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-rw-r--r--net/9p/trans_virtio.c796
1 files changed, 796 insertions, 0 deletions
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
new file mode 100644
index 000000000..36b5f72e2
--- /dev/null
+++ b/net/9p/trans_virtio.c
@@ -0,0 +1,796 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * The Virtio 9p transport driver
+ *
+ * This is a block based transport driver based on the lguest block driver
+ * code.
+ *
+ * Copyright (C) 2007, 2008 Eric Van Hensbergen, IBM Corporation
+ *
+ * Based on virtio console driver
+ * Copyright (C) 2006, 2007 Rusty Russell, IBM Corporation
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/in.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/ipv6.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/un.h>
+#include <linux/uaccess.h>
+#include <linux/inet.h>
+#include <linux/idr.h>
+#include <linux/file.h>
+#include <linux/highmem.h>
+#include <linux/slab.h>
+#include <net/9p/9p.h>
+#include <linux/parser.h>
+#include <net/9p/client.h>
+#include <net/9p/transport.h>
+#include <linux/scatterlist.h>
+#include <linux/swap.h>
+#include <linux/virtio.h>
+#include <linux/virtio_9p.h>
+#include "trans_common.h"
+
+#define VIRTQUEUE_NUM 128
+
+/* a single mutex to manage channel initialization and attachment */
+static DEFINE_MUTEX(virtio_9p_lock);
+static DECLARE_WAIT_QUEUE_HEAD(vp_wq);
+static atomic_t vp_pinned = ATOMIC_INIT(0);
+
+/**
+ * struct virtio_chan - per-instance transport information
+ * @inuse: whether the channel is in use
+ * @lock: protects multiple elements within this structure
+ * @client: client instance
+ * @vdev: virtio dev associated with this channel
+ * @vq: virtio queue associated with this channel
+ * @sg: scatter gather list which is used to pack a request (protected?)
+ *
+ * We keep all per-channel information in a structure.
+ * This structure is allocated within the devices dev->mem space.
+ * A pointer to the structure will get put in the transport private.
+ *
+ */
+
+struct virtio_chan {
+ bool inuse;
+
+ spinlock_t lock;
+
+ struct p9_client *client;
+ struct virtio_device *vdev;
+ struct virtqueue *vq;
+ int ring_bufs_avail;
+ wait_queue_head_t *vc_wq;
+ /* This is global limit. Since we don't have a global structure,
+ * will be placing it in each channel.
+ */
+ unsigned long p9_max_pages;
+ /* Scatterlist: can be too big for stack. */
+ struct scatterlist sg[VIRTQUEUE_NUM];
+ /*
+ * tag name to identify a mount null terminated
+ */
+ char *tag;
+
+ struct list_head chan_list;
+};
+
+static struct list_head virtio_chan_list;
+
+/* How many bytes left in this page. */
+static unsigned int rest_of_page(void *data)
+{
+ return PAGE_SIZE - offset_in_page(data);
+}
+
+/**
+ * p9_virtio_close - reclaim resources of a channel
+ * @client: client instance
+ *
+ * This reclaims a channel by freeing its resources and
+ * reseting its inuse flag.
+ *
+ */
+
+static void p9_virtio_close(struct p9_client *client)
+{
+ struct virtio_chan *chan = client->trans;
+
+ mutex_lock(&virtio_9p_lock);
+ if (chan)
+ chan->inuse = false;
+ mutex_unlock(&virtio_9p_lock);
+}
+
+/**
+ * req_done - callback which signals activity from the server
+ * @vq: virtio queue activity was received on
+ *
+ * This notifies us that the server has triggered some activity
+ * on the virtio channel - most likely a response to request we
+ * sent. Figure out which requests now have responses and wake up
+ * those threads.
+ *
+ * Bugs: could do with some additional sanity checking, but appears to work.
