xref: /linux/arch/arm64/kvm/hyp/vhe/switch.c (revision 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d)
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/switch.h>
8 
9 #include <linux/arm-smccc.h>
10 #include <linux/kvm_host.h>
11 #include <linux/types.h>
12 #include <linux/jump_label.h>
13 #include <linux/percpu.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 #include <asm/vectors.h>
30 
31 /* VHE specific context */
32 DEFINE_PER_CPU(struct kvm_host_data, kvm_host_data);
33 DEFINE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt);
34 DEFINE_PER_CPU(unsigned long, kvm_hyp_vector);
35 
36 /*
37  * HCR_EL2 bits that the NV guest can freely change (no RES0/RES1
38  * semantics, irrespective of the configuration), but that cannot be
39  * applied to the actual HW as things would otherwise break badly.
40  *
41  * - TGE: we want the guest to use EL1, which is incompatible with
42  *   this bit being set
43  *
44  * - API/APK: they are already accounted for by vcpu_load(), and can
45  *   only take effect across a load/put cycle (such as ERET)
46  *
47  * - FIEN: no way we let a guest have access to the RAS "Common Fault
48  *   Injection" thing, whatever that does
49  */
50 #define NV_HCR_GUEST_EXCLUDE	(HCR_TGE | HCR_API | HCR_APK | HCR_FIEN)
51 
52 static u64 __compute_hcr(struct kvm_vcpu *vcpu)
53 {
54 	u64 guest_hcr, hcr = vcpu->arch.hcr_el2;
55 
56 	if (!vcpu_has_nv(vcpu))
57 		return hcr;
58 
59 	/*
60 	 * We rely on the invariant that a vcpu entered from HYP
61 	 * context must also exit in the same context, as only an ERET
62 	 * instruction can kick us out of it, and we obviously trap
63 	 * that sucker. PSTATE.M will get fixed-up on exit.
64 	 */
65 	if (is_hyp_ctxt(vcpu)) {
66 		host_data_set_flag(VCPU_IN_HYP_CONTEXT);
67 
68 		hcr |= HCR_NV | HCR_NV2 | HCR_AT | HCR_TTLB;
69 
70 		if (!vcpu_el2_e2h_is_set(vcpu))
71 			hcr |= HCR_NV1;
72 
73 		/* Publish the guest's view of HCR_EL2 to the HW */
74 		if (cpus_have_final_cap(ARM64_HAS_NV3) && vcpu_el2_e2h_is_set(vcpu))
75 			write_sysreg_s(__vcpu_sys_reg(vcpu, HCR_EL2), SYS_NVHCR_EL2);
76 		else
77 			__vcpu_assign_sys_reg(vcpu, NVHCR_EL2, __vcpu_sys_reg(vcpu, HCR_EL2));
78 
79 		/*
80 		 * Nothing in HCR_EL2 should impact running in hypervisor
81 		 * context, apart from bits we have defined as RESx (E2H,
82 		 * HCD and co), or that cannot be set directly (the EXCLUDE
83 		 * bits). Given that we OR the guest's view with the host's,
84 		 * we can use the 0 value as the starting point, and only
85 		 * use the config-driven RES1 bits.
86 		 */
87 		guest_hcr = kvm_vcpu_apply_reg_masks(vcpu, HCR_EL2, 0);
88 
89 		write_sysreg_s(vcpu->arch.ctxt.vncr_array, SYS_VNCR_EL2);
90 	} else {
91 		host_data_clear_flag(VCPU_IN_HYP_CONTEXT);
92 
93 		guest_hcr = __vcpu_sys_reg(vcpu, HCR_EL2);
94 		if (guest_hcr & HCR_NV) {
95 			u64 va = __fix_to_virt(vncr_fixmap(smp_processor_id()));
96 
97 			/* Inherit the low bits from the actual register */
98 			va |= __vcpu_sys_reg(vcpu, VNCR_EL2) & GENMASK(PAGE_SHIFT - 1, 0);
99 			write_sysreg_s(va, SYS_VNCR_EL2);
100 
101 			/* Force NV2 in case the guest is forgetful... */
102 			guest_hcr |= HCR_NV2;
103 		}
104 
105 		/*
106 		 * Exclude the guest's TWED configuration if it hasn't set TWE
107 		 * to avoid potentially delaying traps for the host.
