[PATCH 09/22] virtio_pci: move old defines to legacy, introduce new structure.

[Rusty Russell <rusty@rustcorp.com.au>]

We don't *remove* the old ones, unless VIRTIO_PCI_NO_LEGACY is defined,
but they get a friendly #warning about the change.

Note that config option is not prompted; we always enable it for now.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 drivers/virtio/Kconfig             |   12 +
 drivers/virtio/Makefile            |    2 +-
 drivers/virtio/virtio_pci.c        |  858 ------------------------------------
 drivers/virtio/virtio_pci_legacy.c |  858 ++++++++++++++++++++++++++++++++++++
 include/uapi/linux/virtio_pci.h    |   61 ++-
 5 files changed, 911 insertions(+), 880 deletions(-)
 delete mode 100644 drivers/virtio/virtio_pci.c
 create mode 100644 drivers/virtio/virtio_pci_legacy.c

diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index c6683f2..65de1b2 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -22,6 +22,18 @@ config VIRTIO_PCI
 
 	  If unsure, say M.
 
+config VIRTIO_PCI_LEGACY
+	bool
+	default y
+	depends on VIRTIO_PCI
+	---help---
+	  The old BAR0 virtio pci layout was deprecated early 2013.
+
+	  So look out into your driveway.  Do you have a flying car?  If
+	  so, you can happily disable this option and virtio will not
+	  break.  Otherwise, leave it set.  Unless you're testing what
+	  life will be like in The Future.
+
 config VIRTIO_BALLOON
 	tristate "Virtio balloon driver"
 	depends on VIRTIO
diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
index 9076635..23834f5 100644
--- a/drivers/virtio/Makefile
+++ b/drivers/virtio/Makefile
@@ -1,4 +1,4 @@
 obj-$(CONFIG_VIRTIO) += virtio.o virtio_ring.o
 obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o
-obj-$(CONFIG_VIRTIO_PCI) += virtio_pci.o
+obj-$(CONFIG_VIRTIO_PCI_LEGACY) += virtio_pci_legacy.o
 obj-$(CONFIG_VIRTIO_BALLOON) += virtio_balloon.o
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
deleted file mode 100644
index 8d081ea..0000000
--- a/drivers/virtio/virtio_pci.c
+++ /dev/null
@@ -1,858 +0,0 @@
-/*
- * Virtio PCI driver
- *
- * This module allows virtio devices to be used over a virtual PCI device.
- * This can be used with QEMU based VMMs like KVM or Xen.
- *
- * Copyright IBM Corp. 2007
- *
- * Authors:
- *  Anthony Liguori  <aliguori@us.ibm.com>
- *
- * This work is licensed under the terms of the GNU GPL, version 2 or later.
- * See the COPYING file in the top-level directory.
- *
- */
-
-#include <linux/module.h>
-#include <linux/list.h>
-#include <linux/pci.h>
-#include <linux/slab.h>
-#include <linux/interrupt.h>
-#include <linux/virtio.h>
-#include <linux/virtio_config.h>
-#include <linux/virtio_ring.h>
-#include <linux/virtio_pci.h>
-#include <linux/highmem.h>
-#include <linux/spinlock.h>
-
-MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>");
-MODULE_DESCRIPTION("virtio-pci");
-MODULE_LICENSE("GPL");
-MODULE_VERSION("1");
-
-/* Our device structure */
-struct virtio_pci_device
-{
-	struct virtio_device vdev;
-	struct pci_dev *pci_dev;
-
-	/* the IO mapping for the PCI config space */
-	void __iomem *ioaddr;
-
-	/* a list of queues so we can dispatch IRQs */
-	spinlock_t lock;
-	struct list_head virtqueues;
-
-	/* MSI-X support */
-	int msix_enabled;
-	int intx_enabled;
-	struct msix_entry *msix_entries;
-	cpumask_var_t *msix_affinity_masks;
-	/* Name strings for interrupts. This size should be enough,
-	 * and I'm too lazy to allocate each name separately. */
-	char (*msix_names)[256];
-	/* Number of available vectors */
-	unsigned msix_vectors;
-	/* Vectors allocated, excluding per-vq vectors if any */
-	unsigned msix_used_vectors;
-
-	/* Status saved during hibernate/restore */
-	u8 saved_status;
-
-	/* Whether we have vector per vq */
-	bool per_vq_vectors;
-};
-
-/* Constants for MSI-X */
-/* Use first vector for configuration changes, second and the rest for
- * virtqueues Thus, we need at least 2 vectors for MSI. */
-enum {
-	VP_MSIX_CONFIG_VECTOR = 0,
-	VP_MSIX_VQ_VECTOR = 1,
-};
-
-struct virtio_pci_vq_info
-{
-	/* the actual virtqueue */
-	struct virtqueue *vq;
-
-	/* the number of entries in the queue */
-	int num;
-
-	/* the virtual address of the ring queue */
-	void *queue;
-
-	/* the list node for the virtqueues list */
-	struct list_head node;
-
-	/* MSI-X vector (or none) */
-	unsigned msix_vector;
-};
-
-/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
-static DEFINE_PCI_DEVICE_TABLE(virtio_pci_id_table) = {
-	{ PCI_DEVICE(0x1af4, PCI_ANY_ID) },
-	{ 0 }
-};
-
-MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
-
-/* Convert a generic virtio device to our structure */
-static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
-{
-	return container_of(vdev, struct virtio_pci_device, vdev);
-}
-
-/* virtio config->get_features() implementation */
-static u64 vp_get_features(struct virtio_device *vdev)
-{
-	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-
-	/* We only support 32 feature bits. */
-	return ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
-}
-
-/* virtio config->finalize_features() implementation */
-static void vp_finalize_features(struct virtio_device *vdev)
-{
-	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-
-	/* Give virtio_ring a chance to accept features. */
-	vring_transport_features(vdev);
-
-	/* We only support 32 feature bits. */
-	iowrite32(vdev->features, vp_dev->ioaddr+VIRTIO_PCI_GUEST_FEATURES);
-}
-
-/* Device config access: we use guest endian, as per spec. */
-static void vp_get(struct virtio_device *vdev, unsigned offset,
-		   void *buf, unsigned len)
-{
-	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-	void __iomem *ioaddr = vp_dev->ioaddr +
-				VIRTIO_PCI_CONFIG(vp_dev) + offset;
-	u8 *ptr = buf;
-	int i;
-
-	for (i = 0; i < len; i++)
-		ptr[i] = ioread8(ioaddr + i);
-}
-
-#define VP_GETx(bits)							\
-static u##bits vp_get##bits(struct virtio_device *vdev, unsigned int offset) \
-{									\
-	u##bits v;							\
-	vp_get(vdev, offset, &v, sizeof(v));				\
-	return v;							\
-}
-
-VP_GETx(8)
-VP_GETx(16)
-VP_GETx(32)
-VP_GETx(64)
-
-static void vp_set(struct virtio_device *vdev, unsigned offset,
-		   const void *buf, unsigned len)
-{
-	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-	void __iomem *ioaddr = vp_dev->ioaddr +
-				VIRTIO_PCI_CONFIG(vp_dev) + offset;
-	const u8 *ptr = buf;
-	int i;
-
-	for (i = 0; i < len; i++)
-		iowrite8(ptr[i], ioaddr + i);
-}
-
-#define VP_SETx(bits)							\
-static void vp_set##bits(struct virtio_device *vdev, unsigned int offset, \
-			 u##bits v)					\
-{									\
-	vp_set(vdev, offset, &v, sizeof(v));				\
-}
-
-VP_SETx(8)
-VP_SETx(16)
-VP_SETx(32)
-VP_SETx(64)
-
-/* config->{get,set}_status() implementations */
-static u8 vp_get_status(struct virtio_device *vdev)
-{
-	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-	return ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
-}
-
-static void vp_set_status(struct virtio_device *vdev, u8 status)
-{
-	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-	/* We should never be setting status to 0. */
