Linux 6.7-rc7
[linux-modified.git] / arch / arm64 / kvm / vgic / vgic-mmio-v2.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * VGICv2 MMIO handling functions
4  */
5
6 #include <linux/irqchip/arm-gic.h>
7 #include <linux/kvm.h>
8 #include <linux/kvm_host.h>
9 #include <linux/nospec.h>
10
11 #include <kvm/iodev.h>
12 #include <kvm/arm_vgic.h>
13
14 #include "vgic.h"
15 #include "vgic-mmio.h"
16
17 /*
18  * The Revision field in the IIDR have the following meanings:
19  *
20  * Revision 1: Report GICv2 interrupts as group 0 instead of group 1
21  * Revision 2: Interrupt groups are guest-configurable and signaled using
22  *             their configured groups.
23  */
24
25 static unsigned long vgic_mmio_read_v2_misc(struct kvm_vcpu *vcpu,
26                                             gpa_t addr, unsigned int len)
27 {
28         struct vgic_dist *vgic = &vcpu->kvm->arch.vgic;
29         u32 value;
30
31         switch (addr & 0x0c) {
32         case GIC_DIST_CTRL:
33                 value = vgic->enabled ? GICD_ENABLE : 0;
34                 break;
35         case GIC_DIST_CTR:
36                 value = vgic->nr_spis + VGIC_NR_PRIVATE_IRQS;
37                 value = (value >> 5) - 1;
38                 value |= (atomic_read(&vcpu->kvm->online_vcpus) - 1) << 5;
39                 break;
40         case GIC_DIST_IIDR:
41                 value = (PRODUCT_ID_KVM << GICD_IIDR_PRODUCT_ID_SHIFT) |
42                         (vgic->implementation_rev << GICD_IIDR_REVISION_SHIFT) |
43                         (IMPLEMENTER_ARM << GICD_IIDR_IMPLEMENTER_SHIFT);
44                 break;
45         default:
46                 return 0;
47         }
48
49         return value;
50 }
51
52 static void vgic_mmio_write_v2_misc(struct kvm_vcpu *vcpu,
53                                     gpa_t addr, unsigned int len,
54                                     unsigned long val)
55 {
56         struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
57         bool was_enabled = dist->enabled;
58
59         switch (addr & 0x0c) {
60         case GIC_DIST_CTRL:
61                 dist->enabled = val & GICD_ENABLE;
62                 if (!was_enabled && dist->enabled)
63                         vgic_kick_vcpus(vcpu->kvm);
64                 break;
65         case GIC_DIST_CTR:
66         case GIC_DIST_IIDR:
67                 /* Nothing to do */
68                 return;
69         }
70 }
71
72 static int vgic_mmio_uaccess_write_v2_misc(struct kvm_vcpu *vcpu,
73                                            gpa_t addr, unsigned int len,
74                                            unsigned long val)
75 {
76         struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
77         u32 reg;
78
79         switch (addr & 0x0c) {
80         case GIC_DIST_IIDR:
81                 reg = vgic_mmio_read_v2_misc(vcpu, addr, len);
82                 if ((reg ^ val) & ~GICD_IIDR_REVISION_MASK)
83                         return -EINVAL;
84
85                 /*
86                  * If we observe a write to GICD_IIDR we know that userspace
87                  * has been updated and has had a chance to cope with older
88                  * kernels (VGICv2 IIDR.Revision == 0) incorrectly reporting
89                  * interrupts as group 1, and therefore we now allow groups to
90                  * be user writable.  Doing this by default would break
91                  * migration from old kernels to new kernels with legacy
92                  * userspace.