+ *
+ */
+
+static void req_done(struct virtqueue *vq)
+{
+ struct virtio_chan *chan = vq->vdev->priv;
+ unsigned int len;
+ struct p9_req_t *req;
+ bool need_wakeup = false;
+ unsigned long flags;
+
+ p9_debug(P9_DEBUG_TRANS, ": request done\n");
+
+ spin_lock_irqsave(&chan->lock, flags);
+ while ((req = virtqueue_get_buf(chan->vq, &len)) != NULL) {
+ if (!chan->ring_bufs_avail) {
+ chan->ring_bufs_avail = 1;
+ need_wakeup = true;
+ }
+
+ if (len) {
+ req->rc.size = len;
+ p9_client_cb(chan->client, req, REQ_STATUS_RCVD);
+ }
+ }
+ spin_unlock_irqrestore(&chan->lock, flags);
+ /* Wakeup if anyone waiting for VirtIO ring space. */
+ if (need_wakeup)
+ wake_up(chan->vc_wq);
+}
+
+/**
+ * pack_sg_list - pack a scatter gather list from a linear buffer
+ * @sg: scatter/gather list to pack into
+ * @start: which segment of the sg_list to start at
+ * @limit: maximum segment to pack data to
+ * @data: data to pack into scatter/gather list
+ * @count: amount of data to pack into the scatter/gather list
+ *
+ * sg_lists have multiple segments of various sizes. This will pack
+ * arbitrary data into an existing scatter gather list, segmenting the
+ * data as necessary within constraints.
+ *
+ */
+
+static int pack_sg_list(struct scatterlist *sg, int start,
+ int limit, char *data, int count)
+{
+ int s;
+ int index = start;
+
+ while (count) {
+ s = rest_of_page(data);
+ if (s > count)
+ s = count;
+ BUG_ON(index >= limit);
+ /* Make sure we don't terminate early. */
+ sg_unmark_end(&sg[index]);
+ sg_set_buf(&sg[index++], data, s);
+ count -= s;
+ data += s;
+ }
+ if (index-start)
+ sg_mark_end(&sg[index - 1]);
+ return index-start;
+}
+
+/* We don't currently allow canceling of virtio requests */
+static int p9_virtio_cancel(struct p9_client *client, struct p9_req_t *req)
+{
+ return 1;
+}
+
+/* Reply won't come, so drop req ref */
+static int p9_virtio_cancelled(struct p9_client *client, struct p9_req_t *req)
+{
+ p9_req_put(req);
+ return 0;
+}
+
+/**
+ * pack_sg_list_p - Just like pack_sg_list. Instead of taking a buffer,
+ * this takes a list of pages.
+ * @sg: scatter/gather list to pack into
+ * @start: which segment of the sg_list to start at
+ * @pdata: a list of pages to add into sg.
+ * @nr_pages: number of pages to pack into the scatter/gather list
+ * @offs: amount of data in the beginning of first page _not_ to pack
+ * @count: amount of data to pack into the scatter/gather list
+ */
+static int
+pack_sg_list_p(struct scatterlist *sg, int start, int limit,
+ struct page **pdata, int nr_pages, size_t offs, int count)
+{
+ int i = 0, s;
+ int data_off = offs;
+ int index = start;
+
+ BUG_ON(nr_pages > (limit - start));
+ /*
+ * if the first page doesn't start at
+ * page boundary find the offset
+ */
+ while (nr_pages) {
+ s = PAGE_SIZE - data_off;
+ if (s > count)
+ s = count;
+ BUG_ON(index >= limit);
+ /* Make sure we don't terminate early. */
+ sg_unmark_end(&sg[index]);
+ sg_set_page(&sg[index++], pdata[i++], s, data_off);
+ data_off = 0;
+ count -= s;
+ nr_pages--;
+ }
+
+ if (index-start)
+ sg_mark_end(&sg[index - 1]);
+ return index - start;
+}
+
+/**
+ * p9_virtio_request - issue a request
+ * @client: client instance issuing the request
+ * @req: request to be issued
+ *
+ */
+
+static int
+p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
+{
+ int err;
+ int in, out, out_sgs, in_sgs;
+ unsigned long flags;
+ struct virtio_chan *chan = client->trans;
+ struct scatterlist *sgs[2];
+
+ p9_debug(P9_DEBUG_TRANS, "9p debug: virtio request\n");
+
+ req->status = REQ_STATUS_SENT;
+req_retry:
+ spin_lock_irqsave(&chan->lock, flags);
+
+ out_sgs = in_sgs = 0;
+ /* Handle out VirtIO ring buffers */
+ out = pack_sg_list(chan->sg, 0,
+ VIRTQUEUE_NUM, req->tc.sdata, req->tc.size);
+ if (out)
+ sgs[out_sgs++] = chan->sg;
