xref: /openbmc/linux/arch/arm64/kvm/vgic/vgic-debug.c (revision f0032773)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2016 Linaro
4  * Author: Christoffer Dall <christoffer.dall@linaro.org>
5  */
6 
7 #include <linux/cpu.h>
8 #include <linux/debugfs.h>
9 #include <linux/interrupt.h>
10 #include <linux/kvm_host.h>
11 #include <linux/seq_file.h>
12 #include <kvm/arm_vgic.h>
13 #include <asm/kvm_mmu.h>
14 #include "vgic.h"
15 
16 /*
17  * Structure to control looping through the entire vgic state.  We start at
18  * zero for each field and move upwards.  So, if dist_id is 0 we print the
19  * distributor info.  When dist_id is 1, we have already printed it and move
20  * on.
21  *
22  * When vcpu_id < nr_cpus we print the vcpu info until vcpu_id == nr_cpus and
23  * so on.
24  */
25 struct vgic_state_iter {
26 	int nr_cpus;
27 	int nr_spis;
28 	int nr_lpis;
29 	int dist_id;
30 	int vcpu_id;
31 	int intid;
32 	int lpi_idx;
33 	u32 *lpi_array;
34 };
35 
iter_next(struct vgic_state_iter * iter)36 static void iter_next(struct vgic_state_iter *iter)
37 {
38 	if (iter->dist_id == 0) {
39 		iter->dist_id++;
40 		return;
41 	}
42 
43 	iter->intid++;
44 	if (iter->intid == VGIC_NR_PRIVATE_IRQS &&
45 	    ++iter->vcpu_id < iter->nr_cpus)
46 		iter->intid = 0;
47 
48 	if (iter->intid >= (iter->nr_spis + VGIC_NR_PRIVATE_IRQS)) {
49 		if (iter->lpi_idx < iter->nr_lpis)
50 			iter->intid = iter->lpi_array[iter->lpi_idx];
51 		iter->lpi_idx++;
52 	}
53 }
54 
iter_init(struct kvm * kvm,struct vgic_state_iter * iter,loff_t pos)55 static void iter_init(struct kvm *kvm, struct vgic_state_iter *iter,
56 		      loff_t pos)
57 {
58 	int nr_cpus = atomic_read(&kvm->online_vcpus);
59 
60 	memset(iter, 0, sizeof(*iter));
61 
62 	iter->nr_cpus = nr_cpus;
63 	iter->nr_spis = kvm->arch.vgic.nr_spis;
64 	if (kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) {
65 		iter->nr_lpis = vgic_copy_lpi_list(kvm, NULL, &iter->lpi_array);
66 		if (iter->nr_lpis < 0)
67 			iter->nr_lpis = 0;
68 	}
69 
70 	/* Fast forward to the right position if needed */
71 	while (pos--)
72 		iter_next(iter);
73 }
74 
end_of_vgic(struct vgic_state_iter * iter)75 static bool end_of_vgic(struct vgic_state_iter *iter)
76 {
77 	return iter->dist_id > 0 &&
78 		iter->vcpu_id == iter->nr_cpus &&
79 		iter->intid >= (iter->nr_spis + VGIC_NR_PRIVATE_IRQS) &&
80 		iter->lpi_idx > iter->nr_lpis;
81 }
82 
vgic_debug_start(struct seq_file * s,loff_t * pos)83 static void *vgic_debug_start(struct seq_file *s, loff_t *pos)
84 {
85 	struct kvm *kvm = s->private;
86 	struct vgic_state_iter *iter;
87 
88 	mutex_lock(&kvm->arch.config_lock);
89 	iter = kvm->arch.vgic.iter;
90 	if (iter) {
91 		iter = ERR_PTR(-EBUSY);
92 		goto out;
93 	}
94 
95 	iter = kmalloc(sizeof(*iter), GFP_KERNEL);
96 	if (!iter) {
97 		iter = ERR_PTR(-ENOMEM);
98 		goto out;
99 	}
100 
101 	iter_init(kvm, iter, *pos);
102 	kvm->arch.vgic.iter = iter;
103 
104 	if (end_of_vgic(iter))
105 		iter = NULL;
106 out:
107 	mutex_unlock(&kvm->arch.config_lock);
108 	return iter;
109 }
110 
vgic_debug_next(struct seq_file * s,void * v,loff_t * pos)111 static void *vgic_debug_next(struct seq_file *s, void *v, loff_t *pos)
112 {
113 	struct kvm *kvm = s->private;
114 	struct vgic_state_iter *iter = kvm->arch.vgic.iter;
115 
116 	++*pos;
117 	iter_next(iter);
118 	if (end_of_vgic(iter))
119 		iter = NULL;
120 	return iter;
121 }
122 
vgic_debug_stop(struct seq_file * s,void * v)123 static void vgic_debug_stop(struct seq_file *s, void *v)
124 {
125 	struct kvm *kvm = s->private;
126 	struct vgic_state_iter *iter;
127 
128 	/*
129 	 * If the seq file wasn't properly opened, there's nothing to clearn
130 	 * up.