-	BUG_ON(status == 0);
-	iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
-}
-
-/* wait for pending irq handlers */
-static void vp_synchronize_vectors(struct virtio_device *vdev)
-{
-	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-	int i;
-
-	if (vp_dev->intx_enabled)
-		synchronize_irq(vp_dev->pci_dev->irq);
-
-	for (i = 0; i < vp_dev->msix_vectors; ++i)
-		synchronize_irq(vp_dev->msix_entries[i].vector);
-}
-
-static void vp_reset(struct virtio_device *vdev)
-{
-	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-	/* 0 status means a reset. */
-	iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
-	/* Flush out the status write, and flush in device writes,
-	 * including MSi-X interrupts, if any. */
-	ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
-	/* Flush pending VQ/configuration callbacks. */
-	vp_synchronize_vectors(vdev);
-}
-
-/* the notify function used when creating a virt queue */
-static void vp_notify(struct virtqueue *vq)
-{
-	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
-
-	/* we write the queue's selector into the notification register to
-	 * signal the other end */
-	iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY);
-}
-
-/* Handle a configuration change: Tell driver if it wants to know. */
-static irqreturn_t vp_config_changed(int irq, void *opaque)
-{
-	struct virtio_pci_device *vp_dev = opaque;
-	struct virtio_driver *drv;
-	drv = container_of(vp_dev->vdev.dev.driver,
-			   struct virtio_driver, driver);
-
-	if (drv && drv->config_changed)
-		drv->config_changed(&vp_dev->vdev);
-	return IRQ_HANDLED;
-}
-
-/* Notify all virtqueues on an interrupt. */
-static irqreturn_t vp_vring_interrupt(int irq, void *opaque)
-{
-	struct virtio_pci_device *vp_dev = opaque;
-	struct virtio_pci_vq_info *info;
-	irqreturn_t ret = IRQ_NONE;
-	unsigned long flags;
-
-	spin_lock_irqsave(&vp_dev->lock, flags);
-	list_for_each_entry(info, &vp_dev->virtqueues, node) {
-		if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
-			ret = IRQ_HANDLED;
-	}
-	spin_unlock_irqrestore(&vp_dev->lock, flags);
-
-	return ret;
-}
-
-/* A small wrapper to also acknowledge the interrupt when it's handled.
- * I really need an EIO hook for the vring so I can ack the interrupt once we
- * know that we'll be handling the IRQ but before we invoke the callback since
- * the callback may notify the host which results in the host attempting to
- * raise an interrupt that we would then mask once we acknowledged the
- * interrupt. */
-static irqreturn_t vp_interrupt(int irq, void *opaque)
-{
-	struct virtio_pci_device *vp_dev = opaque;
-	u8 isr;
-
-	/* reading the ISR has the effect of also clearing it so it's very
-	 * important to save off the value. */
-	isr = ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
-
-	/* It's definitely not us if the ISR was not high */
-	if (!isr)
-		return IRQ_NONE;
-
-	/* Configuration change?  Tell driver if it wants to know. */
-	if (isr & VIRTIO_PCI_ISR_CONFIG)
-		vp_config_changed(irq, opaque);
-
-	return vp_vring_interrupt(irq, opaque);
-}
-
-static void vp_free_vectors(struct virtio_device *vdev)
-{
-	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-	int i;
-
-	if (vp_dev->intx_enabled) {
-		free_irq(vp_dev->pci_dev->irq, vp_dev);
-		vp_dev->intx_enabled = 0;
-	}
-
-	for (i = 0; i < vp_dev->msix_used_vectors; ++i)
-		free_irq(vp_dev->msix_entries[i].vector, vp_dev);
-
-	for (i = 0; i < vp_dev->msix_vectors; i++)
-		if (vp_dev->msix_affinity_masks[i])
-			free_cpumask_var(vp_dev->msix_affinity_masks[i]);
-
-	if (vp_dev->msix_enabled) {
-		/* Disable the vector used for configuration */
-		iowrite16(VIRTIO_MSI_NO_VECTOR,
-			  vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
-		/* Flush the write out to device */
-		ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
-
-		pci_disable_msix(vp_dev->pci_dev);
-		vp_dev->msix_enabled = 0;
-		vp_dev->msix_vectors = 0;
-	}
-
-	vp_dev->msix_used_vectors = 0;
-	kfree(vp_dev->msix_names);
-	vp_dev->msix_names = NULL;
-	kfree(vp_dev->msix_entries);
-	vp_dev->msix_entries = NULL;
-	kfree(vp_dev->msix_affinity_masks);
-	vp_dev->msix_affinity_masks = NULL;
-}
-
-static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
-				   bool per_vq_vectors)
-{
-	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-	const char *name = dev_name(&vp_dev->vdev.dev);
-	unsigned i, v;
-	int err = -ENOMEM;
-
-	vp_dev->msix_entries = kmalloc(nvectors * sizeof *vp_dev->msix_entries,
-				       GFP_KERNEL);
-	if (!vp_dev->msix_entries)
-		goto error;
-	vp_dev->msix_names = kmalloc(nvectors * sizeof *vp_dev->msix_names,
-				     GFP_KERNEL);
-	if (!vp_dev->msix_names)
-		goto error;
-	vp_dev->msix_affinity_masks
-		= kzalloc(nvectors * sizeof *vp_dev->msix_affinity_masks,
-			  GFP_KERNEL);
-	if (!vp_dev->msix_affinity_masks)
-		goto error;
-	for (i = 0; i < nvectors; ++i)
-		if (!alloc_cpumask_var(&vp_dev->msix_affinity_masks[i],
-					GFP_KERNEL))
-			goto error;
-
-	for (i = 0; i < nvectors; ++i)
-		vp_dev->msix_entries[i].entry = i;
-
-	/* pci_enable_msix returns positive if we can't get this many. */
-	err = pci_enable_msix(vp_dev->pci_dev, vp_dev->msix_entries, nvectors);
-	if (err > 0)
-		err = -ENOSPC;
-	if (err)
-		goto error;
-	vp_dev->msix_vectors = nvectors;
-	vp_dev->msix_enabled = 1;
-
-	/* Set the vector used for configuration */
-	v = vp_dev->msix_used_vectors;
-	snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
-		 "%s-config", name);
-	err = request_irq(vp_dev->msix_entries[v].vector,
-			  vp_config_changed, 0, vp_dev->msix_names[v],
-			  vp_dev);
-	if (err)
-		goto error;
-	++vp_dev->msix_used_vectors;
-
-	iowrite16(v, vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
-	/* Verify we had enough resources to assign the vector */
-	v = ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
-	if (v == VIRTIO_MSI_NO_VECTOR) {
-		err = -EBUSY;
-		goto error;
-	}
-
-	if (!per_vq_vectors) {
-		/* Shared vector for all VQs */
-		v = vp_dev->msix_used_vectors;
-		snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
-			 "%s-virtqueues", name);
-		err = request_irq(vp_dev->msix_entries[v].vector,
-				  vp_vring_interrupt, 0, vp_dev->msix_names[v],
-				  vp_dev);
-		if (err)
-			goto error;
-		++vp_dev->msix_used_vectors;
-	}
-	return 0;
-error:
-	vp_free_vectors(vdev);
-	return err;
-}
-
-static int vp_request_intx(struct virtio_device *vdev)
-{
-	int err;
-	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-
-	err = request_irq(vp_dev->pci_dev->irq, vp_interrupt,
-			  IRQF_SHARED, dev_name(&vdev->dev), vp_dev);
-	if (!err)
-		vp_dev->intx_enabled = 1;
-	return err;
-}
-
-static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
-				  void (*callback)(struct virtqueue *vq),
-				  const char *name,
-				  u16 msix_vec)
-{
-	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-	struct virtio_pci_vq_info *info;
-	struct virtqueue *vq;
-	unsigned long flags, size;
-	u16 num;
-	int err;
-
-	/* Select the queue we're interested in */
-	iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
-
