arch/x86/kvm/debugfs.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Kernel-based Virtual Machine driver for Linux
   4  *
   5  * Copyright 2016 Red Hat, Inc. and/or its affiliates.
   6  */
   7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   8
   9 #include <linux/kvm_host.h>
  10 #include <linux/debugfs.h>
  11 #include "lapic.h"
  12 #include "mmu.h"
  13 #include "mmu/mmu_internal.h"
  14
  15 static int vcpu_get_timer_advance_ns(void *data, u64 *val)
  16 {
  17         struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
  18         *val = vcpu->arch.apic->lapic_timer.timer_advance_ns;
  19         return 0;
  20 }
  21
  22 DEFINE_SIMPLE_ATTRIBUTE(vcpu_timer_advance_ns_fops, vcpu_get_timer_advance_ns, NULL, "%llu\n");
  23
  24 static int vcpu_get_guest_mode(void *data, u64 *val)
  25 {
  26         struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
  27         *val = vcpu->stat.guest_mode;
  28         return 0;
  29 }
  30
  31 DEFINE_SIMPLE_ATTRIBUTE(vcpu_guest_mode_fops, vcpu_get_guest_mode, NULL, "%lld\n");
  32
  33 static int vcpu_get_tsc_offset(void *data, u64 *val)
  34 {
  35         struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
  36         *val = vcpu->arch.tsc_offset;
  37         return 0;
  38 }
  39
  40 DEFINE_SIMPLE_ATTRIBUTE(vcpu_tsc_offset_fops, vcpu_get_tsc_offset, NULL, "%lld\n");
  41
  42 static int vcpu_get_tsc_scaling_ratio(void *data, u64 *val)
  43 {
  44         struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
  45         *val = vcpu->arch.tsc_scaling_ratio;
  46         return 0;
  47 }
  48
  49 DEFINE_SIMPLE_ATTRIBUTE(vcpu_tsc_scaling_fops, vcpu_get_tsc_scaling_ratio, NULL, "%llu\n");
  50
  51 static int vcpu_get_tsc_scaling_frac_bits(void *data, u64 *val)
  52 {
  53         *val = kvm_caps.tsc_scaling_ratio_frac_bits;
  54         return 0;
  55 }
  56
  57 DEFINE_SIMPLE_ATTRIBUTE(vcpu_tsc_scaling_frac_fops, vcpu_get_tsc_scaling_frac_bits, NULL, "%llu\n");
  58
  59 void kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu, struct dentry *debugfs_dentry)
  60 {
  61         debugfs_create_file("guest_mode", 0444, debugfs_dentry, vcpu,
  62                             &vcpu_guest_mode_fops);
  63         debugfs_create_file("tsc-offset", 0444, debugfs_dentry, vcpu,
  64                             &vcpu_tsc_offset_fops);
  65
  66         if (lapic_in_kernel(vcpu))
  67                 debugfs_create_file("lapic_timer_advance_ns", 0444,
  68                                     debugfs_dentry, vcpu,
  69                                     &vcpu_timer_advance_ns_fops);
  70
  71         if (kvm_caps.has_tsc_control) {
  72                 debugfs_create_file("tsc-scaling-ratio", 0444,
  73                                     debugfs_dentry, vcpu,
  74                                     &vcpu_tsc_scaling_fops);
  75                 debugfs_create_file("tsc-scaling-ratio-frac-bits", 0444,
  76                                     debugfs_dentry, vcpu,
  77                                     &vcpu_tsc_scaling_frac_fops);
  78         }
  79 }
  80
  81 /*
  82  * This covers statistics <1024 (11=log(1024)+1), which should be enough to
  83  * cover RMAP_RECYCLE_THRESHOLD.
