[PATCH 4/4] virtio: console: Add support for multiple devices and ports
Amit Shah
amitshah at gmx.net
Fri Feb 5 04:50:34 UTC 2010
From: Amit Shah <amit.shah at redhat.com>
This commit backports virtio console functionality that will be
introduced in the 2.6.34 kernel for a guest-host communication channel.
See the Fedora feature page for more information:
https://fedoraproject.org/wiki/Features/VirtioSerial
For easier to review, split-up patches, see the linux-next tree.
This commit adds support for multiple ports per virtio-console device
and also adds the ability to add multiple such devices. There's also
support for hotplugging and unplugging of ports, 'naming' of ports so
that userspace apps on the guest can identify the corresponding port on
the host.
Signed-off-by: Amit Shah <amit.shah at redhat.com>
---
drivers/char/Kconfig | 8 +
drivers/char/virtio_console.c | 1510 ++++++++++++++++++++++++++++++++++++----
include/linux/virtio_console.h | 30 +-
3 files changed, 1398 insertions(+), 150 deletions(-)
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index e023682..3141dd3 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -666,6 +666,14 @@ config VIRTIO_CONSOLE
help
Virtio console for use with lguest and other hypervisors.
+ Also serves as a general-purpose serial device for data
+ transfer between the guest and host. Character devices at
+ /dev/vportNpn will be created when corresponding ports are
+ found, where N is the device number and n is the port number
+ within that device. If specified by the host, a sysfs
+ attribute called 'name' will be populated with a name for
+ the port which can be used by udev scripts to create a
+ symlink to the device.
config HVCS
tristate "IBM Hypervisor Virtual Console Server support"
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index a035ae3..a3f1f73 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -1,18 +1,6 @@
-/*D:300
- * The Guest console driver
- *
- * Writing console drivers is one of the few remaining Dark Arts in Linux.
- * Fortunately for us, the path of virtual consoles has been well-trodden by
- * the PowerPC folks, who wrote "hvc_console.c" to generically support any
- * virtual console. We use that infrastructure which only requires us to write
- * the basic put_chars and get_chars functions and call the right register
- * functions.
- :*/
-
-/*M:002 The console can be flooded: while the Guest is processing input the
- * Host can send more. Buffering in the Host could alleviate this, but it is a
- * difficult problem in general. :*/
-/* Copyright (C) 2006, 2007 Rusty Russell, IBM Corporation
+/*
+ * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
+ * Copyright (C) 2009, 2010 Red Hat, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -28,142 +16,684 @@
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
+#include <linux/cdev.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
#include <linux/err.h>
+#include <linux/fs.h>
#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
#include <linux/virtio.h>
#include <linux/virtio_console.h>
+#include <linux/wait.h>
+#include <linux/workqueue.h>
#include "hvc_console.h"
-/*D:340 These represent our input and output console queues, and the virtio
- * operations for them. */
-static struct virtqueue *in_vq, *out_vq;
-static struct virtio_device *vdev;
+/*
+ * This is a global struct for storing common data for all the devices
+ * this driver handles.
+ *
+ * Mainly, it has a linked list for all the consoles in one place so
+ * that callbacks from hvc for get_chars(), put_chars() work properly
+ * across multiple devices and multiple ports per device.
+ */
+struct ports_driver_data {
+ /* Used for registering chardevs */
+ struct class *class;
+
+ /* Used for exporting per-port information to debugfs */
+ struct dentry *debugfs_dir;
+
+ /* Number of devices this driver is handling */
+ unsigned int index;
+
+ /*
+ * This is used to keep track of the number of hvc consoles
+ * spawned by this driver. This number is given as the first
+ * argument to hvc_alloc(). To correctly map an initial
+ * console spawned via hvc_instantiate to the console being
+ * hooked up via hvc_alloc, we need to pass the same vtermno.
+ *
+ * We also just assume the first console being initialised was
+ * the first one that got used as the initial console.