-	/* Check if queue is either not available or already active. */
-	num = ioread16(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
-	if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
-		return ERR_PTR(-ENOENT);
-
-	/* allocate and fill out our structure the represents an active
-	 * queue */
-	info = kmalloc(sizeof(struct virtio_pci_vq_info), GFP_KERNEL);
-	if (!info)
-		return ERR_PTR(-ENOMEM);
-
-	info->num = num;
-	info->msix_vector = msix_vec;
-
-	size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN));
-	info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO);
-	if (info->queue == NULL) {
-		err = -ENOMEM;
-		goto out_info;
-	}
-
-	/* activate the queue */
-	iowrite32(virt_to_phys(info->queue) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT,
-		  vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
-
-	/* create the vring */
-	vq = vring_new_virtqueue(index, info->num, VIRTIO_PCI_VRING_ALIGN, vdev,
-				 true, info->queue, vp_notify, callback, name);
-	if (!vq) {
-		err = -ENOMEM;
-		goto out_activate_queue;
-	}
-
-	vq->priv = info;
-	info->vq = vq;
-
-	if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
-		iowrite16(msix_vec, vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
-		msix_vec = ioread16(vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
-		if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
-			err = -EBUSY;
-			goto out_assign;
-		}
-	}
-
-	if (callback) {
-		spin_lock_irqsave(&vp_dev->lock, flags);
-		list_add(&info->node, &vp_dev->virtqueues);
-		spin_unlock_irqrestore(&vp_dev->lock, flags);
-	} else {
-		INIT_LIST_HEAD(&info->node);
-	}
-
-	return vq;
-
-out_assign:
-	vring_del_virtqueue(vq);
-out_activate_queue:
-	iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
-	free_pages_exact(info->queue, size);
-out_info:
-	kfree(info);
-	return ERR_PTR(err);
-}
-
-static void vp_del_vq(struct virtqueue *vq)
-{
-	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
-	struct virtio_pci_vq_info *info = vq->priv;
-	unsigned long flags, size;
-
-	spin_lock_irqsave(&vp_dev->lock, flags);
-	list_del(&info->node);
-	spin_unlock_irqrestore(&vp_dev->lock, flags);
-
-	iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
-
-	if (vp_dev->msix_enabled) {
-		iowrite16(VIRTIO_MSI_NO_VECTOR,
-			  vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
-		/* Flush the write out to device */
-		ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
-	}
-
-	vring_del_virtqueue(vq);
-
-	/* Select and deactivate the queue */
-	iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
-
-	size = PAGE_ALIGN(vring_size(info->num, VIRTIO_PCI_VRING_ALIGN));
-	free_pages_exact(info->queue, size);
-	kfree(info);
-}
-
-/* the config->del_vqs() implementation */
-static void vp_del_vqs(struct virtio_device *vdev)
-{
-	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-	struct virtqueue *vq, *n;
-	struct virtio_pci_vq_info *info;
-
-	list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
-		info = vq->priv;
-		if (vp_dev->per_vq_vectors &&
-			info->msix_vector != VIRTIO_MSI_NO_VECTOR)
-			free_irq(vp_dev->msix_entries[info->msix_vector].vector,
-				 vq);
-		vp_del_vq(vq);
-	}
-	vp_dev->per_vq_vectors = false;
-
-	vp_free_vectors(vdev);
-}
-
-static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs,
-			      struct virtqueue *vqs[],
-			      vq_callback_t *callbacks[],
-			      const char *names[],
-			      bool use_msix,
-			      bool per_vq_vectors)
-{
-	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-	u16 msix_vec;
-	int i, err, nvectors, allocated_vectors;
-
-	if (!use_msix) {
-		/* Old style: one normal interrupt for change and all vqs. */
-		err = vp_request_intx(vdev);
-		if (err)
-			goto error_request;
-	} else {
-		if (per_vq_vectors) {
-			/* Best option: one for change interrupt, one per vq. */
-			nvectors = 1;
-			for (i = 0; i < nvqs; ++i)
-				if (callbacks[i])
-					++nvectors;
-		} else {
-			/* Second best: one for change, shared for all vqs. */
-			nvectors = 2;
-		}
-
-		err = vp_request_msix_vectors(vdev, nvectors, per_vq_vectors);
-		if (err)
-			goto error_request;
-	}
-
-	vp_dev->per_vq_vectors = per_vq_vectors;
-	allocated_vectors = vp_dev->msix_used_vectors;
-	for (i = 0; i < nvqs; ++i) {
-		if (!names[i]) {
-			vqs[i] = NULL;
-			continue;
-		} else if (!callbacks[i] || !vp_dev->msix_enabled)
-			msix_vec = VIRTIO_MSI_NO_VECTOR;
-		else if (vp_dev->per_vq_vectors)
-			msix_vec = allocated_vectors++;
-		else
-			msix_vec = VP_MSIX_VQ_VECTOR;
-		vqs[i] = setup_vq(vdev, i, callbacks[i], names[i], msix_vec);
-		if (IS_ERR(vqs[i])) {
-			err = PTR_ERR(vqs[i]);
-			goto error_find;
-		}
-
-		if (!vp_dev->per_vq_vectors || msix_vec == VIRTIO_MSI_NO_VECTOR)
-			continue;
-
-		/* allocate per-vq irq if available and necessary */
-		snprintf(vp_dev->msix_names[msix_vec],
-			 sizeof *vp_dev->msix_names,
-			 "%s-%s",
-			 dev_name(&vp_dev->vdev.dev), names[i]);
-		err = request_irq(vp_dev->msix_entries[msix_vec].vector,
-				  vring_interrupt, 0,
-				  vp_dev->msix_names[msix_vec],
-				  vqs[i]);
-		if (err) {
-			vp_del_vq(vqs[i]);
-			goto error_find;
-		}
-	}
-	return 0;
-
-error_find:
-	vp_del_vqs(vdev);
-
-error_request:
-	return err;
-}
-
-/* the config->find_vqs() implementation */
-static int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
-		       struct virtqueue *vqs[],
-		       vq_callback_t *callbacks[],
-		       const char *names[])
-{
-	int err;
-
-	/* Try MSI-X with one vector per queue. */
-	err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names, true, true);
-	if (!err)
-		return 0;
-	/* Fallback: MSI-X with one vector for config, one shared for queues. */
-	err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
-				 true, false);
-	if (!err)
-		return 0;
-	/* Finally fall back to regular interrupts. */
-	return vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
-				  false, false);
-}
-
-static const char *vp_bus_name(struct virtio_device *vdev)
-{
-	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-
-	return pci_name(vp_dev->pci_dev);
-}
-
-/* Setup the affinity for a virtqueue:
- * - force the affinity for per vq vector
- * - OR over all affinities for shared MSI
- * - ignore the affinity request if we're using INTX
- */
-static int vp_set_vq_affinity(struct virtqueue *vq, int cpu)
-{
-	struct virtio_device *vdev = vq->vdev;
-	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-	struct virtio_pci_vq_info *info = vq->priv;
-	struct cpumask *mask;
-	unsigned int irq;
-
-	if (!vq->callback)
-		return -EINVAL;
-
-	if (vp_dev->msix_enabled) {
-		mask = vp_dev->msix_affinity_masks[info->msix_vector];
-		irq = vp_dev->msix_entries[info->msix_vector].vector;
-		if (cpu == -1)
-			irq_set_affinity_hint(irq, NULL);
-		else {
-			cpumask_set_cpu(cpu, mask);
-			irq_set_affinity_hint(irq, mask);
-		}
-	}
-	return 0;
-}
-
-static const struct virtio_config_ops virtio_pci_config_ops = {
-	.get8		= vp_get8,
-	.set8		= vp_set8,
-	.get16		= vp_get16,
-	.set16		= vp_set16,
-	.get32		= vp_get32,
-	.set32		= vp_set32,
