• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright (C) 2012 - Virtual Open Systems and Columbia University
3  * Authors: Rusty Russell <rusty@rustcorp.com.au>
4  *          Christoffer Dall <c.dall@virtualopensystems.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License, version 2, as
8  * published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
18  */
19 #include <linux/mm.h>
20 #include <linux/kvm_host.h>
21 #include <linux/uaccess.h>
22 #include <asm/kvm_arm.h>
23 #include <asm/kvm_host.h>
24 #include <asm/kvm_emulate.h>
25 #include <asm/kvm_coproc.h>
26 #include <asm/kvm_mmu.h>
27 #include <asm/cacheflush.h>
28 #include <asm/cputype.h>
29 #include <trace/events/kvm.h>
30 #include <asm/vfp.h>
31 #include "../vfp/vfpinstr.h"
32 
33 #include "trace.h"
34 #include "coproc.h"
35 
36 
37 /******************************************************************************
38  * Co-processor emulation
39  *****************************************************************************/
40 
41 /* 3 bits per cache level, as per CLIDR, but non-existent caches always 0 */
42 static u32 cache_levels;
43 
44 /* CSSELR values; used to index KVM_REG_ARM_DEMUX_ID_CCSIDR */
45 #define CSSELR_MAX 12
46 
47 /*
48  * kvm_vcpu_arch.cp15 holds cp15 registers as an array of u32, but some
49  * of cp15 registers can be viewed either as couple of two u32 registers
50  * or one u64 register. Current u64 register encoding is that least
51  * significant u32 word is followed by most significant u32 word.
52  */
vcpu_cp15_reg64_set(struct kvm_vcpu * vcpu,const struct coproc_reg * r,u64 val)53 static inline void vcpu_cp15_reg64_set(struct kvm_vcpu *vcpu,
54 				       const struct coproc_reg *r,
55 				       u64 val)
56 {
57 	vcpu->arch.cp15[r->reg] = val & 0xffffffff;
58 	vcpu->arch.cp15[r->reg + 1] = val >> 32;
59 }
60 
vcpu_cp15_reg64_get(struct kvm_vcpu * vcpu,const struct coproc_reg * r)61 static inline u64 vcpu_cp15_reg64_get(struct kvm_vcpu *vcpu,
62 				      const struct coproc_reg *r)
63 {
64 	u64 val;
65 
66 	val = vcpu->arch.cp15[r->reg + 1];
67 	val = val << 32;
68 	val = val | vcpu->arch.cp15[r->reg];
69 	return val;
70 }
71 
kvm_handle_cp10_id(struct kvm_vcpu * vcpu,struct kvm_run * run)72 int kvm_handle_cp10_id(struct kvm_vcpu *vcpu, struct kvm_run *run)
73 {
74 	kvm_inject_undefined(vcpu);
75 	return 1;
76 }
77 
kvm_handle_cp_0_13_access(struct kvm_vcpu * vcpu,struct kvm_run * run)78 int kvm_handle_cp_0_13_access(struct kvm_vcpu *vcpu, struct kvm_run *run)
79 {
80 	/*
81 	 * We can get here, if the host has been built without VFPv3 support,
82 	 * but the guest attempted a floating point operation.
83 	 */
84 	kvm_inject_undefined(vcpu);
85 	return 1;
86 }
87 
kvm_handle_cp14_load_store(struct kvm_vcpu * vcpu,struct kvm_run * run)88 int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu, struct kvm_run *run)
89 {
90 	kvm_inject_undefined(vcpu);
91 	return 1;
92 }
93 
kvm_handle_cp14_access(struct kvm_vcpu * vcpu,struct kvm_run * run)94 int kvm_handle_cp14_access(struct kvm_vcpu *vcpu, struct kvm_run *run)
95 {
96 	kvm_inject_undefined(vcpu);
97 	return 1;
98 }
99 
reset_mpidr(struct kvm_vcpu * vcpu,const struct coproc_reg * r)100 static void reset_mpidr(struct kvm_vcpu *vcpu, const struct coproc_reg *r)
101 {
102 	/*
103 	 * Compute guest MPIDR. We build a virtual cluster out of the
104 	 * vcpu_id, but we read the 'U' bit from the underlying
105 	 * hardware directly.
106 	 */
107 	vcpu->arch.cp15[c0_MPIDR] = ((read_cpuid_mpidr() & MPIDR_SMP_BITMASK) |
108 				     ((vcpu->vcpu_id >> 2) << MPIDR_LEVEL_BITS) |
109 				     (vcpu->vcpu_id & 3));
110 }
111 
112 /* TRM entries A7:4.3.31 A15:4.3.28 - RO WI */
access_actlr(struct kvm_vcpu * vcpu,const struct coproc_params * p,const struct coproc_reg * r)113 static bool access_actlr(struct kvm_vcpu *vcpu,
114 			 const struct coproc_params *p,
115 			 const struct coproc_reg *r)
116 {
117 	if (p->is_write)
118 		return ignore_write(vcpu, p);
119 
120 	*vcpu_reg(vcpu, p->Rt1) = vcpu->arch.cp15[c1_ACTLR];
121 	return true;
122 }
123 
124 /* TRM entries A7:4.3.56, A15:4.3.60 - R/O. */
access_cbar(struct kvm_vcpu * vcpu,const struct coproc_params * p,const struct coproc_reg * r)125 static bool access_cbar(struct kvm_vcpu *vcpu,
126 			const struct coproc_params *p,
127 			const struct coproc_reg *r)
128 {
129 	if (p->is_write)
130 		return write_to_read_only(vcpu, p);
131 	return read_zero(vcpu, p);
132 }
133 
134 /* TRM entries A7:4.3.49, A15:4.3.48 - R/O WI */
access_l2ctlr(struct kvm_vcpu * vcpu,const struct coproc_params * p,const struct coproc_reg * r)135 static bool access_l2ctlr(struct kvm_vcpu *vcpu,
136 			  const struct coproc_params *p,
137 			  const struct coproc_reg *r)
138 {
139 	if (p->is_write)
140 		return ignore_write(vcpu, p);
141 
142 	*vcpu_reg(vcpu, p->Rt1) = vcpu->arch.cp15[c9_L2CTLR];
143 	return true;
144 }
145 
reset_l2ctlr(struct kvm_vcpu * vcpu,const struct coproc_reg * r)146 static void reset_l2ctlr(struct kvm_vcpu *vcpu, const struct coproc_reg *r)
147 {
148 	u32 l2ctlr, ncores;
149 
150 	asm volatile("mrc p15, 1, %0, c9, c0, 2\n" : "=r" (l2ctlr));
151 	l2ctlr &= ~(3 << 24);
152 	ncores = atomic_read(&vcpu->kvm->online_vcpus) - 1;
153 	/* How many cores in the current cluster and the next ones */
154 	ncores -= (vcpu->vcpu_id & ~3);
155 	/* Cap it to the maximum number of cores in a single cluster */
156 	ncores = min(ncores, 3U);
157 	l2ctlr |= (ncores & 3) << 24;
158 
159 	vcpu->arch.cp15[c9_L2CTLR] = l2ctlr;
160 }
161 
reset_actlr(struct kvm_vcpu * vcpu,const struct coproc_reg * r)162 static void reset_actlr(struct kvm_vcpu *vcpu, const struct coproc_reg *r)
163 {
164 	u32 actlr;
165 
166 	/* ACTLR contains SMP bit: make sure you create all cpus first! */
167 	asm volatile("mrc p15, 0, %0, c1, c0, 1\n" : "=r" (actlr));
168 	/* Make the SMP bit consistent with the guest configuration */
169 	if (atomic_read(&vcpu->kvm->online_vcpus) > 1)
170 		actlr |= 1U << 6;
171 	else
172 		actlr &= ~(1U << 6);
173 
174 	vcpu->arch.cp15[c1_ACTLR] = actlr;
175 }
176 
177 /*
178  * TRM entries: A7:4.3.50, A15:4.3.49
179  * R/O WI (even if NSACR.NS_L2ERR, a write of 1 is ignored).
