path: root/virt/kvm/assigned-dev.c

/*
 * Kernel-based Virtual Machine - device assignment support
 *
 * Copyright (C) 2010 Red Hat, Inc. and/or its affiliates.
 *
 * This work is licensed under the terms of the GNU GPL, version 2.  See
 * the COPYING file in the top-level directory.
 *
 */

#include <linux/kvm_host.h>
#include <linux/kvm.h>
#include <linux/uaccess.h>
#include <linux/vmalloc.h>
#include <linux/errno.h>
#include <linux/spinlock.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/namei.h>
#include <linux/fs.h>
#include "irq.h"

static struct kvm_assigned_dev_kernel *kvm_find_assigned_dev(struct list_head *head,
						      int assigned_dev_id)
{
	struct list_head *ptr;
	struct kvm_assigned_dev_kernel *match;

	list_for_each(ptr, head) {
		match = list_entry(ptr, struct kvm_assigned_dev_kernel, list);
		if (match->assigned_dev_id == assigned_dev_id)
			return match;
	}
	return NULL;
}

static int find_index_from_host_irq(struct kvm_assigned_dev_kernel
				    *assigned_dev, int irq)
{
	int i, index;
	struct msix_entry *host_msix_entries;

	host_msix_entries = assigned_dev->host_msix_entries;

	index = -1;
	for (i = 0; i < assigned_dev->entries_nr; i++)
		if (irq == host_msix_entries[i].vector) {
			index = i;
			break;
		}
	if (index < 0)
		printk(KERN_WARNING "Fail to find correlated MSI-X entry!\n");

	return index;
}

static irqreturn_t kvm_assigned_dev_intx(int irq, void *dev_id)
{
	struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
	int ret;

	spin_lock(&assigned_dev->intx_lock);
	if (pci_check_and_mask_intx(assigned_dev->dev)) {
		assigned_dev->host_irq_disabled = true;
		ret = IRQ_WAKE_THREAD;
	} else
		ret = IRQ_NONE;
	spin_unlock(&assigned_dev->intx_lock);

	return ret;
}

static void
kvm_assigned_dev_raise_guest_irq(struct kvm_assigned_dev_kernel *assigned_dev,
				 int vector)
{
	if (unlikely(assigned_dev->irq_requested_type &
		     KVM_DEV_IRQ_GUEST_INTX)) {
		spin_lock(&assigned_dev->intx_mask_lock);
		if (!(assigned_dev->flags & KVM_DEV_ASSIGN_MASK_INTX))
			kvm_set_irq(assigned_dev->kvm,
				    assigned_dev->irq_source_id, vector, 1);
		spin_unlock(&assigned_dev->intx_mask_lock);
	} else
		kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id,
			    vector, 1);
}

static irqreturn_t kvm_assigned_dev_thread_intx(int irq, void *dev_id)
{
	struct kvm_assigned_dev_kernel *assigned_dev = dev_id;

	if (!(assigned_dev->flags & KVM_DEV_ASSIGN_PCI_2_3)) {
		spin_lock_irq(&assigned_dev->intx_lock);
		disable_irq_nosync(irq);
		assigned_dev->host_irq_disabled = true;
		spin_unlock_irq(&assigned_dev->intx_lock);
	}

	kvm_assigned_dev_raise_guest_irq(assigned_dev,
					 assigned_dev->guest_irq);

	return IRQ_HANDLED;
}

#ifdef __KVM_HAVE_MSI
static irqreturn_t kvm_assigned_dev_thread_msi(int irq, void *dev_id)
{
	struct kvm_assigned_dev_kernel *assigned_dev = dev_id;

	kvm_assigned_dev_raise_guest_irq(assigned_dev,
					 assigned_dev->guest_irq);

	return IRQ_HANDLED;
}
#endif

#ifdef __KVM_HAVE_MSIX
static irqreturn_t kvm_assigned_dev_thread_msix(int irq, void *dev_id)
{
	struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
	int index = find_index_from_host_irq(assigned_dev, irq);
	u32 vector;

	if (index >= 0) {
		vector = assigned_dev->guest_msix_entries[index].vector;
		kvm_assigned_dev_raise_guest_irq(assigned_dev, vector);
	}

	return IRQ_HANDLED;
}
#endif

/* Ack the irq line for an assigned device */
static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
{
	struct kvm_assigned_dev_kernel *dev =
		container_of(kian, struct kvm_assigned_dev_kernel,
			     ack_notifier);

	kvm_set_irq(dev->kvm, dev->irq_source_id, dev->guest_irq, 0);

	spin_lock(&dev->intx_mask_lock);

	if (!(dev->flags & KVM_DEV_ASSIGN_MASK_INTX)) {
		bool reassert = false;

		spin_lock_irq(&