1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2012,2013 - ARM Ltd
4  * Author: Marc Zyngier <marc.zyngier@arm.com>
5  *
6  * Derived from arch/arm/include/kvm_emulate.h
7  * Copyright (C) 2012 - Virtual Open Systems and Columbia University
8  * Author: Christoffer Dall <c.dall@virtualopensystems.com>
9  */
10 
11 #ifndef __ARM64_KVM_EMULATE_H__
12 #define __ARM64_KVM_EMULATE_H__
13 
14 #include <linux/kvm_host.h>
15 
16 #include <asm/debug-monitors.h>
17 #include <asm/esr.h>
18 #include <asm/kvm_arm.h>
19 #include <asm/kvm_hyp.h>
20 #include <asm/ptrace.h>
21 #include <asm/cputype.h>
22 #include <asm/virt.h>
23 
24 #define CURRENT_EL_SP_EL0_VECTOR	0x0
25 #define CURRENT_EL_SP_ELx_VECTOR	0x200
26 #define LOWER_EL_AArch64_VECTOR		0x400
27 #define LOWER_EL_AArch32_VECTOR		0x600
28 
29 enum exception_type {
30 	except_type_sync	= 0,
31 	except_type_irq		= 0x80,
32 	except_type_fiq		= 0x100,
33 	except_type_serror	= 0x180,
34 };
35 
36 #define kvm_exception_type_names		\
37 	{ except_type_sync,	"SYNC"   },	\
38 	{ except_type_irq,	"IRQ"    },	\
39 	{ except_type_fiq,	"FIQ"    },	\
40 	{ except_type_serror,	"SERROR" }
41 
42 bool kvm_condition_valid32(const struct kvm_vcpu *vcpu);
43 void kvm_skip_instr32(struct kvm_vcpu *vcpu);
44 
45 void kvm_inject_undefined(struct kvm_vcpu *vcpu);
46 void kvm_inject_vabt(struct kvm_vcpu *vcpu);
47 void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr);
48 void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr);
49 void kvm_inject_size_fault(struct kvm_vcpu *vcpu);
50 
51 void kvm_vcpu_wfi(struct kvm_vcpu *vcpu);
52 
53 void kvm_emulate_nested_eret(struct kvm_vcpu *vcpu);
54 int kvm_inject_nested_sync(struct kvm_vcpu *vcpu, u64 esr_el2);
55 int kvm_inject_nested_irq(struct kvm_vcpu *vcpu);
56 
57 #if defined(__KVM_VHE_HYPERVISOR__) || defined(__KVM_NVHE_HYPERVISOR__)
58 static __always_inline bool vcpu_el1_is_32bit(struct kvm_vcpu *vcpu)
59 {
60 	return !(vcpu->arch.hcr_el2 & HCR_RW);
61 }
62 #else
63 static __always_inline bool vcpu_el1_is_32bit(struct kvm_vcpu *vcpu)
64 {
65 	struct kvm *kvm = vcpu->kvm;
66 
67 	WARN_ON_ONCE(!test_bit(KVM_ARCH_FLAG_REG_WIDTH_CONFIGURED,
68 			       &kvm->arch.flags));
69 
70 	return test_bit(KVM_ARCH_FLAG_EL1_32BIT, &kvm->arch.flags);
71 }
72 #endif
73 
74 static inline void vcpu_reset_hcr(struct kvm_vcpu *vcpu)
75 {
76 	vcpu->arch.hcr_el2 = HCR_GUEST_FLAGS;
77 	if (is_kernel_in_hyp_mode())
78 		vcpu->arch.hcr_el2 |= HCR_E2H;
79 	if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN)) {
80 		/* route synchronous external abort exceptions to EL2 */
81 		vcpu->arch.hcr_el2 |= HCR_TEA;
82 		/* trap error record accesses */
83 		vcpu->arch.hcr_el2 |= HCR_TERR;
84 	}
85 
86 	if (cpus_have_const_cap(ARM64_HAS_STAGE2_FWB)) {
87 		vcpu->arch.hcr_el2 |= HCR_FWB;
88 	} else {
89 		/*
90 		 * For non-FWB CPUs, we trap VM ops (HCR_EL2.TVM) until M+C
91 		 * get set in SCTLR_EL1 such that we can detect when the guest
92 		 * MMU gets turned on and do the necessary cache maintenance
93 		 * then.