180  */
access_l2ectlr(struct kvm_vcpu * vcpu,const struct coproc_params * p,const struct coproc_reg * r)181 static bool access_l2ectlr(struct kvm_vcpu *vcpu,
182 			   const struct coproc_params *p,
183 			   const struct coproc_reg *r)
184 {
185 	if (p->is_write)
186 		return ignore_write(vcpu, p);
187 
188 	*vcpu_reg(vcpu, p->Rt1) = 0;
189 	return true;
190 }
191 
192 /*
193  * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
194  */
access_dcsw(struct kvm_vcpu * vcpu,const struct coproc_params * p,const struct coproc_reg * r)195 static bool access_dcsw(struct kvm_vcpu *vcpu,
196 			const struct coproc_params *p,
197 			const struct coproc_reg *r)
198 {
199 	if (!p->is_write)
200 		return read_from_write_only(vcpu, p);
201 
202 	kvm_set_way_flush(vcpu);
203 	return true;
204 }
205 
206 /*
207  * Generic accessor for VM registers. Only called as long as HCR_TVM
208  * is set.  If the guest enables the MMU, we stop trapping the VM
209  * sys_regs and leave it in complete control of the caches.
210  *
211  * Used by the cpu-specific code.
212  */
access_vm_reg(struct kvm_vcpu * vcpu,const struct coproc_params * p,const struct coproc_reg * r)213 bool access_vm_reg(struct kvm_vcpu *vcpu,
214 		   const struct coproc_params *p,
215 		   const struct coproc_reg *r)
216 {
217 	bool was_enabled = vcpu_has_cache_enabled(vcpu);
218 
219 	BUG_ON(!p->is_write);
220 
221 	vcpu->arch.cp15[r->reg] = *vcpu_reg(vcpu, p->Rt1);
222 	if (p->is_64bit)
223 		vcpu->arch.cp15[r->reg + 1] = *vcpu_reg(vcpu, p->Rt2);
224 
225 	kvm_toggle_cache(vcpu, was_enabled);
226 	return true;
227 }
228 
229 /*
230  * We could trap ID_DFR0 and tell the guest we don't support performance
231  * monitoring.  Unfortunately the patch to make the kernel check ID_DFR0 was
232  * NAKed, so it will read the PMCR anyway.
233  *
234  * Therefore we tell the guest we have 0 counters.  Unfortunately, we
235  * must always support PMCCNTR (the cycle counter): we just RAZ/WI for
236  * all PM registers, which doesn't crash the guest kernel at least.
237  */
pm_fake(struct kvm_vcpu * vcpu,const struct coproc_params * p,const struct coproc_reg * r)238 static bool pm_fake(struct kvm_vcpu *vcpu,
239 		    const struct coproc_params *p,
240 		    const struct coproc_reg *r)
241 {
242 	if (p->is_write)
243 		return ignore_write(vcpu, p);
244 	else
245 		return read_zero(vcpu, p);
246 }
247 
248 #define access_pmcr pm_fake
249 #define access_pmcntenset pm_fake
250 #define access_pmcntenclr pm_fake
251 #define access_pmovsr pm_fake
252 #define access_pmselr pm_fake
253 #define access_pmceid0 pm_fake
254 #define access_pmceid1 pm_fake
255 #define access_pmccntr pm_fake
256 #define access_pmxevtyper pm_fake
257 #define access_pmxevcntr pm_fake
258 #define access_pmuserenr pm_fake
259 #define access_pmintenset pm_fake
260 #define access_pmintenclr pm_fake
261 
262 /* Architected CP15 registers.
263  * CRn denotes the primary register number, but is copied to the CRm in the
264  * user space API for 64-bit register access in line with the terminology used
265  * in the ARM ARM.
266  * Important: Must be sorted ascending by CRn, CRM, Op1, Op2 and with 64-bit
267  *            registers preceding 32-bit ones.
268  */
269 static const struct coproc_reg cp15_regs[] = {
270 	/* MPIDR: we use VMPIDR for guest access. */
271 	{ CRn( 0), CRm( 0), Op1( 0), Op2( 5), is32,
272 			NULL, reset_mpidr, c0_MPIDR },
273 
274 	/* CSSELR: swapped by interrupt.S. */
275 	{ CRn( 0), CRm( 0), Op1( 2), Op2( 0), is32,
276 			NULL, reset_unknown, c0_CSSELR },
277 
278 	/* ACTLR: trapped by HCR.TAC bit. */
279 	{ CRn( 1), CRm( 0), Op1( 0), Op2( 1), is32,
280 			access_actlr, reset_actlr, c1_ACTLR },
281 
282 	/* CPACR: swapped by interrupt.S. */
283 	{ CRn( 1), CRm( 0), Op1( 0), Op2( 2), is32,
284 			NULL, reset_val, c1_CPACR, 0x00000000 },
285 
286 	/* TTBR0/TTBR1/TTBCR: swapped by interrupt.S. */
287 	{ CRm64( 2), Op1( 0), is64, access_vm_reg, reset_unknown64, c2_TTBR0 },
288 	{ CRn(2), CRm( 0), Op1( 0), Op2( 0), is32,
289 			access_vm_reg, reset_unknown, c2_TTBR0 },
290 	{ CRn(2), CRm( 0), Op1( 0), Op2( 1), is32,
291 			access_vm_reg, reset_unknown, c2_TTBR1 },
292 	{ CRn( 2), CRm( 0), Op1( 0), Op2( 2), is32,
293 			access_vm_reg, reset_val, c2_TTBCR, 0x00000000 },
294 	{ CRm64( 2), Op1( 1), is64, access_vm_reg, reset_unknown64, c2_TTBR1 },
295 
296 
297 	/* DACR: swapped by interrupt.S. */
298 	{ CRn( 3), CRm( 0), Op1( 0), Op2( 0), is32,
299 			access_vm_reg, reset_unknown, c3_DACR },
300 
301 	/* DFSR/IFSR/ADFSR/AIFSR: swapped by interrupt.S. */
302 	{ CRn( 5), CRm( 0), Op1( 0), Op2( 0), is32,
303 			access_vm_reg, reset_unknown, c5_DFSR },
304 	{ CRn( 5), CRm( 0), Op1( 0), Op2( 1), is32,
305 			access_vm_reg, reset_unknown, c5_IFSR },
306 	{ CRn( 5), CRm( 1), Op1( 0), Op2( 0), is32,
307 			access_vm_reg, reset_unknown, c5_ADFSR },
308 	{ CRn( 5), CRm( 1), Op1( 0), Op2( 1), is32,
309 			access_vm_reg, reset_unknown, c5_AIFSR },
310 
311 	/* DFAR/IFAR: swapped by interrupt.S. */
312 	{ CRn( 6), CRm( 0), Op1( 0), Op2( 0), is32,
313 			access_vm_reg, reset_unknown, c6_DFAR },
314 	{ CRn( 6), CRm( 0), Op1( 0), Op2( 2), is32,
315 			access_vm_reg, reset_unknown, c6_IFAR },
316 
317 	/* PAR swapped by interrupt.S */
318 	{ CRm64( 7), Op1( 0), is64, NULL, reset_unknown64, c7_PAR },
319 
320 	/*
321 	 * DC{C,I,CI}SW operations:
322 	 */
323 	{ CRn( 7), CRm( 6), Op1( 0), Op2( 2), is32, access_dcsw},
324 	{ CRn( 7), CRm(10), Op1( 0), Op2( 2), is32, access_dcsw},
325 	{ CRn( 7), CRm(14), Op1( 0), Op2( 2), is32, access_dcsw},
326 	/*
327 	 * L2CTLR access (guest wants to know #CPUs).