93                  */
94                 reg = FIELD_GET(GICD_IIDR_REVISION_MASK, reg);
95                 switch (reg) {
96                 case KVM_VGIC_IMP_REV_2:
97                 case KVM_VGIC_IMP_REV_3:
98                         vcpu->kvm->arch.vgic.v2_groups_user_writable = true;
99                         dist->implementation_rev = reg;
100                         return 0;
101                 default:
102                         return -EINVAL;
103                 }
104         }
105
106         vgic_mmio_write_v2_misc(vcpu, addr, len, val);
107         return 0;
108 }
109
110 static int vgic_mmio_uaccess_write_v2_group(struct kvm_vcpu *vcpu,
111                                             gpa_t addr, unsigned int len,
112                                             unsigned long val)
113 {
114         if (vcpu->kvm->arch.vgic.v2_groups_user_writable)
115                 vgic_mmio_write_group(vcpu, addr, len, val);
116
117         return 0;
118 }
119
120 static void vgic_mmio_write_sgir(struct kvm_vcpu *source_vcpu,
121                                  gpa_t addr, unsigned int len,
122                                  unsigned long val)
123 {
124         int nr_vcpus = atomic_read(&source_vcpu->kvm->online_vcpus);
125         int intid = val & 0xf;
126         int targets = (val >> 16) & 0xff;
127         int mode = (val >> 24) & 0x03;
128         struct kvm_vcpu *vcpu;
129         unsigned long flags, c;
130
131         switch (mode) {
132         case 0x0:               /* as specified by targets */
133                 break;
134         case 0x1:
135                 targets = (1U << nr_vcpus) - 1;                 /* all, ... */
136                 targets &= ~(1U << source_vcpu->vcpu_id);       /* but self */
137                 break;
138         case 0x2:               /* this very vCPU only */
139                 targets = (1U << source_vcpu->vcpu_id);
140                 break;
141         case 0x3:               /* reserved */
142                 return;
143         }
144
145         kvm_for_each_vcpu(c, vcpu, source_vcpu->kvm) {
146                 struct vgic_irq *irq;
147
148                 if (!(targets & (1U << c)))
149                         continue;
150
151                 irq = vgic_get_irq(source_vcpu->kvm, vcpu, intid);
152
153                 raw_spin_lock_irqsave(&irq->irq_lock, flags);
154                 irq->pending_latch = true;
155                 irq->source |= 1U << source_vcpu->vcpu_id;
156
157                 vgic_queue_irq_unlock(source_vcpu->kvm, irq, flags);
158                 vgic_put_irq(source_vcpu->kvm, irq);
159         }
160 }
161
162 static unsigned long vgic_mmio_read_target(struct kvm_vcpu *vcpu,
163                                            gpa_t addr, unsigned int len)
164 {
165         u32 intid = VGIC_ADDR_TO_INTID(addr, 8);
166         int i;
167         u64 val = 0;
168
169         for (i = 0; i < len; i++) {
170                 struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
171
172                 val |= (u64)irq->targets << (i * 8);
173
174                 vgic_put_irq(vcpu->kvm, irq);
175         }
176
177         return val;
178 }
179
180 static void vgic_mmio_write_target(struct kvm_vcpu *vcpu,
181                                    gpa_t addr, unsigned int len,
182                                    unsigned long val)
183 {
184         u32 intid = VGIC_ADDR_TO_INTID(addr, 8);
185         u8 cpu_mask = GENMASK(atomic_read(&vcpu->kvm->online_vcpus) - 1, 0);
186         int i;
187         unsigned long flags;
188
189         /* GICD_ITARGETSR[0-7] are read-only */
190         if (intid < VGIC_NR_PRIVATE_IRQS)
191                 return;
192
193         for (i = 0; i < len; i++) {
194                 struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, NULL, intid + i);
195                 int target;
196
197                 raw_spin_lock_irqsave(&irq->irq_lock, flags);
198
199                 irq->targets = (val >> (i * 8)) & cpu_mask;
200                 target = irq->targets ? __ffs(irq->targets) : 0;
201                 irq->target_vcpu = kvm_get_vcpu(vcpu->kvm, target);
202
203                 raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
204                 vgic_put_irq(vcpu->kvm, irq);
205         }
206 }
207
208 static unsigned long vgic_mmio_read_sgipend(struct kvm_vcpu *vcpu,
209                                             gpa_t addr, unsigned int len)
210 {
211         u32 intid = addr & 0x0f;
212         int i;
213         u64 val = 0;
214
215         for (i = 0; i < len; i++) {
216                 struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
217
218                 val |= (u64)irq->source << (i * 8);
219
220                 vgic_put_irq(vcpu->kvm, irq);
221         }
222         return val;
223 }
224
225 static void vgic_mmio_write_sgipendc(struct kvm_vcpu *vcpu,
