[PATCH] virtio: Add platform bus driver for memory mapped virtio device
Pawel Moll
pawel.moll at arm.com
Wed Sep 28 09:47:43 EDT 2011
This patch, based on virtio PCI driver, adds support for memory
mapped (platform) virtio device. This should allow environments
like qemu to use virtio-based block & network devices even on
platforms without PCI support.
One can define and register a platform device which resources
will describe memory mapped control registers and "mailbox"
interrupt. Such device can be also instantiated using the Device
Tree node with compatible property equal "virtio,mmio".
Cc: Rusty Russell <rusty at rustcorp.com.au>
Cc: Anthony Liguori <aliguori at us.ibm.com>
Cc: Michael S.Tsirkin <mst at redhat.com>
Signed-off-by: Pawel Moll <pawel.moll at arm.com>
---
So here I am with the first non-RFC patch :-) It will be followed by the
spec, as we discussed, in the form of an appendix to the main document.
Comparing to RFCv3 I've added "version" register, to make the device's
evolution easier. I hope the code is good enough for next merge window,
if you think otherwise - please, do shout! ;-)
If there are no objections I'll ask Peter to start adding support for
this into qemu. I've tested the driver with a virtio block device in
our proprietary emulation environment and it works just fine :-)
Cheers!
Pawel
Documentation/devicetree/bindings/virtio/mmio.txt | 17 +
drivers/virtio/Kconfig | 11 +
drivers/virtio/Makefile | 1 +
drivers/virtio/virtio_mmio.c | 459 +++++++++++++++++++++
include/linux/virtio_mmio.h | 92 ++++
5 files changed, 580 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/virtio/mmio.txt
create mode 100644 drivers/virtio/virtio_mmio.c
create mode 100644 include/linux/virtio_mmio.h
diff --git a/Documentation/devicetree/bindings/virtio/mmio.txt b/Documentation/devicetree/bindings/virtio/mmio.txt
new file mode 100644
index 0000000..5069c1b
--- /dev/null
+++ b/Documentation/devicetree/bindings/virtio/mmio.txt
@@ -0,0 +1,17 @@
+* virtio memory mapped device
+
+See http://ozlabs.org/~rusty/virtio-spec/ for more details.
+
+Required properties:
+
+- compatible: "virtio,mmio" compatibility string
+- reg: control registers base address and size including configuration space
+- interrupts: interrupt generated by the device
+
+Example:
+
+ virtio_block at 3000 {
+ compatible = "virtio,mmio";
+ reg = <0x3000 0x100>;
+ interrupts = <41>;
+ }
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index 57e493b..816ed08 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -35,4 +35,15 @@ config VIRTIO_BALLOON
If unsure, say M.
+ config VIRTIO_MMIO
+ tristate "Platform bus driver for memory mapped virtio devices (EXPERIMENTAL)"
+ depends on EXPERIMENTAL
+ select VIRTIO
+ select VIRTIO_RING
+ ---help---
+ This drivers provides support for memory mapped virtio
+ platform device driver.
+
+ If unsure, say N.
+
endmenu
diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
index 6738c44..5a4c63c 100644
--- a/drivers/virtio/Makefile
+++ b/drivers/virtio/Makefile
@@ -1,4 +1,5 @@
obj-$(CONFIG_VIRTIO) += virtio.o
obj-$(CONFIG_VIRTIO_RING) += virtio_ring.o
+obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o
obj-$(CONFIG_VIRTIO_PCI) += virtio_pci.o
obj-$(CONFIG_VIRTIO_BALLOON) += virtio_balloon.o
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
new file mode 100644
index 0000000..3c8d52f
--- /dev/null
+++ b/drivers/virtio/virtio_mmio.c
@@ -0,0 +1,459 @@
+/*
+ * Virtio memory mapped device driver
+ *
+ * Copyright 2011, ARM Ltd.
+ *
+ * This module allows virtio devices to be used over a virtual, memory mapped
+ * platform device.
