linux/virt/kvm/arm/vgic/vgic-debug.c
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   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 */
  36struct vgic_state_iter {
  37        int nr_cpus;
  38        int nr_spis;
  39        int dist_id;
  40        int vcpu_id;
  41        int intid;
  42};
  43
  44static 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
  57static 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
  72static 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
  79static 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;
 102out:
 103        mutex_unlock(&kvm->lock);
 104        return iter;
 105}
 106
 107static 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
 119static 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
 138static 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
 153static 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
 169static 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
 208static 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
 237static 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
 244static 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
 258static 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
 266int 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
 280int vgic_debug_destroy(struct kvm *kvm)
 281{
 282        return 0;
 283}
 284