+ */
+ unsigned int next_vtermno;
+
+ /* All the console devices handled by this driver */
+ struct list_head consoles;
+};
+static struct ports_driver_data pdrvdata;
+
+DEFINE_SPINLOCK(pdrvdata_lock);
+
+/* This struct holds information that's relevant only for console ports */
+struct console {
+ /* We'll place all consoles in a list in the pdrvdata struct */
+ struct list_head list;
+
+ /* The hvc device associated with this console port */
+ struct hvc_struct *hvc;
+
+ /*
+ * This number identifies the number that we used to register
+ * with hvc in hvc_instantiate() and hvc_alloc(); this is the
+ * number passed on by the hvc callbacks to us to
+ * differentiate between the other console ports handled by
+ * this driver
+ */
+ u32 vtermno;
+};
+
+struct port_buffer {
+ char *buf;
+
+ /* size of the buffer in *buf above */
+ size_t size;
+
+ /* used length of the buffer */
+ size_t len;
+ /* offset in the buf from which to consume data */
+ size_t offset;
+};
+
+/*
+ * This is a per-device struct that stores data common to all the
+ * ports for that device (vdev->priv).
+ */
+struct ports_device {
+ /*
+ * Workqueue handlers where we process deferred work after
+ * notification
+ */
+ struct work_struct control_work;
+ struct work_struct config_work;
+
+ struct list_head ports;
+
+ /* To protect the list of ports */
+ spinlock_t ports_lock;
+
+ /* To protect the vq operations for the control channel */
+ spinlock_t cvq_lock;
-/* This is our input buffer, and how much data is left in it. */
-static unsigned int in_len;
-static char *in, *inbuf;
+ /* The current config space is stored here */
+ struct virtio_console_config config;
-/* The operations for our console. */
-static struct hv_ops virtio_cons;
+ /* The virtio device we're associated with */
+ struct virtio_device *vdev;
-/* The hvc device */
-static struct hvc_struct *hvc;
+ /*
+ * A couple of virtqueues for the control channel: one for
+ * guest->host transfers, one for host->guest transfers
+ */
+ struct virtqueue *c_ivq, *c_ovq;
-/*D:310 The put_chars() callback is pretty straightforward.
+ /* Array of per-port IO virtqueues */
+ struct virtqueue **in_vqs, **out_vqs;
+
+ /* Used for numbering devices for sysfs and debugfs */
+ unsigned int drv_index;
+
+ /* Major number for this device. Ports will be created as minors. */
+ int chr_major;
+};
+
+/* This struct holds the per-port data */
+struct port {
+ /* Next port in the list, head is in the ports_device */
+ struct list_head list;
+
+ /* Pointer to the parent virtio_console device */
+ struct ports_device *portdev;
+
+ /* The current buffer from which data has to be fed to readers */
+ struct port_buffer *inbuf;
+
+ /*
+ * To protect the operations on the in_vq associated with this
+ * port. Has to be a spinlock because it can be called from
+ * interrupt context (get_char()).
+ */
+ spinlock_t inbuf_lock;
+
+ /* The IO vqs for this port */
+ struct virtqueue *in_vq, *out_vq;
+
+ /* File in the debugfs directory that exposes this port's information */
+ struct dentry *debugfs_file;
+
+ /*
+ * The entries in this struct will be valid if this port is
+ * hooked up to an hvc console
+ */
+ struct console cons;
+
+ /* Each port associates with a separate char device */
+ struct cdev cdev;
+ struct device *dev;
+
+ /* A waitqueue for poll() or blocking read operations */
+ wait_queue_head_t waitqueue;
+
+ /* The 'name' of the port that we expose via sysfs properties */
+ char *name;
+
+ /* The 'id' to identify the port with the Host */
+ u32 id;
+
+ /* Is the host device open */
+ bool host_connected;
+
+ /* We should allow only one process to open a port */