108 		 */
109 		if (!(guest_hcr & HCR_TWE))
110 			guest_hcr &= ~(HCR_EL2_TWEDEn | HCR_EL2_TWEDEL);
111 	}
112 
113 	BUG_ON(host_data_test_flag(VCPU_IN_HYP_CONTEXT) &&
114 	       host_data_test_flag(L1_VNCR_MAPPED));
115 
116 	return hcr | (guest_hcr & ~NV_HCR_GUEST_EXCLUDE);
117 }
118 
119 static void __activate_traps(struct kvm_vcpu *vcpu)
120 {
121 	u64 val;
122 
123 	___activate_traps(vcpu, __compute_hcr(vcpu));
124 
125 	if (has_cntpoff()) {
126 		struct timer_map map;
127 
128 		get_timer_map(vcpu, &map);
129 
130 		/*
131 		 * We're entrering the guest. Reload the correct
132 		 * values from memory now that TGE is clear.
133 		 */
134 		if (map.direct_ptimer == vcpu_ptimer(vcpu))
135 			val = __vcpu_sys_reg(vcpu, CNTP_CVAL_EL0);
136 		if (map.direct_ptimer == vcpu_hptimer(vcpu))
137 			val = __vcpu_sys_reg(vcpu, CNTHP_CVAL_EL2);
138 
139 		if (map.direct_ptimer) {
140 			write_sysreg_el0(val, SYS_CNTP_CVAL);
141 			isb();
142 		}
143 	}
144 
145 	__activate_cptr_traps(vcpu);
146 
147 	write_sysreg(__this_cpu_read(kvm_hyp_vector), vbar_el1);
148 }
149 NOKPROBE_SYMBOL(__activate_traps);
150 
151 static void __deactivate_traps(struct kvm_vcpu *vcpu)
152 {
153 	const char *host_vectors = vectors;
154 
155 	___deactivate_traps(vcpu);
156 
157 	write_sysreg_hcr(HCR_HOST_VHE_FLAGS);
158 
159 	if (has_cntpoff()) {
160 		struct timer_map map;
161 		u64 val, offset;
162 
163 		get_timer_map(vcpu, &map);
164 
165 		/*
166 		 * We're exiting the guest. Save the latest CVAL value
167 		 * to memory and apply the offset now that TGE is set.
168 		 */
169 		val = read_sysreg_el0(SYS_CNTP_CVAL);
170 		if (map.direct_ptimer == vcpu_ptimer(vcpu))
171 			__vcpu_assign_sys_reg(vcpu, CNTP_CVAL_EL0, val);
172 		if (map.direct_ptimer == vcpu_hptimer(vcpu))
173 			__vcpu_assign_sys_reg(vcpu, CNTHP_CVAL_EL2, val);
174 
175 		offset = read_sysreg_s(SYS_CNTPOFF_EL2);
176 
177 		if (map.direct_ptimer && offset) {
178 			write_sysreg_el0(val + offset, SYS_CNTP_CVAL);
179 			isb();
180 		}
181 	}
182 
183 	/*
184 	 * ARM errata 1165522 and 1530923 require the actual execution of the
185 	 * above before we can switch to the EL2/EL0 translation regime used by
186 	 * the host.
