vgic-debug.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2016 Linaro
 * Author: Christoffer Dall <christoffer.dall@linaro.org>
 */
 
#include <linux/cpu.h>
#include <linux/debugfs.h>
#include <linux/interrupt.h>
#include <linux/kvm_host.h>
#include <linux/seq_file.h>
#include <kvm/arm_vgic.h>
#include <asm/kvm_mmu.h>
#include "vgic.h"
 
/*
 * Structure to control looping through the entire vgic state.  We start at
 * zero for each field and move upwards.  So, if dist_id is 0 we print the
 * distributor info.  When dist_id is 1, we have already printed it and move
 * on.
 *
 * When vcpu_id < nr_cpus we print the vcpu info until vcpu_id == nr_cpus and
 * so on.
 */
struct vgic_state_iter {
    int nr_cpus;
    int nr_spis;
    int nr_lpis;
    int dist_id;
    int vcpu_id;
    int intid;
    int lpi_idx;
    u32 *lpi_array;
};
 
static void iter_next(struct vgic_state_iter *iter)
{
    if (iter->dist_id == 0) {
        iter->dist_id++;
        return;
    }
 
    iter->intid++;
    if (iter->intid == VGIC_NR_PRIVATE_IRQS &&
        ++iter->vcpu_id < iter->nr_cpus)
        iter->intid = 0;
 
    if (iter->intid >= (iter->nr_spis + VGIC_NR_PRIVATE_IRQS)) {
        if (iter->lpi_idx < iter->nr_lpis)
            iter->intid = iter->lpi_array[iter->lpi_idx];
        iter->lpi_idx++;
    }
}
 
static void iter_init(struct kvm *kvm, struct vgic_state_iter *iter,
              loff_t pos)
{
    int nr_cpus = atomic_read(&kvm->online_vcpus);
 
    memset(iter, 0, sizeof(*iter));
 
    iter->nr_cpus = nr_cpus;
    iter->nr_spis = kvm->arch.vgic.nr_spis;
    if (kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) {
        iter->nr_lpis = vgic_copy_lpi_list(kvm, NULL, &iter->lpi_array);
        if (iter->nr_lpis < 0)
            iter->nr_lpis = 0;
    }
 
    /* Fast forward to the right position if needed */
    while (pos--)
        iter_next(iter);
}
 
static bool end_of_vgic(struct vgic_state_iter *iter)
{
    return iter->dist_id > 0 &&
        iter->vcpu_id == iter->nr_cpus &&
        iter->intid >= (iter->nr_spis + VGIC_NR_PRIVATE_IRQS) &&
        iter->lpi_idx > iter->nr_lpis;
}
 
static void *vgic_debug_start(struct seq_file *s, loff_t *pos)
{
    struct kvm *kvm = s->private;
    struct vgic_state_iter *iter;
 
    mutex_lock(&kvm->arch.config_lock);
    iter = kvm->arch.vgic.iter;
    if (iter) {
        iter = ERR_PTR(-EBUSY);
        goto out;
    }
 
    iter = kmalloc(sizeof(*iter), GFP_KERNEL);
    if (!iter) {
        iter = ERR_PTR(-ENOMEM);
        goto out;
    }
 
    iter_init(kvm, iter, *pos);
    kvm->arch.vgic.iter = iter;
 
    if (end_of_vgic(iter))
        iter = NULL;
out:
    mutex_unlock(&kvm->arch.config_lock);
    return iter;
}
 
static void *vgic_debug_next(struct seq_file *s, void *v, loff_t *pos)
{
    struct kvm *kvm = s->private;
    struct vgic_state_iter *iter = kvm->arch.vgic.iter;
 
    ++*pos;
    iter_next(iter);
    if (end_of_vgic(iter))
        iter = NULL;
    return iter;
}
 
static void vgic_debug_stop(struct seq_file *s, void *v)
{
    struct kvm *kvm = s->private;
    struct vgic_state_iter *iter;
 
