1 /*
2  * Copyright (C) 2016 Linaro
3  * Author: Christoffer Dall <christoffer.dall@linaro.org>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
16  */
17 
18 #include <linux/cpu.h>
19 #include <linux/debugfs.h>
20 #include <linux/interrupt.h>
21 #include <linux/kvm_host.h>
22 #include <linux/seq_file.h>
23 #include <kvm/arm_vgic.h>
24 #include <asm/kvm_mmu.h>
25 #include "vgic.h"
26 
27 /*
28  * Structure to control looping through the entire vgic state.  We start at
29  * zero for each field and move upwards.  So, if dist_id is 0 we print the
30  * distributor info.  When dist_id is 1, we have already printed it and move
31  * on.
32  *
33  * When vcpu_id < nr_cpus we print the vcpu info until vcpu_id == nr_cpus and
34  * so on.
35  */
36 struct vgic_state_iter {
37 	int nr_cpus;
38 	int nr_spis;
39 	int nr_lpis;
40 	int dist_id;
41 	int vcpu_id;
42 	int intid;
43 	int lpi_idx;
44 	u32 *lpi_array;
45 };
46 
iter_next(struct vgic_state_iter * iter)47 static void iter_next(struct vgic_state_iter *iter)
48 {
49 	if (iter->dist_id == 0) {
50 		iter->dist_id++;
51 		return;
52 	}
53 
54 	iter->intid++;
55 	if (iter->intid == VGIC_NR_PRIVATE_IRQS &&
56 	    ++iter->vcpu_id < iter->nr_cpus)
57 		iter->intid = 0;
58 
59 	if (iter->intid >= (iter->nr_spis + VGIC_NR_PRIVATE_IRQS)) {
60 		if (iter->lpi_idx < iter->nr_lpis)
61 			iter->intid = iter->lpi_array[iter->lpi_idx];
62 		iter->lpi_idx++;
63 	}
64 }
65 
iter_init(struct kvm * kvm,struct vgic_state_iter * iter,loff_t pos)66 static void iter_init(struct kvm *kvm, struct vgic_state_iter *iter,
67 		      loff_t pos)
68 {
69 	int nr_cpus = atomic_read(&kvm->online_vcpus);
70 
71 	memset(iter, 0, sizeof(*iter));
72 
73 	iter->nr_cpus = nr_cpus;
74 	iter->nr_spis = kvm->arch.vgic.nr_spis;
75 	if (kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) {
76 		iter->nr_lpis = vgic_copy_lpi_list(kvm, NULL, &iter->lpi_array);
77 		if (iter->nr_lpis < 0)
78 			iter->nr_lpis = 0;
79 	}
80 
81 	/* Fast forward to the right position if needed */
82 	while (pos--)
83 		iter_next(iter);
84 }
85 
end_of_vgic(struct vgic_state_iter * iter)86 static bool end_of_vgic(struct vgic_state_iter *iter)
87 {
88 	return iter->dist_id > 0 &&
89 		iter->vcpu_id == iter->nr_cpus &&
90 		iter->intid >= (iter->nr_spis + VGIC_NR_PRIVATE_IRQS) &&
91 		iter->lpi_idx > iter->nr_lpis;
92 }
93 
vgic_debug_start(struct seq_file * s,loff_t * pos)94 static void *vgic_debug_start(struct seq_file *s, loff_t *pos)
95 {
96 	struct kvm *kvm = (struct kvm *)s->private;
97 	struct vgic_state_iter *iter;
98 
99 	mutex_lock(&kvm->lock);
100 	iter = kvm->arch.vgic.iter;
101 	if (iter) {
102 		iter = ERR_PTR(-EBUSY);
103 		goto out;
104 	}
105 
106 	iter = kmalloc(sizeof(*iter), GFP_KERNEL);
107 	if (!iter) {
108 		iter = ERR_PTR(-ENOMEM);
109 		goto out;
110 	}
111 
112 	iter_init(kvm, iter, *pos);
113 	kvm->arch.vgic.iter = iter;
114 
115 	if (end_of_vgic(iter))
116 		iter = NULL;
117 out:
118 	mutex_unlock(&kvm->lock);
119 	return iter;
120 }
121 
vgic_debug_next(struct seq_file * s,void * v,loff_t * pos)122 static void *vgic_debug_next(struct seq_file *s, void *v, loff_t *pos)
123 {
124 	struct kvm *kvm = (struct kvm *)s->private;
125 	struct vgic_state_iter *iter = kvm->arch.vgic.iter;
126 
127 	++*pos;
128 	iter_next(iter);
129 	if (end_of_vgic(iter))
130 		iter = NULL;
131 	return iter;
132 }
133 
vgic_debug_stop(struct seq_file * s,void * v)134 static void vgic_debug_stop(struct seq_file *s, void *v)
135 {
136 	struct kvm *kvm = (struct kvm *)s->private;
137 	struct vgic_state_iter *iter;
138 
139 	/*
140 	 * If the seq file wasn't properly opened, there's nothing to clearn
141 	 * up.