187 	 */
188 	asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_SPECULATIVE_AT));
189 
190 	__deactivate_cptr_traps(vcpu);
191 
192 	if (!arm64_kernel_unmapped_at_el0())
193 		host_vectors = __this_cpu_read(this_cpu_vector);
194 	write_sysreg(host_vectors, vbar_el1);
195 }
196 NOKPROBE_SYMBOL(__deactivate_traps);
197 
198 /*
199  * Disable IRQs in __vcpu_{load,put}_{activate,deactivate}_traps() to
200  * prevent a race condition between context switching of PMUSERENR_EL0
201  * in __{activate,deactivate}_traps_common() and IPIs that attempts to
202  * update PMUSERENR_EL0. See also kvm_set_pmuserenr().
203  */
204 static void __vcpu_load_activate_traps(struct kvm_vcpu *vcpu)
205 {
206 	unsigned long flags;
207 
208 	local_irq_save(flags);
209 	__activate_traps_common(vcpu);
210 	local_irq_restore(flags);
211 }
212 
213 static void __vcpu_put_deactivate_traps(struct kvm_vcpu *vcpu)
214 {
215 	unsigned long flags;
216 
217 	local_irq_save(flags);
218 	__deactivate_traps_common(vcpu);
219 	local_irq_restore(flags);
220 }
221 
222 void kvm_vcpu_load_vhe(struct kvm_vcpu *vcpu)
223 {
224 	host_data_ptr(host_ctxt)->__hyp_running_vcpu = vcpu;
225 
226 	__vcpu_load_switch_sysregs(vcpu);
227 	__vcpu_load_activate_traps(vcpu);
228 	__load_stage2(vcpu->arch.hw_mmu);
229 }
230 
231 void kvm_vcpu_put_vhe(struct kvm_vcpu *vcpu)
232 {
233 	__vcpu_put_deactivate_traps(vcpu);
234 	__vcpu_put_switch_sysregs(vcpu);
235 
236 	host_data_ptr(host_ctxt)->__hyp_running_vcpu = NULL;
237 }
238 
239 static u64 compute_emulated_cntx_ctl_el0(struct kvm_vcpu *vcpu,
240 					 enum vcpu_sysreg reg)
241 {
242 	unsigned long ctl;
243 	u64 cval, cnt;
244 	bool stat;
245 
246 	switch (reg) {
247 	case CNTP_CTL_EL0:
248 		cval = __vcpu_sys_reg(vcpu, CNTP_CVAL_EL0);
249 		ctl  = __vcpu_sys_reg(vcpu, CNTP_CTL_EL0);
250 		cnt  = compute_counter_value(vcpu_ptimer(vcpu));
251 		break;
252 	case CNTV_CTL_EL0:
253 		cval = __vcpu_sys_reg(vcpu, CNTV_CVAL_EL0);
254 		ctl  = __vcpu_sys_reg(vcpu, CNTV_CTL_EL0);
255 		cnt  = compute_counter_value(vcpu_vtimer(vcpu));
256 		break;
257 	default:
258 		BUG();
259 	}
260 
261 	stat = cval <= cnt;
262 	__assign_bit(__ffs(ARCH_TIMER_CTRL_IT_STAT), &ctl, stat);
263 
264 	return ctl;
265 }
266 
267 static bool kvm_hyp_handle_timer(struct kvm_vcpu *vcpu, u64 *exit_code)
268 {
269 	u64 esr, val;
270 
271 	/*
272 	 * Having FEAT_ECV allows for a better quality of timer emulation.
273 	 * However, this comes at a huge cost in terms of traps. Try and
274 	 * satisfy the reads from guest's hypervisor context without
275 	 * returning to the kernel if we can.
