u64 *spsr, *sysreg;
206
207 if (!vcpu_el1_is_32bit(vcpu))
208 return;
209
210 spsr = vcpu->arch.ctxt.gp_regs.spsr;
211 sysreg = vcpu->arch.ctxt.sys_regs;
212
213 write_sysreg(spsr[KVM_SPSR_ABT], spsr_abt);
214 write_sysreg(spsr[KVM_SPSR_UND], spsr_und);
215 write_sysreg(spsr[KVM_SPSR_IRQ], spsr_irq);
216 write_sysreg(spsr[KVM_SPSR_FIQ], spsr_fiq);
217
218 write_sysreg(sysreg[DACR32_EL2], dacr32_el2);
219 write_sysreg(sysreg[IFSR32_EL2], ifsr32_el2);
220
221 if (has_vhe() || vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY)
222 write_sysreg(sysreg[DBGVCR32_EL2], dbgvcr32_el2);
223 }
224
225 /**
226 * kvm_vcpu_load_sysregs - Load guest system registers to the physical CPU
227 *
228 * @vcpu: The VCPU pointer
229 *
230 * Load system registers that do not affect the host's execution, for
231 * example EL1 system registers on a VHE system where the host kernel
232 * runs at EL2. This function is called from KVM's vcpu_load() function
233 * and loading system register state early avoids having to load them on
234 * every entry to the VM.
235 */
kvm_vcpu_load_sysregs(struct kvm_vcpu * vcpu)236 void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu)
237 {
238 struct kvm_cpu_context *host_ctxt = vcpu->arch.host_cpu_context;
239 struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt;
240
241 if (!has_vhe())
242 return;
243
244 __sysreg_save_user_state(host_ctxt);
245
246 /*
247 * Load guest EL1 and user state
248 *
249 * We must restore the 32-bit state before the sysregs, thanks
250 * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72).
251 */
252 __sysreg32_restore_state(vcpu);
253 __sysreg_restore_user_state(guest_ctxt);
254 __sysreg_restore_el1_state(guest_ctxt);
255
256 vcpu->arch.sysregs_loaded_on_cpu = true;
257
258 activate_traps_vhe_load(vcpu);
259 }
260
261 /**
262 * kvm_vcpu_put_sysregs - Restore host system registers to the physical CPU
263 *
264 * @vcpu: The VCPU pointer
265 *
266 * Save guest system registers that do not affect the host's execution, for
267 * example EL1 system registers on a VHE system where the host kernel
268 * runs at EL2. This function is called from KVM's vcpu_put() function
269 * and deferring saving system register state until we're no longer running the
270 * VCPU avoids having to save them on every exit from the VM.
271 */
kvm_vcpu_put_sysregs(struct kvm_vcpu * vcpu)272 void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu)
273 {
274 struct kvm_cpu_context *host_ctxt = vcpu->arch.host_cpu_context;
275 struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt;
276
277 if (!has_vhe())
278 return;
279
280 deactivate_traps_vhe_put();
281
282 __sysreg_save_el1_state(guest_ctxt);
283 __sysreg_save_user_state(guest_ctxt);
284 __sysreg32_save_state(vcpu);
285
286 /* Restore host user state */
287 __sysreg_restore_user_state(host_ctxt);
288
289 vcpu->arch.sysregs_loaded_on_cpu = false;
290 }
291