-	.get64		= vp_get64,
-	.set64		= vp_set64,
-	.get_status	= vp_get_status,
-	.set_status	= vp_set_status,
-	.reset		= vp_reset,
-	.find_vqs	= vp_find_vqs,
-	.del_vqs	= vp_del_vqs,
-	.get_features	= vp_get_features,
-	.finalize_features = vp_finalize_features,
-	.bus_name	= vp_bus_name,
-	.set_vq_affinity = vp_set_vq_affinity,
-};
-
-static void virtio_pci_release_dev(struct device *_d)
-{
-	/*
-	 * No need for a release method as we allocate/free
-	 * all devices together with the pci devices.
-	 * Provide an empty one to avoid getting a warning from core.
-	 */
-}
-
-/* the PCI probing function */
-static int virtio_pci_probe(struct pci_dev *pci_dev,
-			    const struct pci_device_id *id)
-{
-	struct virtio_pci_device *vp_dev;
-	int err;
-
-	/* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
-	if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
-		return -ENODEV;
-
-	if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
-		printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
-		       VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
-		return -ENODEV;
-	}
-
-	/* allocate our structure and fill it out */
-	vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
-	if (vp_dev == NULL)
-		return -ENOMEM;
-
-	vp_dev->vdev.dev.parent = &pci_dev->dev;
-	vp_dev->vdev.dev.release = virtio_pci_release_dev;
-	vp_dev->vdev.config = &virtio_pci_config_ops;
-	vp_dev->pci_dev = pci_dev;
-	INIT_LIST_HEAD(&vp_dev->virtqueues);
-	spin_lock_init(&vp_dev->lock);
-
-	/* Disable MSI/MSIX to bring device to a known good state. */
-	pci_msi_off(pci_dev);
-
-	/* enable the device */
-	err = pci_enable_device(pci_dev);
-	if (err)
-		goto out;
-
-	err = pci_request_regions(pci_dev, "virtio-pci");
-	if (err)
-		goto out_enable_device;
-
-	vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
-	if (vp_dev->ioaddr == NULL) {
-		err = -ENOMEM;
-		goto out_req_regions;
-	}
-
-	pci_set_drvdata(pci_dev, vp_dev);
-	pci_set_master(pci_dev);
-
-	/* we use the subsystem vendor/device id as the virtio vendor/device
-	 * id.  this allows us to use the same PCI vendor/device id for all
-	 * virtio devices and to identify the particular virtio driver by
-	 * the subsystem ids */
-	vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
-	vp_dev->vdev.id.device = pci_dev->subsystem_device;
-
-	/* finally register the virtio device */
-	err = register_virtio_device(&vp_dev->vdev);
-	if (err)
-		goto out_set_drvdata;
-
-	return 0;
-
-out_set_drvdata:
-	pci_set_drvdata(pci_dev, NULL);
-	pci_iounmap(pci_dev, vp_dev->ioaddr);
-out_req_regions:
-	pci_release_regions(pci_dev);
-out_enable_device:
-	pci_disable_device(pci_dev);
-out:
-	kfree(vp_dev);
-	return err;
-}
-
-static void virtio_pci_remove(struct pci_dev *pci_dev)
-{
-	struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
-
-	unregister_virtio_device(&vp_dev->vdev);
-
-	vp_del_vqs(&vp_dev->vdev);
-	pci_set_drvdata(pci_dev, NULL);
-	pci_iounmap(pci_dev, vp_dev->ioaddr);
-	pci_release_regions(pci_dev);
-	pci_disable_device(pci_dev);
-	kfree(vp_dev);
-}
-
-#ifdef CONFIG_PM
-static int virtio_pci_freeze(struct device *dev)
-{
-	struct pci_dev *pci_dev = to_pci_dev(dev);
-	struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
-	struct virtio_driver *drv;
-	int ret;
-
-	drv = container_of(vp_dev->vdev.dev.driver,
-			   struct virtio_driver, driver);
-
-	ret = 0;
-	vp_dev->saved_status = vp_get_status(&vp_dev->vdev);
-	if (drv && drv->freeze)
-		ret = drv->freeze(&vp_dev->vdev);
-
-	if (!ret)
-		pci_disable_device(pci_dev);
-	return ret;
-}
-
-static int virtio_pci_restore(struct device *dev)
-{
-	struct pci_dev *pci_dev = to_pci_dev(dev);
-	struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
-	struct virtio_driver *drv;
-	int ret;
-
-	drv = container_of(vp_dev->vdev.dev.driver,
-			   struct virtio_driver, driver);
-
-	ret = pci_enable_device(pci_dev);
-	if (ret)
-		return ret;
-
-	pci_set_master(pci_dev);
-	vp_finalize_features(&vp_dev->vdev);
-
-	if (drv && drv->restore)
-		ret = drv->restore(&vp_dev->vdev);
-
-	/* Finally, tell the device we're all set */
-	if (!ret)
-		vp_set_status(&vp_dev->vdev, vp_dev->saved_status);
-
-	return ret;
-}
-
-static const struct dev_pm_ops virtio_pci_pm_ops = {
-	SET_SYSTEM_SLEEP_PM_OPS(virtio_pci_freeze, virtio_pci_restore)
-};
-#endif
-
-static struct pci_driver virtio_pci_driver = {
-	.name		= "virtio-pci",
-	.id_table	= virtio_pci_id_table,
-	.probe		= virtio_pci_probe,
-	.remove		= virtio_pci_remove,
-#ifdef CONFIG_PM
-	.driver.pm	= &virtio_pci_pm_ops,
-#endif
-};
-
-module_pci_driver(virtio_pci_driver);
diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci_legacy.c
new file mode 100644
index 0000000..77baa7c
--- /dev/null
+++ b/drivers/virtio/virtio_pci_legacy.c
@@ -0,0 +1,858 @@
+/*
+ * Virtio PCI driver (legacy mode)
+ *
+ * This module allows virtio devices to be used over a virtual PCI device.
+ * This can be used with QEMU based VMMs like KVM or Xen.
+ *
+ * Copyright IBM Corp. 2007
+ *
+ * Authors:
+ *  Anthony Liguori  <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/virtio.h>
+#include <linux/virtio_config.h>
+#include <linux/virtio_ring.h>
+#include <linux/virtio_pci.h>
+#include <linux/highmem.h>
+#include <linux/spinlock.h>
+
+MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>");
+MODULE_DESCRIPTION("virtio-pci-legacy");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("1");
+
+/* Our device structure */
+struct virtio_pci_device
+{
+	struct virtio_device vdev;
+	struct pci_dev *pci_dev;
+
+	/* the IO mapping for the PCI config space */
+	void __iomem *ioaddr;
+
+	/* a list of queues so we can dispatch IRQs */
+	spinlock_t lock;
+	struct list_head virtqueues;
+
+	/* MSI-X support */
+	int msix_enabled;
+	int intx_enabled;
+	struct msix_entry *msix_entries;
+	cpumask_var_t *msix_affinity_masks;
+	/* Name strings for interrupts. This size should be enough,
+	 * and I'm too lazy to allocate each name separately. */
+	char (*msix_names)[256];
+	/* Number of available vectors */
+	unsigned msix_vectors;
+	/* Vectors allocated, excluding per-vq vectors if any */
+	unsigned msix_used_vectors;
+
+	/* Status saved during hibernate/restore */
+	u8 saved_status;
+
+	/* Whether we have vector per vq */
+	bool per_vq_vectors;
+};
+
+/* Constants for MSI-X */
+/* Use first vector for configuration changes, second and the rest for
+ * virtqueues Thus, we need at least 2 vectors for MSI. */
+enum {
+	VP_MSIX_CONFIG_VECTOR = 0,
+	VP_MSIX_VQ_VECTOR = 1,
+};
+
+struct virtio_pci_vq_info
+{
+	/* the actual virtqueue */
+	struct virtqueue *vq;
+
+	/* the number of entries in the queue */
+	int num;
+
+	/* the virtual address of the ring queue */
+	void *queue;
+
+	/* the list node for the virtqueues list */
+	struct list_head node;
+
+	/* MSI-X vector (or none) */
+	unsigned msix_vector;
+};
+
+/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
+static DEFINE_PCI_DEVICE_TABLE(virtio_pci_id_table) = {
+	{ PCI_DEVICE(0x1af4, PCI_ANY_ID) },
+	{ 0 }
+};
+
+MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
+
+/* Convert a generic virtio device to our structure */