276 	 */
277 	if (!is_hyp_ctxt(vcpu))
278 		return false;
279 
280 	esr = kvm_vcpu_get_esr(vcpu);
281 	if ((esr & ESR_ELx_SYS64_ISS_DIR_MASK) != ESR_ELx_SYS64_ISS_DIR_READ)
282 		return false;
283 
284 	switch (esr_sys64_to_sysreg(esr)) {
285 	case SYS_CNTP_CTL_EL02:
286 		val = compute_emulated_cntx_ctl_el0(vcpu, CNTP_CTL_EL0);
287 		break;
288 	case SYS_CNTP_CTL_EL0:
289 		if (vcpu_el2_e2h_is_set(vcpu))
290 			val = read_sysreg_el0(SYS_CNTP_CTL);
291 		else
292 			val = compute_emulated_cntx_ctl_el0(vcpu, CNTP_CTL_EL0);
293 		break;
294 	case SYS_CNTP_CVAL_EL02:
295 		val = __vcpu_sys_reg(vcpu, CNTP_CVAL_EL0);
296 		break;
297 	case SYS_CNTP_CVAL_EL0:
298 		if (vcpu_el2_e2h_is_set(vcpu)) {
299 			val = read_sysreg_el0(SYS_CNTP_CVAL);
300 
301 			if (!has_cntpoff())
302 				val -= timer_get_offset(vcpu_hptimer(vcpu));
303 		} else {
304 			val = __vcpu_sys_reg(vcpu, CNTP_CVAL_EL0);
305 		}
306 		break;
307 	case SYS_CNTPCT_EL0:
308 	case SYS_CNTPCTSS_EL0:
309 		val = compute_counter_value(vcpu_hptimer(vcpu));
310 		break;
311 	case SYS_CNTV_CTL_EL02:
312 		val = compute_emulated_cntx_ctl_el0(vcpu, CNTV_CTL_EL0);
313 		break;
314 	case SYS_CNTV_CTL_EL0:
315 		if (vcpu_el2_e2h_is_set(vcpu))
316 			val = read_sysreg_el0(SYS_CNTV_CTL);
317 		else
318 			val = compute_emulated_cntx_ctl_el0(vcpu, CNTV_CTL_EL0);
319 		break;
320 	case SYS_CNTV_CVAL_EL02:
321 		val = __vcpu_sys_reg(vcpu, CNTV_CVAL_EL0);
322 		break;
323 	case SYS_CNTV_CVAL_EL0:
324 		if (vcpu_el2_e2h_is_set(vcpu))
325 			val = read_sysreg_el0(SYS_CNTV_CVAL);
326 		else
327 			val = __vcpu_sys_reg(vcpu, CNTV_CVAL_EL0);
328 		break;
329 	case SYS_CNTVCT_EL0:
330 	case SYS_CNTVCTSS_EL0:
331 		val = compute_counter_value(vcpu_hvtimer(vcpu));
332 		break;
333 	default:
334 		return false;
335 	}
336 
337 	vcpu_set_reg(vcpu, kvm_vcpu_sys_get_rt(vcpu), val);
338 	__kvm_skip_instr(vcpu);
339 
340 	return true;
341 }
342 
343 static bool kvm_hyp_handle_eret(struct kvm_vcpu *vcpu, u64 *exit_code)
344 {
345 	u64 esr = kvm_vcpu_get_esr(vcpu);
346 	u64 spsr, elr, mode;
347 
348 	/* With NV3, the fast path is handled in HW */
349 	if (cpus_have_final_cap(ARM64_HAS_NV3) && vcpu_el2_e2h_is_set(vcpu))
350 		return false;
351 
352 	/*
353 	 * Going through the whole put/load motions is a waste of time
354 	 * if this is a VHE guest hypervisor returning to its own
355 	 * userspace, or the hypervisor performing a local exception
356 	 * return. No need to save/restore registers, no need to
357 	 * switch S2 MMU. Just do the canonical ERET unless we are in
358 	 * nested context.
359 	 *
360 	 * Note that this is made possible because KVM itself never traps
361 	 * ERET when running an L2. The consequence is that any ERET trap is
362 	 * the result of HCR_EL2 or HFGITR_EL2 programming by L1 for its own
363 	 * guest, and the exception must be forwarded to L1.