  84  */
  85 #define  RMAP_LOG_SIZE  11
  86
  87 static const char *kvm_lpage_str[KVM_NR_PAGE_SIZES] = { "4K", "2M", "1G" };
  88
  89 static int kvm_mmu_rmaps_stat_show(struct seq_file *m, void *v)
  90 {
  91         struct kvm_rmap_head *rmap;
  92         struct kvm *kvm = m->private;
  93         struct kvm_memory_slot *slot;
  94         struct kvm_memslots *slots;
  95         unsigned int lpage_size, index;
  96         /* Still small enough to be on the stack */
  97         unsigned int *log[KVM_NR_PAGE_SIZES], *cur;
  98         int i, j, k, l, ret;
  99
 100         if (!kvm_memslots_have_rmaps(kvm))
 101                 return 0;
 102
 103         ret = -ENOMEM;
 104         memset(log, 0, sizeof(log));
 105         for (i = 0; i < KVM_NR_PAGE_SIZES; i++) {
 106                 log[i] = kcalloc(RMAP_LOG_SIZE, sizeof(unsigned int), GFP_KERNEL);
 107                 if (!log[i])
 108                         goto out;
 109         }
 110
 111         mutex_lock(&kvm->slots_lock);
 112         write_lock(&kvm->mmu_lock);
 113
 114         for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) {
 115                 int bkt;
 116
 117                 slots = __kvm_memslots(kvm, i);
 118                 kvm_for_each_memslot(slot, bkt, slots)
 119                         for (k = 0; k < KVM_NR_PAGE_SIZES; k++) {
 120                                 rmap = slot->arch.rmap[k];
 121                                 lpage_size = kvm_mmu_slot_lpages(slot, k + 1);
 122                                 cur = log[k];
 123                                 for (l = 0; l < lpage_size; l++) {
 124                                         index = ffs(pte_list_count(&rmap[l]));
 125                                         if (WARN_ON_ONCE(index >= RMAP_LOG_SIZE))
 126                                                 index = RMAP_LOG_SIZE - 1;
 127                                         cur[index]++;
 128                                 }
 129                         }
 130         }
 131
 132         write_unlock(&kvm->mmu_lock);
 133         mutex_unlock(&kvm->slots_lock);
 134
 135         /* index=0 counts no rmap; index=1 counts 1 rmap */
 136         seq_printf(m, "Rmap_Count:\t0\t1\t");
 137         for (i = 2; i < RMAP_LOG_SIZE; i++) {
 138                 j = 1 << (i - 1);
 139                 k = (1 << i) - 1;
 140                 seq_printf(m, "%d-%d\t", j, k);
 141         }
 142         seq_printf(m, "\n");
 143
 144         for (i = 0; i < KVM_NR_PAGE_SIZES; i++) {
 145                 seq_printf(m, "Level=%s:\t", kvm_lpage_str[i]);
 146                 cur = log[i];
 147                 for (j = 0; j < RMAP_LOG_SIZE; j++)
 148                         seq_printf(m, "%d\t", cur[j]);
 149                 seq_printf(m, "\n");
 150         }
 151
 152         ret = 0;
 153 out:
 154         for (i = 0; i < KVM_NR_PAGE_SIZES; i++)
 155                 kfree(log[i]);
 156
 157         return ret;
 158 }
 159
 160 static int kvm_mmu_rmaps_stat_open(struct inode *inode, struct file *file)
 161 {
 162         struct kvm *kvm = inode->i_private;
 163         int r;
 164
 165         if (!kvm_get_kvm_safe(kvm))
 166                 return -ENOENT;
 167
 168         r = single_open(file, kvm_mmu_rmaps_stat_show, kvm);
 169         if (r < 0)
 170                 kvm_put_kvm(kvm);
 171
 172         return r;
 173 }
 174
 175 static int kvm_mmu_rmaps_stat_release(struct inode *inode, struct file *file)
 176 {
 177         struct kvm *kvm = inode->i_private;
 178
 179         kvm_put_kvm(kvm);
 180
 181         return single_release(inode, file);
 182 }
 183
 184 static const struct file_operations mmu_rmaps_stat_fops = {
 185         .owner          = THIS_MODULE,
 186         .open           = kvm_mmu_rmaps_stat_open,
 187         .read           = seq_read,
 188         .llseek         = seq_lseek,
 189         .release        = kvm_mmu_rmaps_stat_release,
 190 };
 191
 192 void kvm_arch_create_vm_debugfs(struct kvm *kvm)
 193 {
 194         debugfs_create_file("mmu_rmaps_stat", 0644, kvm->debugfs_dentry, kvm,
 195                             &mmu_rmaps_stat_fops);
 196 }