+static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
+{
+	return container_of(vdev, struct virtio_pci_device, vdev);
+}
+
+/* virtio config->get_features() implementation */
+static u64 vp_get_features(struct virtio_device *vdev)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+
+	/* We only support 32 feature bits. */
+	return ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
+}
+
+/* virtio config->finalize_features() implementation */
+static void vp_finalize_features(struct virtio_device *vdev)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+
+	/* Give virtio_ring a chance to accept features. */
+	vring_transport_features(vdev);
+
+	/* We only support 32 feature bits. */
+	iowrite32(vdev->features, vp_dev->ioaddr+VIRTIO_PCI_GUEST_FEATURES);
+}
+
+/* Device config access: we use guest endian, as per spec. */
+static void vp_get(struct virtio_device *vdev, unsigned offset,
+		   void *buf, unsigned len)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+	void __iomem *ioaddr = vp_dev->ioaddr +
+				VIRTIO_PCI_CONFIG(vp_dev) + offset;
+	u8 *ptr = buf;
+	int i;
+
+	for (i = 0; i < len; i++)
+		ptr[i] = ioread8(ioaddr + i);
+}
+
+#define VP_GETx(bits)							\
+static u##bits vp_get##bits(struct virtio_device *vdev, unsigned int offset) \
+{									\
+	u##bits v;							\
+	vp_get(vdev, offset, &v, sizeof(v));				\
+	return v;							\
+}
+
+VP_GETx(8)
+VP_GETx(16)
+VP_GETx(32)
+VP_GETx(64)
+
+static void vp_set(struct virtio_device *vdev, unsigned offset,
+		   const void *buf, unsigned len)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+	void __iomem *ioaddr = vp_dev->ioaddr +
+				VIRTIO_PCI_CONFIG(vp_dev) + offset;
+	const u8 *ptr = buf;
+	int i;
+
+	for (i = 0; i < len; i++)
+		iowrite8(ptr[i], ioaddr + i);
+}
+
+#define VP_SETx(bits)							\
+static void vp_set##bits(struct virtio_device *vdev, unsigned int offset, \
+			 u##bits v)					\
+{									\
+	vp_set(vdev, offset, &v, sizeof(v));				\
+}
+
+VP_SETx(8)
+VP_SETx(16)
+VP_SETx(32)
+VP_SETx(64)
+
+/* config->{get,set}_status() implementations */
+static u8 vp_get_status(struct virtio_device *vdev)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+	return ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
+}
+
+static void vp_set_status(struct virtio_device *vdev, u8 status)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+	/* We should never be setting status to 0. */
+	BUG_ON(status == 0);
+	iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
+}
+
+/* wait for pending irq handlers */
+static void vp_synchronize_vectors(struct virtio_device *vdev)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+	int i;
+
+	if (vp_dev->intx_enabled)
+		synchronize_irq(vp_dev->pci_dev->irq);
+
+	for (i = 0; i < vp_dev->msix_vectors; ++i)
+		synchronize_irq(vp_dev->msix_entries[i].vector);
+}
+
+static void vp_reset(struct virtio_device *vdev)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+	/* 0 status means a reset. */
+	iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
+	/* Flush out the status write, and flush in device writes,
+	 * including MSi-X interrupts, if any. */
+	ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
+	/* Flush pending VQ/configuration callbacks. */
+	vp_synchronize_vectors(vdev);
+}
+
+/* the notify function used when creating a virt queue */
+static void vp_notify(struct virtqueue *vq)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
+
+	/* we write the queue's selector into the notification register to
+	 * signal the other end */
+	iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY);
+}
+
+/* Handle a configuration change: Tell driver if it wants to know. */
+static irqreturn_t vp_config_changed(int irq, void *opaque)
+{
+	struct virtio_pci_device *vp_dev = opaque;
+	struct virtio_driver *drv;
+	drv = container_of(vp_dev->vdev.dev.driver,
+			   struct virtio_driver, driver);
+
+	if (drv && drv->config_changed)
+		drv->config_changed(&vp_dev->vdev);
+	return IRQ_HANDLED;
+}
+
+/* Notify all virtqueues on an interrupt. */
+static irqreturn_t vp_vring_interrupt(int irq, void *opaque)
+{
+	struct virtio_pci_device *vp_dev = opaque;
+	struct virtio_pci_vq_info *info;
+	irqreturn_t ret = IRQ_NONE;
+	unsigned long flags;
+
+	spin_lock_irqsave(&vp_dev->lock, flags);
+	list_for_each_entry(info, &vp_dev->virtqueues, node) {
+		if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
+			ret = IRQ_HANDLED;
+	}
+	spin_unlock_irqrestore(&vp_dev->lock, flags);
+
+	return ret;
+}
+
+/* A small wrapper to also acknowledge the interrupt when it's handled.
+ * I really need an EIO hook for the vring so I can ack the interrupt once we
+ * know that we'll be handling the IRQ but before we invoke the callback since
+ * the callback may notify the host which results in the host attempting to
+ * raise an interrupt that we would then mask once we acknowledged the
+ * interrupt. */
+static irqreturn_t vp_interrupt(int irq, void *opaque)
+{
+	struct virtio_pci_device *vp_dev = opaque;
+	u8 isr;
+
+	/* reading the ISR has the effect of also clearing it so it's very
+	 * important to save off the value. */
+	isr = ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
+
+	/* It's definitely not us if the ISR was not high */
+	if (!isr)
+		return IRQ_NONE;
+
+	/* Configuration change?  Tell driver if it wants to know. */
+	if (isr & VIRTIO_PCI_ISR_CONFIG)
+		vp_config_changed(irq, opaque);
+
+	return vp_vring_interrupt(irq, opaque);
+}
+
+static void vp_free_vectors(struct virtio_device *vdev)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+	int i;
+
+	if (vp_dev->intx_enabled) {
+		free_irq(vp_dev->pci_dev->irq, vp_dev);
+		vp_dev->intx_enabled = 0;
+	}
+
+	for (i = 0; i < vp_dev->msix_used_vectors; ++i)
+		free_irq(vp_dev->msix_entries[i].vector, vp_dev);
+
+	for (i = 0; i < vp_dev->msix_vectors; i++)
+		if (vp_dev->msix_affinity_masks[i])
+			free_cpumask_var(vp_dev->msix_affinity_masks[i]);
+
+	if (vp_dev->msix_enabled) {
+		/* Disable the vector used for configuration */
+		iowrite16(VIRTIO_MSI_NO_VECTOR,
+			  vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
+		/* Flush the write out to device */
+		ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
+
+		pci_disable_msix(vp_dev->pci_dev);
+		vp_dev->msix_enabled = 0;
+		vp_dev->msix_vectors = 0;
+	}
+
+	vp_dev->msix_used_vectors = 0;
+	kfree(vp_dev->msix_names);
+	vp_dev->msix_names = NULL;
+	kfree(vp_dev->msix_entries);
+	vp_dev->msix_entries = NULL;
+	kfree(vp_dev->msix_affinity_masks);
+	vp_dev->msix_affinity_masks = NULL;
+}
+
+static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
+				   bool per_vq_vectors)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+	const char *name = dev_name(&vp_dev->vdev.dev);
+	unsigned i, v;
+	int err = -ENOMEM;
+
+	vp_dev->msix_entries = kmalloc(nvectors * sizeof *vp_dev->msix_entries,
+				       GFP_KERNEL);
+	if (!vp_dev->msix_entries)
+		goto error;
+	vp_dev->msix_names = kmalloc(nvectors * sizeof *vp_dev->msix_names,
+				     GFP_KERNEL);
+	if (!vp_dev->msix_names)
