xref: /openbmc/linux/arch/arm64/kvm/sys_regs.c (revision 4949009e)
1 /*
2  * Copyright (C) 2012,2013 - ARM Ltd
3  * Author: Marc Zyngier <marc.zyngier@arm.com>
4  *
5  * Derived from arch/arm/kvm/coproc.c:
6  * Copyright (C) 2012 - Virtual Open Systems and Columbia University
7  * Authors: Rusty Russell <rusty@rustcorp.com.au>
8  *          Christoffer Dall <c.dall@virtualopensystems.com>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License, version 2, as
12  * published by the Free Software Foundation.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
21  */
22 
23 #include <linux/mm.h>
24 #include <linux/kvm_host.h>
25 #include <linux/uaccess.h>
26 #include <asm/kvm_arm.h>
27 #include <asm/kvm_host.h>
28 #include <asm/kvm_emulate.h>
29 #include <asm/kvm_coproc.h>
30 #include <asm/kvm_mmu.h>
31 #include <asm/cacheflush.h>
32 #include <asm/cputype.h>
33 #include <asm/debug-monitors.h>
34 #include <trace/events/kvm.h>
35 
36 #include "sys_regs.h"
37 
38 /*
39  * All of this file is extremly similar to the ARM coproc.c, but the
40  * types are different. My gut feeling is that it should be pretty
41  * easy to merge, but that would be an ABI breakage -- again. VFP
42  * would also need to be abstracted.
43  *
44  * For AArch32, we only take care of what is being trapped. Anything
45  * that has to do with init and userspace access has to go via the
46  * 64bit interface.
47  */
48 
49 /* 3 bits per cache level, as per CLIDR, but non-existent caches always 0 */
50 static u32 cache_levels;
51 
52 /* CSSELR values; used to index KVM_REG_ARM_DEMUX_ID_CCSIDR */
53 #define CSSELR_MAX 12
54 
55 /* Which cache CCSIDR represents depends on CSSELR value. */
56 static u32 get_ccsidr(u32 csselr)
57 {
58 	u32 ccsidr;
59 
60 	/* Make sure noone else changes CSSELR during this! */
61 	local_irq_disable();
62 	/* Put value into CSSELR */
63 	asm volatile("msr csselr_el1, %x0" : : "r" (csselr));
64 	isb();
65 	/* Read result out of CCSIDR */
66 	asm volatile("mrs %0, ccsidr_el1" : "=r" (ccsidr));
67 	local_irq_enable();
68 
69 	return ccsidr;
70 }
71 
72 /*
73  * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
74  */
75 static bool access_dcsw(struct kvm_vcpu *vcpu,
76 			const struct sys_reg_params *p,
77 			const struct sys_reg_desc *r)
78 {
79 	if (!p->is_write)
80 		return read_from_write_only(vcpu, p);
81 
82 	kvm_set_way_flush(vcpu);
83 	return true;
84 }
85 
86 /*
87  * Generic accessor for VM registers. Only called as long as HCR_TVM
88  * is set. If the guest enables the MMU, we stop trapping the VM
89  * sys_regs and leave it in complete control of the caches.
90  */
91 static bool access_vm_reg(struct kvm_vcpu *vcpu,
92 			  const struct sys_reg_params *p,
93 			  const struct sys_reg_desc *r)
94 {
95 	unsigned long val;
96 	bool was_enabled = vcpu_has_cache_enabled(vcpu);
97 
98 	BUG_ON(!p->is_write);
99 
100 	val = *vcpu_reg(vcpu, p->Rt);
101 	if (!p->is_aarch32) {
102 		vcpu_sys_reg(vcpu, r->reg) = val;
103 	} else {
104 		if (!p->is_32bit)
105 			vcpu_cp15_64_high(vcpu, r->reg) = val >> 32;
106 		vcpu_cp15_64_low(vcpu, r->reg) = val & 0xffffffffUL;
107 	}
108 
109 	kvm_toggle_cache(vcpu, was_enabled);
110 	return true;
111 }
112 
113 static bool trap_raz_wi(struct kvm_vcpu *vcpu,
114 			const struct sys_reg_params *p,
115 			const struct sys_reg_desc *r)
116 {
117 	if (p->is_write)
118 		return ignore_write(vcpu, p);
119 	else
120 		return read_zero(vcpu, p);
121 }
122 
123 static bool trap_oslsr_el1(struct kvm_vcpu *vcpu,
124 			   const struct sys_reg_params *p,
125 			   const struct sys_reg_desc *r)
126 {
127 	if (p->is_write) {
128 		return ignore_write(vcpu, p);
129 	} else {
130 		*vcpu_reg(vcpu, p->Rt) = (1 << 3);
131 		return true;
132 	}
133 }
134 
135 static bool trap_dbgauthstatus_el1(struct kvm_vcpu *vcpu,
136 				   const struct sys_reg_params *p,
137 				   const struct sys_reg_desc *r)
138 {
139 	if (p->is_write) {
140 		return ignore_write(vcpu, p);
141 	} else {
142 		u32 val;
143 		asm volatile("mrs %0, dbgauthstatus_el1" : "=r" (val));
144 		*vcpu_reg(vcpu, p->Rt) = val;
145 		return true;
146 	}
147 }
148 
149 /*
150  * We want to avoid world-switching all the DBG registers all the
151  * time:
152  *
153  * - If we've touched any debug register, it is likely that we're
154  *   going to touch more of them. It then makes sense to disable the
155  *   traps and start doing the save/restore dance
156  * - If debug is active (DBG_MDSCR_KDE or DBG_MDSCR_MDE set), it is
157  *   then mandatory to save/restore the registers, as the guest
158  *   depends on them.
159  *
160  * For this, we use a DIRTY bit, indicating the guest has modified the
161  * debug registers, used as follow:
162  *
163  * On guest entry:
164  * - If the dirty bit is set (because we're coming back from trapping),
165  *   disable the traps, save host registers, restore guest registers.
166  * - If debug is actively in use (DBG_MDSCR_KDE or DBG_MDSCR_MDE set),
167  *   set the dirty bit, disable the traps, save host registers,
168  *   restore guest registers.
169  * - Otherwise, enable the traps
170  *
171  * On guest exit:
172  * - If the dirty bit is set, save guest registers, restore host
173  *   registers and clear the dirty bit. This ensure that the host can
174  *   now use the debug registers.
175  */
176 static bool trap_debug_regs(struct kvm_vcpu *vcpu,
177 			    const struct sys_reg_params *p,
178 			    const struct sys_reg_desc *r)
179 {
180 	if (p->is_write) {
181 		vcpu_sys_reg(vcpu, r->reg) = *vcpu_reg(vcpu, p->Rt);
182 		vcpu->arch.debug_flags |= KVM_ARM64_DEBUG_DIRTY;
183 	} else {
184 		*vcpu_reg(vcpu, p->Rt) = vcpu_sys_reg(vcpu, r->reg);
185 	}
186 
187 	return true;
188 }
189 
190 static void reset_amair_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
191 {
192 	u64 amair;
193 
194 	asm volatile("mrs %0, amair_el1\n" : "=r" (amair));
195 	vcpu_sys_reg(vcpu, AMAIR_EL1) = amair;
196 }
197 
198 static void reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
199 {
200 	/*
201 	 * Simply map the vcpu_id into the Aff0 field of the MPIDR.
202 	 */
203 	vcpu_sys_reg(vcpu, MPIDR_EL1) = (1UL << 31) | (vcpu->vcpu_id & 0xff);
204 }
205 
206 /* Silly macro to expand the DBG{BCR,BVR,WVR,WCR}n_EL1 registers in one go */
207 #define DBG_BCR_BVR_WCR_WVR_EL1(n)					\
208 	/* DBGBVRn_EL1 */						\
209 	{ Op0(0b10), Op1(0b000), CRn(0b0000), CRm((n)), Op2(0b100),	\
210 	  trap_debug_regs, reset_val, (DBGBVR0_EL1 + (n)), 0 },		\
211 	/* DBGBCRn_EL1 */						\
212 	{ Op0(0b10), Op1(0b000), CRn(0b0000), CRm((n)), Op2(0b101),	\
213 	  trap_debug_regs, reset_val, (DBGBCR0_EL1 + (n)), 0 },		\
214 	/* DBGWVRn_EL1 */						\
215 	{ Op0(0b10), Op1(0b000), CRn(0b0000), CRm((n)), Op2(0b110),	\
216 	  trap_debug_regs, reset_val, (DBGWVR0_EL1 + (n)), 0 },		\
217 	/* DBGWCRn_EL1 */						\
218 	{ Op0(0b10), Op1(0b000), CRn(0b0000), CRm((n)), Op2(0b111),	\
219 	  trap_debug_regs, reset_val, (DBGWCR0_EL1 + (n)), 0 }
220 
221 /*
222  * Architected system registers.