328 	 */
329 	{ CRn( 9), CRm( 0), Op1( 1), Op2( 2), is32,
330 			access_l2ctlr, reset_l2ctlr, c9_L2CTLR },
331 	{ CRn( 9), CRm( 0), Op1( 1), Op2( 3), is32, access_l2ectlr},
332 
333 	/*
334 	 * Dummy performance monitor implementation.
335 	 */
336 	{ CRn( 9), CRm(12), Op1( 0), Op2( 0), is32, access_pmcr},
337 	{ CRn( 9), CRm(12), Op1( 0), Op2( 1), is32, access_pmcntenset},
338 	{ CRn( 9), CRm(12), Op1( 0), Op2( 2), is32, access_pmcntenclr},
339 	{ CRn( 9), CRm(12), Op1( 0), Op2( 3), is32, access_pmovsr},
340 	{ CRn( 9), CRm(12), Op1( 0), Op2( 5), is32, access_pmselr},
341 	{ CRn( 9), CRm(12), Op1( 0), Op2( 6), is32, access_pmceid0},
342 	{ CRn( 9), CRm(12), Op1( 0), Op2( 7), is32, access_pmceid1},
343 	{ CRn( 9), CRm(13), Op1( 0), Op2( 0), is32, access_pmccntr},
344 	{ CRn( 9), CRm(13), Op1( 0), Op2( 1), is32, access_pmxevtyper},
345 	{ CRn( 9), CRm(13), Op1( 0), Op2( 2), is32, access_pmxevcntr},
346 	{ CRn( 9), CRm(14), Op1( 0), Op2( 0), is32, access_pmuserenr},
347 	{ CRn( 9), CRm(14), Op1( 0), Op2( 1), is32, access_pmintenset},
348 	{ CRn( 9), CRm(14), Op1( 0), Op2( 2), is32, access_pmintenclr},
349 
350 	/* PRRR/NMRR (aka MAIR0/MAIR1): swapped by interrupt.S. */
351 	{ CRn(10), CRm( 2), Op1( 0), Op2( 0), is32,
352 			access_vm_reg, reset_unknown, c10_PRRR},
353 	{ CRn(10), CRm( 2), Op1( 0), Op2( 1), is32,
354 			access_vm_reg, reset_unknown, c10_NMRR},
355 
356 	/* AMAIR0/AMAIR1: swapped by interrupt.S. */
357 	{ CRn(10), CRm( 3), Op1( 0), Op2( 0), is32,
358 			access_vm_reg, reset_unknown, c10_AMAIR0},
359 	{ CRn(10), CRm( 3), Op1( 0), Op2( 1), is32,
360 			access_vm_reg, reset_unknown, c10_AMAIR1},
361 
362 	/* VBAR: swapped by interrupt.S. */
363 	{ CRn(12), CRm( 0), Op1( 0), Op2( 0), is32,
364 			NULL, reset_val, c12_VBAR, 0x00000000 },
365 
366 	/* CONTEXTIDR/TPIDRURW/TPIDRURO/TPIDRPRW: swapped by interrupt.S. */
367 	{ CRn(13), CRm( 0), Op1( 0), Op2( 1), is32,
368 			access_vm_reg, reset_val, c13_CID, 0x00000000 },
369 	{ CRn(13), CRm( 0), Op1( 0), Op2( 2), is32,
370 			NULL, reset_unknown, c13_TID_URW },
371 	{ CRn(13), CRm( 0), Op1( 0), Op2( 3), is32,
372 			NULL, reset_unknown, c13_TID_URO },
373 	{ CRn(13), CRm( 0), Op1( 0), Op2( 4), is32,
374 			NULL, reset_unknown, c13_TID_PRIV },
375 
376 	/* CNTKCTL: swapped by interrupt.S. */
377 	{ CRn(14), CRm( 1), Op1( 0), Op2( 0), is32,
378 			NULL, reset_val, c14_CNTKCTL, 0x00000000 },
379 
380 	/* The Configuration Base Address Register. */
381 	{ CRn(15), CRm( 0), Op1( 4), Op2( 0), is32, access_cbar},
382 };
383 
384 /* Target specific emulation tables */
385 static struct kvm_coproc_target_table *target_tables[KVM_ARM_NUM_TARGETS];
386 
kvm_register_target_coproc_table(struct kvm_coproc_target_table * table)387 void kvm_register_target_coproc_table(struct kvm_coproc_target_table *table)
388 {
389 	unsigned int i;
390 
391 	for (i = 1; i < table->num; i++)
392 		BUG_ON(cmp_reg(&table->table[i-1],
393 			       &table->table[i]) >= 0);
394 
395 	target_tables[table->target] = table;
396 }
397 
398 /* Get specific register table for this target. */
get_target_table(unsigned target,size_t * num)399 static const struct coproc_reg *get_target_table(unsigned target, size_t *num)
400 {
401 	struct kvm_coproc_target_table *table;
402 
403 	table = target_tables[target];
404 	*num = table->num;
405 	return table->table;
406 }
407 
find_reg(const struct coproc_params * params,const struct coproc_reg table[],unsigned int num)408 static const struct coproc_reg *find_reg(const struct coproc_params *params,
409 					 const struct coproc_reg table[],
410 					 unsigned int num)
411 {
412 	unsigned int i;
413 
414 	for (i = 0; i < num; i++) {
415 		const struct coproc_reg *r = &table[i];
416 
417 		if (params->is_64bit != r->is_64)
418 			continue;
419 		if (params->CRn != r->CRn)
420 			continue;
421 		if (params->CRm != r->CRm)
422 			continue;
423 		if (params->Op1 != r->Op1)
424 			continue;
425 		if (params->Op2 != r->Op2)
426 			continue;
427 
428 		return r;
429 	}
430 	return NULL;
431 }
432 
emulate_cp15(struct kvm_vcpu * vcpu,const struct coproc_params * params)433 static int emulate_cp15(struct kvm_vcpu *vcpu,
434 			const struct coproc_params *params)
435 {
436 	size_t num;
437 	const struct coproc_reg *table, *r;
438 
439 	trace_kvm_emulate_cp15_imp(params->Op1, params->Rt1, params->CRn,
440 				   params->CRm, params->Op2, params->is_write);
441 
442 	table = get_target_table(vcpu->arch.target, &num);
443 
444 	/* Search target-specific then generic table. */
445 	r = find_reg(params, table, num);
446 	if (!r)
447 		r = find_reg(params, cp15_regs, ARRAY_SIZE(cp15_regs));
448 
449 	if (likely(r)) {
450 		/* If we don't have an accessor, we should never get here! */
451 		BUG_ON(!r->access);
452 
453 		if (likely(r->access(vcpu, params, r))) {
454 			/* Skip instruction, since it was emulated */
455 			kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
456 			return 1;
457 		}
458 		/* If access function fails, it should complain. */