+		goto error;
+	vp_dev->msix_affinity_masks
+		= kzalloc(nvectors * sizeof *vp_dev->msix_affinity_masks,
+			  GFP_KERNEL);
+	if (!vp_dev->msix_affinity_masks)
+		goto error;
+	for (i = 0; i < nvectors; ++i)
+		if (!alloc_cpumask_var(&vp_dev->msix_affinity_masks[i],
+					GFP_KERNEL))
+			goto error;
+
+	for (i = 0; i < nvectors; ++i)
+		vp_dev->msix_entries[i].entry = i;
+
+	/* pci_enable_msix returns positive if we can't get this many. */
+	err = pci_enable_msix(vp_dev->pci_dev, vp_dev->msix_entries, nvectors);
+	if (err > 0)
+		err = -ENOSPC;
+	if (err)
+		goto error;
+	vp_dev->msix_vectors = nvectors;
+	vp_dev->msix_enabled = 1;
+
+	/* Set the vector used for configuration */
+	v = vp_dev->msix_used_vectors;
+	snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
+		 "%s-config", name);
+	err = request_irq(vp_dev->msix_entries[v].vector,
+			  vp_config_changed, 0, vp_dev->msix_names[v],
+			  vp_dev);
+	if (err)
+		goto error;
+	++vp_dev->msix_used_vectors;
+
+	iowrite16(v, vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
+	/* Verify we had enough resources to assign the vector */
+	v = ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
+	if (v == VIRTIO_MSI_NO_VECTOR) {
+		err = -EBUSY;
+		goto error;
+	}
+
+	if (!per_vq_vectors) {
+		/* Shared vector for all VQs */
+		v = vp_dev->msix_used_vectors;
+		snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
+			 "%s-virtqueues", name);
+		err = request_irq(vp_dev->msix_entries[v].vector,
+				  vp_vring_interrupt, 0, vp_dev->msix_names[v],
+				  vp_dev);
+		if (err)
+			goto error;
+		++vp_dev->msix_used_vectors;
+	}
+	return 0;
+error:
+	vp_free_vectors(vdev);
+	return err;
+}
+
+static int vp_request_intx(struct virtio_device *vdev)
+{
+	int err;
+	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+
+	err = request_irq(vp_dev->pci_dev->irq, vp_interrupt,
+			  IRQF_SHARED, dev_name(&vdev->dev), vp_dev);
+	if (!err)
+		vp_dev->intx_enabled = 1;
+	return err;
+}
+
+static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
+				  void (*callback)(struct virtqueue *vq),
+				  const char *name,
+				  u16 msix_vec)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+	struct virtio_pci_vq_info *info;
+	struct virtqueue *vq;
+	unsigned long flags, size;
+	u16 num;
+	int err;
+
+	/* Select the queue we're interested in */
+	iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
+
+	/* Check if queue is either not available or already active. */
+	num = ioread16(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
+	if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
+		return ERR_PTR(-ENOENT);
+
+	/* allocate and fill out our structure the represents an active
+	 * queue */
+	info = kmalloc(sizeof(struct virtio_pci_vq_info), GFP_KERNEL);
+	if (!info)
+		return ERR_PTR(-ENOMEM);
+
+	info->num = num;
+	info->msix_vector = msix_vec;
+
+	size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN));
+	info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO);
+	if (info->queue == NULL) {
+		err = -ENOMEM;
+		goto out_info;
+	}
+
+	/* activate the queue */
+	iowrite32(virt_to_phys(info->queue) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT,
+		  vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
+
+	/* create the vring */
+	vq = vring_new_virtqueue(index, info->num, VIRTIO_PCI_VRING_ALIGN, vdev,
+				 true, info->queue, vp_notify, callback, name);
+	if (!vq) {
+		err = -ENOMEM;
+		goto out_activate_queue;
+	}
+
+	vq->priv = info;
+	info->vq = vq;
+
+	if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
+		iowrite16(msix_vec, vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
+		msix_vec = ioread16(vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
+		if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
+			err = -EBUSY;
+			goto out_assign;
+		}
+	}
+
+	if (callback) {
+		spin_lock_irqsave(&vp_dev->lock, flags);
+		list_add(&info->node, &vp_dev->virtqueues);
+		spin_unlock_irqrestore(&vp_dev->lock, flags);
+	} else {
+		INIT_LIST_HEAD(&info->node);
+	}
+
+	return vq;
+
+out_assign:
+	vring_del_virtqueue(vq);
+out_activate_queue:
+	iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
+	free_pages_exact(info->queue, size);
+out_info:
+	kfree(info);
+	return ERR_PTR(err);
+}
+
+static void vp_del_vq(struct virtqueue *vq)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
+	struct virtio_pci_vq_info *info = vq->priv;
+	unsigned long flags, size;
+
+	spin_lock_irqsave(&vp_dev->lock, flags);
+	list_del(&info->node);
+	spin_unlock_irqrestore(&vp_dev->lock, flags);
+
+	iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
+
+	if (vp_dev->msix_enabled) {
+		iowrite16(VIRTIO_MSI_NO_VECTOR,
+			  vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
+		/* Flush the write out to device */
+		ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
+	}
+
+	vring_del_virtqueue(vq);
+
+	/* Select and deactivate the queue */
+	iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
+
+	size = PAGE_ALIGN(vring_size(info->num, VIRTIO_PCI_VRING_ALIGN));
+	free_pages_exact(info->queue, size);
+	kfree(info);
+}
+
+/* the config->del_vqs() implementation */
+static void vp_del_vqs(struct virtio_device *vdev)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+	struct virtqueue *vq, *n;
+	struct virtio_pci_vq_info *info;
+
+	list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
+		info = vq->priv;
+		if (vp_dev->per_vq_vectors &&
+			info->msix_vector != VIRTIO_MSI_NO_VECTOR)
+			free_irq(vp_dev->msix_entries[info->msix_vector].vector,
+				 vq);
+		vp_del_vq(vq);
+	}
+	vp_dev->per_vq_vectors = false;
+
+	vp_free_vectors(vdev);
+}
+
+static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs,
+			      struct virtqueue *vqs[],
+			      vq_callback_t *callbacks[],
+			      const char *names[],
+			      bool use_msix,
+			      bool per_vq_vectors)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+	u16 msix_vec;
+	int i, err, nvectors, allocated_vectors;
+
+	if (!use_msix) {
+		/* Old style: one normal interrupt for change and all vqs. */
+		err = vp_request_intx(vdev);
+		if (err)
+			goto error_request;
+	} else {
+		if (per_vq_vectors) {
+			/* Best option: one for change interrupt, one per vq. */
+			nvectors = 1;
+			for (i = 0; i < nvqs; ++i)
+				if (callbacks[i])
+					++nvectors;
+		} else {
+			/* Second best: one for change, shared for all vqs. */
+			nvectors = 2;
+		}
+
+		err = vp_request_msix_vectors(vdev, nvectors, per_vq_vectors);
+		if (err)
+			goto error_request;
+	}
+
+	vp_dev->per_vq_vectors = per_vq_vectors;
+	allocated_vectors = vp_dev->msix_used_vectors;
+	for (i = 0; i < nvqs; ++i) {
+		if (!names[i]) {
+			vqs[i] = NULL;
+			continue;
+		} else if (!callbacks[i] || !vp_dev->msix_enabled)
+			msix_vec = VIRTIO_MSI_NO_VECTOR;
+		else if (vp_dev->per_vq_vectors)
+			msix_vec = allocated_vectors++;
+		else
+			msix_vec = VP_MSIX_VQ_VECTOR;
+		vqs[i] = setup_vq(vdev, i, callbacks[i], names[i], msix_vec);
+		if (IS_ERR(vqs[i])) {
+			err = PTR_ERR(vqs[i]);
+			goto error_find;
+		}
+
+		if (!vp_dev->per_vq_vectors || msix_vec == VIRTIO_MSI_NO_VECTOR)