223  * Important: Must be sorted ascending by Op0, Op1, CRn, CRm, Op2
224  *
225  * We could trap ID_DFR0 and tell the guest we don't support performance
226  * monitoring.  Unfortunately the patch to make the kernel check ID_DFR0 was
227  * NAKed, so it will read the PMCR anyway.
228  *
229  * Therefore we tell the guest we have 0 counters.  Unfortunately, we
230  * must always support PMCCNTR (the cycle counter): we just RAZ/WI for
231  * all PM registers, which doesn't crash the guest kernel at least.
232  *
233  * Debug handling: We do trap most, if not all debug related system
234  * registers. The implementation is good enough to ensure that a guest
235  * can use these with minimal performance degradation. The drawback is
236  * that we don't implement any of the external debug, none of the
237  * OSlock protocol. This should be revisited if we ever encounter a
238  * more demanding guest...
239  */
240 static const struct sys_reg_desc sys_reg_descs[] = {
241 	/* DC ISW */
242 	{ Op0(0b01), Op1(0b000), CRn(0b0111), CRm(0b0110), Op2(0b010),
243 	  access_dcsw },
244 	/* DC CSW */
245 	{ Op0(0b01), Op1(0b000), CRn(0b0111), CRm(0b1010), Op2(0b010),
246 	  access_dcsw },
247 	/* DC CISW */
248 	{ Op0(0b01), Op1(0b000), CRn(0b0111), CRm(0b1110), Op2(0b010),
249 	  access_dcsw },
250 
251 	DBG_BCR_BVR_WCR_WVR_EL1(0),
252 	DBG_BCR_BVR_WCR_WVR_EL1(1),
253 	/* MDCCINT_EL1 */
254 	{ Op0(0b10), Op1(0b000), CRn(0b0000), CRm(0b0010), Op2(0b000),
255 	  trap_debug_regs, reset_val, MDCCINT_EL1, 0 },
256 	/* MDSCR_EL1 */
257 	{ Op0(0b10), Op1(0b000), CRn(0b0000), CRm(0b0010), Op2(0b010),
258 	  trap_debug_regs, reset_val, MDSCR_EL1, 0 },
259 	DBG_BCR_BVR_WCR_WVR_EL1(2),
260 	DBG_BCR_BVR_WCR_WVR_EL1(3),
261 	DBG_BCR_BVR_WCR_WVR_EL1(4),
262 	DBG_BCR_BVR_WCR_WVR_EL1(5),
263 	DBG_BCR_BVR_WCR_WVR_EL1(6),
264 	DBG_BCR_BVR_WCR_WVR_EL1(7),
265 	DBG_BCR_BVR_WCR_WVR_EL1(8),
266 	DBG_BCR_BVR_WCR_WVR_EL1(9),
267 	DBG_BCR_BVR_WCR_WVR_EL1(10),
268 	DBG_BCR_BVR_WCR_WVR_EL1(11),
269 	DBG_BCR_BVR_WCR_WVR_EL1(12),
270 	DBG_BCR_BVR_WCR_WVR_EL1(13),
271 	DBG_BCR_BVR_WCR_WVR_EL1(14),
272 	DBG_BCR_BVR_WCR_WVR_EL1(15),
273 
274 	/* MDRAR_EL1 */
275 	{ Op0(0b10), Op1(0b000), CRn(0b0001), CRm(0b0000), Op2(0b000),
276 	  trap_raz_wi },
277 	/* OSLAR_EL1 */
278 	{ Op0(0b10), Op1(0b000), CRn(0b0001), CRm(0b0000), Op2(0b100),
279 	  trap_raz_wi },
280 	/* OSLSR_EL1 */
281 	{ Op0(0b10), Op1(0b000), CRn(0b0001), CRm(0b0001), Op2(0b100),
282 	  trap_oslsr_el1 },
283 	/* OSDLR_EL1 */
284 	{ Op0(0b10), Op1(0b000), CRn(0b0001), CRm(0b0011), Op2(0b100),
285 	  trap_raz_wi },
286 	/* DBGPRCR_EL1 */
287 	{ Op0(0b10), Op1(0b000), CRn(0b0001), CRm(0b0100), Op2(0b100),
288 	  trap_raz_wi },
289 	/* DBGCLAIMSET_EL1 */
290 	{ Op0(0b10), Op1(0b000), CRn(0b0111), CRm(0b1000), Op2(0b110),
291 	  trap_raz_wi },
292 	/* DBGCLAIMCLR_EL1 */
293 	{ Op0(0b10), Op1(0b000), CRn(0b0111), CRm(0b1001), Op2(0b110),
294 	  trap_raz_wi },
295 	/* DBGAUTHSTATUS_EL1 */
296 	{ Op0(0b10), Op1(0b000), CRn(0b0111), CRm(0b1110), Op2(0b110),
297 	  trap_dbgauthstatus_el1 },
298 
299 	/* TEECR32_EL1 */
300 	{ Op0(0b10), Op1(0b010), CRn(0b0000), CRm(0b0000), Op2(0b000),
301 	  NULL, reset_val, TEECR32_EL1, 0 },
302 	/* TEEHBR32_EL1 */
303 	{ Op0(0b10), Op1(0b010), CRn(0b0001), CRm(0b0000), Op2(0b000),
304 	  NULL, reset_val, TEEHBR32_EL1, 0 },
305 
306 	/* MDCCSR_EL1 */
307 	{ Op0(0b10), Op1(0b011), CRn(0b0000), CRm(0b0001), Op2(0b000),
308 	  trap_raz_wi },
309 	/* DBGDTR_EL0 */
310 	{ Op0(0b10), Op1(0b011), CRn(0b0000), CRm(0b0100), Op2(0b000),
311 	  trap_raz_wi },
312 	/* DBGDTR[TR]X_EL0 */
313 	{ Op0(0b10), Op1(0b011), CRn(0b0000), CRm(0b0101), Op2(0b000),
314 	  trap_raz_wi },
315 
316 	/* DBGVCR32_EL2 */
317 	{ Op0(0b10), Op1(0b100), CRn(0b0000), CRm(0b0111), Op2(0b000),
318 	  NULL, reset_val, DBGVCR32_EL2, 0 },
319 
320 	/* MPIDR_EL1 */
321 	{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0000), Op2(0b101),
322 	  NULL, reset_mpidr, MPIDR_EL1 },
323 	/* SCTLR_EL1 */
324 	{ Op0(0b11), Op1(0b000), CRn(0b0001), CRm(0b0000), Op2(0b000),
325 	  access_vm_reg, reset_val, SCTLR_EL1, 0x00C50078 },
326 	/* CPACR_EL1 */
327 	{ Op0(0b11), Op1(0b000), CRn(0b0001), CRm(0b0000), Op2(0b010),
328 	  NULL, reset_val, CPACR_EL1, 0 },
329 	/* TTBR0_EL1 */
330 	{ Op0(0b11), Op1(0b000), CRn(0b0010), CRm(0b0000), Op2(0b000),
331 	  access_vm_reg, reset_unknown, TTBR0_EL1 },
332 	/* TTBR1_EL1 */
333 	{ Op0(0b11), Op1(0b000), CRn(0b0010), CRm(0b0000), Op2(0b001),
334 	  access_vm_reg, reset_unknown, TTBR1_EL1 },
335 	/* TCR_EL1 */
336 	{ Op0(0b11), Op1(0b000), CRn(0b0010), CRm(0b0000), Op2(0b010),
337 	  access_vm_reg, reset_val, TCR_EL1, 0 },
338 
339 	/* AFSR0_EL1 */
340 	{ Op0(0b11), Op1(0b000), CRn(0b0101), CRm(0b0001), Op2(0b000),
341 	  access_vm_reg, reset_unknown, AFSR0_EL1 },
342 	/* AFSR1_EL1 */
343 	{ Op0(0b11), Op1(0b000), CRn(0b0101), CRm(0b0001), Op2(0b001),
344 	  access_vm_reg, reset_unknown, AFSR1_EL1 },
345 	/* ESR_EL1 */
346 	{ Op0(0b11), Op1(0b000), CRn(0b0101), CRm(0b0010), Op2(0b000),
347 	  access_vm_reg, reset_unknown, ESR_EL1 },
348 	/* FAR_EL1 */
349 	{ Op0(0b11), Op1(0b000), CRn(0b0110), CRm(0b0000), Op2(0b000),
350 	  access_vm_reg, reset_unknown, FAR_EL1 },
351 	/* PAR_EL1 */
352 	{ Op0(0b11), Op1(0b000), CRn(0b0111), CRm(0b0100), Op2(0b000),
353 	  NULL, reset_unknown, PAR_EL1 },
354 
355 	/* PMINTENSET_EL1 */