459 	} else {
460 		kvm_err("Unsupported guest CP15 access at: %08lx\n",
461 			*vcpu_pc(vcpu));
462 		print_cp_instr(params);
463 	}
464 	kvm_inject_undefined(vcpu);
465 	return 1;
466 }
467 
468 /**
469  * kvm_handle_cp15_64 -- handles a mrrc/mcrr trap on a guest CP15 access
470  * @vcpu: The VCPU pointer
471  * @run:  The kvm_run struct
472  */
kvm_handle_cp15_64(struct kvm_vcpu * vcpu,struct kvm_run * run)473 int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
474 {
475 	struct coproc_params params;
476 
477 	params.CRn = (kvm_vcpu_get_hsr(vcpu) >> 1) & 0xf;
478 	params.Rt1 = (kvm_vcpu_get_hsr(vcpu) >> 5) & 0xf;
479 	params.is_write = ((kvm_vcpu_get_hsr(vcpu) & 1) == 0);
480 	params.is_64bit = true;
481 
482 	params.Op1 = (kvm_vcpu_get_hsr(vcpu) >> 16) & 0xf;
483 	params.Op2 = 0;
484 	params.Rt2 = (kvm_vcpu_get_hsr(vcpu) >> 10) & 0xf;
485 	params.CRm = 0;
486 
487 	return emulate_cp15(vcpu, &params);
488 }
489 
reset_coproc_regs(struct kvm_vcpu * vcpu,const struct coproc_reg * table,size_t num)490 static void reset_coproc_regs(struct kvm_vcpu *vcpu,
491 			      const struct coproc_reg *table, size_t num)
492 {
493 	unsigned long i;
494 
495 	for (i = 0; i < num; i++)
496 		if (table[i].reset)
497 			table[i].reset(vcpu, &table[i]);
498 }
499 
500 /**
501  * kvm_handle_cp15_32 -- handles a mrc/mcr trap on a guest CP15 access
502  * @vcpu: The VCPU pointer
503  * @run:  The kvm_run struct
504  */
kvm_handle_cp15_32(struct kvm_vcpu * vcpu,struct kvm_run * run)505 int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
506 {
507 	struct coproc_params params;
508 
509 	params.CRm = (kvm_vcpu_get_hsr(vcpu) >> 1) & 0xf;
510 	params.Rt1 = (kvm_vcpu_get_hsr(vcpu) >> 5) & 0xf;
511 	params.is_write = ((kvm_vcpu_get_hsr(vcpu) & 1) == 0);
512 	params.is_64bit = false;
513 
514 	params.CRn = (kvm_vcpu_get_hsr(vcpu) >> 10) & 0xf;
515 	params.Op1 = (kvm_vcpu_get_hsr(vcpu) >> 14) & 0x7;
516 	params.Op2 = (kvm_vcpu_get_hsr(vcpu) >> 17) & 0x7;
517 	params.Rt2 = 0;
518 
519 	return emulate_cp15(vcpu, &params);
520 }
521 
522 /******************************************************************************
523  * Userspace API
524  *****************************************************************************/
525 
index_to_params(u64 id,struct coproc_params * params)526 static bool index_to_params(u64 id, struct coproc_params *params)
527 {
528 	switch (id & KVM_REG_SIZE_MASK) {
529 	case KVM_REG_SIZE_U32:
530 		/* Any unused index bits means it's not valid. */
531 		if (id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK
532 			   | KVM_REG_ARM_COPROC_MASK
533 			   | KVM_REG_ARM_32_CRN_MASK
534 			   | KVM_REG_ARM_CRM_MASK
535 			   | KVM_REG_ARM_OPC1_MASK
536 			   | KVM_REG_ARM_32_OPC2_MASK))
537 			return false;
538 
539 		params->is_64bit = false;
540 		params->CRn = ((id & KVM_REG_ARM_32_CRN_MASK)
541 			       >> KVM_REG_ARM_32_CRN_SHIFT);
542 		params->CRm = ((id & KVM_REG_ARM_CRM_MASK)
543 			       >> KVM_REG_ARM_CRM_SHIFT);
544 		params->Op1 = ((id & KVM_REG_ARM_OPC1_MASK)
545 			       >> KVM_REG_ARM_OPC1_SHIFT);
546 		params->Op2 = ((id & KVM_REG_ARM_32_OPC2_MASK)
547 			       >> KVM_REG_ARM_32_OPC2_SHIFT);
548 		return true;
549 	case KVM_REG_SIZE_U64:
550 		/* Any unused index bits means it's not valid. */
551 		if (id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK
552 			      | KVM_REG_ARM_COPROC_MASK
553 			      | KVM_REG_ARM_CRM_MASK
554 			      | KVM_REG_ARM_OPC1_MASK))
555 			return false;
556 		params->is_64bit = true;
557 		/* CRm to CRn: see cp15_to_index for details */
558 		params->CRn = ((id & KVM_REG_ARM_CRM_MASK)
559 			       >> KVM_REG_ARM_CRM_SHIFT);
560 		params->Op1 = ((id & KVM_REG_ARM_OPC1_MASK)
561 			       >> KVM_REG_ARM_OPC1_SHIFT);
562 		params->Op2 = 0;
563 		params->CRm = 0;
564 		return true;
565 	default:
566 		return false;
567 	}
568 }
569 
570 /* Decode an index value, and find the cp15 coproc_reg entry. */
index_to_coproc_reg(struct kvm_vcpu * vcpu,u64 id)571 static const struct coproc_reg *index_to_coproc_reg(struct kvm_vcpu *vcpu,
572 						    u64 id)
573 {
574 	size_t num;
575 	const struct coproc_reg *table, *r;
576 	struct coproc_params params;
577 
578 	/* We only do cp15 for now. */
579 	if ((id & KVM_REG_ARM_COPROC_MASK) >> KVM_REG_ARM_COPROC_SHIFT != 15)
580 		return NULL;
581 
582 	if (!index_to_params(id, &params))
583 		return NULL;
584 
585 	table = get_target_table(vcpu->arch.target, &num);
586 	r = find_reg(&params, table, num);
587 	if (!r)
588 		r = find_reg(&params, cp15_regs, ARRAY_SIZE(cp15_regs));
589 
590 	/* Not saved in the cp15 array? */
591 	if (r && !r->reg)
592 		r = NULL;
593 
594 	return r;
595 }
596 
597 /*
598  * These are the invariant cp15 registers: we let the guest see the host
599  * versions of these, so they're part of the guest state.
600  *
601  * A future CPU may provide a mechanism to present different values to
602  * the guest, or a future kvm may trap them.