+			continue;
+
+		/* allocate per-vq irq if available and necessary */
+		snprintf(vp_dev->msix_names[msix_vec],
+			 sizeof *vp_dev->msix_names,
+			 "%s-%s",
+			 dev_name(&vp_dev->vdev.dev), names[i]);
+		err = request_irq(vp_dev->msix_entries[msix_vec].vector,
+				  vring_interrupt, 0,
+				  vp_dev->msix_names[msix_vec],
+				  vqs[i]);
+		if (err) {
+			vp_del_vq(vqs[i]);
+			goto error_find;
+		}
+	}
+	return 0;
+
+error_find:
+	vp_del_vqs(vdev);
+
+error_request:
+	return err;
+}
+
+/* the config->find_vqs() implementation */
+static int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
+		       struct virtqueue *vqs[],
+		       vq_callback_t *callbacks[],
+		       const char *names[])
+{
+	int err;
+
+	/* Try MSI-X with one vector per queue. */
+	err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names, true, true);
+	if (!err)
+		return 0;
+	/* Fallback: MSI-X with one vector for config, one shared for queues. */
+	err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
+				 true, false);
+	if (!err)
+		return 0;
+	/* Finally fall back to regular interrupts. */
+	return vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
+				  false, false);
+}
+
+static const char *vp_bus_name(struct virtio_device *vdev)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+
+	return pci_name(vp_dev->pci_dev);
+}
+
+/* Setup the affinity for a virtqueue:
+ * - force the affinity for per vq vector
+ * - OR over all affinities for shared MSI
+ * - ignore the affinity request if we're using INTX
+ */
+static int vp_set_vq_affinity(struct virtqueue *vq, int cpu)
+{
+	struct virtio_device *vdev = vq->vdev;
+	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+	struct virtio_pci_vq_info *info = vq->priv;
+	struct cpumask *mask;
+	unsigned int irq;
+
+	if (!vq->callback)
+		return -EINVAL;
+
+	if (vp_dev->msix_enabled) {
+		mask = vp_dev->msix_affinity_masks[info->msix_vector];
+		irq = vp_dev->msix_entries[info->msix_vector].vector;
+		if (cpu == -1)
+			irq_set_affinity_hint(irq, NULL);
+		else {
+			cpumask_set_cpu(cpu, mask);
+			irq_set_affinity_hint(irq, mask);
+		}
+	}
+	return 0;
+}
+
+static const struct virtio_config_ops virtio_pci_config_ops = {
+	.get8		= vp_get8,
+	.set8		= vp_set8,
+	.get16		= vp_get16,
+	.set16		= vp_set16,
+	.get32		= vp_get32,
+	.set32		= vp_set32,
+	.get64		= vp_get64,
+	.set64		= vp_set64,
+	.get_status	= vp_get_status,
+	.set_status	= vp_set_status,
+	.reset		= vp_reset,
+	.find_vqs	= vp_find_vqs,
+	.del_vqs	= vp_del_vqs,
+	.get_features	= vp_get_features,
+	.finalize_features = vp_finalize_features,
+	.bus_name	= vp_bus_name,
+	.set_vq_affinity = vp_set_vq_affinity,
+};
+
+static void virtio_pci_release_dev(struct device *_d)
+{
+	/*
+	 * No need for a release method as we allocate/free
+	 * all devices together with the pci devices.
+	 * Provide an empty one to avoid getting a warning from core.
+	 */
+}
+
+/* the PCI probing function */
+static int virtio_pci_probe(struct pci_dev *pci_dev,
+			    const struct pci_device_id *id)
+{
+	struct virtio_pci_device *vp_dev;
+	int err;
+
+	/* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
+	if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
+		return -ENODEV;
+
+	if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
+		printk(KERN_ERR "virtio_pci_legacy: expected ABI version %d, got %d\n",
+		       VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
+		return -ENODEV;
+	}
+
+	/* allocate our structure and fill it out */
+	vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
+	if (vp_dev == NULL)
+		return -ENOMEM;
+
+	vp_dev->vdev.dev.parent = &pci_dev->dev;
+	vp_dev->vdev.dev.release = virtio_pci_release_dev;
+	vp_dev->vdev.config = &virtio_pci_config_ops;
+	vp_dev->pci_dev = pci_dev;
+	INIT_LIST_HEAD(&vp_dev->virtqueues);
+	spin_lock_init(&vp_dev->lock);
+
+	/* Disable MSI/MSIX to bring device to a known good state. */
+	pci_msi_off(pci_dev);
+
+	/* enable the device */
+	err = pci_enable_device(pci_dev);
+	if (err)
+		goto out;
+
+	err = pci_request_regions(pci_dev, "virtio-pci-legacy");
+	if (err)
+		goto out_enable_device;
+
+	vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
+	if (vp_dev->ioaddr == NULL) {
+		err = -ENOMEM;
+		goto out_req_regions;
+	}
+
+	pci_set_drvdata(pci_dev, vp_dev);
+	pci_set_master(pci_dev);
+
+	/* we use the subsystem vendor/device id as the virtio vendor/device
+	 * id.  this allows us to use the same PCI vendor/device id for all
+	 * virtio devices and to identify the particular virtio driver by
+	 * the subsystem ids */
+	vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
+	vp_dev->vdev.id.device = pci_dev->subsystem_device;
+
+	/* finally register the virtio device */
+	err = register_virtio_device(&vp_dev->vdev);
+	if (err)
+		goto out_set_drvdata;
+
+	return 0;
+
+out_set_drvdata:
+	pci_set_drvdata(pci_dev, NULL);
+	pci_iounmap(pci_dev, vp_dev->ioaddr);
+out_req_regions:
+	pci_release_regions(pci_dev);
+out_enable_device:
+	pci_disable_device(pci_dev);
+out:
+	kfree(vp_dev);
+	return err;
+}
+
+static void virtio_pci_remove(struct pci_dev *pci_dev)
+{
+	struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
+
+	unregister_virtio_device(&vp_dev->vdev);
+
+	vp_del_vqs(&vp_dev->vdev);
+	pci_set_drvdata(pci_dev, NULL);
+	pci_iounmap(pci_dev, vp_dev->ioaddr);
+	pci_release_regions(pci_dev);
+	pci_disable_device(pci_dev);
+	kfree(vp_dev);
+}
+
+#ifdef CONFIG_PM
+static int virtio_pci_freeze(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
+	struct virtio_driver *drv;
+	int ret;
+
+	drv = container_of(vp_dev->vdev.dev.driver,
+			   struct virtio_driver, driver);
+
+	ret = 0;
+	vp_dev->saved_status = vp_get_status(&vp_dev->vdev);
+	if (drv && drv->freeze)
+		ret = drv->freeze(&vp_dev->vdev);
+
+	if (!ret)
+		pci_disable_device(pci_dev);
+	return ret;
+}
+
+static int virtio_pci_restore(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
+	struct virtio_driver *drv;
+	int ret;
+
+	drv = container_of(vp_dev->vdev.dev.driver,
+			   struct virtio_driver, driver);
+
+	ret = pci_enable_device(pci_dev);
+	if (ret)
+		return ret;
+
+	pci_set_master(pci_dev);
+	vp_finalize_features(&vp_dev->vdev);
+
+	if (drv && drv->restore)
+		ret = drv->restore(&vp_dev->vdev);
+
+	/* Finally, tell the device we're all set */
+	if (!ret)
+		vp_set_status(&vp_dev->vdev, vp_dev->saved_status);
+
+	return ret;
+}
+
+static const struct dev_pm_ops virtio_pci_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(virtio_pci_freeze, virtio_pci_restore)
+};
+#endif
+
+static struct pci_driver virtio_pci_driver_legacy = {
+	.name		= "virtio-pci-legacy",
+	.id_table	= virtio_pci_id_table,
+	.probe		= virtio_pci_probe,
+	.remove		= virtio_pci_remove,
+#ifdef CONFIG_PM
+	.driver.pm	= &virtio_pci_pm_ops,
+#endif
+};
+
+module_pci_driver(virtio_pci_driver_legacy);
diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h
index b0e7c91..9eb6373 100644
--- a/include/uapi/linux/virtio_pci.h
+++ b/include/uapi/linux/virtio_pci.h
@@ -42,56 +42,75 @@
 #include <linux/virtio_config.h>
 