364 	 */
365 	if (is_nested_ctxt(vcpu))
366 		return false;
367 
368 	spsr = read_sysreg_el1(SYS_SPSR);
369 	mode = spsr & (PSR_MODE_MASK | PSR_MODE32_BIT);
370 
371 	switch (mode) {
372 	case PSR_MODE_EL0t:
373 		if (!(vcpu_el2_e2h_is_set(vcpu) && vcpu_el2_tge_is_set(vcpu)))
374 			return false;
375 		break;
376 	case PSR_MODE_EL2t:
377 		mode = PSR_MODE_EL1t;
378 		break;
379 	case PSR_MODE_EL2h:
380 		mode = PSR_MODE_EL1h;
381 		break;
382 	default:
383 		return false;
384 	}
385 
386 	/* If ERETAx fails, take the slow path */
387 	if (esr_iss_is_eretax(esr)) {
388 		if (!(vcpu_has_ptrauth(vcpu) && kvm_auth_eretax(vcpu, &elr)))
389 			return false;
390 	} else {
391 		elr = read_sysreg_el1(SYS_ELR);
392 	}
393 
394 	spsr = (spsr & ~(PSR_MODE_MASK | PSR_MODE32_BIT)) | mode;
395 
396 	write_sysreg_el2(spsr, SYS_SPSR);
397 	write_sysreg_el2(elr, SYS_ELR);
398 
399 	return true;
400 }
401 
402 static bool kvm_hyp_handle_tlbi_el2(struct kvm_vcpu *vcpu, u64 *exit_code)
403 {
404 	int ret = -EINVAL;
405 	u32 instr;
406 	u64 val;
407 
408 	/*
409 	 * Ideally, we would never trap on EL2 S1 TLB invalidations using
410 	 * the EL1 instructions when the guest's HCR_EL2.{E2H,TGE}=={1,1}.
411 	 * But "thanks" to FEAT_NV2, we don't trap writes to HCR_EL2,
412 	 * meaning that we can't track changes to the virtual TGE bit. So we
413 	 * have to leave HCR_EL2.TTLB set on the host. Oopsie...
414 	 *
415 	 * Try and handle these invalidation as quickly as possible, without
416 	 * fully exiting. Note that we don't need to consider any forwarding
417 	 * here, as having E2H+TGE set is the very definition of being
418 	 * InHost.
419 	 *
420 	 * For the lesser hypervisors out there that have failed to get on
421 	 * with the VHE program, we can also handle the nVHE style of EL2
422 	 * invalidation.
423 	 */
424 	if (!(is_hyp_ctxt(vcpu)))
425 		return false;
426 
427 	instr = esr_sys64_to_sysreg(kvm_vcpu_get_esr(vcpu));
428 	val = vcpu_get_reg(vcpu, kvm_vcpu_sys_get_rt(vcpu));
429 
430 	if ((kvm_supported_tlbi_s1e1_op(vcpu, instr) &&
431 	     vcpu_el2_e2h_is_set(vcpu) && vcpu_el2_tge_is_set(vcpu)) ||
432 	    kvm_supported_tlbi_s1e2_op (vcpu, instr))
433 		ret = __kvm_tlbi_s1e2(NULL, val, instr);
434 
435 	if (ret)
436 		return false;
437 
438 	/*
439 	 * If we have to check for any VNCR TLB being invalidated, go back
440 	 * to the slow path for further processing.
441 	 *
442 	 * The synchronisation betweem TLBI and walk is provided by the
443 	 * speculative increment of the TLB counter on walk, and the
444 	 * invalidation counter. Yes, this is fiddly.