+ *
+ * Registers layout (all 32-bit wide):
+ *
+ * offset name description
+ * ------ ---------------- -----------------
+ *
+ * 0x000 MagicValue Magic value "virt"
+ * 0x004 Version Device version (current max. 1)
+ * 0x008 DeviceID Virtio device ID
+ * 0x00c VendorID Virtio vendor ID
+ *
+ * 0x010 HostFeatures Features supported by the host
+ * 0x014 HostFeaturesSel Set of host features to access via HostFeatures
+ *
+ * 0x020 GuestFeatures Features activated by the guest
+ * 0x024 GuestFeaturesSel Set of activated features to set via GuestFeatures
+ * 0x028 GuestPageSize Size of guest's memory page in bytes
+ *
+ * 0x030 QueueSel Queue selector
+ * 0x034 QueueNum Queue size for the currently selected queue
+ * 0x038 QueueAlign Used Ring alignment for the current queue
+ * 0x03c QueuePFN PFN for the currently selected queue
+
+ * 0x050 QueueNotify Queue notifier
+ * 0x060 InterruptACK Interrupt acknowledge register
+ * 0x070 Status Device status register
+ *
+ * 0x100+ Device-specific configuration space
+ *
+ * Based on Virtio PCI driver by Anthony Liguori, copyright IBM Corp. 2007
+ *
+ * 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/highmem.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/virtio.h>
+#include <linux/virtio_config.h>
+#include <linux/virtio_mmio.h>
+#include <linux/virtio_ring.h>
+
+
+
+/* The alignment to use between consumer and producer parts of vring.
+ * Currently hardcoded to page size. */
+#define VIRTIO_MMIO_VRING_ALIGN PAGE_SIZE
+
+
+
+#define to_virtio_mmio_device(_plat_dev) \
+ container_of(_plat_dev, struct virtio_mmio_device, vdev)
+
+struct virtio_mmio_device {
+ struct virtio_device vdev;
+ struct platform_device *pdev;
+
+ void __iomem *base;
+ unsigned long version;
+
+ /* a list of queues so we can dispatch IRQs */
+ spinlock_t lock;
+ struct list_head virtqueues;
+};
+
+struct virtio_mmio_vq_info {
+ /* the actual virtqueue */
+ struct virtqueue *vq;
+
+ /* the number of entries in the queue */
+ int num;
+
+ /* the index of the queue */
+ int queue_index;
+
+ /* the virtual address of the ring queue */
+ void *queue;
+
+ /* the list node for the virtqueues list */
+ struct list_head node;
+};
+
+
+
+/* Configuration interface */
+
+static u32 vm_get_features(struct virtio_device *vdev)
+{
+ struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+
+ /* TODO: Features > 32 bits */
+ writel(0, vm_dev->base + VIRTIO_MMIO_HOST_FEATURES_SEL);
+
+ return readl(vm_dev->base + VIRTIO_MMIO_HOST_FEATURES);
+}
+
+static void vm_finalize_features(struct virtio_device *vdev)
+{
+ struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+ int i;
+
+ /* Give virtio_ring a chance to accept features. */
+ vring_transport_features(vdev);
+
+ for (i = 0; i < ARRAY_SIZE(vdev->features); i++) {
+ writel(i, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES_SET);
+ writel(vdev->features[i],
+ vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES);
+ }
+}
+
+static void vm_get(struct virtio_device *vdev, unsigned offset,
+ void *buf, unsigned len)
+{
+ struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+ u8 *ptr = buf;
+ int i;
+
+ for (i = 0; i < len; i++)
+ ptr[i] = readb(vm_dev->base + VIRTIO_MMIO_CONFIG + offset + i);
+}
+
+static void vm_set(struct virtio_device *vdev, unsigned offset,
+ const void *buf, unsigned len)
+{
+ struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+ const u8 *ptr = buf;
