debugfs.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
 * Kernel-based Virtual Machine driver for Linux
 *
 * Copyright 2016 Red Hat, Inc. and/or its affiliates.
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
#include <linux/kvm_host.h>
#include <linux/debugfs.h>
#include "lapic.h"
#include "mmu.h"
#include "mmu/mmu_internal.h"
 
static int vcpu_get_timer_advance_ns(void *data, u64 *val)
{
    struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
    *val = vcpu->arch.apic->lapic_timer.timer_advance_ns;
    return 0;
}
 
DEFINE_SIMPLE_ATTRIBUTE(vcpu_timer_advance_ns_fops, vcpu_get_timer_advance_ns, NULL, "%llu\n");
 
static int vcpu_get_guest_mode(void *data, u64 *val)
{
    struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
    *val = vcpu->stat.guest_mode;
    return 0;
}
 
DEFINE_SIMPLE_ATTRIBUTE(vcpu_guest_mode_fops, vcpu_get_guest_mode, NULL, "%lld\n");
 
static int vcpu_get_tsc_offset(void *data, u64 *val)
{
    struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
    *val = vcpu->arch.tsc_offset;
    return 0;
}
 
DEFINE_SIMPLE_ATTRIBUTE(vcpu_tsc_offset_fops, vcpu_get_tsc_offset, NULL, "%lld\n");
 
static int vcpu_get_tsc_scaling_ratio(void *data, u64 *val)
{
    struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
    *val = vcpu->arch.tsc_scaling_ratio;
    return 0;
}
 
DEFINE_SIMPLE_ATTRIBUTE(vcpu_tsc_scaling_fops, vcpu_get_tsc_scaling_ratio, NULL, "%llu\n");
 
static int vcpu_get_tsc_scaling_frac_bits(void *data, u64 *val)
{
    *val = kvm_caps.tsc_scaling_ratio_frac_bits;
    return 0;
}
 
DEFINE_SIMPLE_ATTRIBUTE(vcpu_tsc_scaling_frac_fops, vcpu_get_tsc_scaling_frac_bits, NULL, "%llu\n");
 
void kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu, struct dentry *debugfs_dentry)
{
    debugfs_create_file("guest_mode", 0444, debugfs_dentry, vcpu,
                &vcpu_guest_mode_fops);
    debugfs_create_file("tsc-offset", 0444, debugfs_dentry, vcpu,
                &vcpu_tsc_offset_fops);
 
    if (lapic_in_kernel(vcpu))
        debugfs_create_file("lapic_timer_advance_ns", 0444,
                    debugfs_dentry, vcpu,
                    &vcpu_timer_advance_ns_fops);
 
    if (kvm_caps.has_tsc_control) {
        debugfs_create_file("tsc-scaling-ratio", 0444,
                    debugfs_dentry, vcpu,
                    &vcpu_tsc_scaling_fops);
        debugfs_create_file("tsc-scaling-ratio-frac-bits", 0444,
                    debugfs_dentry, vcpu,
                    &vcpu_tsc_scaling_frac_fops);
    }
}
 
/*
 * This covers statistics <1024 (11=log(1024)+1), which should be enough to
 * cover RMAP_RECYCLE_THRESHOLD.
 */
#define  RMAP_LOG_SIZE  11
 
static const char *kvm_lpage_str[KVM_NR_PAGE_SIZES] = { "4K", "2M", "1G" };
 
static int kvm_mmu_rmaps_stat_show(struct seq_file *m, void *v)
{
    struct kvm_rmap_head *rmap;
    struct kvm *kvm = m->private;
    struct kvm_memory_slot *slot;
    struct kvm_memslots *slots;
    unsigned int lpage_size, index;
    /* Still small enough to be on the stack */
    unsigned int *log[KVM_NR_PAGE_SIZES], *cur;
    int i, j, k, l, ret;
 
    if (!kvm_memslots_have_rmaps(kvm))
        return 0;
 
    ret = -ENOMEM;
    memset(log, 0, sizeof(log));
    for (i = 0; i < KVM_NR_PAGE_SIZES; i++) {
        log[i] = kcalloc(RMAP_LOG_SIZE, sizeof(unsigned int), GFP_KERNEL);
        if (!log[i])
            goto out;
    }
 
    mutex_lock(&kvm->slots_lock);
    write_lock(&kvm->mmu_lock);
 
    for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) {
        int bkt;
 
        slots = __kvm_memslots(kvm, i);
        kvm_for_each_memslot(slot, bkt, slots)
            for (k = 0; k < KVM_NR_PAGE_SIZES; k++) {
                rmap = slot->arch.rmap[k];
                lpage_size = kvm_mmu_slot_lpages(slot, k + 1);
                cur = log[k];
                for (l = 0; l < lpage_size; l++) {
                    index = ffs(pte_list_count(&rmap[l]));
                    if (WARN_ON_ONCE(index >= RMAP_LOG_SIZE))
                        index = RMAP_LOG_SIZE - 1;
                    cur[index]++;
                }
            }
    }
 
    write_unlock(&kvm->mmu_lock);
    mutex_unlock(&kvm->slots_lock);
 
    /* index=0 counts no rmap; index=1 counts 1 rmap */
    seq_printf(m, "Rmap_Count:\t0\t1\t");
    for (i = 2; i < RMAP_LOG_SIZE; i++) {
        j = 1 << (i - 1);
        k = (1 << i) - 1;
        seq_printf(m, "%d-%d\t", j, k);
    }
    seq_printf(m, "\n");
 
    for (i = 0; i < KVM_NR_PAGE_SIZES; i++) {
        seq_printf(m, "Level=%s:\t", kvm_lpage_str[i]);
        cur = log[i];
        for (j = 0; j < RMAP_LOG_SIZE; j++)
            seq_printf(m, "%d\t", cur[j]);
        seq_printf(m, "\n");
    }
 
    ret = 0;
out:
    for (i = 0; i < KVM_NR_PAGE_SIZES; i++)
        kfree(log[i]);
 
    return ret;
}
 
static int kvm_mmu_rmaps_stat_open(struct inode *inode, struct file *file)
{
    struct kvm *kvm = inode->i_private;
    int r;
 
    if (!kvm_get_kvm_safe(kvm))
        return -ENOENT;
 
    r = single_open(file, kvm_mmu_rmaps_stat_show, kvm);
    if (r < 0)
        kvm_put_kvm(kvm);
 
    return r;
}
 
static int kvm_mmu_rmaps_stat_release(struct inode *inode, struct file *file)
{
    struct kvm *kvm = inode->i_private;
 
    kvm_put_kvm(kvm);
 
    return single_release(inode, file);
}
 
static const struct file_operations mmu_rmaps_stat_fops = {
    .owner      = THIS_MODULE,
    .open       = kvm_mmu_rmaps_stat_open,
    .read       = seq_read,
    .llseek     = seq_lseek,
    .release    = kvm_mmu_rmaps_stat_release,
};
 
int kvm_arch_create_vm_debugfs(struct kvm *kvm)
{
    debugfs_create_file("mmu_rmaps_stat", 0644, kvm->debugfs_dentry, kvm,
                &mmu_rmaps_stat_fops);
    return 0;
}