94 		 */
95 		vcpu->arch.hcr_el2 |= HCR_TVM;
96 	}
97 
98 	if (vcpu_el1_is_32bit(vcpu))
99 		vcpu->arch.hcr_el2 &= ~HCR_RW;
100 
101 	if (kvm_has_mte(vcpu->kvm))
102 		vcpu->arch.hcr_el2 |= HCR_ATA;
103 }
104 
105 static inline unsigned long *vcpu_hcr(struct kvm_vcpu *vcpu)
106 {
107 	return (unsigned long *)&vcpu->arch.hcr_el2;
108 }
109 
110 static inline void vcpu_clear_wfx_traps(struct kvm_vcpu *vcpu)
111 {
112 	vcpu->arch.hcr_el2 &= ~HCR_TWE;
113 	if (atomic_read(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe.vlpi_count) ||
114 	    vcpu->kvm->arch.vgic.nassgireq)
115 		vcpu->arch.hcr_el2 &= ~HCR_TWI;
116 	else
117 		vcpu->arch.hcr_el2 |= HCR_TWI;
118 }
119 
120 static inline void vcpu_set_wfx_traps(struct kvm_vcpu *vcpu)
121 {
122 	vcpu->arch.hcr_el2 |= HCR_TWE;
123 	vcpu->arch.hcr_el2 |= HCR_TWI;
124 }
125 
126 static inline void vcpu_ptrauth_enable(struct kvm_vcpu *vcpu)
127 {
128 	vcpu->arch.hcr_el2 |= (HCR_API | HCR_APK);
129 }
130 
131 static inline void vcpu_ptrauth_disable(struct kvm_vcpu *vcpu)
132 {
133 	vcpu->arch.hcr_el2 &= ~(HCR_API | HCR_APK);
134 }
135 
136 static inline unsigned long vcpu_get_vsesr(struct kvm_vcpu *vcpu)
137 {
138 	return vcpu->arch.vsesr_el2;
139 }
140 
141 static inline void vcpu_set_vsesr(struct kvm_vcpu *vcpu, u64 vsesr)
142 {
143 	vcpu->arch.vsesr_el2 = vsesr;
144 }
145 
146 static __always_inline unsigned long *vcpu_pc(const struct kvm_vcpu *vcpu)
147 {
148 	return (unsigned long *)&vcpu_gp_regs(vcpu)->pc;
149 }
150 
151 static __always_inline unsigned long *vcpu_cpsr(const struct kvm_vcpu *vcpu)
152 {
153 	return (unsigned long *)&vcpu_gp_regs(vcpu)->pstate;
154 }
155 
156 static __always_inline bool vcpu_mode_is_32bit(const struct kvm_vcpu *vcpu)
157 {
158 	return !!(*vcpu_cpsr(vcpu) & PSR_MODE32_BIT);
159 }
160 
161 static __always_inline bool kvm_condition_valid(const struct kvm_vcpu *vcpu)
162 {
163 	if (vcpu_mode_is_32bit(vcpu))
164 		return kvm_condition_valid32(vcpu);
165 
166 	return true;
167 }
168 
169 static inline void vcpu_set_thumb(struct kvm_vcpu *vcpu)
170 {
171 	*vcpu_cpsr(vcpu) |= PSR_AA32_T_BIT;
172 }
173 
174 /*
175  * vcpu_get_reg and vcpu_set_reg should always be passed a register number
176  * coming from a read of ESR_EL2. Otherwise, it may give the wrong result on
177  * AArch32 with banked registers.