+ int i;
+
+ for (i = 0; i < len; i++)
+ writeb(ptr[i], vm_dev->base + VIRTIO_MMIO_CONFIG + offset + i);
+}
+
+static u8 vm_get_status(struct virtio_device *vdev)
+{
+ struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+
+ return readl(vm_dev->base + VIRTIO_MMIO_STATUS) & 0xff;
+}
+
+static void vm_set_status(struct virtio_device *vdev, u8 status)
+{
+ struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+
+ /* We should never be setting status to 0. */
+ BUG_ON(status == 0);
+
+ writel(status, vm_dev->base + VIRTIO_MMIO_STATUS);
+}
+
+static void vm_reset(struct virtio_device *vdev)
+{
+ struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+
+ /* 0 status means a reset. */
+ writel(0, vm_dev->base + VIRTIO_MMIO_STATUS);
+}
+
+
+
+/* Transport interface */
+
+/* the notify function used when creating a virt queue */
+static void vm_notify(struct virtqueue *vq)
+{
+ struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
+ struct virtio_mmio_vq_info *info = vq->priv;
+
+ /* We write the queue's selector into the notification register to
+ * signal the other end */
+ writel(info->queue_index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
+}
+
+/* Notify all virtqueues on an interrupt. */
+static irqreturn_t vm_interrupt(int irq, void *opaque)
+{
+ struct virtio_mmio_device *vm_dev = opaque;
+ struct virtio_mmio_vq_info *info;
+ irqreturn_t ret = IRQ_NONE;
+ unsigned long flags;
+
+ writel(1, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK);
+
+ spin_lock_irqsave(&vm_dev->lock, flags);
+ list_for_each_entry(info, &vm_dev->virtqueues, node) {
+ if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
+ ret = IRQ_HANDLED;
+ }
+ spin_unlock_irqrestore(&vm_dev->lock, flags);
+
+ return ret;
+}
+
+
+
+static void vm_del_vq(struct virtqueue *vq)
+{
+ struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
+ struct virtio_mmio_vq_info *info = vq->priv;
+ unsigned long flags, size;
+
+ spin_lock_irqsave(&vm_dev->lock, flags);
+ list_del(&info->node);
+ spin_unlock_irqrestore(&vm_dev->lock, flags);
+
+ vring_del_virtqueue(vq);
+
+ /* Select and deactivate the queue */
+ writel(info->queue_index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
+ writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
+
+ size = PAGE_ALIGN(vring_size(info->num, VIRTIO_MMIO_VRING_ALIGN));
+ free_pages_exact(info->queue, size);
+ kfree(info);
+}
+
+static void vm_del_vqs(struct virtio_device *vdev)
+{
+ struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+ struct virtqueue *vq, *n;
+
+ list_for_each_entry_safe(vq, n, &vdev->vqs, list)
+ vm_del_vq(vq);
+
+ free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev);
+}
+
+
+
+static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
+ void (*callback)(struct virtqueue *vq),
+ const char *name)
+{
+ struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+ struct virtio_mmio_vq_info *info;
+ struct virtqueue *vq;
+ unsigned long flags, size;
+ u16 num;
+ int err;
+
+ /* Select the queue we're interested in */
+ writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
+
+ /* TODO: Write requested queue size to VIRTIO_MMIO_QUEUE_NUM */
+
+ /* Check if queue is either not available or already active. */
+ num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM);
+ if (!num || readl(vm_dev->base + VIRTIO_MMIO_QUEUE_PFN)) {
+ err = -ENOENT;
+ goto error_available;
+ }
+