+
+ in = pack_sg_list(chan->sg, out,
+ VIRTQUEUE_NUM, req->rc.sdata, req->rc.capacity);
+ if (in)
+ sgs[out_sgs + in_sgs++] = chan->sg + out;
+
+ err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req,
+ GFP_ATOMIC);
+ if (err < 0) {
+ if (err == -ENOSPC) {
+ chan->ring_bufs_avail = 0;
+ spin_unlock_irqrestore(&chan->lock, flags);
+ err = wait_event_killable(*chan->vc_wq,
+ chan->ring_bufs_avail);
+ if (err == -ERESTARTSYS)
+ return err;
+
+ p9_debug(P9_DEBUG_TRANS, "Retry virtio request\n");
+ goto req_retry;
+ } else {
+ spin_unlock_irqrestore(&chan->lock, flags);
+ p9_debug(P9_DEBUG_TRANS,
+ "virtio rpc add_sgs returned failure\n");
+ return -EIO;
+ }
+ }
+ virtqueue_kick(chan->vq);
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n");
+ return 0;
+}
+
+static int p9_get_mapped_pages(struct virtio_chan *chan,
+ struct page ***pages,
+ struct iov_iter *data,
+ int count,
+ size_t *offs,
+ int *need_drop)
+{
+ int nr_pages;
+ int err;
+
+ if (!iov_iter_count(data))
+ return 0;
+
+ if (!iov_iter_is_kvec(data)) {
+ int n;
+ /*
+ * We allow only p9_max_pages pinned. We wait for the
+ * Other zc request to finish here
+ */
+ if (atomic_read(&vp_pinned) >= chan->p9_max_pages) {
+ err = wait_event_killable(vp_wq,
+ (atomic_read(&vp_pinned) < chan->p9_max_pages));
+ if (err == -ERESTARTSYS)
+ return err;
+ }
+ n = iov_iter_get_pages_alloc(data, pages, count, offs);
+ if (n < 0)
+ return n;
+ *need_drop = 1;
+ nr_pages = DIV_ROUND_UP(n + *offs, PAGE_SIZE);
+ atomic_add(nr_pages, &vp_pinned);
+ return n;
+ } else {
+ /* kernel buffer, no need to pin pages */
+ int index;
+ size_t len;
+ void *p;
+
+ /* we'd already checked that it's non-empty */
+ while (1) {
+ len = iov_iter_single_seg_count(data);
+ if (likely(len)) {
+ p = data->kvec->iov_base + data->iov_offset;
+ break;
+ }
+ iov_iter_advance(data, 0);
+ }
+ if (len > count)
+ len = count;
+
+ nr_pages = DIV_ROUND_UP((unsigned long)p + len, PAGE_SIZE) -
+ (unsigned long)p / PAGE_SIZE;
+
+ *pages = kmalloc_array(nr_pages, sizeof(struct page *),
+ GFP_NOFS);
+ if (!*pages)
+ return -ENOMEM;
+
+ *need_drop = 0;
+ p -= (*offs = offset_in_page(p));
+ for (index = 0; index < nr_pages; index++) {
+ if (is_vmalloc_addr(p))
+ (*pages)[index] = vmalloc_to_page(p);
+ else
+ (*pages)[index] = kmap_to_page(p);
+ p += PAGE_SIZE;
+ }
+ return len;
+ }
+}
+
+/**
+ * p9_virtio_zc_request - issue a zero copy request
+ * @client: client instance issuing the request
+ * @req: request to be issued
+ * @uidata: user buffer that should be used for zero copy read
+ * @uodata: user buffer that should be used for zero copy write
+ * @inlen: read buffer size
+ * @outlen: write buffer size
+ * @in_hdr_len: reader header size, This is the size of response protocol data
+ *
+ */
+static int
+p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req,
+ struct iov_iter *uidata, struct iov_iter *uodata,
+ int inlen, int outlen, int in_hdr_len)
+{
+ int in, out, err, out_sgs, in_sgs;
+ unsigned long flags;
+ int in_nr_pages = 0, out_nr_pages = 0;
+ struct page **in_pages = NULL, **out_pages = NULL;
+ struct virtio_chan *chan = client->trans;
+ struct scatterlist *sgs[4];
+ size_t offs = 0;
+ int need_drop = 0;
+ int kicked = 0;
+
+ p9_debug(P9_DEBUG_TRANS, "virtio request\n");
+
+ if (uodata) {
+ __le32 sz;
+ int n = p9_get_mapped_pages(chan, &out_pages, uodata,
+ outlen, &offs, &need_drop);
+ if (n < 0) {
+ err = n;
+ goto err_out;
+ }
+ out_nr_pages = DIV_ROUND_UP(n + offs, PAGE_SIZE);
+ if (n != outlen) {
+ __le32 v = cpu_to_le32(n);
+ memcpy(&req->tc.sdata[req->tc.size - 4], &v, 4);
+ outlen = n;
+ }
+ /* The size field of the message must include the length of the
+ * header and the length of the data. We didn't actually know
+ * the length of the data until this point so add it in now.