178  */
179 static __always_inline unsigned long vcpu_get_reg(const struct kvm_vcpu *vcpu,
180 					 u8 reg_num)
181 {
182 	return (reg_num == 31) ? 0 : vcpu_gp_regs(vcpu)->regs[reg_num];
183 }
184 
185 static __always_inline void vcpu_set_reg(struct kvm_vcpu *vcpu, u8 reg_num,
186 				unsigned long val)
187 {
188 	if (reg_num != 31)
189 		vcpu_gp_regs(vcpu)->regs[reg_num] = val;
190 }
191 
192 static inline bool vcpu_is_el2_ctxt(const struct kvm_cpu_context *ctxt)
193 {
194 	switch (ctxt->regs.pstate & (PSR_MODE32_BIT | PSR_MODE_MASK)) {
195 	case PSR_MODE_EL2h:
196 	case PSR_MODE_EL2t:
197 		return true;
198 	default:
199 		return false;
200 	}
201 }
202 
203 static inline bool vcpu_is_el2(const struct kvm_vcpu *vcpu)
204 {
205 	return vcpu_is_el2_ctxt(&vcpu->arch.ctxt);
206 }
207 
208 static inline bool __vcpu_el2_e2h_is_set(const struct kvm_cpu_context *ctxt)
209 {
210 	return ctxt_sys_reg(ctxt, HCR_EL2) & HCR_E2H;
211 }
212 
213 static inline bool vcpu_el2_e2h_is_set(const struct kvm_vcpu *vcpu)
214 {
215 	return __vcpu_el2_e2h_is_set(&vcpu->arch.ctxt);
216 }
217 
218 static inline bool __vcpu_el2_tge_is_set(const struct kvm_cpu_context *ctxt)
219 {
220 	return ctxt_sys_reg(ctxt, HCR_EL2) & HCR_TGE;
221 }
222 
223 static inline bool vcpu_el2_tge_is_set(const struct kvm_vcpu *vcpu)
224 {
225 	return __vcpu_el2_tge_is_set(&vcpu->arch.ctxt);
226 }
227 
228 static inline bool __is_hyp_ctxt(const struct kvm_cpu_context *ctxt)
229 {
230 	/*
231 	 * We are in a hypervisor context if the vcpu mode is EL2 or
232 	 * E2H and TGE bits are set. The latter means we are in the user space
233 	 * of the VHE kernel. ARMv8.1 ARM describes this as 'InHost'
234 	 *
235 	 * Note that the HCR_EL2.{E2H,TGE}={0,1} isn't really handled in the
236 	 * rest of the KVM code, and will result in a misbehaving guest.
237 	 */
238 	return vcpu_is_el2_ctxt(ctxt) ||
239 		(__vcpu_el2_e2h_is_set(ctxt) && __vcpu_el2_tge_is_set(ctxt)) ||
240 		__vcpu_el2_tge_is_set(ctxt);
241 }
242 
243 static inline bool is_hyp_ctxt(const struct kvm_vcpu *vcpu)
244 {
245 	return __is_hyp_ctxt(&vcpu->arch.ctxt);
246 }
247 
248 /*
249  * The layout of SPSR for an AArch32 state is different when observed from an
250  * AArch64 SPSR_ELx or an AArch32 SPSR_*. This function generates the AArch32
251  * view given an AArch64 view.
252  *
253  * In ARM DDI 0487E.a see:
254  *
255  * - The AArch64 view (SPSR_EL2) in section C5.2.18, page C5-426
256  * - The AArch32 view (SPSR_abt) in section G8.2.126, page G8-6256
257  * - The AArch32 view (SPSR_und) in section G8.2.132, page G8-6280
258  *
259  * Which show the following differences:
260  *
261  * | Bit | AA64 | AA32 | Notes                       |
262  * +-----+------+------+-----------------------------|
263  * | 24  | DIT  | J    | J is RES0 in ARMv8          |
264  * | 21  | SS   | DIT  | SS doesn't exist in AArch32 |
265  *
266  * ... and all other bits are (currently) common.