356 	{ Op0(0b11), Op1(0b000), CRn(0b1001), CRm(0b1110), Op2(0b001),
357 	  trap_raz_wi },
358 	/* PMINTENCLR_EL1 */
359 	{ Op0(0b11), Op1(0b000), CRn(0b1001), CRm(0b1110), Op2(0b010),
360 	  trap_raz_wi },
361 
362 	/* MAIR_EL1 */
363 	{ Op0(0b11), Op1(0b000), CRn(0b1010), CRm(0b0010), Op2(0b000),
364 	  access_vm_reg, reset_unknown, MAIR_EL1 },
365 	/* AMAIR_EL1 */
366 	{ Op0(0b11), Op1(0b000), CRn(0b1010), CRm(0b0011), Op2(0b000),
367 	  access_vm_reg, reset_amair_el1, AMAIR_EL1 },
368 
369 	/* VBAR_EL1 */
370 	{ Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b0000), Op2(0b000),
371 	  NULL, reset_val, VBAR_EL1, 0 },
372 
373 	/* ICC_SRE_EL1 */
374 	{ Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b1100), Op2(0b101),
375 	  trap_raz_wi },
376 
377 	/* CONTEXTIDR_EL1 */
378 	{ Op0(0b11), Op1(0b000), CRn(0b1101), CRm(0b0000), Op2(0b001),
379 	  access_vm_reg, reset_val, CONTEXTIDR_EL1, 0 },
380 	/* TPIDR_EL1 */
381 	{ Op0(0b11), Op1(0b000), CRn(0b1101), CRm(0b0000), Op2(0b100),
382 	  NULL, reset_unknown, TPIDR_EL1 },
383 
384 	/* CNTKCTL_EL1 */
385 	{ Op0(0b11), Op1(0b000), CRn(0b1110), CRm(0b0001), Op2(0b000),
386 	  NULL, reset_val, CNTKCTL_EL1, 0},
387 
388 	/* CSSELR_EL1 */
389 	{ Op0(0b11), Op1(0b010), CRn(0b0000), CRm(0b0000), Op2(0b000),
390 	  NULL, reset_unknown, CSSELR_EL1 },
391 
392 	/* PMCR_EL0 */
393 	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b000),
394 	  trap_raz_wi },
395 	/* PMCNTENSET_EL0 */
396 	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b001),
397 	  trap_raz_wi },
398 	/* PMCNTENCLR_EL0 */
399 	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b010),
400 	  trap_raz_wi },
401 	/* PMOVSCLR_EL0 */
402 	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b011),
403 	  trap_raz_wi },
404 	/* PMSWINC_EL0 */
405 	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b100),
406 	  trap_raz_wi },
407 	/* PMSELR_EL0 */
408 	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b101),
409 	  trap_raz_wi },
410 	/* PMCEID0_EL0 */
411 	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b110),
412 	  trap_raz_wi },
413 	/* PMCEID1_EL0 */
414 	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b111),
415 	  trap_raz_wi },
416 	/* PMCCNTR_EL0 */
417 	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1101), Op2(0b000),
418 	  trap_raz_wi },
419 	/* PMXEVTYPER_EL0 */
420 	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1101), Op2(0b001),
421 	  trap_raz_wi },
422 	/* PMXEVCNTR_EL0 */
423 	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1101), Op2(0b010),
424 	  trap_raz_wi },
425 	/* PMUSERENR_EL0 */
426 	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1110), Op2(0b000),
427 	  trap_raz_wi },
428 	/* PMOVSSET_EL0 */
429 	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1110), Op2(0b011),
430 	  trap_raz_wi },
431 
432 	/* TPIDR_EL0 */
433 	{ Op0(0b11), Op1(0b011), CRn(0b1101), CRm(0b0000), Op2(0b010),
434 	  NULL, reset_unknown, TPIDR_EL0 },
435 	/* TPIDRRO_EL0 */
436 	{ Op0(0b11), Op1(0b011), CRn(0b1101), CRm(0b0000), Op2(0b011),
437 	  NULL, reset_unknown, TPIDRRO_EL0 },
438 
439 	/* DACR32_EL2 */
440 	{ Op0(0b11), Op1(0b100), CRn(0b0011), CRm(0b0000), Op2(0b000),
441 	  NULL, reset_unknown, DACR32_EL2 },
442 	/* IFSR32_EL2 */
443 	{ Op0(0b11), Op1(0b100), CRn(0b0101), CRm(0b0000), Op2(0b001),
444 	  NULL, reset_unknown, IFSR32_EL2 },
445 	/* FPEXC32_EL2 */
446 	{ Op0(0b11), Op1(0b100), CRn(0b0101), CRm(0b0011), Op2(0b000),
447 	  NULL, reset_val, FPEXC32_EL2, 0x70 },
448 };
449 
450 static bool trap_dbgidr(struct kvm_vcpu *vcpu,
451 			const struct sys_reg_params *p,
452 			const struct sys_reg_desc *r)
453 {
454 	if (p->is_write) {
455 		return ignore_write(vcpu, p);
456 	} else {
457 		u64 dfr = read_cpuid(ID_AA64DFR0_EL1);
458 		u64 pfr = read_cpuid(ID_AA64PFR0_EL1);
459 		u32 el3 = !!((pfr >> 12) & 0xf);
460 
461 		*vcpu_reg(vcpu, p->Rt) = ((((dfr >> 20) & 0xf) << 28) |
462 					  (((dfr >> 12) & 0xf) << 24) |
463 					  (((dfr >> 28) & 0xf) << 20) |
464 					  (6 << 16) | (el3 << 14) | (el3 << 12));
465 		return true;
466 	}
467 }
468 
469 static bool trap_debug32(struct kvm_vcpu *vcpu,
470 			 const struct sys_reg_params *p,
471 			 const struct sys_reg_desc *r)
472 {
473 	if (p->is_write) {
474 		vcpu_cp14(vcpu, r->reg) = *vcpu_reg(vcpu, p->Rt);
475 		vcpu->arch.debug_flags |= KVM_ARM64_DEBUG_DIRTY;
476 	} else {
477 		*vcpu_reg(vcpu, p->Rt) = vcpu_cp14(vcpu, r->reg);
478 	}
479 
480 	return true;
481 }
482 
483 #define DBG_BCR_BVR_WCR_WVR(n)					\
484 	/* DBGBVRn */						\
485 	{ Op1( 0), CRn( 0), CRm((n)), Op2( 4), trap_debug32,	\
486 	  NULL, (cp14_DBGBVR0 + (n) * 2) },			\
487 	/* DBGBCRn */						\
488 	{ Op1( 0), CRn( 0), CRm((n)), Op2( 5), trap_debug32,	\
489 	  NULL, (cp14_DBGBCR0 + (n) * 2) },			\
490 	/* DBGWVRn */						\
491 	{ Op1( 0), CRn( 0), CRm((n)), Op2( 6), trap_debug32,	\
492 	  NULL, (cp14_DBGWVR0 + (n) * 2) },			\
493 	/* DBGWCRn */						\
494 	{ Op1( 0), CRn( 0), CRm((n)), Op2( 7), trap_debug32,	\
495 	  NULL, (cp14_DBGWCR0 + (n) * 2) }
496 
497 #define DBGBXVR(n)						\
498 	{ Op1( 0), CRn( 1), CRm((n)), Op2( 1), trap_debug32,	\
499 	  NULL, cp14_DBGBXVR0 + n * 2 }
500 
501 /*
502  * Trapped cp14 registers. We generally ignore most of the external
503  * debug, on the principle that they don't really make sense to a
504  * guest. Revisit this one day, whould this principle change.