+ bool guest_connected;
+};
+
+/* This is the very early arch-specified put chars function. */
+static int (*early_put_chars)(u32, const char *, int);
+
+static struct port *find_port_by_vtermno(u32 vtermno)
+{
+ struct port *port;
+ struct console *cons;
+ unsigned long flags;
+
+ spin_lock_irqsave(&pdrvdata_lock, flags);
+ list_for_each_entry(cons, &pdrvdata.consoles, list) {
+ if (cons->vtermno == vtermno) {
+ port = container_of(cons, struct port, cons);
+ goto out;
+ }
+ }
+ port = NULL;
+out:
+ spin_unlock_irqrestore(&pdrvdata_lock, flags);
+ return port;
+}
+
+static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
+{
+ struct port *port;
+ unsigned long flags;
+
+ spin_lock_irqsave(&portdev->ports_lock, flags);
+ list_for_each_entry(port, &portdev->ports, list)
+ if (port->id == id)
+ goto out;
+ port = NULL;
+out:
+ spin_unlock_irqrestore(&portdev->ports_lock, flags);
+
+ return port;
+}
+
+static struct port *find_port_by_vq(struct ports_device *portdev,
+ struct virtqueue *vq)
+{
+ struct port *port;
+ unsigned long flags;
+
+ spin_lock_irqsave(&portdev->ports_lock, flags);
+ list_for_each_entry(port, &portdev->ports, list)
+ if (port->in_vq == vq || port->out_vq == vq)
+ goto out;
+ port = NULL;
+out:
+ spin_unlock_irqrestore(&portdev->ports_lock, flags);
+ return port;
+}
+
+static bool is_console_port(struct port *port)
+{
+ if (port->cons.hvc)
+ return true;
+ return false;
+}
+
+static inline bool use_multiport(struct ports_device *portdev)
+{
+ /*
+ * This condition can be true when put_chars is called from
+ * early_init
+ */
+ if (!portdev->vdev)
+ return 0;
+ return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
+}
+
+static void free_buf(struct port_buffer *buf)
+{
+ kfree(buf->buf);
+ kfree(buf);
+}
+
+static struct port_buffer *alloc_buf(size_t buf_size)
+{
+ struct port_buffer *buf;
+
+ buf = kmalloc(sizeof(*buf), GFP_KERNEL);
+ if (!buf)
+ goto fail;
+ buf->buf = kzalloc(buf_size, GFP_KERNEL);
+ if (!buf->buf)
+ goto free_buf;
+ buf->len = 0;
+ buf->offset = 0;
+ buf->size = buf_size;
+ return buf;
+
+free_buf:
+ kfree(buf);
+fail:
+ return NULL;
+}
+
+/* Callers should take appropriate locks */
+static void *get_inbuf(struct port *port)
+{
+ struct port_buffer *buf;
+ struct virtqueue *vq;
+ unsigned int len;
+
+ vq = port->in_vq;
+ buf = vq->vq_ops->get_buf(vq, &len);
+ if (buf) {
+ buf->len = len;
+ buf->offset = 0;
+ }
+ return buf;
+}
+
+/*
+ * Create a scatter-gather list representing our input buffer and put
+ * it in the queue.
*
- * We turn the characters into a scatter-gather list, add it to the output
- * queue and then kick the Host. Then we sit here waiting for it to finish:
- * inefficient in theory, but in practice implementations will do it
- * immediately (lguest's Launcher does). */
-static int put_chars(u32 vtermno, const char *buf, int count)
+ * Callers should take appropriate locks.
+ */
+static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
{
struct scatterlist sg[1];
+ int ret;
+
+ sg_init_one(sg, buf->buf, buf->size);
+
+ ret = vq->vq_ops->add_buf(vq, sg, 0, 1, buf);
+ vq->vq_ops->kick(vq);
+ return ret;
+}
+
+/* Discard any unread data this port has. Callers lockers. */
+static void discard_port_data(struct port *port)
+{
+ struct port_buffer *buf;
+ struct virtqueue *vq;
unsigned int len;
- /* This is a convenient routine to initialize a single-elem sg list */
- sg_init_one(sg, buf, count);
+ vq = port->in_vq;
+ if (port->inbuf)
+ buf = port->inbuf;
+ else
+ buf = vq->vq_ops->get_buf(vq, &len);
- /* add_buf wants a token to identify this buffer: we hand it any
- * non-NULL pointer, since there's only ever one buffer. */