+ /* Allocate and fill out our structure the represents an active
+ * queue */
+ info = kmalloc(sizeof(struct virtio_mmio_vq_info), GFP_KERNEL);
+ if (!info) {
+ err = -ENOMEM;
+ goto error_kmalloc;
+ }
+
+ info->queue_index = index;
+ info->num = num;
+
+ size = PAGE_ALIGN(vring_size(num, VIRTIO_MMIO_VRING_ALIGN));
+ info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
+ if (info->queue == NULL) {
+ err = -ENOMEM;
+ goto error_alloc_pages;
+ }
+
+ /* Activate the queue */
+ writel(VIRTIO_MMIO_VRING_ALIGN,
+ vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN);
+ writel(virt_to_phys(info->queue) >> PAGE_SHIFT,
+ vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
+
+ /* Create the vring */
+ vq = vring_new_virtqueue(info->num, VIRTIO_MMIO_VRING_ALIGN,
+ vdev, info->queue, vm_notify, callback, name);
+ if (!vq) {
+ err = -ENOMEM;
+ goto error_new_virtqueue;
+ }
+
+ vq->priv = info;
+ info->vq = vq;
+
+ spin_lock_irqsave(&vm_dev->lock, flags);
+ list_add(&info->node, &vm_dev->virtqueues);
+ spin_unlock_irqrestore(&vm_dev->lock, flags);
+
+ return vq;
+
+error_new_virtqueue:
+ writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
+ free_pages_exact(info->queue, size);
+error_alloc_pages:
+ kfree(info);
+error_kmalloc:
+error_available:
+ return ERR_PTR(err);
+}
+
+static int vm_find_vqs(struct virtio_device *vdev, unsigned nvqs,
+ struct virtqueue *vqs[],
+ vq_callback_t *callbacks[],
+ const char *names[])
+{
+ struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+ unsigned int irq = platform_get_irq(vm_dev->pdev, 0);
+ int i, err;
+
+ err = request_irq(irq, vm_interrupt, IRQF_SHARED,
+ dev_name(&vdev->dev), vm_dev);
+ if (err)
+ return err;
+
+ for (i = 0; i < nvqs; ++i) {
+ vqs[i] = vm_setup_vq(vdev, i, callbacks[i], names[i]);
+ if (IS_ERR(vqs[i])) {
+ vm_del_vqs(vdev);
+ free_irq(irq, vm_dev);
+ return PTR_ERR(vqs[i]);
+ }
+ }
+
+ return 0;
+}
+
+
+
+static struct virtio_config_ops virtio_mmio_config_ops = {
+ .get = vm_get,
+ .set = vm_set,
+ .get_status = vm_get_status,
+ .set_status = vm_set_status,
+ .reset = vm_reset,
+ .find_vqs = vm_find_vqs,
+ .del_vqs = vm_del_vqs,
+ .get_features = vm_get_features,
+ .finalize_features = vm_finalize_features,
+};
+
+
+
+/* Platform device */
+
+static int __devinit virtio_mmio_probe(struct platform_device *pdev)
+{
+ struct virtio_mmio_device *vm_dev;
+ struct resource *mem;
+ unsigned long magic;
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!mem)
+ return -EINVAL;
+
+ if (!devm_request_mem_region(&pdev->dev, mem->start,
+ resource_size(mem), pdev->name))
+ return -EBUSY;
+
+ vm_dev = devm_kzalloc(&pdev->dev, sizeof(struct virtio_mmio_device),
+ GFP_KERNEL);
+ if (!vm_dev)
+ return -ENOMEM;
+
+ vm_dev->vdev.dev.parent = &pdev->dev;
+ vm_dev->vdev.config = &virtio_mmio_config_ops;
+ vm_dev->pdev = pdev;
+ INIT_LIST_HEAD(&vm_dev->virtqueues);
+ spin_lock_init(&vm_dev->lock);
+
+ vm_dev->base = devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
+ if (vm_dev->base == NULL)
+ return -EFAULT;
+
+ /* Check magic value */
+ magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE);
+ if (memcmp(&magic, "virt", 4) != 0) {
+ dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic);
+ return -ENODEV;
+ }
+
+ /* Check device version */
+ vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION);
+ if (vm_dev->version != 1) {
+ dev_err(&pdev->dev, "Version %ld not supported!\n",
+ vm_dev->version);
