// 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,
};

void kvm_arch_create_vm_debugfs(struct kvm *kvm)
{
        debugfs_create_file("mmu_rmaps_stat", 0644, kvm->debugfs_dentry, kvm,
                            &mmu_rmaps_stat_fops);
}