+ */
+ sz = cpu_to_le32(req->tc.size + outlen);
+ memcpy(&req->tc.sdata[0], &sz, sizeof(sz));
+ } else if (uidata) {
+ int n = p9_get_mapped_pages(chan, &in_pages, uidata,
+ inlen, &offs, &need_drop);
+ if (n < 0) {
+ err = n;
+ goto err_out;
+ }
+ in_nr_pages = DIV_ROUND_UP(n + offs, PAGE_SIZE);
+ if (n != inlen) {
+ __le32 v = cpu_to_le32(n);
+ memcpy(&req->tc.sdata[req->tc.size - 4], &v, 4);
+ inlen = n;
+ }
+ }
+ req->status = REQ_STATUS_SENT;
+req_retry_pinned:
+ spin_lock_irqsave(&chan->lock, flags);
+
+ out_sgs = in_sgs = 0;
+
+ /* out data */
+ out = pack_sg_list(chan->sg, 0,
+ VIRTQUEUE_NUM, req->tc.sdata, req->tc.size);
+
+ if (out)
+ sgs[out_sgs++] = chan->sg;
+
+ if (out_pages) {
+ sgs[out_sgs++] = chan->sg + out;
+ out += pack_sg_list_p(chan->sg, out, VIRTQUEUE_NUM,
+ out_pages, out_nr_pages, offs, outlen);
+ }
+
+ /*
+ * Take care of in data
+ * For example TREAD have 11.
+ * 11 is the read/write header = PDU Header(7) + IO Size (4).
+ * Arrange in such a way that server places header in the
+ * alloced memory and payload onto the user buffer.
+ */
+ in = pack_sg_list(chan->sg, out,
+ VIRTQUEUE_NUM, req->rc.sdata, in_hdr_len);
+ if (in)
+ sgs[out_sgs + in_sgs++] = chan->sg + out;
+
+ if (in_pages) {
+ sgs[out_sgs + in_sgs++] = chan->sg + out + in;
+ in += pack_sg_list_p(chan->sg, out + in, VIRTQUEUE_NUM,
+ in_pages, in_nr_pages, offs, inlen);
+ }
+
+ BUG_ON(out_sgs + in_sgs > ARRAY_SIZE(sgs));
+ err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req,
+ GFP_ATOMIC);
+ if (err < 0) {
+ if (err == -ENOSPC) {
+ chan->ring_bufs_avail = 0;
+ spin_unlock_irqrestore(&chan->lock, flags);
+ err = wait_event_killable(*chan->vc_wq,
+ chan->ring_bufs_avail);
+ if (err == -ERESTARTSYS)
+ goto err_out;
+
+ p9_debug(P9_DEBUG_TRANS, "Retry virtio request\n");
+ goto req_retry_pinned;
+ } else {
+ spin_unlock_irqrestore(&chan->lock, flags);
+ p9_debug(P9_DEBUG_TRANS,
+ "virtio rpc add_sgs returned failure\n");
+ err = -EIO;
+ goto err_out;
+ }
+ }
+ virtqueue_kick(chan->vq);
+ spin_unlock_irqrestore(&chan->lock, flags);
+ kicked = 1;
+ p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n");
+ err = wait_event_killable(req->wq, req->status >= REQ_STATUS_RCVD);
+ /*
+ * Non kernel buffers are pinned, unpin them
+ */
+err_out:
+ if (need_drop) {
+ if (in_pages) {
+ p9_release_pages(in_pages, in_nr_pages);
+ atomic_sub(in_nr_pages, &vp_pinned);
+ }
+ if (out_pages) {
+ p9_release_pages(out_pages, out_nr_pages);
+ atomic_sub(out_nr_pages, &vp_pinned);
+ }
+ /* wakeup anybody waiting for slots to pin pages */
+ wake_up(&vp_wq);
+ }
+ kvfree(in_pages);
+ kvfree(out_pages);
+ if (!kicked) {
+ /* reply won't come */
+ p9_req_put(req);
+ }
+ return err;
+}
+
+static ssize_t p9_mount_tag_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct virtio_chan *chan;
+ struct virtio_device *vdev;
+ int tag_len;
+
+ vdev = dev_to_virtio(dev);
+ chan = vdev->priv;
+ tag_len = strlen(chan->tag);
+
+ memcpy(buf, chan->tag, tag_len + 1);
+
+ return tag_len + 1;
+}
+
+static DEVICE_ATTR(mount_tag, 0444, p9_mount_tag_show, NULL);
+
+/**
+ * p9_virtio_probe - probe for existence of 9P virtio channels
+ * @vdev: virtio device to probe
+ *
+ * This probes for existing virtio channels.