505  */
506 static const struct sys_reg_desc cp14_regs[] = {
507 	/* DBGIDR */
508 	{ Op1( 0), CRn( 0), CRm( 0), Op2( 0), trap_dbgidr },
509 	/* DBGDTRRXext */
510 	{ Op1( 0), CRn( 0), CRm( 0), Op2( 2), trap_raz_wi },
511 
512 	DBG_BCR_BVR_WCR_WVR(0),
513 	/* DBGDSCRint */
514 	{ Op1( 0), CRn( 0), CRm( 1), Op2( 0), trap_raz_wi },
515 	DBG_BCR_BVR_WCR_WVR(1),
516 	/* DBGDCCINT */
517 	{ Op1( 0), CRn( 0), CRm( 2), Op2( 0), trap_debug32 },
518 	/* DBGDSCRext */
519 	{ Op1( 0), CRn( 0), CRm( 2), Op2( 2), trap_debug32 },
520 	DBG_BCR_BVR_WCR_WVR(2),
521 	/* DBGDTR[RT]Xint */
522 	{ Op1( 0), CRn( 0), CRm( 3), Op2( 0), trap_raz_wi },
523 	/* DBGDTR[RT]Xext */
524 	{ Op1( 0), CRn( 0), CRm( 3), Op2( 2), trap_raz_wi },
525 	DBG_BCR_BVR_WCR_WVR(3),
526 	DBG_BCR_BVR_WCR_WVR(4),
527 	DBG_BCR_BVR_WCR_WVR(5),
528 	/* DBGWFAR */
529 	{ Op1( 0), CRn( 0), CRm( 6), Op2( 0), trap_raz_wi },
530 	/* DBGOSECCR */
531 	{ Op1( 0), CRn( 0), CRm( 6), Op2( 2), trap_raz_wi },
532 	DBG_BCR_BVR_WCR_WVR(6),
533 	/* DBGVCR */
534 	{ Op1( 0), CRn( 0), CRm( 7), Op2( 0), trap_debug32 },
535 	DBG_BCR_BVR_WCR_WVR(7),
536 	DBG_BCR_BVR_WCR_WVR(8),
537 	DBG_BCR_BVR_WCR_WVR(9),
538 	DBG_BCR_BVR_WCR_WVR(10),
539 	DBG_BCR_BVR_WCR_WVR(11),
540 	DBG_BCR_BVR_WCR_WVR(12),
541 	DBG_BCR_BVR_WCR_WVR(13),
542 	DBG_BCR_BVR_WCR_WVR(14),
543 	DBG_BCR_BVR_WCR_WVR(15),
544 
545 	/* DBGDRAR (32bit) */
546 	{ Op1( 0), CRn( 1), CRm( 0), Op2( 0), trap_raz_wi },
547 
548 	DBGBXVR(0),
549 	/* DBGOSLAR */
550 	{ Op1( 0), CRn( 1), CRm( 0), Op2( 4), trap_raz_wi },
551 	DBGBXVR(1),
552 	/* DBGOSLSR */
553 	{ Op1( 0), CRn( 1), CRm( 1), Op2( 4), trap_oslsr_el1 },
554 	DBGBXVR(2),
555 	DBGBXVR(3),
556 	/* DBGOSDLR */
557 	{ Op1( 0), CRn( 1), CRm( 3), Op2( 4), trap_raz_wi },
558 	DBGBXVR(4),
559 	/* DBGPRCR */
560 	{ Op1( 0), CRn( 1), CRm( 4), Op2( 4), trap_raz_wi },
561 	DBGBXVR(5),
562 	DBGBXVR(6),
563 	DBGBXVR(7),
564 	DBGBXVR(8),
565 	DBGBXVR(9),
566 	DBGBXVR(10),
567 	DBGBXVR(11),
568 	DBGBXVR(12),
569 	DBGBXVR(13),
570 	DBGBXVR(14),
571 	DBGBXVR(15),
572 
573 	/* DBGDSAR (32bit) */
574 	{ Op1( 0), CRn( 2), CRm( 0), Op2( 0), trap_raz_wi },
575 
576 	/* DBGDEVID2 */
577 	{ Op1( 0), CRn( 7), CRm( 0), Op2( 7), trap_raz_wi },
578 	/* DBGDEVID1 */
579 	{ Op1( 0), CRn( 7), CRm( 1), Op2( 7), trap_raz_wi },
580 	/* DBGDEVID */
581 	{ Op1( 0), CRn( 7), CRm( 2), Op2( 7), trap_raz_wi },
582 	/* DBGCLAIMSET */
583 	{ Op1( 0), CRn( 7), CRm( 8), Op2( 6), trap_raz_wi },
584 	/* DBGCLAIMCLR */
585 	{ Op1( 0), CRn( 7), CRm( 9), Op2( 6), trap_raz_wi },
586 	/* DBGAUTHSTATUS */
587 	{ Op1( 0), CRn( 7), CRm(14), Op2( 6), trap_dbgauthstatus_el1 },
588 };
589 
590 /* Trapped cp14 64bit registers */
591 static const struct sys_reg_desc cp14_64_regs[] = {
592 	/* DBGDRAR (64bit) */
593 	{ Op1( 0), CRm( 1), .access = trap_raz_wi },
594 
595 	/* DBGDSAR (64bit) */
596 	{ Op1( 0), CRm( 2), .access = trap_raz_wi },
597 };
598 
599 /*
600  * Trapped cp15 registers. TTBR0/TTBR1 get a double encoding,
601  * depending on the way they are accessed (as a 32bit or a 64bit
602  * register).
603  */
604 static const struct sys_reg_desc cp15_regs[] = {
605 	{ Op1( 0), CRn( 1), CRm( 0), Op2( 0), access_vm_reg, NULL, c1_SCTLR },
606 	{ Op1( 0), CRn( 2), CRm( 0), Op2( 0), access_vm_reg, NULL, c2_TTBR0 },
607 	{ Op1( 0), CRn( 2), CRm( 0), Op2( 1), access_vm_reg, NULL, c2_TTBR1 },
608 	{ Op1( 0), CRn( 2), CRm( 0), Op2( 2), access_vm_reg, NULL, c2_TTBCR },
609 	{ Op1( 0), CRn( 3), CRm( 0), Op2( 0), access_vm_reg, NULL, c3_DACR },
610 	{ Op1( 0), CRn( 5), CRm( 0), Op2( 0), access_vm_reg, NULL, c5_DFSR },
611 	{ Op1( 0), CRn( 5), CRm( 0), Op2( 1), access_vm_reg, NULL, c5_IFSR },
612 	{ Op1( 0), CRn( 5), CRm( 1), Op2( 0), access_vm_reg, NULL, c5_ADFSR },
613 	{ Op1( 0), CRn( 5), CRm( 1), Op2( 1), access_vm_reg, NULL, c5_AIFSR },
614 	{ Op1( 0), CRn( 6), CRm( 0), Op2( 0), access_vm_reg, NULL, c6_DFAR },
615 	{ Op1( 0), CRn( 6), CRm( 0), Op2( 2), access_vm_reg, NULL, c6_IFAR },
616 
617 	/*
618 	 * DC{C,I,CI}SW operations:
619 	 */
620 	{ Op1( 0), CRn( 7), CRm( 6), Op2( 2), access_dcsw },
621 	{ Op1( 0), CRn( 7), CRm(10), Op2( 2), access_dcsw },
622 	{ Op1( 0), CRn( 7), CRm(14), Op2( 2), access_dcsw },
623 
624 	/* PMU */
625 	{ Op1( 0), CRn( 9), CRm(12), Op2( 0), trap_raz_wi },
626 	{ Op1( 0), CRn( 9), CRm(12), Op2( 1), trap_raz_wi },
627 	{ Op1( 0), CRn( 9), CRm(12), Op2( 2), trap_raz_wi },
628 	{ Op1( 0), CRn( 9), CRm(12), Op2( 3), trap_raz_wi },
629 	{ Op1( 0), CRn( 9), CRm(12), Op2( 5), trap_raz_wi },
630 	{ Op1( 0), CRn( 9), CRm(12), Op2( 6), trap_raz_wi },
631 	{ Op1( 0), CRn( 9), CRm(12), Op2( 7), trap_raz_wi },
632 	{ Op1( 0), CRn( 9), CRm(13), Op2( 0), trap_raz_wi },
633 	{ Op1( 0), CRn( 9), CRm(13), Op2( 1), trap_raz_wi },
634 	{ Op1( 0), CRn( 9), CRm(13), Op2( 2), trap_raz_wi },
635 	{ Op1( 0), CRn( 9), CRm(14), Op2( 0), trap_raz_wi },
636 	{ Op1( 0), CRn( 9), CRm(14), Op2( 1), trap_raz_wi },
637 	{ Op1( 0), CRn( 9), CRm(14), Op2( 2), trap_raz_wi },
638 
639 	{ Op1( 0), CRn(10), CRm( 2), Op2( 0), access_vm_reg, NULL, c10_PRRR },
640 	{ Op1( 0), CRn(10), CRm( 2), Op2( 1), access_vm_reg, NULL, c10_NMRR },
641 	{ Op1( 0), CRn(10), CRm( 3), Op2( 0), access_vm_reg, NULL, c10_AMAIR0 },
642 	{ Op1( 0), CRn(10), CRm( 3), Op2( 1), access_vm_reg, NULL, c10_AMAIR1 },
643 
644 	/* ICC_SRE */
645 	{ Op1( 0), CRn(12), CRm(12), Op2( 5), trap_raz_wi },
646 
647 	{ Op1( 0), CRn(13), CRm( 0), Op2( 1), access_vm_reg, NULL, c13_CID },
648 };
649 
650 static const struct sys_reg_desc cp15_64_regs[] = {
651 	{ Op1( 0), CRn( 0), CRm( 2), Op2( 0), access_vm_reg, NULL, c2_TTBR0 },
652 	{ Op1( 1), CRn( 0), CRm( 2), Op2( 0), access_vm_reg, NULL, c2_TTBR1 },
653 };
654 
655 /* Target specific emulation tables */
656 static struct kvm_sys_reg_target_table *target_tables[KVM_ARM_NUM_TARGETS];
657 
658 void kvm_register_target_sys_reg_table(unsigned int target,
659 				       struct kvm_sys_reg_target_table *table)
660 {
661 	target_tables[target] = table;
662 }
663 
664 /* Get specific register table for this target. */
665 static const struct sys_reg_desc *get_target_table(unsigned target,
666 						   bool mode_is_64,
667 						   size_t *num)
668 {
669 	struct kvm_sys_reg_target_table *table;
670 
671 	table = target_tables[target];
672 	if (mode_is_64) {
673 		*num = table->table64.num;
674 		return table->table64.table;
675 	} else {
676 		*num = table->table32.num;
677 		return table->table32.table;
678 	}
679 }
680 
681 static const struct sys_reg_desc *find_reg(const struct sys_reg_params *params,
682 					 const struct sys_reg_desc table[],
683 					 unsigned int num)
684 {
685 	unsigned int i;
686 
687 	for (i = 0; i < num; i++) {