- if (out_vq->vq_ops->add_buf(out_vq, sg, 1, 0, (void *)1) >= 0) {
- /* Tell Host to go! */
- out_vq->vq_ops->kick(out_vq);
- /* Chill out until it's done with the buffer. */
- while (!out_vq->vq_ops->get_buf(out_vq, &len))
- cpu_relax();
+ if (!buf)
+ return;
+
+ if (add_inbuf(vq, buf) < 0) {
+ buf->len = buf->offset = 0;
+ dev_warn(port->dev, "Error adding buffer back to vq\n");
+ return;
}
- /* We're expected to return the amount of data we wrote: all of it. */
- return count;
+ port->inbuf = NULL;
+}
+
+static bool port_has_data(struct port *port)
+{
+ unsigned long flags;
+ bool ret;
+
+ ret = false;
+ spin_lock_irqsave(&port->inbuf_lock, flags);
+ if (port->inbuf)
+ ret = true;
+ spin_unlock_irqrestore(&port->inbuf_lock, flags);
+
+ return ret;
}
-/* Create a scatter-gather list representing our input buffer and put it in the
- * queue. */
-static void add_inbuf(void)
+static ssize_t send_control_msg(struct port *port, unsigned int event,
+ unsigned int value)
{
struct scatterlist sg[1];
- sg_init_one(sg, inbuf, PAGE_SIZE);
+ struct virtio_console_control cpkt;
+ struct virtqueue *vq;
+ int len;
+
+ if (!use_multiport(port->portdev))
+ return 0;
+
+ cpkt.id = port->id;
+ cpkt.event = event;
+ cpkt.value = value;
- /* We should always be able to add one buffer to an empty queue. */
- if (in_vq->vq_ops->add_buf(in_vq, sg, 0, 1, inbuf) < 0)
- BUG();
- in_vq->vq_ops->kick(in_vq);
+ vq = port->portdev->c_ovq;
+
+ sg_init_one(sg, &cpkt, sizeof(cpkt));
+ if (vq->vq_ops->add_buf(vq, sg, 1, 0, &cpkt) >= 0) {
+ vq->vq_ops->kick(vq);
+ while (!vq->vq_ops->get_buf(vq, &len))
+ cpu_relax();
+ }
+ return 0;
}
-/*D:350 get_chars() is the callback from the hvc_console infrastructure when
- * an interrupt is received.
- *
- * Most of the code deals with the fact that the hvc_console() infrastructure
- * only asks us for 16 bytes at a time. We keep in_offset and in_used fields
- * for partially-filled buffers. */
-static int get_chars(u32 vtermno, char *buf, int count)
+static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count)
{
- /* If we don't have an input queue yet, we can't get input. */
- BUG_ON(!in_vq);
+ struct scatterlist sg[1];
+ struct virtqueue *out_vq;
+ ssize_t ret;
+ unsigned int len;
+
+ out_vq = port->out_vq;
+
+ sg_init_one(sg, in_buf, in_count);
+ ret = out_vq->vq_ops->add_buf(out_vq, sg, 1, 0, in_buf);
+
+ /* Tell Host to go! */
+ out_vq->vq_ops->kick(out_vq);
+
+ if (ret < 0) {
+ len = 0;
+ goto fail;
+ }
+
+ /*
+ * Wait till the host acknowledges it pushed out the data we
+ * sent. Also ensure we return to userspace the number of
+ * bytes that were successfully consumed by the host.
+ */
+ while (!out_vq->vq_ops->get_buf(out_vq, &len))
+ cpu_relax();
+fail:
+ /* We're expected to return the amount of data we wrote */
+ return len;
+}
+
+/*
+ * Give out the data that's requested from the buffer that we have
+ * queued up.
+ */
+static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
+ bool to_user)
+{
+ struct port_buffer *buf;
+ unsigned long flags;
+
+ if (!out_count || !port_has_data(port))
+ return 0;
+
+ buf = port->inbuf;
+ out_count = min(out_count, buf->len - buf->offset);
+
+ if (to_user) {
+ ssize_t ret;
+
+ ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
+ if (ret)
+ return -EFAULT;
+ } else {
+ memcpy(out_buf, buf->buf + buf->offset, out_count);
+ }
+
+ buf->offset += out_count;
- /* No buffer? Try to get one. */
- if (!in_len) {
- in = in_vq->vq_ops->get_buf(in_vq, &in_len);
- if (!in)
+ if (buf->offset == buf->len) {
+ /*
+ * We're done using all the data in this buffer.
+ * Re-queue so that the Host can send us more data.