267  */
268 static inline unsigned long host_spsr_to_spsr32(unsigned long spsr)
269 {
270 	const unsigned long overlap = BIT(24) | BIT(21);
271 	unsigned long dit = !!(spsr & PSR_AA32_DIT_BIT);
272 
273 	spsr &= ~overlap;
274 
275 	spsr |= dit << 21;
276 
277 	return spsr;
278 }
279 
280 static inline bool vcpu_mode_priv(const struct kvm_vcpu *vcpu)
281 {
282 	u32 mode;
283 
284 	if (vcpu_mode_is_32bit(vcpu)) {
285 		mode = *vcpu_cpsr(vcpu) & PSR_AA32_MODE_MASK;
286 		return mode > PSR_AA32_MODE_USR;
287 	}
288 
289 	mode = *vcpu_cpsr(vcpu) & PSR_MODE_MASK;
290 
291 	return mode != PSR_MODE_EL0t;
292 }
293 
294 static __always_inline u64 kvm_vcpu_get_esr(const struct kvm_vcpu *vcpu)
295 {
296 	return vcpu->arch.fault.esr_el2;
297 }
298 
299 static __always_inline int kvm_vcpu_get_condition(const struct kvm_vcpu *vcpu)
300 {
301 	u64 esr = kvm_vcpu_get_esr(vcpu);
302 
303 	if (esr & ESR_ELx_CV)
304 		return (esr & ESR_ELx_COND_MASK) >> ESR_ELx_COND_SHIFT;
305 
306 	return -1;
307 }
308 
309 static __always_inline unsigned long kvm_vcpu_get_hfar(const struct kvm_vcpu *vcpu)
310 {
311 	return vcpu->arch.fault.far_el2;
312 }
313 
314 static __always_inline phys_addr_t kvm_vcpu_get_fault_ipa(const struct kvm_vcpu *vcpu)
315 {
316 	return ((phys_addr_t)vcpu->arch.fault.hpfar_el2 & HPFAR_MASK) << 8;
317 }
318 
319 static inline u64 kvm_vcpu_get_disr(const struct kvm_vcpu *vcpu)
320 {
321 	return vcpu->arch.fault.disr_el1;
322 }
323 
324 static inline u32 kvm_vcpu_hvc_get_imm(const struct kvm_vcpu *vcpu)
325 {
326 	return kvm_vcpu_get_esr(vcpu) & ESR_ELx_xVC_IMM_MASK;
327 }
328 
329 static __always_inline bool kvm_vcpu_dabt_isvalid(const struct kvm_vcpu *vcpu)
330 {
331 	return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_ISV);
332 }
333 
334 static inline unsigned long kvm_vcpu_dabt_iss_nisv_sanitized(const struct kvm_vcpu *vcpu)
335 {
336 	return kvm_vcpu_get_esr(vcpu) & (ESR_ELx_CM | ESR_ELx_WNR | ESR_ELx_FSC);
337 }
338 
339 static inline bool kvm_vcpu_dabt_issext(const struct kvm_vcpu *vcpu)
340 {
341 	return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_SSE);
342 }
343 
344 static inline bool kvm_vcpu_dabt_issf(const struct kvm_vcpu *vcpu)
345 {
346 	return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_SF);
347 }
348 
349 static __always_inline int kvm_vcpu_dabt_get_rd(const struct kvm_vcpu *vcpu)
350 {
351 	return (kvm_vcpu_get_esr(vcpu) & ESR_ELx_SRT_MASK) >> ESR_ELx_SRT_SHIFT;
352 }
353 
354 static __always_inline bool kvm_vcpu_abt_iss1tw(const struct kvm_vcpu *vcpu)
355 {
356 	return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_S1PTW);
357 }
358 
359 /* Always check for S1PTW *before* using this. */
360 static __always_inline bool kvm_vcpu_dabt_iswrite(const struct kvm_vcpu *vcpu)
361 {
362 	return kvm_vcpu_get_esr(vcpu) & ESR_ELx_WNR;
363 }