688 		const struct sys_reg_desc *r = &table[i];
689 
690 		if (params->Op0 != r->Op0)
691 			continue;
692 		if (params->Op1 != r->Op1)
693 			continue;
694 		if (params->CRn != r->CRn)
695 			continue;
696 		if (params->CRm != r->CRm)
697 			continue;
698 		if (params->Op2 != r->Op2)
699 			continue;
700 
701 		return r;
702 	}
703 	return NULL;
704 }
705 
706 int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu, struct kvm_run *run)
707 {
708 	kvm_inject_undefined(vcpu);
709 	return 1;
710 }
711 
712 /*
713  * emulate_cp --  tries to match a sys_reg access in a handling table, and
714  *                call the corresponding trap handler.
715  *
716  * @params: pointer to the descriptor of the access
717  * @table: array of trap descriptors
718  * @num: size of the trap descriptor array
719  *
720  * Return 0 if the access has been handled, and -1 if not.
721  */
722 static int emulate_cp(struct kvm_vcpu *vcpu,
723 		      const struct sys_reg_params *params,
724 		      const struct sys_reg_desc *table,
725 		      size_t num)
726 {
727 	const struct sys_reg_desc *r;
728 
729 	if (!table)
730 		return -1;	/* Not handled */
731 
732 	r = find_reg(params, table, num);
733 
734 	if (r) {
735 		/*
736 		 * Not having an accessor means that we have
737 		 * configured a trap that we don't know how to
738 		 * handle. This certainly qualifies as a gross bug
739 		 * that should be fixed right away.
740 		 */
741 		BUG_ON(!r->access);
742 
743 		if (likely(r->access(vcpu, params, r))) {
744 			/* Skip instruction, since it was emulated */
745 			kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
746 		}
747 
748 		/* Handled */
749 		return 0;
750 	}
751 
752 	/* Not handled */
753 	return -1;
754 }
755 
756 static void unhandled_cp_access(struct kvm_vcpu *vcpu,
757 				struct sys_reg_params *params)
758 {
759 	u8 hsr_ec = kvm_vcpu_trap_get_class(vcpu);
760 	int cp;
761 
762 	switch(hsr_ec) {
763 	case ESR_EL2_EC_CP15_32:
764 	case ESR_EL2_EC_CP15_64:
765 		cp = 15;
766 		break;
767 	case ESR_EL2_EC_CP14_MR:
768 	case ESR_EL2_EC_CP14_64:
769 		cp = 14;
770 		break;
771 	default:
772 		WARN_ON((cp = -1));
773 	}
774 
775 	kvm_err("Unsupported guest CP%d access at: %08lx\n",
776 		cp, *vcpu_pc(vcpu));
777 	print_sys_reg_instr(params);
778 	kvm_inject_undefined(vcpu);
779 }
780 
781 /**
782  * kvm_handle_cp_64 -- handles a mrrc/mcrr trap on a guest CP15 access
783  * @vcpu: The VCPU pointer
784  * @run:  The kvm_run struct
785  */
786 static int kvm_handle_cp_64(struct kvm_vcpu *vcpu,
787 			    const struct sys_reg_desc *global,
788 			    size_t nr_global,
789 			    const struct sys_reg_desc *target_specific,
790 			    size_t nr_specific)
791 {
792 	struct sys_reg_params params;
793 	u32 hsr = kvm_vcpu_get_hsr(vcpu);
794 	int Rt2 = (hsr >> 10) & 0xf;
795 
796 	params.is_aarch32 = true;
797 	params.is_32bit = false;
798 	params.CRm = (hsr >> 1) & 0xf;
799 	params.Rt = (hsr >> 5) & 0xf;
800 	params.is_write = ((hsr & 1) == 0);
801 
802 	params.Op0 = 0;
803 	params.Op1 = (hsr >> 16) & 0xf;
804 	params.Op2 = 0;
805 	params.CRn = 0;
806 
807 	/*
808 	 * Massive hack here. Store Rt2 in the top 32bits so we only
809 	 * have one register to deal with. As we use the same trap
810 	 * backends between AArch32 and AArch64, we get away with it.
811 	 */
812 	if (params.is_write) {
813 		u64 val = *vcpu_reg(vcpu, params.Rt);
814 		val &= 0xffffffff;
815 		val |= *vcpu_reg(vcpu, Rt2) << 32;
816 		*vcpu_reg(vcpu, params.Rt) = val;
817 	}
818 
819 	if (!emulate_cp(vcpu, &params, target_specific, nr_specific))
820 		goto out;
821 	if (!emulate_cp(vcpu, &params, global, nr_global))
822 		goto out;
823 
824 	unhandled_cp_access(vcpu, &params);
825 
826 out:
827 	/* Do the opposite hack for the read side */
828 	if (!params.is_write) {
829 		u64 val = *vcpu_reg(vcpu, params.Rt);
830 		val >>= 32;
831 		*vcpu_reg(vcpu, Rt2) = val;
832 	}
833 
834 	return 1;
835 }
836 
837 /**
838  * kvm_handle_cp15_32 -- handles a mrc/mcr trap on a guest CP15 access
839  * @vcpu: The VCPU pointer
840  * @run:  The kvm_run struct
841  */
842 static int kvm_handle_cp_32(struct kvm_vcpu *vcpu,
843 			    const struct sys_reg_desc *global,
844 			    size_t nr_global,
845 			    const struct sys_reg_desc *target_specific,
846 			    size_t nr_specific)
847 {
848 	struct sys_reg_params params;
849 	u32 hsr = kvm_vcpu_get_hsr(vcpu);
850 
851 	params.is_aarch32 = true;
852 	params.is_32bit = true;
853 	params.CRm = (hsr >> 1) & 0xf;
854 	params.Rt  = (hsr >> 5) & 0xf;
855 	params.is_write = ((hsr & 1) == 0);
856 	params.CRn = (hsr >> 10) & 0xf;
857 	params.Op0 = 0;
858 	params.Op1 = (hsr >> 14) & 0x7;
859 	params.Op2 = (hsr >> 17) & 0x7;
860 
861 	if (!emulate_cp(vcpu, &params, target_specific, nr_specific))
862 		return 1;
863 	if (!emulate_cp(vcpu, &params, global, nr_global))
864 		return 1;
865 
866 	unhandled_cp_access(vcpu, &params);
867 	return 1;
868 }
869 
870 int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
871 {
872 	const struct sys_reg_desc *target_specific;
873 	size_t num;
874 
875 	target_specific = get_target_table(vcpu->arch.target, false, &num);
876 	return kvm_handle_cp_64(vcpu,
877 				cp15_64_regs, ARRAY_SIZE(cp15_64_regs),
878 				target_specific, num);
879 }
880 
881 int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
882 {
883 	const struct sys_reg_desc *target_specific;
884 	size_t num;
885 
886 	target_specific = get_target_table(vcpu->arch.target, false, &num);
887 	return kvm_handle_cp_32(vcpu,
888 				cp15_regs, ARRAY_SIZE(cp15_regs),
889 				target_specific, num);
890 }
891 
892 int kvm_handle_cp14_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
893 {
894 	return kvm_handle_cp_64(vcpu,
895 				cp14_64_regs, ARRAY_SIZE(cp14_64_regs),
896 				NULL, 0);
897 }
898 
899 int kvm_handle_cp14_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
900 {
901 	return kvm_handle_cp_32(vcpu,
902 				cp14_regs, ARRAY_SIZE(cp14_regs),
903 				NULL, 0);
904 }
905 
906 static int emulate_sys_reg(struct kvm_vcpu *vcpu,
907 			   const struct sys_reg_params *params)
908 {
909 	size_t num;
910 	const struct sys_reg_desc *table, *r;
911 
912 	table = get_target_table(vcpu->arch.target, true, &num);
913 
914 	/* Search target-specific then generic table. */
915 	r = find_reg(params, table, num);
916 	if (!r)
917 		r = find_reg(params, sys_reg_descs, ARRAY_SIZE(sys_reg_descs));
918 
919 	if (likely(r)) {
920 		/*
921 		 * Not having an accessor means that we have
922 		 * configured a trap that we don't know how to
923 		 * handle. This certainly qualifies as a gross bug
924 		 * that should be fixed right away.