445 	 */
446 	if (vcpu_el2_e2h_is_set(vcpu) && vcpu_el2_tge_is_set(vcpu) &&
447 	    atomic_read(&vcpu->kvm->arch.vncr_tlb_count))
448 		return false;
449 
450 	__kvm_skip_instr(vcpu);
451 
452 	return true;
453 }
454 
455 static bool kvm_hyp_handle_cpacr_el1(struct kvm_vcpu *vcpu, u64 *exit_code)
456 {
457 	u64 esr = kvm_vcpu_get_esr(vcpu);
458 	int rt;
459 
460 	if (cpus_have_final_cap(ARM64_HAS_NV2P1))
461 		return false;
462 
463 	if (!is_hyp_ctxt(vcpu) || esr_sys64_to_sysreg(esr) != SYS_CPACR_EL1)
464 		return false;
465 
466 	rt = kvm_vcpu_sys_get_rt(vcpu);
467 
468 	if ((esr & ESR_ELx_SYS64_ISS_DIR_MASK) == ESR_ELx_SYS64_ISS_DIR_READ) {
469 		vcpu_set_reg(vcpu, rt, __vcpu_sys_reg(vcpu, CPTR_EL2));
470 	} else {
471 		vcpu_write_sys_reg(vcpu, vcpu_get_reg(vcpu, rt), CPTR_EL2);
472 		__activate_cptr_traps(vcpu);
473 	}
474 
475 	__kvm_skip_instr(vcpu);
476 
477 	return true;
478 }
479 
480 static bool kvm_hyp_handle_zcr_el2(struct kvm_vcpu *vcpu, u64 *exit_code)
481 {
482 	u32 sysreg = esr_sys64_to_sysreg(kvm_vcpu_get_esr(vcpu));
483 
484 	if (!vcpu_has_nv(vcpu))
485 		return false;
486 
487 	if (sysreg != SYS_ZCR_EL2)
488 		return false;
489 
490 	if (guest_owns_fp_regs())
491 		return false;
492 
493 	/*
494 	 * ZCR_EL2 traps are handled in the slow path, with the expectation
495 	 * that the guest's FP context has already been loaded onto the CPU.
496 	 *
497 	 * Load the guest's FP context and unconditionally forward to the
498 	 * slow path for handling (i.e. return false).
499 	 */
500 	kvm_hyp_handle_fpsimd(vcpu, exit_code);
501 	return false;
502 }
503 
504 static bool kvm_hyp_handle_sysreg_vhe(struct kvm_vcpu *vcpu, u64 *exit_code)
505 {
506 	if (kvm_hyp_handle_tlbi_el2(vcpu, exit_code))
507 		return true;
508 
509 	if (kvm_hyp_handle_timer(vcpu, exit_code))
510 		return true;
511 
512 	if (kvm_hyp_handle_cpacr_el1(vcpu, exit_code))
513 		return true;
514 
515 	if (kvm_hyp_handle_zcr_el2(vcpu, exit_code))
516 		return true;
517 
518 	return kvm_hyp_handle_sysreg(vcpu, exit_code);
519 }
520 
521 static bool kvm_hyp_handle_impdef(struct kvm_vcpu *vcpu, u64 *exit_code)
522 {
523 	u64 iss;
524 
525 	if (!cpus_have_final_cap(ARM64_WORKAROUND_PMUV3_IMPDEF_TRAPS))
526 		return false;
527 
528 	/*
529 	 * Compute a synthetic ESR for a sysreg trap. Conveniently, AFSR1_EL2
530 	 * is populated with a correct ISS for a sysreg trap. These fruity
531 	 * parts are 64bit only, so unconditionally set IL.