603  */
604 /* Unfortunately, there's no register-argument for mrc, so generate. */
605 #define FUNCTION_FOR32(crn, crm, op1, op2, name)			\
606 	static void get_##name(struct kvm_vcpu *v,			\
607 			       const struct coproc_reg *r)		\
608 	{								\
609 		u32 val;						\
610 									\
611 		asm volatile("mrc p15, " __stringify(op1)		\
612 			     ", %0, c" __stringify(crn)			\
613 			     ", c" __stringify(crm)			\
614 			     ", " __stringify(op2) "\n" : "=r" (val));	\
615 		((struct coproc_reg *)r)->val = val;			\
616 	}
617 
618 FUNCTION_FOR32(0, 0, 0, 0, MIDR)
619 FUNCTION_FOR32(0, 0, 0, 1, CTR)
620 FUNCTION_FOR32(0, 0, 0, 2, TCMTR)
621 FUNCTION_FOR32(0, 0, 0, 3, TLBTR)
622 FUNCTION_FOR32(0, 0, 0, 6, REVIDR)
623 FUNCTION_FOR32(0, 1, 0, 0, ID_PFR0)
624 FUNCTION_FOR32(0, 1, 0, 1, ID_PFR1)
625 FUNCTION_FOR32(0, 1, 0, 2, ID_DFR0)
626 FUNCTION_FOR32(0, 1, 0, 3, ID_AFR0)
627 FUNCTION_FOR32(0, 1, 0, 4, ID_MMFR0)
628 FUNCTION_FOR32(0, 1, 0, 5, ID_MMFR1)
629 FUNCTION_FOR32(0, 1, 0, 6, ID_MMFR2)
630 FUNCTION_FOR32(0, 1, 0, 7, ID_MMFR3)
631 FUNCTION_FOR32(0, 2, 0, 0, ID_ISAR0)
632 FUNCTION_FOR32(0, 2, 0, 1, ID_ISAR1)
633 FUNCTION_FOR32(0, 2, 0, 2, ID_ISAR2)
634 FUNCTION_FOR32(0, 2, 0, 3, ID_ISAR3)
635 FUNCTION_FOR32(0, 2, 0, 4, ID_ISAR4)
636 FUNCTION_FOR32(0, 2, 0, 5, ID_ISAR5)
637 FUNCTION_FOR32(0, 0, 1, 1, CLIDR)
638 FUNCTION_FOR32(0, 0, 1, 7, AIDR)
639 
640 /* ->val is filled in by kvm_invariant_coproc_table_init() */
641 static struct coproc_reg invariant_cp15[] = {
642 	{ CRn( 0), CRm( 0), Op1( 0), Op2( 0), is32, NULL, get_MIDR },
643 	{ CRn( 0), CRm( 0), Op1( 0), Op2( 1), is32, NULL, get_CTR },
644 	{ CRn( 0), CRm( 0), Op1( 0), Op2( 2), is32, NULL, get_TCMTR },
645 	{ CRn( 0), CRm( 0), Op1( 0), Op2( 3), is32, NULL, get_TLBTR },
646 	{ CRn( 0), CRm( 0), Op1( 0), Op2( 6), is32, NULL, get_REVIDR },
647 
648 	{ CRn( 0), CRm( 1), Op1( 0), Op2( 0), is32, NULL, get_ID_PFR0 },
649 	{ CRn( 0), CRm( 1), Op1( 0), Op2( 1), is32, NULL, get_ID_PFR1 },
650 	{ CRn( 0), CRm( 1), Op1( 0), Op2( 2), is32, NULL, get_ID_DFR0 },
651 	{ CRn( 0), CRm( 1), Op1( 0), Op2( 3), is32, NULL, get_ID_AFR0 },
652 	{ CRn( 0), CRm( 1), Op1( 0), Op2( 4), is32, NULL, get_ID_MMFR0 },
653 	{ CRn( 0), CRm( 1), Op1( 0), Op2( 5), is32, NULL, get_ID_MMFR1 },
654 	{ CRn( 0), CRm( 1), Op1( 0), Op2( 6), is32, NULL, get_ID_MMFR2 },
655 	{ CRn( 0), CRm( 1), Op1( 0), Op2( 7), is32, NULL, get_ID_MMFR3 },
656 
657 	{ CRn( 0), CRm( 2), Op1( 0), Op2( 0), is32, NULL, get_ID_ISAR0 },
658 	{ CRn( 0), CRm( 2), Op1( 0), Op2( 1), is32, NULL, get_ID_ISAR1 },
659 	{ CRn( 0), CRm( 2), Op1( 0), Op2( 2), is32, NULL, get_ID_ISAR2 },
660 	{ CRn( 0), CRm( 2), Op1( 0), Op2( 3), is32, NULL, get_ID_ISAR3 },
661 	{ CRn( 0), CRm( 2), Op1( 0), Op2( 4), is32, NULL, get_ID_ISAR4 },
662 	{ CRn( 0), CRm( 2), Op1( 0), Op2( 5), is32, NULL, get_ID_ISAR5 },
663 
664 	{ CRn( 0), CRm( 0), Op1( 1), Op2( 1), is32, NULL, get_CLIDR },
665 	{ CRn( 0), CRm( 0), Op1( 1), Op2( 7), is32, NULL, get_AIDR },
666 };
667 
668 /*
669  * Reads a register value from a userspace address to a kernel
670  * variable. Make sure that register size matches sizeof(*__val).
671  */
reg_from_user(void * val,const void __user * uaddr,u64 id)672 static int reg_from_user(void *val, const void __user *uaddr, u64 id)
673 {
674 	if (copy_from_user(val, uaddr, KVM_REG_SIZE(id)) != 0)
675 		return -EFAULT;
676 	return 0;
677 }
678 
679 /*
680  * Writes a register value to a userspace address from a kernel variable.
681  * Make sure that register size matches sizeof(*__val).
682  */
reg_to_user(void __user * uaddr,const void * val,u64 id)683 static int reg_to_user(void __user *uaddr, const void *val, u64 id)
684 {
685 	if (copy_to_user(uaddr, val, KVM_REG_SIZE(id)) != 0)
686 		return -EFAULT;
687 	return 0;
688 }
689 
get_invariant_cp15(u64 id,void __user * uaddr)690 static int get_invariant_cp15(u64 id, void __user *uaddr)
691 {
692 	struct coproc_params params;
693 	const struct coproc_reg *r;
694 	int ret;
695 
696 	if (!index_to_params(id, &params))
697 		return -ENOENT;
698 
699 	r = find_reg(&params, invariant_cp15, ARRAY_SIZE(invariant_cp15));
700 	if (!r)
701 		return -ENOENT;
702 
703 	ret = -ENOENT;
704 	if (KVM_REG_SIZE(id) == 4) {
705 		u32 val = r->val;
706 
707 		ret = reg_to_user(uaddr, &val, id);
708 	} else if (KVM_REG_SIZE(id) == 8) {
709 		ret = reg_to_user(uaddr, &r->val, id);
710 	}
711 	return ret;
712 }
713 
set_invariant_cp15(u64 id,void __user * uaddr)714 static int set_invariant_cp15(u64 id, void __user *uaddr)
715 {
716 	struct coproc_params params;
717 	const struct coproc_reg *r;
718 	int err;
719 	u64 val;
720 
721 	if (!index_to_params(id, &params))
722 		return -ENOENT;
723 	r = find_reg(&params, invariant_cp15, ARRAY_SIZE(invariant_cp15));
724 	if (!r)
725 		return -ENOENT;
726 
727 	err = -ENOENT;
728 	if (KVM_REG_SIZE(id) == 4) {
729 		u32 val32;
730 
731 		err = reg_from_user(&val32, uaddr, id);
732 		if (!err)
733 			val = val32;
734 	} else if (KVM_REG_SIZE(id) == 8) {
735 		err = reg_from_user(&val, uaddr, id);
736 	}
737 	if (err)
738 		return err;
739 
740 	/* This is what we mean by invariant: you can't change it. */
741 	if (r->val != val)
742 		return -EINVAL;
743 
744 	return 0;
745 }
746 
is_valid_cache(u32 val)747 static bool is_valid_cache(u32 val)
748 {
749 	u32 level, ctype;
750 
751 	if (val >= CSSELR_MAX)
752 		return false;
753 