226                                      gpa_t addr, unsigned int len,
227                                      unsigned long val)
228 {
229         u32 intid = addr & 0x0f;
230         int i;
231         unsigned long flags;
232
233         for (i = 0; i < len; i++) {
234                 struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
235
236                 raw_spin_lock_irqsave(&irq->irq_lock, flags);
237
238                 irq->source &= ~((val >> (i * 8)) & 0xff);
239                 if (!irq->source)
240                         irq->pending_latch = false;
241
242                 raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
243                 vgic_put_irq(vcpu->kvm, irq);
244         }
245 }
246
247 static void vgic_mmio_write_sgipends(struct kvm_vcpu *vcpu,
248                                      gpa_t addr, unsigned int len,
249                                      unsigned long val)
250 {
251         u32 intid = addr & 0x0f;
252         int i;
253         unsigned long flags;
254
255         for (i = 0; i < len; i++) {
256                 struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
257
258                 raw_spin_lock_irqsave(&irq->irq_lock, flags);
259
260                 irq->source |= (val >> (i * 8)) & 0xff;
261
262                 if (irq->source) {
263                         irq->pending_latch = true;
264                         vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
265                 } else {
266                         raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
267                 }
268                 vgic_put_irq(vcpu->kvm, irq);
269         }
270 }
271
272 #define GICC_ARCH_VERSION_V2    0x2
273
274 /* These are for userland accesses only, there is no guest-facing emulation. */
275 static unsigned long vgic_mmio_read_vcpuif(struct kvm_vcpu *vcpu,
276                                            gpa_t addr, unsigned int len)
277 {
278         struct vgic_vmcr vmcr;
279         u32 val;
280
281         vgic_get_vmcr(vcpu, &vmcr);
282
283         switch (addr & 0xff) {
284         case GIC_CPU_CTRL:
285                 val = vmcr.grpen0 << GIC_CPU_CTRL_EnableGrp0_SHIFT;
286                 val |= vmcr.grpen1 << GIC_CPU_CTRL_EnableGrp1_SHIFT;
287                 val |= vmcr.ackctl << GIC_CPU_CTRL_AckCtl_SHIFT;
288                 val |= vmcr.fiqen << GIC_CPU_CTRL_FIQEn_SHIFT;
289                 val |= vmcr.cbpr << GIC_CPU_CTRL_CBPR_SHIFT;
290                 val |= vmcr.eoim << GIC_CPU_CTRL_EOImodeNS_SHIFT;
291
292                 break;
293         case GIC_CPU_PRIMASK:
294                 /*
295                  * Our KVM_DEV_TYPE_ARM_VGIC_V2 device ABI exports the
296                  * PMR field as GICH_VMCR.VMPriMask rather than
297                  * GICC_PMR.Priority, so we expose the upper five bits of
298                  * priority mask to userspace using the lower bits in the
299                  * unsigned long.
300                  */
301                 val = (vmcr.pmr & GICV_PMR_PRIORITY_MASK) >>
302                         GICV_PMR_PRIORITY_SHIFT;
303                 break;
304         case GIC_CPU_BINPOINT:
305                 val = vmcr.bpr;
306                 break;
307         case GIC_CPU_ALIAS_BINPOINT:
308                 val = vmcr.abpr;
309                 break;
310         case GIC_CPU_IDENT:
311                 val = ((PRODUCT_ID_KVM << 20) |
312                        (GICC_ARCH_VERSION_V2 << 16) |
313                        IMPLEMENTER_ARM);
314                 break;
315         default:
316                 return 0;
317         }
318
319         return val;
320 }
321
322 static void vgic_mmio_write_vcpuif(struct kvm_vcpu *vcpu,
323                                    gpa_t addr, unsigned int len,
324                                    unsigned long val)
325 {
326         struct vgic_vmcr vmcr;
327
328         vgic_get_vmcr(vcpu, &vmcr);
329
330         switch (addr & 0xff) {
331         case GIC_CPU_CTRL:
332                 vmcr.grpen0 = !!(val & GIC_CPU_CTRL_EnableGrp0);
333                 vmcr.grpen1 = !!(val & GIC_CPU_CTRL_EnableGrp1);
334                 vmcr.ackctl = !!(val & GIC_CPU_CTRL_AckCtl);
335                 vmcr.fiqen = !!(val & GIC_CPU_CTRL_FIQEn);
336                 vmcr.cbpr = !!(val & GIC_CPU_CTRL_CBPR);
337                 vmcr.eoim = !!(val & GIC_CPU_CTRL_EOImodeNS);
338
339                 break;
340         case GIC_CPU_PRIMASK:
341                 /*
342                  * Our KVM_DEV_TYPE_ARM_VGIC_V2 device ABI exports the
343                  * PMR field as GICH_VMCR.VMPriMask rather than
344                  * GICC_PMR.Priority, so we expose the upper five bits of
345                  * priority mask to userspace using the lower bits in the
346                  * unsigned long.