532 	 */
533 	iss = ESR_ELx_ISS(read_sysreg_s(SYS_AFSR1_EL2));
534 	vcpu->arch.fault.esr_el2 = FIELD_PREP(ESR_ELx_EC_MASK, ESR_ELx_EC_SYS64) |
535 				   FIELD_PREP(ESR_ELx_ISS_MASK, iss) |
536 				   ESR_ELx_IL;
537 	return false;
538 }
539 
540 static const exit_handler_fn hyp_exit_handlers[] = {
541 	[0 ... ESR_ELx_EC_MAX]		= NULL,
542 	[ESR_ELx_EC_CP15_32]		= kvm_hyp_handle_cp15_32,
543 	[ESR_ELx_EC_SYS64]		= kvm_hyp_handle_sysreg_vhe,
544 	[ESR_ELx_EC_SVE]		= kvm_hyp_handle_fpsimd,
545 	[ESR_ELx_EC_FP_ASIMD]		= kvm_hyp_handle_fpsimd,
546 	[ESR_ELx_EC_IABT_LOW]		= kvm_hyp_handle_iabt_low,
547 	[ESR_ELx_EC_DABT_LOW]		= kvm_hyp_handle_dabt_low,
548 	[ESR_ELx_EC_WATCHPT_LOW]	= kvm_hyp_handle_watchpt_low,
549 	[ESR_ELx_EC_ERET]		= kvm_hyp_handle_eret,
550 	[ESR_ELx_EC_MOPS]		= kvm_hyp_handle_mops,
551 
552 	/* Apple shenanigans */
553 	[0x3F]				= kvm_hyp_handle_impdef,
554 };
555 
556 static void fixup_nv_guest_exit(struct kvm_vcpu *vcpu)
557 {
558 	/*
559 	 * If we were in HYP context on entry, adjust the PSTATE view
560 	 * so that the usual helpers work correctly. This enforces our
561 	 * invariant that the guest's HYP context status is preserved
562 	 * across a run.
563 	 */
564 	if (unlikely(host_data_test_flag(VCPU_IN_HYP_CONTEXT))) {
565 		u64 mode = *vcpu_cpsr(vcpu) & (PSR_MODE_MASK | PSR_MODE32_BIT);
566 		u64 hcr;
567 
568 		switch (mode) {
569 		case PSR_MODE_EL1t:
570 			mode = PSR_MODE_EL2t;
571 			break;
572 		case PSR_MODE_EL1h:
573 			mode = PSR_MODE_EL2h;
574 			break;
575 		}
576 
577 		*vcpu_cpsr(vcpu) &= ~(PSR_MODE_MASK | PSR_MODE32_BIT);
578 		*vcpu_cpsr(vcpu) |= mode;
579 
580 		/* Publish the latest HCR_EL2 to the emulation */
581 		hcr = (cpus_have_final_cap(ARM64_HAS_NV3) &&
582 		       vcpu_el2_e2h_is_set(vcpu)) ?
583 			read_sysreg_s(SYS_NVHCR_EL2) :
584 			__vcpu_sys_reg(vcpu, NVHCR_EL2);
585 
586 		__vcpu_assign_sys_reg(vcpu, HCR_EL2, hcr);
587 	}
588 
589 	/* Apply extreme paranoia! */
590 	BUG_ON(!!host_data_test_flag(VCPU_IN_HYP_CONTEXT) != is_hyp_ctxt(vcpu));
591 }
592 
593 static bool fixup_guest_exit(struct kvm_vcpu *vcpu, u64 *exit_code)
594 {
595 	synchronize_vcpu_pstate(vcpu);
596 
597 	if (vcpu_has_nv(vcpu))
598 		fixup_nv_guest_exit(vcpu);
599 
600 	return __fixup_guest_exit(vcpu, exit_code, hyp_exit_handlers);
601 }
602 
603 /* Switch to the guest for VHE systems running in EL2 */
604 static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
605 {
606 	struct kvm_cpu_context *host_ctxt;
607 	struct kvm_cpu_context *guest_ctxt;
608 	u64 exit_code;
609 
610 	host_ctxt = host_data_ptr(host_ctxt);
611 	guest_ctxt = &vcpu->arch.ctxt;
612 
613 	fpsimd_lazy_switch_to_guest(vcpu);
614 
615 	sysreg_save_host_state_vhe(host_ctxt);
616 
617 	/*
618 	 * Note that ARM erratum 1165522 requires us to configure both stage 1
619 	 * and stage 2 translation for the guest context before we clear
620 	 * HCR_EL2.TGE. The stage 1 and stage 2 guest context has already been
621 	 * loaded on the CPU in kvm_vcpu_load_vhe().