754 	/* Bottom bit is Instruction or Data bit.  Next 3 bits are level. */
755         level = (val >> 1);
756         ctype = (cache_levels >> (level * 3)) & 7;
757 
758 	switch (ctype) {
759 	case 0: /* No cache */
760 		return false;
761 	case 1: /* Instruction cache only */
762 		return (val & 1);
763 	case 2: /* Data cache only */
764 	case 4: /* Unified cache */
765 		return !(val & 1);
766 	case 3: /* Separate instruction and data caches */
767 		return true;
768 	default: /* Reserved: we can't know instruction or data. */
769 		return false;
770 	}
771 }
772 
773 /* Which cache CCSIDR represents depends on CSSELR value. */
get_ccsidr(u32 csselr)774 static u32 get_ccsidr(u32 csselr)
775 {
776 	u32 ccsidr;
777 
778 	/* Make sure noone else changes CSSELR during this! */
779 	local_irq_disable();
780 	/* Put value into CSSELR */
781 	asm volatile("mcr p15, 2, %0, c0, c0, 0" : : "r" (csselr));
782 	isb();
783 	/* Read result out of CCSIDR */
784 	asm volatile("mrc p15, 1, %0, c0, c0, 0" : "=r" (ccsidr));
785 	local_irq_enable();
786 
787 	return ccsidr;
788 }
789 
demux_c15_get(u64 id,void __user * uaddr)790 static int demux_c15_get(u64 id, void __user *uaddr)
791 {
792 	u32 val;
793 	u32 __user *uval = uaddr;
794 
795 	/* Fail if we have unknown bits set. */
796 	if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK
797 		   | ((1 << KVM_REG_ARM_COPROC_SHIFT)-1)))
798 		return -ENOENT;
799 
800 	switch (id & KVM_REG_ARM_DEMUX_ID_MASK) {
801 	case KVM_REG_ARM_DEMUX_ID_CCSIDR:
802 		if (KVM_REG_SIZE(id) != 4)
803 			return -ENOENT;
804 		val = (id & KVM_REG_ARM_DEMUX_VAL_MASK)
805 			>> KVM_REG_ARM_DEMUX_VAL_SHIFT;
806 		if (!is_valid_cache(val))
807 			return -ENOENT;
808 
809 		return put_user(get_ccsidr(val), uval);
810 	default:
811 		return -ENOENT;
812 	}
813 }
814 
demux_c15_set(u64 id,void __user * uaddr)815 static int demux_c15_set(u64 id, void __user *uaddr)
816 {
817 	u32 val, newval;
818 	u32 __user *uval = uaddr;
819 
820 	/* Fail if we have unknown bits set. */
821 	if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK
822 		   | ((1 << KVM_REG_ARM_COPROC_SHIFT)-1)))
823 		return -ENOENT;
824 
825 	switch (id & KVM_REG_ARM_DEMUX_ID_MASK) {
826 	case KVM_REG_ARM_DEMUX_ID_CCSIDR:
827 		if (KVM_REG_SIZE(id) != 4)
828 			return -ENOENT;
829 		val = (id & KVM_REG_ARM_DEMUX_VAL_MASK)
830 			>> KVM_REG_ARM_DEMUX_VAL_SHIFT;
831 		if (!is_valid_cache(val))
832 			return -ENOENT;
833 
834 		if (get_user(newval, uval))
835 			return -EFAULT;
836 
837 		/* This is also invariant: you can't change it. */
838 		if (newval != get_ccsidr(val))
839 			return -EINVAL;
840 		return 0;
841 	default:
842 		return -ENOENT;
843 	}
844 }
845 
846 #ifdef CONFIG_VFPv3
847 static const int vfp_sysregs[] = { KVM_REG_ARM_VFP_FPEXC,
848 				   KVM_REG_ARM_VFP_FPSCR,
849 				   KVM_REG_ARM_VFP_FPINST,
850 				   KVM_REG_ARM_VFP_FPINST2,
851 				   KVM_REG_ARM_VFP_MVFR0,
852 				   KVM_REG_ARM_VFP_MVFR1,
853 				   KVM_REG_ARM_VFP_FPSID };
854 
num_fp_regs(void)855 static unsigned int num_fp_regs(void)
856 {
857 	if (((fmrx(MVFR0) & MVFR0_A_SIMD_MASK) >> MVFR0_A_SIMD_BIT) == 2)
858 		return 32;
859 	else
860 		return 16;
861 }
862 
num_vfp_regs(void)863 static unsigned int num_vfp_regs(void)
864 {
865 	/* Normal FP regs + control regs. */
866 	return num_fp_regs() + ARRAY_SIZE(vfp_sysregs);
867 }
868 
copy_vfp_regids(u64 __user * uindices)869 static int copy_vfp_regids(u64 __user *uindices)
870 {
871 	unsigned int i;
872 	const u64 u32reg = KVM_REG_ARM | KVM_REG_SIZE_U32 | KVM_REG_ARM_VFP;
873 	const u64 u64reg = KVM_REG_ARM | KVM_REG_SIZE_U64 | KVM_REG_ARM_VFP;
874 
875 	for (i = 0; i < num_fp_regs(); i++) {
876 		if (put_user((u64reg | KVM_REG_ARM_VFP_BASE_REG) + i,
877 			     uindices))
878 			return -EFAULT;
879 		uindices++;
880 	}
881 
882 	for (i = 0; i < ARRAY_SIZE(vfp_sysregs); i++) {
883 		if (put_user(u32reg | vfp_sysregs[i], uindices))
884 			return -EFAULT;
885 		uindices++;
886 	}
887 
888 	return num_vfp_regs();
889 }
890 
vfp_get_reg(const struct kvm_vcpu * vcpu,u64 id,void __user * uaddr)891 static int vfp_get_reg(const struct kvm_vcpu *vcpu, u64 id, void __user *uaddr)
892 {
893 	u32 vfpid = (id & KVM_REG_ARM_VFP_MASK);
894 	u32 val;
895 
896 	/* Fail if we have unknown bits set. */
897 	if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK
898 		   | ((1 << KVM_REG_ARM_COPROC_SHIFT)-1)))
899 		return -ENOENT;
900 
901 	if (vfpid < num_fp_regs()) {
902 		if (KVM_REG_SIZE(id) != 8)
903 			return -ENOENT;
904 		return reg_to_user(uaddr, &vcpu->arch.vfp_guest.fpregs[vfpid],
905 				   id);
906 	}
907 
908 	/* FP control registers are all 32 bit. */
909 	if (KVM_REG_SIZE(id) != 4)
910 		return -ENOENT;
911 
912 	switch (vfpid) {
913 	case KVM_REG_ARM_VFP_FPEXC:
914 		return reg_to_user(uaddr, &vcpu->arch.vfp_guest.fpexc, id);
915 	case KVM_REG_ARM_VFP_FPSCR:
916 		return reg_to_user(uaddr, &vcpu->arch.vfp_guest.fpscr, id);
917 	case KVM_REG_ARM_VFP_FPINST:
918 		return reg_to_user(uaddr, &vcpu->arch.vfp_guest.fpinst, id);
919 	case KVM_REG_ARM_VFP_FPINST2:
920 		return reg_to_user(uaddr, &vcpu->arch.vfp_guest.fpinst2, id);
921 	case KVM_REG_ARM_VFP_MVFR0:
922 		val = fmrx(MVFR0);
923 		return reg_to_user(uaddr, &val, id);
924 	case KVM_REG_ARM_VFP_MVFR1:
925 		val = fmrx(MVFR1);
926 		return reg_to_user(uaddr, &val, id);
927 	case KVM_REG_ARM_VFP_FPSID:
928 		val = fmrx(FPSID);
