virt/kvm/arm/vgic/vgic-debug.c

   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 dist_id;
  40         int vcpu_id;
  41         int intid;
  42 };
  43
  44 static void iter_next(struct vgic_state_iter *iter)
  45 {
  46         if (iter->dist_id == 0) {
  47                 iter->dist_id++;
  48                 return;
  49         }
  50
  51         iter->intid++;
  52         if (iter->intid == VGIC_NR_PRIVATE_IRQS &&
  53             ++iter->vcpu_id < iter->nr_cpus)
  54                 iter->intid = 0;
  55 }
  56
  57 static void iter_init(struct kvm *kvm, struct vgic_state_iter *iter,
  58                       loff_t pos)
  59 {
  60         int nr_cpus = atomic_read(&kvm->online_vcpus);
  61
  62         memset(iter, 0, sizeof(*iter));
  63
  64         iter->nr_cpus = nr_cpus;
  65         iter->nr_spis = kvm->arch.vgic.nr_spis;
  66
  67         /* Fast forward to the right position if needed */
  68         while (pos--)
  69                 iter_next(iter);
  70 }
  71
  72 static bool end_of_vgic(struct vgic_state_iter *iter)
  73 {
  74         return iter->dist_id > 0 &&
  75                 iter->vcpu_id == iter->nr_cpus &&
  76                 (iter->intid - VGIC_NR_PRIVATE_IRQS) == iter->nr_spis;
  77 }
  78
  79 static void *vgic_debug_start(struct seq_file *s, loff_t *pos)
  80 {
  81         struct kvm *kvm = (struct kvm *)s->private;
  82         struct vgic_state_iter *iter;
  83
  84         mutex_lock(&kvm->lock);
  85         iter = kvm->arch.vgic.iter;
  86         if (iter) {
  87                 iter = ERR_PTR(-EBUSY);
  88                 goto out;
  89         }
  90
  91         iter = kmalloc(sizeof(*iter), GFP_KERNEL);
  92         if (!iter) {
  93                 iter = ERR_PTR(-ENOMEM);
  94                 goto out;
  95         }
  96
  97         iter_init(kvm, iter, *pos);
  98         kvm->arch.vgic.iter = iter;
  99
 100         if (end_of_vgic(iter))
 101                 iter = NULL;
 102 out:
 103         mutex_unlock(&kvm->lock);
 104         return iter;
 105 }
 106
 107 static void *vgic_debug_next(struct seq_file *s, void *v, loff_t *pos)
 108 {
 109         struct kvm *kvm = (struct kvm *)s->private;
 110         struct vgic_state_iter *iter = kvm->arch.vgic.iter;
 111
 112         ++*pos;
 113         iter_next(iter);
 114         if (end_of_vgic(iter))
 115                 iter = NULL;
 116         return iter;
 117 }
 118
 119 static void vgic_debug_stop(struct seq_file *s, void *v)
 120 {
 121         struct kvm *kvm = (struct kvm *)s->private;
 122         struct vgic_state_iter *iter;
 123
 124         /*
 125          * If the seq file wasn't properly opened, there's nothing to clearn
 126          * up.
 127          */
 128         if (IS_ERR(v))
 129                 return;
 130
 131         mutex_lock(&kvm->lock);
 132         iter = kvm->arch.vgic.iter;
 133         kfree(iter);
 134         kvm->arch.vgic.iter = NULL;
 135         mutex_unlock(&kvm->lock);
 136 }
 137
 138 static void print_dist_state(struct seq_file *s, struct vgic_dist *dist)
 139 {
 140         seq_printf(s, "Distributor\n");
 141         seq_printf(s, "===========\n");
 142         seq_printf(s, "vgic_model:\t%s\n",
 143                    (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) ?