364 
365 static inline bool kvm_vcpu_dabt_is_cm(const struct kvm_vcpu *vcpu)
366 {
367 	return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_CM);
368 }
369 
370 static __always_inline unsigned int kvm_vcpu_dabt_get_as(const struct kvm_vcpu *vcpu)
371 {
372 	return 1 << ((kvm_vcpu_get_esr(vcpu) & ESR_ELx_SAS) >> ESR_ELx_SAS_SHIFT);
373 }
374 
375 /* This one is not specific to Data Abort */
376 static __always_inline bool kvm_vcpu_trap_il_is32bit(const struct kvm_vcpu *vcpu)
377 {
378 	return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_IL);
379 }
380 
381 static __always_inline u8 kvm_vcpu_trap_get_class(const struct kvm_vcpu *vcpu)
382 {
383 	return ESR_ELx_EC(kvm_vcpu_get_esr(vcpu));
384 }
385 
386 static inline bool kvm_vcpu_trap_is_iabt(const struct kvm_vcpu *vcpu)
387 {
388 	return kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_IABT_LOW;
389 }
390 
391 static inline bool kvm_vcpu_trap_is_exec_fault(const struct kvm_vcpu *vcpu)
392 {
393 	return kvm_vcpu_trap_is_iabt(vcpu) && !kvm_vcpu_abt_iss1tw(vcpu);
394 }
395 
396 static __always_inline u8 kvm_vcpu_trap_get_fault(const struct kvm_vcpu *vcpu)
397 {
398 	return kvm_vcpu_get_esr(vcpu) & ESR_ELx_FSC;
399 }
400 
401 static __always_inline u8 kvm_vcpu_trap_get_fault_type(const struct kvm_vcpu *vcpu)
402 {
403 	return kvm_vcpu_get_esr(vcpu) & ESR_ELx_FSC_TYPE;
404 }
405 
406 static __always_inline u8 kvm_vcpu_trap_get_fault_level(const struct kvm_vcpu *vcpu)
407 {
408 	return kvm_vcpu_get_esr(vcpu) & ESR_ELx_FSC_LEVEL;
409 }
410 
411 static __always_inline bool kvm_vcpu_abt_issea(const struct kvm_vcpu *vcpu)
412 {
413 	switch (kvm_vcpu_trap_get_fault(vcpu)) {
414 	case ESR_ELx_FSC_EXTABT:
415 	case ESR_ELx_FSC_SEA_TTW0:
416 	case ESR_ELx_FSC_SEA_TTW1:
417 	case ESR_ELx_FSC_SEA_TTW2:
418 	case ESR_ELx_FSC_SEA_TTW3:
419 	case ESR_ELx_FSC_SECC:
420 	case ESR_ELx_FSC_SECC_TTW0:
421 	case ESR_ELx_FSC_SECC_TTW1:
422 	case ESR_ELx_FSC_SECC_TTW2:
423 	case ESR_ELx_FSC_SECC_TTW3:
424 		return true;
425 	default:
426 		return false;
427 	}
428 }
429 
430 static __always_inline int kvm_vcpu_sys_get_rt(struct kvm_vcpu *vcpu)
431 {
432 	u64 esr = kvm_vcpu_get_esr(vcpu);
433 	return ESR_ELx_SYS64_ISS_RT(esr);
434 }
435 
436 static inline bool kvm_is_write_fault(struct kvm_vcpu *vcpu)
437 {
438 	if (kvm_vcpu_abt_iss1tw(vcpu)) {
439 		/*
440 		 * Only a permission fault on a S1PTW should be
441 		 * considered as a write. Otherwise, page tables baked
442 		 * in a read-only memslot will result in an exception
443 		 * being delivered in the guest.
444 		 *
445 		 * The drawback is that we end-up faulting twice if the
446 		 * guest is using any of HW AF/DB: a translation fault
447 		 * to map the page containing the PT (read only at
448 		 * first), then a permission fault to allow the flags
449 		 * to be set.