929 		return reg_to_user(uaddr, &val, id);
930 	default:
931 		return -ENOENT;
932 	}
933 }
934 
vfp_set_reg(struct kvm_vcpu * vcpu,u64 id,const void __user * uaddr)935 static int vfp_set_reg(struct kvm_vcpu *vcpu, u64 id, const void __user *uaddr)
936 {
937 	u32 vfpid = (id & KVM_REG_ARM_VFP_MASK);
938 	u32 val;
939 
940 	/* Fail if we have unknown bits set. */
941 	if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK
942 		   | ((1 << KVM_REG_ARM_COPROC_SHIFT)-1)))
943 		return -ENOENT;
944 
945 	if (vfpid < num_fp_regs()) {
946 		if (KVM_REG_SIZE(id) != 8)
947 			return -ENOENT;
948 		return reg_from_user(&vcpu->arch.vfp_guest.fpregs[vfpid],
949 				     uaddr, id);
950 	}
951 
952 	/* FP control registers are all 32 bit. */
953 	if (KVM_REG_SIZE(id) != 4)
954 		return -ENOENT;
955 
956 	switch (vfpid) {
957 	case KVM_REG_ARM_VFP_FPEXC:
958 		return reg_from_user(&vcpu->arch.vfp_guest.fpexc, uaddr, id);
959 	case KVM_REG_ARM_VFP_FPSCR:
960 		return reg_from_user(&vcpu->arch.vfp_guest.fpscr, uaddr, id);
961 	case KVM_REG_ARM_VFP_FPINST:
962 		return reg_from_user(&vcpu->arch.vfp_guest.fpinst, uaddr, id);
963 	case KVM_REG_ARM_VFP_FPINST2:
964 		return reg_from_user(&vcpu->arch.vfp_guest.fpinst2, uaddr, id);
965 	/* These are invariant. */
966 	case KVM_REG_ARM_VFP_MVFR0:
967 		if (reg_from_user(&val, uaddr, id))
968 			return -EFAULT;
969 		if (val != fmrx(MVFR0))
970 			return -EINVAL;
971 		return 0;
972 	case KVM_REG_ARM_VFP_MVFR1:
973 		if (reg_from_user(&val, uaddr, id))
974 			return -EFAULT;
975 		if (val != fmrx(MVFR1))
976 			return -EINVAL;
977 		return 0;
978 	case KVM_REG_ARM_VFP_FPSID:
979 		if (reg_from_user(&val, uaddr, id))
980 			return -EFAULT;
981 		if (val != fmrx(FPSID))
982 			return -EINVAL;
983 		return 0;
984 	default:
985 		return -ENOENT;
986 	}
987 }
988 #else /* !CONFIG_VFPv3 */
num_vfp_regs(void)989 static unsigned int num_vfp_regs(void)
990 {
991 	return 0;
992 }
993 
copy_vfp_regids(u64 __user * uindices)994 static int copy_vfp_regids(u64 __user *uindices)
995 {
996 	return 0;
997 }
998 
vfp_get_reg(const struct kvm_vcpu * vcpu,u64 id,void __user * uaddr)999 static int vfp_get_reg(const struct kvm_vcpu *vcpu, u64 id, void __user *uaddr)
1000 {
1001 	return -ENOENT;
1002 }
1003 
vfp_set_reg(struct kvm_vcpu * vcpu,u64 id,const void __user * uaddr)1004 static int vfp_set_reg(struct kvm_vcpu *vcpu, u64 id, const void __user *uaddr)
1005 {
1006 	return -ENOENT;
1007 }
1008 #endif /* !CONFIG_VFPv3 */
1009 
kvm_arm_coproc_get_reg(struct kvm_vcpu * vcpu,const struct kvm_one_reg * reg)1010 int kvm_arm_coproc_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
1011 {
1012 	const struct coproc_reg *r;
1013 	void __user *uaddr = (void __user *)(long)reg->addr;
1014 	int ret;
1015 
1016 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
1017 		return demux_c15_get(reg->id, uaddr);
1018 
1019 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_VFP)
1020 		return vfp_get_reg(vcpu, reg->id, uaddr);
1021 
1022 	r = index_to_coproc_reg(vcpu, reg->id);
1023 	if (!r)
1024 		return get_invariant_cp15(reg->id, uaddr);
1025 
1026 	ret = -ENOENT;
1027 	if (KVM_REG_SIZE(reg->id) == 8) {
1028 		u64 val;
1029 
1030 		val = vcpu_cp15_reg64_get(vcpu, r);
1031 		ret = reg_to_user(uaddr, &val, reg->id);
1032 	} else if (KVM_REG_SIZE(reg->id) == 4) {
1033 		ret = reg_to_user(uaddr, &vcpu->arch.cp15[r->reg], reg->id);
1034 	}
1035 
1036 	return ret;
1037 }
1038 
kvm_arm_coproc_set_reg(struct kvm_vcpu * vcpu,const struct kvm_one_reg * reg)1039 int kvm_arm_coproc_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
1040 {
1041 	const struct coproc_reg *r;
1042 	void __user *uaddr = (void __user *)(long)reg->addr;
1043 	int ret;
1044 
1045 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
1046 		return demux_c15_set(reg->id, uaddr);
1047 
1048 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_VFP)
1049 		return vfp_set_reg(vcpu, reg->id, uaddr);
1050 
1051 	r = index_to_coproc_reg(vcpu, reg->id);
1052 	if (!r)
1053 		return set_invariant_cp15(reg->id, uaddr);
1054 
1055 	ret = -ENOENT;
1056 	if (KVM_REG_SIZE(reg->id) == 8) {
1057 		u64 val;
1058 
1059 		ret = reg_from_user(&val, uaddr, reg->id);
1060 		if (!ret)
1061 			vcpu_cp15_reg64_set(vcpu, r, val);
1062 	} else if (KVM_REG_SIZE(reg->id) == 4) {
1063 		ret = reg_from_user(&vcpu->arch.cp15[r->reg], uaddr, reg->id);
1064 	}
1065 
1066 	return ret;
1067 }
1068 
num_demux_regs(void)1069 static unsigned int num_demux_regs(void)
1070 {
1071 	unsigned int i, count = 0;
1072 
1073 	for (i = 0; i < CSSELR_MAX; i++)
1074 		if (is_valid_cache(i))
1075 			count++;
1076 
1077 	return count;
1078 }
1079 
write_demux_regids(u64 __user * uindices)1080 static int write_demux_regids(u64 __user *uindices)
1081 {
1082 	u64 val = KVM_REG_ARM | KVM_REG_SIZE_U32 | KVM_REG_ARM_DEMUX;
1083 	unsigned int i;
1084 
1085 	val |= KVM_REG_ARM_DEMUX_ID_CCSIDR;
1086 	for (i = 0; i < CSSELR_MAX; i++) {
1087 		if (!is_valid_cache(i))
1088 			continue;
1089 		if (put_user(val | i, uindices))
1090 			return -EFAULT;
1091 		uindices++;
1092 	}
1093 	return 0;
1094 }
1095 
cp15_to_index(const struct coproc_reg * reg)1096 static u64 cp15_to_index(const struct coproc_reg *reg)
1097 {
1098 	u64 val = KVM_REG_ARM | (15 << KVM_REG_ARM_COPROC_SHIFT);
1099 	if (reg->is_64) {
1100 		val |= KVM_REG_SIZE_U64;
1101 		val |= (reg->Op1 << KVM_REG_ARM_OPC1_SHIFT);
1102 		/*