+ *
+ */
+
+static int p9_virtio_probe(struct virtio_device *vdev)
+{
+ __u16 tag_len;
+ char *tag;
+ int err;
+ struct virtio_chan *chan;
+
+ if (!vdev->config->get) {
+ dev_err(&vdev->dev, "%s failure: config access disabled\n",
+ __func__);
+ return -EINVAL;
+ }
+
+ chan = kmalloc(sizeof(struct virtio_chan), GFP_KERNEL);
+ if (!chan) {
+ pr_err("Failed to allocate virtio 9P channel\n");
+ err = -ENOMEM;
+ goto fail;
+ }
+
+ chan->vdev = vdev;
+
+ /* We expect one virtqueue, for requests. */
+ chan->vq = virtio_find_single_vq(vdev, req_done, "requests");
+ if (IS_ERR(chan->vq)) {
+ err = PTR_ERR(chan->vq);
+ goto out_free_chan;
+ }
+ chan->vq->vdev->priv = chan;
+ spin_lock_init(&chan->lock);
+
+ sg_init_table(chan->sg, VIRTQUEUE_NUM);
+
+ chan->inuse = false;
+ if (virtio_has_feature(vdev, VIRTIO_9P_MOUNT_TAG)) {
+ virtio_cread(vdev, struct virtio_9p_config, tag_len, &tag_len);
+ } else {
+ err = -EINVAL;
+ goto out_free_vq;
+ }
+ tag = kzalloc(tag_len + 1, GFP_KERNEL);
+ if (!tag) {
+ err = -ENOMEM;
+ goto out_free_vq;
+ }
+
+ virtio_cread_bytes(vdev, offsetof(struct virtio_9p_config, tag),
+ tag, tag_len);
+ chan->tag = tag;
+ err = sysfs_create_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr);
+ if (err) {
+ goto out_free_tag;
+ }
+ chan->vc_wq = kmalloc(sizeof(wait_queue_head_t), GFP_KERNEL);
+ if (!chan->vc_wq) {
+ err = -ENOMEM;
+ goto out_remove_file;
+ }
+ init_waitqueue_head(chan->vc_wq);
+ chan->ring_bufs_avail = 1;
+ /* Ceiling limit to avoid denial of service attacks */
+ chan->p9_max_pages = nr_free_buffer_pages()/4;
+
+ virtio_device_ready(vdev);
+
+ mutex_lock(&virtio_9p_lock);
+ list_add_tail(&chan->chan_list, &virtio_chan_list);
+ mutex_unlock(&virtio_9p_lock);
+
+ /* Let udev rules use the new mount_tag attribute. */
+ kobject_uevent(&(vdev->dev.kobj), KOBJ_CHANGE);
+
+ return 0;
+
+out_remove_file:
+ sysfs_remove_file(&vdev->dev.kobj, &dev_attr_mount_tag.attr);
+out_free_tag:
+ kfree(tag);
+out_free_vq:
+ vdev->config->del_vqs(vdev);
+out_free_chan:
+ kfree(chan);
+fail:
+ return err;
+}
+
+
+/**
+ * p9_virtio_create - allocate a new virtio channel
+ * @client: client instance invoking this transport
+ * @devname: string identifying the channel to connect to (unused)
+ * @args: args passed from sys_mount() for per-transport options (unused)
+ *
+ * This sets up a transport channel for 9p communication. Right now
+ * we only match the first available channel, but eventually we couldlook up
+ * alternate channels by matching devname versus a virtio_config entry.
+ * We use a simple reference count mechanism to ensure that only a single
+ * mount has a channel open at a time.