+ return -ENXIO;
+ }
+
+ vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID);
+ vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID);
+
+ writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
+
+ platform_set_drvdata(pdev, vm_dev);
+
+ return register_virtio_device(&vm_dev->vdev);
+}
+
+static int __devexit virtio_mmio_remove(struct platform_device *pdev)
+{
+ struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev);
+
+ unregister_virtio_device(&vm_dev->vdev);
+
+ return 0;
+}
+
+
+
+/* Platform driver */
+
+static struct of_device_id virtio_mmio_match[] = {
+ { .compatible = "virtio,mmio", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, virtio_mmio_match);
+
+static struct platform_driver virtio_mmio_driver = {
+ .probe = virtio_mmio_probe,
+ .remove = __devexit_p(virtio_mmio_remove),
+ .driver = {
+ .name = "virtio-mmio",
+ .owner = THIS_MODULE,
+ .of_match_table = virtio_mmio_match,
+ },
+};
+
+static int __init virtio_mmio_init(void)
+{
+ return platform_driver_register(&virtio_mmio_driver);
+}
+
+static void __exit virtio_mmio_exit(void)
+{
+ platform_driver_unregister(&virtio_mmio_driver);
+}
+
+module_init(virtio_mmio_init);
+module_exit(virtio_mmio_exit);
+
+MODULE_AUTHOR("Pawel Moll <pawel.moll at arm.com>");
+MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/virtio_mmio.h b/include/linux/virtio_mmio.h
new file mode 100644
index 0000000..5d1ea5c
--- /dev/null
+++ b/include/linux/virtio_mmio.h
@@ -0,0 +1,92 @@
+/*
+ * Virtio platform device driver
+ *
+ * Copyright 2011, ARM Ltd.
+ *
+ * Based on Virtio PCI driver by Anthony Liguori, copyright IBM Corp. 2007
+ *
+ * This header is BSD licensed so anyone can use the definitions to implement
+ * compatible drivers/servers.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of IBM nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef _LINUX_VIRTIO_MMIO_H
+#define _LINUX_VIRTIO_MMIO_H
+
+/* Magic value ("virt" string) */
+#define VIRTIO_MMIO_MAGIC_VALUE 0x000
+
+/* Virtio device version */
+#define VIRTIO_MMIO_VERSION 0x004
+
+/* Virtio device ID */
+#define VIRTIO_MMIO_DEVICE_ID 0x008
+
+/* Virtio vendor ID */
+#define VIRTIO_MMIO_VENDOR_ID 0x00c
+
+/* Bitmask of the features supported by the host (32 bits per set) */
+#define VIRTIO_MMIO_HOST_FEATURES 0x010
+
+/* Host features set selector */
+#define VIRTIO_MMIO_HOST_FEATURES_SEL 0x014
+
+/* Bitmask of features activated by the guest (32 bits per set) */
+#define VIRTIO_MMIO_GUEST_FEATURES 0x020
+
+/* Activated features set selector */
+#define VIRTIO_MMIO_GUEST_FEATURES_SET 0x024
+
+/* Guest's memory page size in bytes */
+#define VIRTIO_MMIO_GUEST_PAGE_SIZE 0x028
+
+/* Queue selector */
+#define VIRTIO_MMIO_QUEUE_SEL 0x030
+
+/* Queue size for the currently selected queue */
+#define VIRTIO_MMIO_QUEUE_NUM 0x034
+
+/* Used Ring alignment for the currently selected queue */
+#define VIRTIO_MMIO_QUEUE_ALIGN 0x038
+
+/* Guest's PFN for the currently selected queue */
+#define VIRTIO_MMIO_QUEUE_PFN 0x03c
+
+/* Queue notifier */
+#define VIRTIO_MMIO_QUEUE_NOTIFY 0x050
+
+/* Interrupt acknowledge */
+#define VIRTIO_MMIO_INTERRUPT_ACK 0x060
+
+/* Device status register */
+#define VIRTIO_MMIO_STATUS 0x070
+
+/* The config space is defined by each driver as
+ * the per-driver configuration space */
+#define VIRTIO_MMIO_CONFIG 0x100
+
+
+
+#endif
--
1.6.3.3
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