    /*
     * If the seq file wasn't properly opened, there's nothing to clearn
     * up.
     */
    if (IS_ERR(v))
        return;
 
    mutex_lock(&kvm->arch.config_lock);
    iter = kvm->arch.vgic.iter;
    kfree(iter->lpi_array);
    kfree(iter);
    kvm->arch.vgic.iter = NULL;
    mutex_unlock(&kvm->arch.config_lock);
}
 
static void print_dist_state(struct seq_file *s, struct vgic_dist *dist)
{
    bool v3 = dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3;
 
    seq_printf(s, "Distributor\n");
    seq_printf(s, "===========\n");
    seq_printf(s, "vgic_model:\t%s\n", v3 ? "GICv3" : "GICv2");
    seq_printf(s, "nr_spis:\t%d\n", dist->nr_spis);
    if (v3)
        seq_printf(s, "nr_lpis:\t%d\n", dist->lpi_list_count);
    seq_printf(s, "enabled:\t%d\n", dist->enabled);
    seq_printf(s, "\n");
 
    seq_printf(s, "P=pending_latch, L=line_level, A=active\n");
    seq_printf(s, "E=enabled, H=hw, C=config (level=1, edge=0)\n");
    seq_printf(s, "G=group\n");
}
 
static void print_header(struct seq_file *s, struct vgic_irq *irq,
             struct kvm_vcpu *vcpu)
{
    int id = 0;
    char *hdr = "SPI ";
 
    if (vcpu) {
        hdr = "VCPU";
        id = vcpu->vcpu_idx;
    }
 
    seq_printf(s, "\n");
    seq_printf(s, "%s%2d TYP   ID TGT_ID PLAEHCG     HWID   TARGET SRC PRI VCPU_ID\n", hdr, id);
    seq_printf(s, "----------------------------------------------------------------\n");
}
 
static void print_irq_state(struct seq_file *s, struct vgic_irq *irq,
                struct kvm_vcpu *vcpu)
{
    char *type;
    bool pending;
 
    if (irq->intid < VGIC_NR_SGIS)
        type = "SGI";
    else if (irq->intid < VGIC_NR_PRIVATE_IRQS)
        type = "PPI";
    else if (irq->intid < VGIC_MAX_SPI)
        type = "SPI";
    else
        type = "LPI";
 
    if (irq->intid ==0 || irq->intid == VGIC_NR_PRIVATE_IRQS)
        print_header(s, irq, vcpu);
 
    pending = irq->pending_latch;
    if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
        int err;
 
        err = irq_get_irqchip_state(irq->host_irq,
                        IRQCHIP_STATE_PENDING,
                        &pending);
        WARN_ON_ONCE(err);
    }
 
    seq_printf(s, "       %s %4d "
              "    %2d "
              "%d%d%d%d%d%d%d "
              "%8d "
              "%8x "
              " %2x "
              "%3d "
              "     %2d "
              "\n",
            type, irq->intid,
            (irq->target_vcpu) ? irq->target_vcpu->vcpu_idx : -1,
            pending,
            irq->line_level,
            irq->active,
            irq->enabled,
            irq->hw,
            irq->config == VGIC_CONFIG_LEVEL,
            irq->group,
            irq->hwintid,
            irq->mpidr,
            irq->source,
            irq->priority,
            (irq->vcpu) ? irq->vcpu->vcpu_idx : -1);
}
 
static int vgic_debug_show(struct seq_file *s, void *v)
{
    struct kvm *kvm = s->private;
    struct vgic_state_iter *iter = v;
    struct vgic_irq *irq;
    struct kvm_vcpu *vcpu = NULL;
    unsigned long flags;
 
    if (iter->dist_id == 0) {
        print_dist_state(s, &kvm->arch.vgic);
        return 0;
    }
 
    if (!kvm->arch.vgic.initialized)
        return 0;
 
    if (iter->vcpu_id < iter->nr_cpus)
        vcpu = kvm_get_vcpu(kvm, iter->vcpu_id);
 
    irq = vgic_get_irq(kvm, vcpu, iter->intid);
    if (!irq) {
        seq_printf(s, "       LPI %4d freed\n", iter->intid);
        return 0;
    }
 
    raw_spin_lock_irqsave(&irq->irq_lock, flags);
    print_irq_state(s, irq, vcpu);
    raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
 
    vgic_put_irq(kvm, irq);
    return 0;
}
 
static const struct seq_operations vgic_debug_sops = {
    .start = vgic_debug_start,
    .next  = vgic_debug_next,
    .stop  = vgic_debug_stop,
    .show  = vgic_debug_show
};
 
DEFINE_SEQ_ATTRIBUTE(vgic_debug);
 
void vgic_debug_init(struct kvm *kvm)
{
    debugfs_create_file("vgic-state", 0444, kvm->debugfs_dentry, kvm,
                &vgic_debug_fops);
}
 
void vgic_debug_destroy(struct kvm *kvm)
{
}