+ */
+ spin_lock_irqsave(&port->inbuf_lock, flags);
+ port->inbuf = NULL;
+
+ if (add_inbuf(port->in_vq, buf) < 0)
+ dev_warn(port->dev, "failed add_buf\n");
+
+ spin_unlock_irqrestore(&port->inbuf_lock, flags);
+ }
+ /* Return the number of bytes actually copied */
+ return out_count;
+}
+
+/* The condition that must be true for polling to end */
+static bool wait_is_over(struct port *port)
+{
+ return port_has_data(port) || !port->host_connected;
+}
+
+static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
+ size_t count, loff_t *offp)
+{
+ struct port *port;
+ ssize_t ret;
+
+ port = filp->private_data;
+
+ if (!port_has_data(port)) {
+ /*
+ * If nothing's connected on the host just return 0 in
+ * case of list_empty; this tells the userspace app
+ * that there's no connection
+ */
+ if (!port->host_connected)
return 0;
+ if (filp->f_flags & O_NONBLOCK)
+ return -EAGAIN;
+
+ ret = wait_event_interruptible(port->waitqueue,
+ wait_is_over(port));
+ if (ret < 0)
+ return ret;
}
+ /*
+ * We could've received a disconnection message while we were
+ * waiting for more data.
+ *
+ * This check is not clubbed in the if() statement above as we
+ * might receive some data as well as the host could get
+ * disconnected after we got woken up from our wait. So we
+ * really want to give off whatever data we have and only then
+ * check for host_connected.
+ */
+ if (!port_has_data(port) && !port->host_connected)
+ return 0;
+
+ return fill_readbuf(port, ubuf, count, true);
+}
+
+static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
+ size_t count, loff_t *offp)
+{
+ struct port *port;
+ char *buf;
+ ssize_t ret;
+
+ port = filp->private_data;
+
+ count = min((size_t)(32 * 1024), count);
+
+ buf = kmalloc(count, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ ret = copy_from_user(buf, ubuf, count);
+ if (ret) {
+ ret = -EFAULT;
+ goto free_buf;
+ }
+
+ ret = send_buf(port, buf, count);
+free_buf:
+ kfree(buf);
+ return ret;
+}
+
+static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
+{
+ struct port *port;
+ unsigned int ret;
+
+ port = filp->private_data;
+ poll_wait(filp, &port->waitqueue, wait);
+
+ ret = 0;
+ if (port->inbuf)
+ ret |= POLLIN | POLLRDNORM;
+ if (port->host_connected)
+ ret |= POLLOUT;
+ if (!port->host_connected)
+ ret |= POLLHUP;
+
+ return ret;
+}
+
+static int port_fops_release(struct inode *inode, struct file *filp)
+{
+ struct port *port;
- /* You want more than we have to give? Well, try wanting less! */
- if (in_len < count)
- count = in_len;
+ port = filp->private_data;
- /* Copy across to their buffer and increment offset. */
- memcpy(buf, in, count);
- in += count;
- in_len -= count;
+ /* Notify host of port being closed */
+ send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
- /* Finished? Re-register buffer so Host will use it again. */
- if (in_len == 0)
- add_inbuf();
+ spin_lock_irq(&port->inbuf_lock);
+ port->guest_connected = false;
- return count;
+ discard_port_data(port);
+
+ spin_unlock_irq(&port->inbuf_lock);
+
+ return 0;
}
-/*:*/
-/*D:320 Console drivers are initialized very early so boot messages can go out,
- * so we do things slightly differently from the generic virtio initialization
- * of the net and block drivers.
+static int port_fops_open(struct inode *inode, struct file *filp)
+{
+ struct cdev *cdev = inode->i_cdev;
+ struct port *port;
+
+ port = container_of(cdev, struct port, cdev);
+ filp->private_data = port;
+
+ /*
+ * Don't allow opening of console port devices -- that's done
+ * via /dev/hvc
+ */
+ if (is_console_port(port))
+ return -ENXIO;
+
+ /* Allow only one process to open a particular port at a time */
+ spin_lock_irq(&port->inbuf_lock);
+ if (port->guest_connected) {
+ spin_unlock_irq(&port->inbuf_lock);
+ return -EMFILE;
+ }
+
+ port->guest_connected = true;
+ spin_unlock_irq(&port->inbuf_lock);
+
+ /* Notify host of port being opened */
+ send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
+
+ return 0;
+}
+
+/*
+ * The file operations that we support: programs in the guest can open
+ * a console device, read from it, write to it, poll for data and
+ * close it. The devices are at
+ * /dev/vport<device number>p<port number>
+ */
+static const struct file_operations port_fops = {
+ .owner = THIS_MODULE,
+ .open = port_fops_open,
+ .read = port_fops_read,
+ .write = port_fops_write,
+ .poll = port_fops_poll,
+ .release = port_fops_release,
+};
+
+/*
+ * The put_chars() callback is pretty straightforward.