131 	 */
132 	if (IS_ERR(v))
133 		return;
134 
135 	mutex_lock(&kvm->arch.config_lock);
136 	iter = kvm->arch.vgic.iter;
137 	kfree(iter->lpi_array);
138 	kfree(iter);
139 	kvm->arch.vgic.iter = NULL;
140 	mutex_unlock(&kvm->arch.config_lock);
141 }
142 
print_dist_state(struct seq_file * s,struct vgic_dist * dist)143 static void print_dist_state(struct seq_file *s, struct vgic_dist *dist)
144 {
145 	bool v3 = dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3;
146 
147 	seq_printf(s, "Distributor\n");
148 	seq_printf(s, "===========\n");
149 	seq_printf(s, "vgic_model:\t%s\n", v3 ? "GICv3" : "GICv2");
150 	seq_printf(s, "nr_spis:\t%d\n", dist->nr_spis);
151 	if (v3)
152 		seq_printf(s, "nr_lpis:\t%d\n", dist->lpi_list_count);
153 	seq_printf(s, "enabled:\t%d\n", dist->enabled);
154 	seq_printf(s, "\n");
155 
156 	seq_printf(s, "P=pending_latch, L=line_level, A=active\n");
157 	seq_printf(s, "E=enabled, H=hw, C=config (level=1, edge=0)\n");
158 	seq_printf(s, "G=group\n");
159 }
160 
print_header(struct seq_file * s,struct vgic_irq * irq,struct kvm_vcpu * vcpu)161 static void print_header(struct seq_file *s, struct vgic_irq *irq,
162 			 struct kvm_vcpu *vcpu)
163 {
164 	int id = 0;
165 	char *hdr = "SPI ";
166 
167 	if (vcpu) {
168 		hdr = "VCPU";
169 		id = vcpu->vcpu_id;
170 	}
171 
172 	seq_printf(s, "\n");
173 	seq_printf(s, "%s%2d TYP   ID TGT_ID PLAEHCG     HWID   TARGET SRC PRI VCPU_ID\n", hdr, id);
174 	seq_printf(s, "----------------------------------------------------------------\n");
175 }
176 
print_irq_state(struct seq_file * s,struct vgic_irq * irq,struct kvm_vcpu * vcpu)177 static void print_irq_state(struct seq_file *s, struct vgic_irq *irq,
178 			    struct kvm_vcpu *vcpu)
179 {
180 	char *type;
181 	bool pending;
182 
183 	if (irq->intid < VGIC_NR_SGIS)
184 		type = "SGI";
185 	else if (irq->intid < VGIC_NR_PRIVATE_IRQS)
186 		type = "PPI";
187 	else if (irq->intid < VGIC_MAX_SPI)
188 		type = "SPI";
189 	else
190 		type = "LPI";
191 
192 	if (irq->intid ==0 || irq->intid == VGIC_NR_PRIVATE_IRQS)
193 		print_header(s, irq, vcpu);
194 
195 	pending = irq->pending_latch;
196 	if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
197 		int err;
198 
199 		err = irq_get_irqchip_state(irq->host_irq,
200 					    IRQCHIP_STATE_PENDING,
201 					    &pending);
202 		WARN_ON_ONCE(err);
203 	}
204 
205 	seq_printf(s, "       %s %4d "
206 		      "    %2d "
207 		      "%d%d%d%d%d%d%d "
208 		      "%8d "
209 		      "%8x "
210 		      " %2x "
211 		      "%3d "
212 		      "     %2d "
213 		      "\n",
214 			type, irq->intid,
215 			(irq->target_vcpu) ? irq->target_vcpu->vcpu_id : -1,
216 			pending,
217 			irq->line_level,
218 			irq->active,
219 			irq->enabled,
220 			irq->hw,
221 			irq->config == VGIC_CONFIG_LEVEL,
222 			irq->group,
223 			irq->hwintid,
224 			irq->mpidr,
225 			irq->source,
226 			irq->priority,
227 			(irq->vcpu) ? irq->vcpu->vcpu_id : -1);
228 }
229 
vgic_debug_show(struct seq_file * s,void * v)230 static int vgic_debug_show(struct seq_file *s, void *v)
231 {
232 	struct kvm *kvm = s->private;
233 	struct vgic_state_iter *iter = v;
234 	struct vgic_irq *irq;
235 	struct kvm_vcpu *vcpu = NULL;
236 	unsigned long flags;
237 
238 	if (iter->dist_id == 0) {
239 		print_dist_state(s, &kvm->arch.vgic);
240 		return 0;
241 	}
242 
243 	if (!kvm->arch.vgic.initialized)
244 		return 0;
245 
246 	if (iter->vcpu_id < iter->nr_cpus)
247 		vcpu = kvm_get_vcpu(kvm, iter->vcpu_id);
248 
249 	irq = vgic_get_irq(kvm, vcpu, iter->intid);
250 	if (!irq) {
251 		seq_printf(s, "       LPI %4d freed\n", iter->intid);
252 		return 0;
253 	}
254 
255 	raw_spin_lock_irqsave(&irq->irq_lock, flags);
256 	print_irq_state(s, irq, vcpu);
257 	raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
258 
259 	vgic_put_irq(kvm, irq);
260 	return 0;
261 }
262 
263 static const struct seq_operations vgic_debug_sops = {
264 	.start = vgic_debug_start,
265 	.next  = vgic_debug_next,
266 	.stop  = vgic_debug_stop,
267 	.show  = vgic_debug_show
268 };
269 
270 DEFINE_SEQ_ATTRIBUTE(vgic_debug);
271 
vgic_debug_init(struct kvm * kvm)272 void vgic_debug_init(struct kvm *kvm)
273 {
274 	debugfs_create_file("vgic-state", 0444, kvm->debugfs_dentry, kvm,
275 			    &vgic_debug_fops);
276 }
277 
vgic_debug_destroy(struct kvm * kvm)278 void vgic_debug_destroy(struct kvm *kvm)
279 {
280 }
281