925 		 */
926 		BUG_ON(!r->access);
927 
928 		if (likely(r->access(vcpu, params, r))) {
929 			/* Skip instruction, since it was emulated */
930 			kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
931 			return 1;
932 		}
933 		/* If access function fails, it should complain. */
934 	} else {
935 		kvm_err("Unsupported guest sys_reg access at: %lx\n",
936 			*vcpu_pc(vcpu));
937 		print_sys_reg_instr(params);
938 	}
939 	kvm_inject_undefined(vcpu);
940 	return 1;
941 }
942 
943 static void reset_sys_reg_descs(struct kvm_vcpu *vcpu,
944 			      const struct sys_reg_desc *table, size_t num)
945 {
946 	unsigned long i;
947 
948 	for (i = 0; i < num; i++)
949 		if (table[i].reset)
950 			table[i].reset(vcpu, &table[i]);
951 }
952 
953 /**
954  * kvm_handle_sys_reg -- handles a mrs/msr trap on a guest sys_reg access
955  * @vcpu: The VCPU pointer
956  * @run:  The kvm_run struct
957  */
958 int kvm_handle_sys_reg(struct kvm_vcpu *vcpu, struct kvm_run *run)
959 {
960 	struct sys_reg_params params;
961 	unsigned long esr = kvm_vcpu_get_hsr(vcpu);
962 
963 	params.is_aarch32 = false;
964 	params.is_32bit = false;
965 	params.Op0 = (esr >> 20) & 3;
966 	params.Op1 = (esr >> 14) & 0x7;
967 	params.CRn = (esr >> 10) & 0xf;
968 	params.CRm = (esr >> 1) & 0xf;
969 	params.Op2 = (esr >> 17) & 0x7;
970 	params.Rt = (esr >> 5) & 0x1f;
971 	params.is_write = !(esr & 1);
972 
973 	return emulate_sys_reg(vcpu, &params);
974 }
975 
976 /******************************************************************************
977  * Userspace API
978  *****************************************************************************/
979 
980 static bool index_to_params(u64 id, struct sys_reg_params *params)
981 {
982 	switch (id & KVM_REG_SIZE_MASK) {
983 	case KVM_REG_SIZE_U64:
984 		/* Any unused index bits means it's not valid. */
985 		if (id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK
986 			      | KVM_REG_ARM_COPROC_MASK
987 			      | KVM_REG_ARM64_SYSREG_OP0_MASK
988 			      | KVM_REG_ARM64_SYSREG_OP1_MASK
989 			      | KVM_REG_ARM64_SYSREG_CRN_MASK
990 			      | KVM_REG_ARM64_SYSREG_CRM_MASK
991 			      | KVM_REG_ARM64_SYSREG_OP2_MASK))
992 			return false;
993 		params->Op0 = ((id & KVM_REG_ARM64_SYSREG_OP0_MASK)
994 			       >> KVM_REG_ARM64_SYSREG_OP0_SHIFT);
995 		params->Op1 = ((id & KVM_REG_ARM64_SYSREG_OP1_MASK)
996 			       >> KVM_REG_ARM64_SYSREG_OP1_SHIFT);
997 		params->CRn = ((id & KVM_REG_ARM64_SYSREG_CRN_MASK)
998 			       >> KVM_REG_ARM64_SYSREG_CRN_SHIFT);
999 		params->CRm = ((id & KVM_REG_ARM64_SYSREG_CRM_MASK)
1000 			       >> KVM_REG_ARM64_SYSREG_CRM_SHIFT);
1001 		params->Op2 = ((id & KVM_REG_ARM64_SYSREG_OP2_MASK)
1002 			       >> KVM_REG_ARM64_SYSREG_OP2_SHIFT);
1003 		return true;
1004 	default:
1005 		return false;
1006 	}
1007 }
1008 
1009 /* Decode an index value, and find the sys_reg_desc entry. */
1010 static const struct sys_reg_desc *index_to_sys_reg_desc(struct kvm_vcpu *vcpu,
1011 						    u64 id)
1012 {
1013 	size_t num;
1014 	const struct sys_reg_desc *table, *r;
1015 	struct sys_reg_params params;
1016 
1017 	/* We only do sys_reg for now. */
1018 	if ((id & KVM_REG_ARM_COPROC_MASK) != KVM_REG_ARM64_SYSREG)
1019 		return NULL;
1020 
1021 	if (!index_to_params(id, &params))
1022 		return NULL;
1023 
1024 	table = get_target_table(vcpu->arch.target, true, &num);
1025 	r = find_reg(&params, table, num);
1026 	if (!r)
1027 		r = find_reg(&params, sys_reg_descs, ARRAY_SIZE(sys_reg_descs));
1028 
1029 	/* Not saved in the sys_reg array? */
1030 	if (r && !r->reg)
1031 		r = NULL;
1032 
1033 	return r;
1034 }
1035 
1036 /*
1037  * These are the invariant sys_reg registers: we let the guest see the
1038  * host versions of these, so they're part of the guest state.
1039  *
1040  * A future CPU may provide a mechanism to present different values to
1041  * the guest, or a future kvm may trap them.