142 	 */
143 	if (IS_ERR(v))
144 		return;
145 
146 	mutex_lock(&kvm->lock);
147 	iter = kvm->arch.vgic.iter;
148 	kfree(iter->lpi_array);
149 	kfree(iter);
150 	kvm->arch.vgic.iter = NULL;
151 	mutex_unlock(&kvm->lock);
152 }
153 
print_dist_state(struct seq_file * s,struct vgic_dist * dist)154 static void print_dist_state(struct seq_file *s, struct vgic_dist *dist)
155 {
156 	bool v3 = dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3;
157 
158 	seq_printf(s, "Distributor\n");
159 	seq_printf(s, "===========\n");
160 	seq_printf(s, "vgic_model:\t%s\n", v3 ? "GICv3" : "GICv2");
161 	seq_printf(s, "nr_spis:\t%d\n", dist->nr_spis);
162 	if (v3)
163 		seq_printf(s, "nr_lpis:\t%d\n", dist->lpi_list_count);
164 	seq_printf(s, "enabled:\t%d\n", dist->enabled);
165 	seq_printf(s, "\n");
166 
167 	seq_printf(s, "P=pending_latch, L=line_level, A=active\n");
168 	seq_printf(s, "E=enabled, H=hw, C=config (level=1, edge=0)\n");
169 	seq_printf(s, "G=group\n");
170 }
171 
print_header(struct seq_file * s,struct vgic_irq * irq,struct kvm_vcpu * vcpu)172 static void print_header(struct seq_file *s, struct vgic_irq *irq,
173 			 struct kvm_vcpu *vcpu)
174 {
175 	int id = 0;
176 	char *hdr = "SPI ";
177 
178 	if (vcpu) {
179 		hdr = "VCPU";
180 		id = vcpu->vcpu_id;
181 	}
182 
183 	seq_printf(s, "\n");
184 	seq_printf(s, "%s%2d TYP   ID TGT_ID PLAEHCG     HWID   TARGET SRC PRI VCPU_ID\n", hdr, id);
185 	seq_printf(s, "----------------------------------------------------------------\n");
186 }
187 
print_irq_state(struct seq_file * s,struct vgic_irq * irq,struct kvm_vcpu * vcpu)188 static void print_irq_state(struct seq_file *s, struct vgic_irq *irq,
189 			    struct kvm_vcpu *vcpu)
190 {
191 	char *type;
192 	if (irq->intid < VGIC_NR_SGIS)
193 		type = "SGI";
194 	else if (irq->intid < VGIC_NR_PRIVATE_IRQS)
195 		type = "PPI";
196 	else if (irq->intid < VGIC_MAX_SPI)
197 		type = "SPI";
198 	else
199 		type = "LPI";
200 
201 	if (irq->intid ==0 || irq->intid == VGIC_NR_PRIVATE_IRQS)
202 		print_header(s, irq, vcpu);
203 
204 	seq_printf(s, "       %s %4d "
205 		      "    %2d "
206 		      "%d%d%d%d%d%d%d "
207 		      "%8d "
208 		      "%8x "
209 		      " %2x "
210 		      "%3d "
211 		      "     %2d "
212 		      "\n",
213 			type, irq->intid,
214 			(irq->target_vcpu) ? irq->target_vcpu->vcpu_id : -1,
215 			irq->pending_latch,
216 			irq->line_level,
217 			irq->active,
218 			irq->enabled,
219 			irq->hw,
220 			irq->config == VGIC_CONFIG_LEVEL,
221 			irq->group,
222 			irq->hwintid,
223 			irq->mpidr,
224 			irq->source,
225 			irq->priority,
226 			(irq->vcpu) ? irq->vcpu->vcpu_id : -1);
227 }
228 
vgic_debug_show(struct seq_file * s,void * v)229 static int vgic_debug_show(struct seq_file *s, void *v)
230 {
231 	struct kvm *kvm = (struct kvm *)s->private;
232 	struct vgic_state_iter *iter = (struct vgic_state_iter *)v;
233 	struct vgic_irq *irq;
234 	struct kvm_vcpu *vcpu = NULL;
235 	unsigned long flags;
236 
237 	if (iter->dist_id == 0) {
238 		print_dist_state(s, &kvm->arch.vgic);
239 		return 0;
240 	}
241 
242 	if (!kvm->arch.vgic.initialized)
243 		return 0;
244 
245 	if (iter->vcpu_id < iter->nr_cpus)
246 		vcpu = kvm_get_vcpu(kvm, iter->vcpu_id);
247 
248 	irq = vgic_get_irq(kvm, vcpu, iter->intid);
249 	if (!irq) {
250 		seq_printf(s, "       LPI %4d freed\n", iter->intid);
251 		return 0;
252 	}
253 
254 	spin_lock_irqsave(&irq->irq_lock, flags);
255 	print_irq_state(s, irq, vcpu);
256 	spin_unlock_irqrestore(&irq->irq_lock, flags);
257 
258 	vgic_put_irq(kvm, irq);
259 	return 0;
260 }
261 
262 static const struct seq_operations vgic_debug_seq_ops = {
263 	.start = vgic_debug_start,
264 	.next  = vgic_debug_next,
265 	.stop  = vgic_debug_stop,
266 	.show  = vgic_debug_show
267 };
268 
debug_open(struct inode * inode,struct file * file)269 static int debug_open(struct inode *inode, struct file *file)
270 {
271 	int ret;
272 	ret = seq_open(file, &vgic_debug_seq_ops);
273 	if (!ret) {
274 		struct seq_file *seq;
275 		/* seq_open will have modified file->private_data */
276 		seq = file->private_data;
277 		seq->private = inode->i_private;
278 	}
279 
280 	return ret;
281 };
282 
283 static const struct file_operations vgic_debug_fops = {
284 	.owner   = THIS_MODULE,
285 	.open    = debug_open,
286 	.read    = seq_read,
287 	.llseek  = seq_lseek,
288 	.release = seq_release
289 };
290 
vgic_debug_init(struct kvm * kvm)291 void vgic_debug_init(struct kvm *kvm)
292 {
293 	debugfs_create_file("vgic-state", 0444, kvm->debugfs_dentry, kvm,
294 			    &vgic_debug_fops);
295 }
296 
vgic_debug_destroy(struct kvm * kvm)297 void vgic_debug_destroy(struct kvm *kvm)
298 {
299 }
300