 144                    "GICv3" : "GICv2");
 145         seq_printf(s, "nr_spis:\t%d\n", dist->nr_spis);
 146         seq_printf(s, "enabled:\t%d\n", dist->enabled);
 147         seq_printf(s, "\n");
 148
 149         seq_printf(s, "P=pending_latch, L=line_level, A=active\n");
 150         seq_printf(s, "E=enabled, H=hw, C=config (level=1, edge=0)\n");
 151 }
 152
 153 static void print_header(struct seq_file *s, struct vgic_irq *irq,
 154                          struct kvm_vcpu *vcpu)
 155 {
 156         int id = 0;
 157         char *hdr = "SPI ";
 158
 159         if (vcpu) {
 160                 hdr = "VCPU";
 161                 id = vcpu->vcpu_id;
 162         }
 163
 164         seq_printf(s, "\n");
 165         seq_printf(s, "%s%2d TYP   ID TGT_ID PLAEHC     HWID   TARGET SRC PRI VCPU_ID\n", hdr, id);
 166         seq_printf(s, "---------------------------------------------------------------\n");
 167 }
 168
 169 static void print_irq_state(struct seq_file *s, struct vgic_irq *irq,
 170                             struct kvm_vcpu *vcpu)
 171 {
 172         char *type;
 173         if (irq->intid < VGIC_NR_SGIS)
 174                 type = "SGI";
 175         else if (irq->intid < VGIC_NR_PRIVATE_IRQS)
 176                 type = "PPI";
 177         else
 178                 type = "SPI";
 179
 180         if (irq->intid ==0 || irq->intid == VGIC_NR_PRIVATE_IRQS)
 181                 print_header(s, irq, vcpu);
 182
 183         seq_printf(s, "       %s %4d "
 184                       "    %2d "
 185                       "%d%d%d%d%d%d "
 186                       "%8d "
 187                       "%8x "
 188                       " %2x "
 189                       "%3d "
 190                       "     %2d "
 191                       "\n",
 192                         type, irq->intid,
 193                         (irq->target_vcpu) ? irq->target_vcpu->vcpu_id : -1,
 194                         irq->pending_latch,
 195                         irq->line_level,
 196                         irq->active,
 197                         irq->enabled,
 198                         irq->hw,
 199                         irq->config == VGIC_CONFIG_LEVEL,
 200                         irq->hwintid,
 201                         irq->mpidr,
 202                         irq->source,
 203                         irq->priority,
 204                         (irq->vcpu) ? irq->vcpu->vcpu_id : -1);
 205
 206 }
 207
 208 static int vgic_debug_show(struct seq_file *s, void *v)
 209 {
 210         struct kvm *kvm = (struct kvm *)s->private;
 211         struct vgic_state_iter *iter = (struct vgic_state_iter *)v;
 212         struct vgic_irq *irq;
 213         struct kvm_vcpu *vcpu = NULL;
 214
 215         if (iter->dist_id == 0) {
 216                 print_dist_state(s, &kvm->arch.vgic);
 217                 return 0;
 218         }
 219
 220         if (!kvm->arch.vgic.initialized)
 221                 return 0;
 222
 223         if (iter->vcpu_id < iter->nr_cpus) {
 224                 vcpu = kvm_get_vcpu(kvm, iter->vcpu_id);
 225                 irq = &vcpu->arch.vgic_cpu.private_irqs[iter->intid];
 226         } else {
 227                 irq = &kvm->arch.vgic.spis[iter->intid - VGIC_NR_PRIVATE_IRQS];
 228         }
 229
 230         spin_lock(&irq->irq_lock);
 231         print_irq_state(s, irq, vcpu);
 232         spin_unlock(&irq->irq_lock);
 233
 234         return 0;
 235 }
 236
 237 static const struct seq_operations vgic_debug_seq_ops = {
 238         .start = vgic_debug_start,
 239         .next  = vgic_debug_next,
 240         .stop  = vgic_debug_stop,
 241         .show  = vgic_debug_show
 242 };
 243
 244 static int debug_open(struct inode *inode, struct file *file)
 245 {
 246         int ret;
 247         ret = seq_open(file, &vgic_debug_seq_ops);
 248         if (!ret) {
 249                 struct seq_file *seq;
 250                 /* seq_open will have modified file->private_data */
 251                 seq = file->private_data;
 252                 seq->private = inode->i_private;
 253         }
 254
 255         return ret;
 256 };
 257
 258 static const struct file_operations vgic_debug_fops = {
 259         .owner   = THIS_MODULE,
 260         .open    = debug_open,
 261         .read    = seq_read,
 262         .llseek  = seq_lseek,
 263         .release = seq_release
 264 };
 265
 266 int vgic_debug_init(struct kvm *kvm)
 267 {
 268         if (!kvm->debugfs_dentry)
 269                 return -ENOENT;
 270
 271         if (!debugfs_create_file("vgic-state", 0444,
 272                                  kvm->debugfs_dentry,
 273                                  kvm,
 274                                  &vgic_debug_fops))
 275                 return -ENOMEM;
 276
 277         return 0;
 278 }
 279
 280 int vgic_debug_destroy(struct kvm *kvm)
 281 {
 282         return 0;
 283 }