1042  */
1043 
1044 #define FUNCTION_INVARIANT(reg)						\
1045 	static void get_##reg(struct kvm_vcpu *v,			\
1046 			      const struct sys_reg_desc *r)		\
1047 	{								\
1048 		u64 val;						\
1049 									\
1050 		asm volatile("mrs %0, " __stringify(reg) "\n"		\
1051 			     : "=r" (val));				\
1052 		((struct sys_reg_desc *)r)->val = val;			\
1053 	}
1054 
1055 FUNCTION_INVARIANT(midr_el1)
1056 FUNCTION_INVARIANT(ctr_el0)
1057 FUNCTION_INVARIANT(revidr_el1)
1058 FUNCTION_INVARIANT(id_pfr0_el1)
1059 FUNCTION_INVARIANT(id_pfr1_el1)
1060 FUNCTION_INVARIANT(id_dfr0_el1)
1061 FUNCTION_INVARIANT(id_afr0_el1)
1062 FUNCTION_INVARIANT(id_mmfr0_el1)
1063 FUNCTION_INVARIANT(id_mmfr1_el1)
1064 FUNCTION_INVARIANT(id_mmfr2_el1)
1065 FUNCTION_INVARIANT(id_mmfr3_el1)
1066 FUNCTION_INVARIANT(id_isar0_el1)
1067 FUNCTION_INVARIANT(id_isar1_el1)
1068 FUNCTION_INVARIANT(id_isar2_el1)
1069 FUNCTION_INVARIANT(id_isar3_el1)
1070 FUNCTION_INVARIANT(id_isar4_el1)
1071 FUNCTION_INVARIANT(id_isar5_el1)
1072 FUNCTION_INVARIANT(clidr_el1)
1073 FUNCTION_INVARIANT(aidr_el1)
1074 
1075 /* ->val is filled in by kvm_sys_reg_table_init() */
1076 static struct sys_reg_desc invariant_sys_regs[] = {
1077 	{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0000), Op2(0b000),
1078 	  NULL, get_midr_el1 },
1079 	{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0000), Op2(0b110),
1080 	  NULL, get_revidr_el1 },
1081 	{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b000),
1082 	  NULL, get_id_pfr0_el1 },
1083 	{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b001),
1084 	  NULL, get_id_pfr1_el1 },
1085 	{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b010),
1086 	  NULL, get_id_dfr0_el1 },
1087 	{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b011),
1088 	  NULL, get_id_afr0_el1 },
1089 	{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b100),
1090 	  NULL, get_id_mmfr0_el1 },
1091 	{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b101),
1092 	  NULL, get_id_mmfr1_el1 },
1093 	{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b110),
1094 	  NULL, get_id_mmfr2_el1 },
1095 	{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0001), Op2(0b111),
1096 	  NULL, get_id_mmfr3_el1 },
1097 	{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0010), Op2(0b000),
1098 	  NULL, get_id_isar0_el1 },
1099 	{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0010), Op2(0b001),
1100 	  NULL, get_id_isar1_el1 },
1101 	{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0010), Op2(0b010),
1102 	  NULL, get_id_isar2_el1 },
1103 	{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0010), Op2(0b011),
1104 	  NULL, get_id_isar3_el1 },
1105 	{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0010), Op2(0b100),
1106 	  NULL, get_id_isar4_el1 },
1107 	{ Op0(0b11), Op1(0b000), CRn(0b0000), CRm(0b0010), Op2(0b101),
1108 	  NULL, get_id_isar5_el1 },
1109 	{ Op0(0b11), Op1(0b001), CRn(0b0000), CRm(0b0000), Op2(0b001),
1110 	  NULL, get_clidr_el1 },
1111 	{ Op0(0b11), Op1(0b001), CRn(0b0000), CRm(0b0000), Op2(0b111),
1112 	  NULL, get_aidr_el1 },
1113 	{ Op0(0b11), Op1(0b011), CRn(0b0000), CRm(0b0000), Op2(0b001),
1114 	  NULL, get_ctr_el0 },
1115 };
1116 
1117 static int reg_from_user(u64 *val, const void __user *uaddr, u64 id)
1118 {
1119 	if (copy_from_user(val, uaddr, KVM_REG_SIZE(id)) != 0)
1120 		return -EFAULT;
1121 	return 0;
1122 }
1123 
1124 static int reg_to_user(void __user *uaddr, const u64 *val, u64 id)
1125 {
1126 	if (copy_to_user(uaddr, val, KVM_REG_SIZE(id)) != 0)
1127 		return -EFAULT;
1128 	return 0;
1129 }
1130 
1131 static int get_invariant_sys_reg(u64 id, void __user *uaddr)
1132 {
1133 	struct sys_reg_params params;
1134 	const struct sys_reg_desc *r;
1135 
1136 	if (!index_to_params(id, &params))
1137 		return -ENOENT;
1138 
1139 	r = find_reg(&params, invariant_sys_regs, ARRAY_SIZE(invariant_sys_regs));
1140 	if (!r)
1141 		return -ENOENT;
1142 
1143 	return reg_to_user(uaddr, &r->val, id);
1144 }
1145 
1146 static int set_invariant_sys_reg(u64 id, void __user *uaddr)
1147 {
1148 	struct sys_reg_params params;
1149 	const struct sys_reg_desc *r;
1150 	int err;
1151 	u64 val = 0; /* Make sure high bits are 0 for 32-bit regs */
1152 
1153 	if (!index_to_params(id, &params))
1154 		return -ENOENT;
1155 	r = find_reg(&params, invariant_sys_regs, ARRAY_SIZE(invariant_sys_regs));
1156 	if (!r)
1157 		return -ENOENT;
1158 
1159 	err = reg_from_user(&val, uaddr, id);
1160 	if (err)
1161 		return err;
1162 
1163 	/* This is what we mean by invariant: you can't change it. */
1164 	if (r->val != val)
1165 		return -EINVAL;
1166 
1167 	return 0;
1168 }
1169 
1170 static bool is_valid_cache(u32 val)
1171 {
1172 	u32 level, ctype;
1173 
1174 	if (val >= CSSELR_MAX)
1175 		return false;
1176 
1177 	/* Bottom bit is Instruction or Data bit.  Next 3 bits are level. */
1178 	level = (val >> 1);
1179 	ctype = (cache_levels >> (level * 3)) & 7;
1180 
1181 	switch (ctype) {
1182 	case 0: /* No cache */
1183 		return false;
1184 	case 1: /* Instruction cache only */
1185 		return (val & 1);
1186 	case 2: /* Data cache only */
1187 	case 4: /* Unified cache */
1188 		return !(val & 1);
1189 	case 3: /* Separate instruction and data caches */
1190 		return true;
1191 	default: /* Reserved: we can't know instruction or data. */
1192 		return false;
1193 	}
1194 }
1195 
1196 static int demux_c15_get(u64 id, void __user *uaddr)
1197 {
1198 	u32 val;
1199 	u32 __user *uval = uaddr;
1200 
1201 	/* Fail if we have unknown bits set. */
1202 	if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK
1203 		   | ((1 << KVM_REG_ARM_COPROC_SHIFT)-1)))
1204 		return -ENOENT;
1205 
1206 	switch (id & KVM_REG_ARM_DEMUX_ID_MASK) {
1207 	case KVM_REG_ARM_DEMUX_ID_CCSIDR:
1208 		if (KVM_REG_SIZE(id) != 4)
1209 			return -ENOENT;
1210 		val = (id & KVM_REG_ARM_DEMUX_VAL_MASK)
1211 			>> KVM_REG_ARM_DEMUX_VAL_SHIFT;
1212 		if (!is_valid_cache(val))
1213 			return -ENOENT;
1214 
1215 		return put_user(get_ccsidr(val), uval);
1216 	default:
1217 		return -ENOENT;
1218 	}
1219 }
1220 
1221 static int demux_c15_set(u64 id, void __user *uaddr)
1222 {
1223 	u32 val, newval;
1224 	u32 __user *uval = uaddr;
1225 
1226 	/* Fail if we have unknown bits set. */
1227 	if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK
1228 		   | ((1 << KVM_REG_ARM_COPROC_SHIFT)-1)))
1229 		return -ENOENT;
1230 
1231 	switch (id & KVM_REG_ARM_DEMUX_ID_MASK) {
1232 	case KVM_REG_ARM_DEMUX_ID_CCSIDR:
1233 		if (KVM_REG_SIZE(id) != 4)
1234 			return -ENOENT;
1235 		val = (id & KVM_REG_ARM_DEMUX_VAL_MASK)
1236 			>> KVM_REG_ARM_DEMUX_VAL_SHIFT;
1237 		if (!is_valid_cache(val))
1238 			return -ENOENT;
1239 
1240 		if (get_user(newval, uval))
1241 			return -EFAULT;
1242 
1243 		/* This is also invariant: you can't change it. */
1244 		if (newval != get_ccsidr(val))
1245 			return -EINVAL;
1246 		return 0;
1247 	default:
1248 		return -ENOENT;
1249 	}
1250 }
1251 
1252 int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
1253 {
1254 	const struct sys_reg_desc *r;
1255 	void __user *uaddr = (void __user *)(unsigned long)reg->addr;
1256 
1257 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