622 	 */
623 	__activate_traps(vcpu);
624 
625 	__kvm_adjust_pc(vcpu);
626 
627 	sysreg_restore_guest_state_vhe(guest_ctxt);
628 	__debug_switch_to_guest(vcpu);
629 
630 	do {
631 		/* Jump in the fire! */
632 		exit_code = __guest_enter(vcpu);
633 
634 		/* And we're baaack! */
635 	} while (fixup_guest_exit(vcpu, &exit_code));
636 
637 	sysreg_save_guest_state_vhe(guest_ctxt);
638 
639 	__deactivate_traps(vcpu);
640 
641 	sysreg_restore_host_state_vhe(host_ctxt);
642 
643 	__debug_switch_to_host(vcpu);
644 
645 	/*
646 	 * Ensure that all system register writes above have taken effect
647 	 * before returning to the host. In VHE mode, CPTR traps for
648 	 * FPSIMD/SVE/SME also apply to EL2, so FPSIMD/SVE/SME state must be
649 	 * manipulated after the ISB.
650 	 */
651 	isb();
652 
653 	fpsimd_lazy_switch_to_host(vcpu);
654 
655 	if (guest_owns_fp_regs())
656 		__fpsimd_save_fpexc32(vcpu);
657 
658 	return exit_code;
659 }
660 NOKPROBE_SYMBOL(__kvm_vcpu_run_vhe);
661 
662 int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
663 {
664 	int ret;
665 
666 	local_daif_mask();
667 
668 	/*
669 	 * Having IRQs masked via PMR when entering the guest means the GIC
670 	 * will not signal the CPU of interrupts of lower priority, and the
671 	 * only way to get out will be via guest exceptions.
672 	 * Naturally, we want to avoid this.
673 	 *
674 	 * local_daif_mask() already sets GIC_PRIO_PSR_I_SET, we just need a
675 	 * dsb to ensure the redistributor is forwards EL2 IRQs to the CPU.
676 	 */
677 	pmr_sync();
678 
679 	ret = __kvm_vcpu_run_vhe(vcpu);
680 
681 	/*
682 	 * local_daif_restore() takes care to properly restore PSTATE.DAIF
683 	 * and the GIC PMR if the host is using IRQ priorities.
684 	 */
685 	local_daif_restore(DAIF_PROCCTX_NOIRQ);
686 
687 	return ret;
688 }
689 
690 static void __noreturn __hyp_call_panic(u64 spsr, u64 elr, u64 par)
691 {
692 	struct kvm_cpu_context *host_ctxt;
693 	struct kvm_vcpu *vcpu;
694 
695 	host_ctxt = host_data_ptr(host_ctxt);
696 	vcpu = host_ctxt->__hyp_running_vcpu;
697 
698 	if (vcpu)
699 		__deactivate_traps(vcpu);
700 	sysreg_restore_host_state_vhe(host_ctxt);
701 
702 	panic("HYP panic:\nPS:%08llx PC:%016llx ESR:%08llx\nFAR:%016llx HPFAR:%016llx PAR:%016llx\nVCPU:%p\n",
703 	      spsr, elr,
704 	      read_sysreg_el2(SYS_ESR), read_sysreg_el2(SYS_FAR),
705 	      read_sysreg(hpfar_el2), par, vcpu);
706 }
707 NOKPROBE_SYMBOL(__hyp_call_panic);
708 
709 void __noreturn hyp_panic(void)
710 {
711 	u64 spsr = read_sysreg_el2(SYS_SPSR);
712 	u64 elr = read_sysreg_el2(SYS_ELR);
713 	u64 par = read_sysreg_par();
714 
715 	__hyp_call_panic(spsr, elr, par);
716 }
717 
718 asmlinkage void kvm_unexpected_el2_exception(void)
719 {
720 	__kvm_unexpected_el2_exception();
721 }
722