1103 		 * CRn always denotes the primary coproc. reg. nr. for the
1104 		 * in-kernel representation, but the user space API uses the
1105 		 * CRm for the encoding, because it is modelled after the
1106 		 * MRRC/MCRR instructions: see the ARM ARM rev. c page
1107 		 * B3-1445
1108 		 */
1109 		val |= (reg->CRn << KVM_REG_ARM_CRM_SHIFT);
1110 	} else {
1111 		val |= KVM_REG_SIZE_U32;
1112 		val |= (reg->Op1 << KVM_REG_ARM_OPC1_SHIFT);
1113 		val |= (reg->Op2 << KVM_REG_ARM_32_OPC2_SHIFT);
1114 		val |= (reg->CRm << KVM_REG_ARM_CRM_SHIFT);
1115 		val |= (reg->CRn << KVM_REG_ARM_32_CRN_SHIFT);
1116 	}
1117 	return val;
1118 }
1119 
copy_reg_to_user(const struct coproc_reg * reg,u64 __user ** uind)1120 static bool copy_reg_to_user(const struct coproc_reg *reg, u64 __user **uind)
1121 {
1122 	if (!*uind)
1123 		return true;
1124 
1125 	if (put_user(cp15_to_index(reg), *uind))
1126 		return false;
1127 
1128 	(*uind)++;
1129 	return true;
1130 }
1131 
1132 /* Assumed ordered tables, see kvm_coproc_table_init. */
walk_cp15(struct kvm_vcpu * vcpu,u64 __user * uind)1133 static int walk_cp15(struct kvm_vcpu *vcpu, u64 __user *uind)
1134 {
1135 	const struct coproc_reg *i1, *i2, *end1, *end2;
1136 	unsigned int total = 0;
1137 	size_t num;
1138 
1139 	/* We check for duplicates here, to allow arch-specific overrides. */
1140 	i1 = get_target_table(vcpu->arch.target, &num);
1141 	end1 = i1 + num;
1142 	i2 = cp15_regs;
1143 	end2 = cp15_regs + ARRAY_SIZE(cp15_regs);
1144 
1145 	BUG_ON(i1 == end1 || i2 == end2);
1146 
1147 	/* Walk carefully, as both tables may refer to the same register. */
1148 	while (i1 || i2) {
1149 		int cmp = cmp_reg(i1, i2);
1150 		/* target-specific overrides generic entry. */
1151 		if (cmp <= 0) {
1152 			/* Ignore registers we trap but don't save. */
1153 			if (i1->reg) {
1154 				if (!copy_reg_to_user(i1, &uind))
1155 					return -EFAULT;
1156 				total++;
1157 			}
1158 		} else {
1159 			/* Ignore registers we trap but don't save. */
1160 			if (i2->reg) {
1161 				if (!copy_reg_to_user(i2, &uind))
1162 					return -EFAULT;
1163 				total++;
1164 			}
1165 		}
1166 
1167 		if (cmp <= 0 && ++i1 == end1)
1168 			i1 = NULL;
1169 		if (cmp >= 0 && ++i2 == end2)
1170 			i2 = NULL;
1171 	}
1172 	return total;
1173 }
1174 
kvm_arm_num_coproc_regs(struct kvm_vcpu * vcpu)1175 unsigned long kvm_arm_num_coproc_regs(struct kvm_vcpu *vcpu)
1176 {
1177 	return ARRAY_SIZE(invariant_cp15)
1178 		+ num_demux_regs()
1179 		+ num_vfp_regs()
1180 		+ walk_cp15(vcpu, (u64 __user *)NULL);
1181 }
1182 
kvm_arm_copy_coproc_indices(struct kvm_vcpu * vcpu,u64 __user * uindices)1183 int kvm_arm_copy_coproc_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
1184 {
1185 	unsigned int i;
1186 	int err;
1187 
1188 	/* Then give them all the invariant registers' indices. */
1189 	for (i = 0; i < ARRAY_SIZE(invariant_cp15); i++) {
1190 		if (put_user(cp15_to_index(&invariant_cp15[i]), uindices))
1191 			return -EFAULT;
1192 		uindices++;
1193 	}
1194 
1195 	err = walk_cp15(vcpu, uindices);
1196 	if (err < 0)
1197 		return err;
1198 	uindices += err;
1199 
1200 	err = copy_vfp_regids(uindices);
1201 	if (err < 0)
1202 		return err;
1203 	uindices += err;
1204 
1205 	return write_demux_regids(uindices);
1206 }
1207 
kvm_coproc_table_init(void)1208 void kvm_coproc_table_init(void)
1209 {
1210 	unsigned int i;
1211 
1212 	/* Make sure tables are unique and in order. */
1213 	for (i = 1; i < ARRAY_SIZE(cp15_regs); i++)
1214 		BUG_ON(cmp_reg(&cp15_regs[i-1], &cp15_regs[i]) >= 0);
1215 
1216 	/* We abuse the reset function to overwrite the table itself. */
1217 	for (i = 0; i < ARRAY_SIZE(invariant_cp15); i++)
1218 		invariant_cp15[i].reset(NULL, &invariant_cp15[i]);
1219 
1220 	/*
1221 	 * CLIDR format is awkward, so clean it up.  See ARM B4.1.20:
1222 	 *
1223 	 *   If software reads the Cache Type fields from Ctype1
1224 	 *   upwards, once it has seen a value of 0b000, no caches
1225 	 *   exist at further-out levels of the hierarchy. So, for
1226 	 *   example, if Ctype3 is the first Cache Type field with a
1227 	 *   value of 0b000, the values of Ctype4 to Ctype7 must be
1228 	 *   ignored.
1229 	 */
1230 	asm volatile("mrc p15, 1, %0, c0, c0, 1" : "=r" (cache_levels));
1231 	for (i = 0; i < 7; i++)
1232 		if (((cache_levels >> (i*3)) & 7) == 0)
1233 			break;
1234 	/* Clear all higher bits. */
1235 	cache_levels &= (1 << (i*3))-1;
1236 }
1237 
1238 /**
1239  * kvm_reset_coprocs - sets cp15 registers to reset value
1240  * @vcpu: The VCPU pointer
1241  *
1242  * This function finds the right table above and sets the registers on the
1243  * virtual CPU struct to their architecturally defined reset values.
1244  */
kvm_reset_coprocs(struct kvm_vcpu * vcpu)1245 void kvm_reset_coprocs(struct kvm_vcpu *vcpu)
1246 {
1247 	size_t num;
1248 	const struct coproc_reg *table;
1249 
1250 	/* Catch someone adding a register without putting in reset entry. */
1251 	memset(vcpu->arch.cp15, 0x42, sizeof(vcpu->arch.cp15));
1252 
1253 	/* Generic chip reset first (so target could override). */
1254 	reset_coproc_regs(vcpu, cp15_regs, ARRAY_SIZE(cp15_regs));
1255 
1256 	table = get_target_table(vcpu->arch.target, &num);
1257 	reset_coproc_regs(vcpu, table, num);
1258 
1259 	for (num = 1; num < NR_CP15_REGS; num++)
1260 		if (vcpu->arch.cp15[num] == 0x42424242)
1261 			panic("Didn't reset vcpu->arch.cp15[%zi]", num);
1262 }
1263