1258 		return demux_c15_get(reg->id, uaddr);
1259 
1260 	if (KVM_REG_SIZE(reg->id) != sizeof(__u64))
1261 		return -ENOENT;
1262 
1263 	r = index_to_sys_reg_desc(vcpu, reg->id);
1264 	if (!r)
1265 		return get_invariant_sys_reg(reg->id, uaddr);
1266 
1267 	return reg_to_user(uaddr, &vcpu_sys_reg(vcpu, r->reg), reg->id);
1268 }
1269 
1270 int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
1271 {
1272 	const struct sys_reg_desc *r;
1273 	void __user *uaddr = (void __user *)(unsigned long)reg->addr;
1274 
1275 	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
1276 		return demux_c15_set(reg->id, uaddr);
1277 
1278 	if (KVM_REG_SIZE(reg->id) != sizeof(__u64))
1279 		return -ENOENT;
1280 
1281 	r = index_to_sys_reg_desc(vcpu, reg->id);
1282 	if (!r)
1283 		return set_invariant_sys_reg(reg->id, uaddr);
1284 
1285 	return reg_from_user(&vcpu_sys_reg(vcpu, r->reg), uaddr, reg->id);
1286 }
1287 
1288 static unsigned int num_demux_regs(void)
1289 {
1290 	unsigned int i, count = 0;
1291 
1292 	for (i = 0; i < CSSELR_MAX; i++)
1293 		if (is_valid_cache(i))
1294 			count++;
1295 
1296 	return count;
1297 }
1298 
1299 static int write_demux_regids(u64 __user *uindices)
1300 {
1301 	u64 val = KVM_REG_ARM64 | KVM_REG_SIZE_U32 | KVM_REG_ARM_DEMUX;
1302 	unsigned int i;
1303 
1304 	val |= KVM_REG_ARM_DEMUX_ID_CCSIDR;
1305 	for (i = 0; i < CSSELR_MAX; i++) {
1306 		if (!is_valid_cache(i))
1307 			continue;
1308 		if (put_user(val | i, uindices))
1309 			return -EFAULT;
1310 		uindices++;
1311 	}
1312 	return 0;
1313 }
1314 
1315 static u64 sys_reg_to_index(const struct sys_reg_desc *reg)
1316 {
1317 	return (KVM_REG_ARM64 | KVM_REG_SIZE_U64 |
1318 		KVM_REG_ARM64_SYSREG |
1319 		(reg->Op0 << KVM_REG_ARM64_SYSREG_OP0_SHIFT) |
1320 		(reg->Op1 << KVM_REG_ARM64_SYSREG_OP1_SHIFT) |
1321 		(reg->CRn << KVM_REG_ARM64_SYSREG_CRN_SHIFT) |
1322 		(reg->CRm << KVM_REG_ARM64_SYSREG_CRM_SHIFT) |
1323 		(reg->Op2 << KVM_REG_ARM64_SYSREG_OP2_SHIFT));
1324 }
1325 
1326 static bool copy_reg_to_user(const struct sys_reg_desc *reg, u64 __user **uind)
1327 {
1328 	if (!*uind)
1329 		return true;
1330 
1331 	if (put_user(sys_reg_to_index(reg), *uind))
1332 		return false;
1333 
1334 	(*uind)++;
1335 	return true;
1336 }
1337 
1338 /* Assumed ordered tables, see kvm_sys_reg_table_init. */
1339 static int walk_sys_regs(struct kvm_vcpu *vcpu, u64 __user *uind)
1340 {
1341 	const struct sys_reg_desc *i1, *i2, *end1, *end2;
1342 	unsigned int total = 0;
1343 	size_t num;
1344 
1345 	/* We check for duplicates here, to allow arch-specific overrides. */
1346 	i1 = get_target_table(vcpu->arch.target, true, &num);
1347 	end1 = i1 + num;
1348 	i2 = sys_reg_descs;
1349 	end2 = sys_reg_descs + ARRAY_SIZE(sys_reg_descs);
1350 
1351 	BUG_ON(i1 == end1 || i2 == end2);
1352 
1353 	/* Walk carefully, as both tables may refer to the same register. */
1354 	while (i1 || i2) {
1355 		int cmp = cmp_sys_reg(i1, i2);
1356 		/* target-specific overrides generic entry. */
1357 		if (cmp <= 0) {
1358 			/* Ignore registers we trap but don't save. */
1359 			if (i1->reg) {
1360 				if (!copy_reg_to_user(i1, &uind))
1361 					return -EFAULT;
1362 				total++;
1363 			}
1364 		} else {
1365 			/* Ignore registers we trap but don't save. */
1366 			if (i2->reg) {
1367 				if (!copy_reg_to_user(i2, &uind))
1368 					return -EFAULT;
1369 				total++;
1370 			}
1371 		}
1372 
1373 		if (cmp <= 0 && ++i1 == end1)
1374 			i1 = NULL;
1375 		if (cmp >= 0 && ++i2 == end2)
1376 			i2 = NULL;
1377 	}
1378 	return total;
1379 }
1380 
1381 unsigned long kvm_arm_num_sys_reg_descs(struct kvm_vcpu *vcpu)
1382 {
1383 	return ARRAY_SIZE(invariant_sys_regs)
1384 		+ num_demux_regs()
1385 		+ walk_sys_regs(vcpu, (u64 __user *)NULL);
1386 }
1387 
1388 int kvm_arm_copy_sys_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
1389 {
1390 	unsigned int i;
1391 	int err;
1392 
1393 	/* Then give them all the invariant registers' indices. */
1394 	for (i = 0; i < ARRAY_SIZE(invariant_sys_regs); i++) {
1395 		if (put_user(sys_reg_to_index(&invariant_sys_regs[i]), uindices))
1396 			return -EFAULT;
1397 		uindices++;
1398 	}
1399 
1400 	err = walk_sys_regs(vcpu, uindices);
1401 	if (err < 0)
1402 		return err;
1403 	uindices += err;
1404 
1405 	return write_demux_regids(uindices);
1406 }
1407 
1408 static int check_sysreg_table(const struct sys_reg_desc *table, unsigned int n)
1409 {
1410 	unsigned int i;
1411 
1412 	for (i = 1; i < n; i++) {
1413 		if (cmp_sys_reg(&table[i-1], &table[i]) >= 0) {
1414 			kvm_err("sys_reg table %p out of order (%d)\n", table, i - 1);
1415 			return 1;
1416 		}
1417 	}
1418 
1419 	return 0;
1420 }
1421 
1422 void kvm_sys_reg_table_init(void)
1423 {
1424 	unsigned int i;
1425 	struct sys_reg_desc clidr;
1426 
1427 	/* Make sure tables are unique and in order. */
1428 	BUG_ON(check_sysreg_table(sys_reg_descs, ARRAY_SIZE(sys_reg_descs)));
1429 	BUG_ON(check_sysreg_table(cp14_regs, ARRAY_SIZE(cp14_regs)));
1430 	BUG_ON(check_sysreg_table(cp14_64_regs, ARRAY_SIZE(cp14_64_regs)));
1431 	BUG_ON(check_sysreg_table(cp15_regs, ARRAY_SIZE(cp15_regs)));
1432 	BUG_ON(check_sysreg_table(cp15_64_regs, ARRAY_SIZE(cp15_64_regs)));
1433 	BUG_ON(check_sysreg_table(invariant_sys_regs, ARRAY_SIZE(invariant_sys_regs)));
1434 
1435 	/* We abuse the reset function to overwrite the table itself. */
1436 	for (i = 0; i < ARRAY_SIZE(invariant_sys_regs); i++)
1437 		invariant_sys_regs[i].reset(NULL, &invariant_sys_regs[i]);
1438 
1439 	/*
1440 	 * CLIDR format is awkward, so clean it up.  See ARM B4.1.20:
1441 	 *
1442 	 *   If software reads the Cache Type fields from Ctype1
1443 	 *   upwards, once it has seen a value of 0b000, no caches
1444 	 *   exist at further-out levels of the hierarchy. So, for
1445 	 *   example, if Ctype3 is the first Cache Type field with a
1446 	 *   value of 0b000, the values of Ctype4 to Ctype7 must be
1447 	 *   ignored.
1448 	 */
1449 	get_clidr_el1(NULL, &clidr); /* Ugly... */
1450 	cache_levels = clidr.val;
1451 	for (i = 0; i < 7; i++)
1452 		if (((cache_levels >> (i*3)) & 7) == 0)
1453 			break;
1454 	/* Clear all higher bits. */
1455 	cache_levels &= (1 << (i*3))-1;
1456 }
1457 
1458 /**
1459  * kvm_reset_sys_regs - sets system registers to reset value
1460  * @vcpu: The VCPU pointer
1461  *
1462  * This function finds the right table above and sets the registers on the
1463  * virtual CPU struct to their architecturally defined reset values.
1464  */
1465 void kvm_reset_sys_regs(struct kvm_vcpu *vcpu)
1466 {
1467 	size_t num;
1468 	const struct sys_reg_desc *table;
1469 
1470 	/* Catch someone adding a register without putting in reset entry. */
1471 	memset(&vcpu->arch.ctxt.sys_regs, 0x42, sizeof(vcpu->arch.ctxt.sys_regs));
1472 
1473 	/* Generic chip reset first (so target could override). */
1474 	reset_sys_reg_descs(vcpu, sys_reg_descs, ARRAY_SIZE(sys_reg_descs));
1475 
1476 	table = get_target_table(vcpu->arch.target, true, &num);
1477 	reset_sys_reg_descs(vcpu, table, num);
1478 
1479 	for (num = 1; num < NR_SYS_REGS; num++)
1480 		if (vcpu_sys_reg(vcpu, num) == 0x4242424242424242)
1481 			panic("Didn't reset vcpu_sys_reg(%zi)", num);
1482 }
1483