347                  */
348                 vmcr.pmr = (val << GICV_PMR_PRIORITY_SHIFT) &
349                         GICV_PMR_PRIORITY_MASK;
350                 break;
351         case GIC_CPU_BINPOINT:
352                 vmcr.bpr = val;
353                 break;
354         case GIC_CPU_ALIAS_BINPOINT:
355                 vmcr.abpr = val;
356                 break;
357         }
358
359         vgic_set_vmcr(vcpu, &vmcr);
360 }
361
362 static unsigned long vgic_mmio_read_apr(struct kvm_vcpu *vcpu,
363                                         gpa_t addr, unsigned int len)
364 {
365         int n; /* which APRn is this */
366
367         n = (addr >> 2) & 0x3;
368
369         if (kvm_vgic_global_state.type == VGIC_V2) {
370                 /* GICv2 hardware systems support max. 32 groups */
371                 if (n != 0)
372                         return 0;
373                 return vcpu->arch.vgic_cpu.vgic_v2.vgic_apr;
374         } else {
375                 struct vgic_v3_cpu_if *vgicv3 = &vcpu->arch.vgic_cpu.vgic_v3;
376
377                 if (n > vgic_v3_max_apr_idx(vcpu))
378                         return 0;
379
380                 n = array_index_nospec(n, 4);
381
382                 /* GICv3 only uses ICH_AP1Rn for memory mapped (GICv2) guests */
383                 return vgicv3->vgic_ap1r[n];
384         }
385 }
386
387 static void vgic_mmio_write_apr(struct kvm_vcpu *vcpu,
388                                 gpa_t addr, unsigned int len,
389                                 unsigned long val)
390 {
391         int n; /* which APRn is this */
392
393         n = (addr >> 2) & 0x3;
394
395         if (kvm_vgic_global_state.type == VGIC_V2) {
396                 /* GICv2 hardware systems support max. 32 groups */
397                 if (n != 0)
398                         return;
399                 vcpu->arch.vgic_cpu.vgic_v2.vgic_apr = val;
400         } else {
401                 struct vgic_v3_cpu_if *vgicv3 = &vcpu->arch.vgic_cpu.vgic_v3;
402
403                 if (n > vgic_v3_max_apr_idx(vcpu))
404                         return;
405
406                 n = array_index_nospec(n, 4);
407
408                 /* GICv3 only uses ICH_AP1Rn for memory mapped (GICv2) guests */
409                 vgicv3->vgic_ap1r[n] = val;
410         }
411 }
412
413 static const struct vgic_register_region vgic_v2_dist_registers[] = {
414         REGISTER_DESC_WITH_LENGTH_UACCESS(GIC_DIST_CTRL,
415                 vgic_mmio_read_v2_misc, vgic_mmio_write_v2_misc,
416                 NULL, vgic_mmio_uaccess_write_v2_misc,
417                 12, VGIC_ACCESS_32bit),
418         REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_IGROUP,
419                 vgic_mmio_read_group, vgic_mmio_write_group,
420                 NULL, vgic_mmio_uaccess_write_v2_group, 1,
421                 VGIC_ACCESS_32bit),
422         REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ENABLE_SET,
423                 vgic_mmio_read_enable, vgic_mmio_write_senable,
424                 NULL, vgic_uaccess_write_senable, 1,
425                 VGIC_ACCESS_32bit),
426         REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ENABLE_CLEAR,
427                 vgic_mmio_read_enable, vgic_mmio_write_cenable,
428                 NULL, vgic_uaccess_write_cenable, 1,
429                 VGIC_ACCESS_32bit),
430         REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PENDING_SET,
431                 vgic_mmio_read_pending, vgic_mmio_write_spending,
432                 vgic_uaccess_read_pending, vgic_uaccess_write_spending, 1,
433                 VGIC_ACCESS_32bit),
434         REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PENDING_CLEAR,
435                 vgic_mmio_read_pending, vgic_mmio_write_cpending,
436                 vgic_uaccess_read_pending, vgic_uaccess_write_cpending, 1,
437                 VGIC_ACCESS_32bit),
438         REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ACTIVE_SET,
439                 vgic_mmio_read_active, vgic_mmio_write_sactive,
440                 vgic_uaccess_read_active, vgic_mmio_uaccess_write_sactive, 1,
441                 VGIC_ACCESS_32bit),
442         REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ACTIVE_CLEAR,
443                 vgic_mmio_read_active, vgic_mmio_write_cactive,
444                 vgic_uaccess_read_active, vgic_mmio_uaccess_write_cactive, 1,
445                 VGIC_ACCESS_32bit),
446         REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PRI,
447                 vgic_mmio_read_priority, vgic_mmio_write_priority, NULL, NULL,
448                 8, VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
449         REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_TARGET,