+ *
+ */
+
+static int
+p9_virtio_create(struct p9_client *client, const char *devname, char *args)
+{
+ struct virtio_chan *chan;
+ int ret = -ENOENT;
+ int found = 0;
+
+ if (devname == NULL)
+ return -EINVAL;
+
+ mutex_lock(&virtio_9p_lock);
+ list_for_each_entry(chan, &virtio_chan_list, chan_list) {
+ if (!strcmp(devname, chan->tag)) {
+ if (!chan->inuse) {
+ chan->inuse = true;
+ found = 1;
+ break;
+ }
+ ret = -EBUSY;
+ }
+ }
+ mutex_unlock(&virtio_9p_lock);
+
+ if (!found) {
+ pr_err("no channels available for device %s\n", devname);
+ return ret;
+ }
+
+ client->trans = (void *)chan;
+ client->status = Connected;
+ chan->client = client;
+
+ return 0;
+}
+
+/**
+ * p9_virtio_remove - clean up resources associated with a virtio device
+ * @vdev: virtio device to remove
+ *
+ */
+
+static void p9_virtio_remove(struct virtio_device *vdev)
+{
+ struct virtio_chan *chan = vdev->priv;
+ unsigned long warning_time;
+
+ mutex_lock(&virtio_9p_lock);
+
+ /* Remove self from list so we don't get new users. */
+ list_del(&chan->chan_list);
+ warning_time = jiffies;
+
+ /* Wait for existing users to close. */
+ while (chan->inuse) {
+ mutex_unlock(&virtio_9p_lock);
+ msleep(250);
+ if (time_after(jiffies, warning_time + 10 * HZ)) {
+ dev_emerg(&vdev->dev,
+ "p9_virtio_remove: waiting for device in use.\n");
+ warning_time = jiffies;
+ }
+ mutex_lock(&virtio_9p_lock);
+ }
+
+ mutex_unlock(&virtio_9p_lock);
+
+ vdev->config->reset(vdev);
+ vdev->config->del_vqs(vdev);
+
+ sysfs_remove_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr);
+ kobject_uevent(&(vdev->dev.kobj), KOBJ_CHANGE);
+ kfree(chan->tag);
+ kfree(chan->vc_wq);
+ kfree(chan);
+
+}
+
+static struct virtio_device_id id_table[] = {
+ { VIRTIO_ID_9P, VIRTIO_DEV_ANY_ID },
+ { 0 },
+};
+
+static unsigned int features[] = {
+ VIRTIO_9P_MOUNT_TAG,
+};
+
+/* The standard "struct lguest_driver": */
+static struct virtio_driver p9_virtio_drv = {
+ .feature_table = features,
+ .feature_table_size = ARRAY_SIZE(features),
+ .driver.name = KBUILD_MODNAME,
+ .driver.owner = THIS_MODULE,
+ .id_table = id_table,
+ .probe = p9_virtio_probe,
+ .remove = p9_virtio_remove,
+};
+
+static struct p9_trans_module p9_virtio_trans = {
+ .name = "virtio",
+ .create = p9_virtio_create,
+ .close = p9_virtio_close,
+ .request = p9_virtio_request,
+ .zc_request = p9_virtio_zc_request,
+ .cancel = p9_virtio_cancel,
+ .cancelled = p9_virtio_cancelled,
+ /*
+ * We leave one entry for input and one entry for response
+ * headers. We also skip one more entry to accomodate, address
+ * that are not at page boundary, that can result in an extra
+ * page in zero copy.
+ */
+ .maxsize = PAGE_SIZE * (VIRTQUEUE_NUM - 3),
+ .def = 1,
+ .owner = THIS_MODULE,
+};
+
+/* The standard init function */
+static int __init p9_virtio_init(void)
+{
+ int rc;
+
+ INIT_LIST_HEAD(&virtio_chan_list);
+
+ v9fs_register_trans(&p9_virtio_trans);
+ rc = register_virtio_driver(&p9_virtio_drv);
+ if (rc)
+ v9fs_unregister_trans(&p9_virtio_trans);
+
+ return rc;
+}
+
+static void __exit p9_virtio_cleanup(void)
+{
+ unregister_virtio_driver(&p9_virtio_drv);
+ v9fs_unregister_trans(&p9_virtio_trans);
+}
+
+module_init(p9_virtio_init);
+module_exit(p9_virtio_cleanup);
+
+MODULE_DEVICE_TABLE(virtio, id_table);
+MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
+MODULE_DESCRIPTION("Virtio 9p Transport");
+MODULE_LICENSE("GPL");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-28 21:18:37 +0000