450 		 */
451 		switch (kvm_vcpu_trap_get_fault_type(vcpu)) {
452 		case ESR_ELx_FSC_PERM:
453 			return true;
454 		default:
455 			return false;
456 		}
457 	}
458 
459 	if (kvm_vcpu_trap_is_iabt(vcpu))
460 		return false;
461 
462 	return kvm_vcpu_dabt_iswrite(vcpu);
463 }
464 
465 static inline unsigned long kvm_vcpu_get_mpidr_aff(struct kvm_vcpu *vcpu)
466 {
467 	return vcpu_read_sys_reg(vcpu, MPIDR_EL1) & MPIDR_HWID_BITMASK;
468 }
469 
470 static inline void kvm_vcpu_set_be(struct kvm_vcpu *vcpu)
471 {
472 	if (vcpu_mode_is_32bit(vcpu)) {
473 		*vcpu_cpsr(vcpu) |= PSR_AA32_E_BIT;
474 	} else {
475 		u64 sctlr = vcpu_read_sys_reg(vcpu, SCTLR_EL1);
476 		sctlr |= SCTLR_ELx_EE;
477 		vcpu_write_sys_reg(vcpu, sctlr, SCTLR_EL1);
478 	}
479 }
480 
481 static inline bool kvm_vcpu_is_be(struct kvm_vcpu *vcpu)
482 {
483 	if (vcpu_mode_is_32bit(vcpu))
484 		return !!(*vcpu_cpsr(vcpu) & PSR_AA32_E_BIT);
485 
486 	if (vcpu_mode_priv(vcpu))
487 		return !!(vcpu_read_sys_reg(vcpu, SCTLR_EL1) & SCTLR_ELx_EE);
488 	else
489 		return !!(vcpu_read_sys_reg(vcpu, SCTLR_EL1) & SCTLR_EL1_E0E);
490 }
491 
492 static inline unsigned long vcpu_data_guest_to_host(struct kvm_vcpu *vcpu,
493 						    unsigned long data,
494 						    unsigned int len)
495 {
496 	if (kvm_vcpu_is_be(vcpu)) {
497 		switch (len) {
498 		case 1:
499 			return data & 0xff;
500 		case 2:
501 			return be16_to_cpu(data & 0xffff);
502 		case 4:
503 			return be32_to_cpu(data & 0xffffffff);
504 		default:
505 			return be64_to_cpu(data);
506 		}
507 	} else {
508 		switch (len) {
509 		case 1:
510 			return data & 0xff;
511 		case 2:
512 			return le16_to_cpu(data & 0xffff);
513 		case 4:
514 			return le32_to_cpu(data & 0xffffffff);
515 		default:
516 			return le64_to_cpu(data);
517 		}
518 	}
519 
520 	return data;		/* Leave LE untouched */
521 }
522 
523 static inline unsigned long vcpu_data_host_to_guest(struct kvm_vcpu *vcpu,
524 						    unsigned long data,
525 						    unsigned int len)
526 {
527 	if (kvm_vcpu_is_be(vcpu)) {
528 		switch (len) {
529 		case 1:
530 			return data & 0xff;
531 		case 2:
532 			return cpu_to_be16(data & 0xffff);
533 		case 4:
534 			return cpu_to_be32(data & 0xffffffff);
535 		default:
536 			return cpu_to_be64(data);
537 		}
538 	} else {
539 		switch (len) {
540 		case 1:
541 			return data & 0xff;
542 		case 2:
543 			return cpu_to_le16(data & 0xffff);
544 		case 4:
545 			return cpu_to_le32(data & 0xffffffff);
546 		default:
547 			return cpu_to_le64(data);
548 		}
549 	}
550 
551 	return data;		/* Leave LE untouched */
552 }
553 
554 static __always_inline void kvm_incr_pc(struct kvm_vcpu *vcpu)
555 {
556 	WARN_ON(vcpu_get_flag(vcpu, PENDING_EXCEPTION));
557 	vcpu_set_flag(vcpu, INCREMENT_PC);
558 }
559 
560 #define kvm_pend_exception(v, e)					\
561 	do {								\
562 		WARN_ON(vcpu_get_flag((v), INCREMENT_PC));		\
563 		vcpu_set_flag((v), PENDING_EXCEPTION);			\
564 		vcpu_set_flag((v), e);					\
565 	} while (0)
566 
567 
568 static inline bool vcpu_has_feature(struct kvm_vcpu *vcpu, int feature)
569 {
570 	return test_bit(feature, vcpu->arch.features);
571 }
572 
573 #endif /* __ARM64_KVM_EMULATE_H__ */
574