450                 vgic_mmio_read_target, vgic_mmio_write_target, NULL, NULL, 8,
451                 VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
452         REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_CONFIG,
453                 vgic_mmio_read_config, vgic_mmio_write_config, NULL, NULL, 2,
454                 VGIC_ACCESS_32bit),
455         REGISTER_DESC_WITH_LENGTH(GIC_DIST_SOFTINT,
456                 vgic_mmio_read_raz, vgic_mmio_write_sgir, 4,
457                 VGIC_ACCESS_32bit),
458         REGISTER_DESC_WITH_LENGTH(GIC_DIST_SGI_PENDING_CLEAR,
459                 vgic_mmio_read_sgipend, vgic_mmio_write_sgipendc, 16,
460                 VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
461         REGISTER_DESC_WITH_LENGTH(GIC_DIST_SGI_PENDING_SET,
462                 vgic_mmio_read_sgipend, vgic_mmio_write_sgipends, 16,
463                 VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
464 };
465
466 static const struct vgic_register_region vgic_v2_cpu_registers[] = {
467         REGISTER_DESC_WITH_LENGTH(GIC_CPU_CTRL,
468                 vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
469                 VGIC_ACCESS_32bit),
470         REGISTER_DESC_WITH_LENGTH(GIC_CPU_PRIMASK,
471                 vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
472                 VGIC_ACCESS_32bit),
473         REGISTER_DESC_WITH_LENGTH(GIC_CPU_BINPOINT,
474                 vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
475                 VGIC_ACCESS_32bit),
476         REGISTER_DESC_WITH_LENGTH(GIC_CPU_ALIAS_BINPOINT,
477                 vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
478                 VGIC_ACCESS_32bit),
479         REGISTER_DESC_WITH_LENGTH(GIC_CPU_ACTIVEPRIO,
480                 vgic_mmio_read_apr, vgic_mmio_write_apr, 16,
481                 VGIC_ACCESS_32bit),
482         REGISTER_DESC_WITH_LENGTH(GIC_CPU_IDENT,
483                 vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4,
484                 VGIC_ACCESS_32bit),
485 };
486
487 unsigned int vgic_v2_init_dist_iodev(struct vgic_io_device *dev)
488 {
489         dev->regions = vgic_v2_dist_registers;
490         dev->nr_regions = ARRAY_SIZE(vgic_v2_dist_registers);
491
492         kvm_iodevice_init(&dev->dev, &kvm_io_gic_ops);
493
494         return SZ_4K;
495 }
496
497 int vgic_v2_has_attr_regs(struct kvm_device *dev, struct kvm_device_attr *attr)
498 {
499         const struct vgic_register_region *region;
500         struct vgic_io_device iodev;
501         struct vgic_reg_attr reg_attr;
502         struct kvm_vcpu *vcpu;
503         gpa_t addr;
504         int ret;
505
506         ret = vgic_v2_parse_attr(dev, attr, &reg_attr);
507         if (ret)
508                 return ret;
509
510         vcpu = reg_attr.vcpu;
511         addr = reg_attr.addr;
512
513         switch (attr->group) {
514         case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
515                 iodev.regions = vgic_v2_dist_registers;
516                 iodev.nr_regions = ARRAY_SIZE(vgic_v2_dist_registers);
517                 iodev.base_addr = 0;
518                 break;
519         case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
520                 iodev.regions = vgic_v2_cpu_registers;
521                 iodev.nr_regions = ARRAY_SIZE(vgic_v2_cpu_registers);
522                 iodev.base_addr = 0;
523                 break;
524         default:
525                 return -ENXIO;
526         }
527
528         /* We only support aligned 32-bit accesses. */
529         if (addr & 3)
530                 return -ENXIO;
531
532         region = vgic_get_mmio_region(vcpu, &iodev, addr, sizeof(u32));
533         if (!region)
534                 return -ENXIO;
535
536         return 0;
537 }
538
539 int vgic_v2_cpuif_uaccess(struct kvm_vcpu *vcpu, bool is_write,
540                           int offset, u32 *val)
541 {
542         struct vgic_io_device dev = {
543                 .regions = vgic_v2_cpu_registers,
544                 .nr_regions = ARRAY_SIZE(vgic_v2_cpu_registers),
545                 .iodev_type = IODEV_CPUIF,
546         };
547
548         return vgic_uaccess(vcpu, &dev, is_write, offset, val);
549 }
550
551 int vgic_v2_dist_uaccess(struct kvm_vcpu *vcpu, bool is_write,
552                          int offset, u32 *val)
553 {
554         struct vgic_io_device dev = {
555                 .regions = vgic_v2_dist_registers,
556                 .nr_regions = ARRAY_SIZE(vgic_v2_dist_registers),
557                 .iodev_type = IODEV_DIST,
558         };
559
560         return vgic_uaccess(vcpu, &dev, is_write, offset, val);
561 }