 /* A 32-bit r/o bitmask of the features supported by the host */
-#define VIRTIO_PCI_HOST_FEATURES	0
+#define VIRTIO_PCI_LEGACY_HOST_FEATURES		0
 
 /* A 32-bit r/w bitmask of features activated by the guest */
-#define VIRTIO_PCI_GUEST_FEATURES	4
+#define VIRTIO_PCI_LEGACY_GUEST_FEATURES	4
 
 /* A 32-bit r/w PFN for the currently selected queue */
-#define VIRTIO_PCI_QUEUE_PFN		8
+#define VIRTIO_PCI_LEGACY_QUEUE_PFN		8
 
 /* A 16-bit r/o queue size for the currently selected queue */
-#define VIRTIO_PCI_QUEUE_NUM		12
+#define VIRTIO_PCI_LEGACY_QUEUE_NUM		12
 
 /* A 16-bit r/w queue selector */
-#define VIRTIO_PCI_QUEUE_SEL		14
+#define VIRTIO_PCI_LEGACY_QUEUE_SEL		14
 
 /* A 16-bit r/w queue notifier */
-#define VIRTIO_PCI_QUEUE_NOTIFY		16
+#define VIRTIO_PCI_LEGACY_QUEUE_NOTIFY		16
 
 /* An 8-bit device status register.  */
-#define VIRTIO_PCI_STATUS		18
+#define VIRTIO_PCI_LEGACY_STATUS		18
 
 /* An 8-bit r/o interrupt status register.  Reading the value will return the
  * current contents of the ISR and will also clear it.  This is effectively
  * a read-and-acknowledge. */
-#define VIRTIO_PCI_ISR			19
-
-/* The bit of the ISR which indicates a device configuration change. */
-#define VIRTIO_PCI_ISR_CONFIG		0x2
+#define VIRTIO_PCI_LEGACY_ISR			19
 
 /* MSI-X registers: only enabled if MSI-X is enabled. */
 /* A 16-bit vector for configuration changes. */
-#define VIRTIO_MSI_CONFIG_VECTOR        20
+#define VIRTIO_MSI_LEGACY_CONFIG_VECTOR        20
 /* A 16-bit vector for selected queue notifications. */
-#define VIRTIO_MSI_QUEUE_VECTOR         22
-/* Vector value used to disable MSI for queue */
-#define VIRTIO_MSI_NO_VECTOR            0xffff
+#define VIRTIO_MSI_LEGACY_QUEUE_VECTOR         22
 
 /* The remaining space is defined by each driver as the per-driver
  * configuration space */
-#define VIRTIO_PCI_CONFIG(dev)		((dev)->msix_enabled ? 24 : 20)
-
-/* Virtio ABI version, this must match exactly */
-#define VIRTIO_PCI_ABI_VERSION		0
+#define VIRTIO_PCI_LEGACY_CONFIG(dev)		((dev)->msix_enabled ? 24 : 20)
 
 /* How many bits to shift physical queue address written to QUEUE_PFN.
  * 12 is historical, and due to x86 page size. */
-#define VIRTIO_PCI_QUEUE_ADDR_SHIFT	12
+#define VIRTIO_PCI_LEGACY_QUEUE_ADDR_SHIFT	12
 
 /* The alignment to use between consumer and producer parts of vring.
  * x86 pagesize again. */
-#define VIRTIO_PCI_VRING_ALIGN		4096
+#define VIRTIO_PCI_LEGACY_VRING_ALIGN		4096
+
+#ifndef VIRTIO_PCI_NO_LEGACY
+/* Don't break compile of old userspace code.  These will go away. */
+#warning "Please support virtio_pci non-legacy mode!"
+#define VIRTIO_PCI_HOST_FEATURES VIRTIO_PCI_LEGACY_HOST_FEATURES
+#define VIRTIO_PCI_GUEST_FEATURES VIRTIO_PCI_LEGACY_GUEST_FEATURES
+#define VIRTIO_PCI_QUEUE_PFN VIRTIO_PCI_LEGACY_QUEUE_PFN
+#define VIRTIO_PCI_QUEUE_NUM VIRTIO_PCI_LEGACY_QUEUE_NUM
+#define VIRTIO_PCI_QUEUE_SEL VIRTIO_PCI_LEGACY_QUEUE_SEL
+#define VIRTIO_PCI_QUEUE_NOTIFY VIRTIO_PCI_LEGACY_QUEUE_NOTIFY
+#define VIRTIO_PCI_STATUS VIRTIO_PCI_LEGACY_STATUS
+#define VIRTIO_PCI_ISR VIRTIO_PCI_LEGACY_ISR
+#define VIRTIO_MSI_CONFIG_VECTOR VIRTIO_MSI_LEGACY_CONFIG_VECTOR
+#define VIRTIO_MSI_QUEUE_VECTOR VIRTIO_MSI_LEGACY_QUEUE_VECTOR
+#define VIRTIO_PCI_CONFIG(dev) VIRTIO_PCI_LEGACY_CONFIG(dev)
+#define VIRTIO_PCI_QUEUE_ADDR_SHIFT VIRTIO_PCI_LEGACY_QUEUE_ADDR_SHIFT
+#define VIRTIO_PCI_VRING_ALIGN VIRTIO_PCI_LEGACY_VRING_ALIGN
+#endif /* ...!KERNEL */
+
+/* Virtio ABI version, this must match exactly */
+#define VIRTIO_PCI_ABI_VERSION		0
+
+/* Vector value used to disable MSI for queue */
+#define VIRTIO_MSI_NO_VECTOR            0xffff
+
+/* The bit of the ISR which indicates a device configuration change. */
+#define VIRTIO_PCI_ISR_CONFIG		0x2
 
 /* IDs for different capabilities.  Must all exist. */
 /* FIXME: Do we win from separating ISR, NOTIFY and COMMON? */
-- 
1.7.10.4