*
- * At this stage, the console is output-only. It's too early to set up a
- * virtqueue, so we let the drivers do some boutique early-output thing. */
-int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
+ * We turn the characters into a scatter-gather list, add it to the
+ * output queue and then kick the Host. Then we sit here waiting for
+ * it to finish: inefficient in theory, but in practice
+ * implementations will do it immediately (lguest's Launcher does).
+ */
+static int put_chars(u32 vtermno, const char *buf, int count)
{
- virtio_cons.put_chars = put_chars;
- return hvc_instantiate(0, 0, &virtio_cons);
+ struct port *port;
+
+ port = find_port_by_vtermno(vtermno);
+ if (!port)
+ return 0;
+
+ if (unlikely(early_put_chars))
+ return early_put_chars(vtermno, buf, count);
+
+ return send_buf(port, (void *)buf, count);
}
/*
- * virtio console configuration. This supports:
- * - console resize
+ * get_chars() is the callback from the hvc_console infrastructure
+ * when an interrupt is received.
+ *
+ * We call out to fill_readbuf that gets us the required data from the
+ * buffers that are queued up.
*/
-static void virtcons_apply_config(struct virtio_device *dev)
+static int get_chars(u32 vtermno, char *buf, int count)
{
+ struct port *port;
+
+ port = find_port_by_vtermno(vtermno);
+ if (!port)
+ return 0;
+
+ /* If we don't have an input queue yet, we can't get input. */
+ BUG_ON(!port->in_vq);
+
+ return fill_readbuf(port, buf, count, false);
+}
+
+static void resize_console(struct port *port)
+{
+ struct virtio_device *vdev;
struct winsize ws;
- if (virtio_has_feature(dev, VIRTIO_CONSOLE_F_SIZE)) {
- dev->config->get(dev,
- offsetof(struct virtio_console_config, cols),
- &ws.ws_col, sizeof(u16));
- dev->config->get(dev,
- offsetof(struct virtio_console_config, rows),
- &ws.ws_row, sizeof(u16));
- hvc_resize(hvc, ws);
+ vdev = port->portdev->vdev;
+ if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)) {
+ vdev->config->get(vdev,
+ offsetof(struct virtio_console_config, cols),
+ &ws.ws_col, sizeof(u16));
+ vdev->config->get(vdev,
+ offsetof(struct virtio_console_config, rows),
+ &ws.ws_row, sizeof(u16));
+ hvc_resize(port->cons.hvc, ws);
}
}
-/*
- * we support only one console, the hvc struct is a global var
- * We set the configuration at this point, since we now have a tty
- */
+/* We set the configuration at this point, since we now have a tty */
static int notifier_add_vio(struct hvc_struct *hp, int data)
{
+ struct port *port;
+
+ port = find_port_by_vtermno(hp->vtermno);
+ if (!port)
+ return -EINVAL;
+
hp->irq_requested = 1;
- virtcons_apply_config(vdev);
+ resize_console(port);
return 0;
}
@@ -173,75 +703,742 @@ static void notifier_del_vio(struct hvc_struct *hp, int data)
hp->irq_requested = 0;
}
-static void hvc_handle_input(struct virtqueue *vq)
+/* The operations for console ports. */
+static const struct hv_ops hv_ops = {
+ .get_chars = get_chars,
+ .put_chars = put_chars,
+ .notifier_add = notifier_add_vio,
+ .notifier_del = notifier_del_vio,
+ .notifier_hangup = notifier_del_vio,
+};
+
+/*
+ * Console drivers are initialized very early so boot messages can go
+ * out, so we do things slightly differently from the generic virtio
+ * initialization of the net and block drivers.
+ *
+ * At this stage, the console is output-only. It's too early to set
+ * up a virtqueue, so we let the drivers do some boutique early-output
+ * thing.
+ */
+int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
+{
+ early_put_chars = put_chars;
+ return hvc_instantiate(0, 0, &hv_ops);
+}
+
+int init_port_console(struct port *port)
+{
+ int ret;
+
+ /*
+ * The Host's telling us this port is a console port. Hook it
+ * up with an hvc console.
+ *
+ * To set up and manage our virtual console, we call
+ * hvc_alloc().
+ *
+ * The first argument of hvc_alloc() is the virtual console
+ * number. The second argument is the parameter for the
+ * notification mechanism (like irq number). We currently
+ * leave this as zero, virtqueues have implicit notifications.
+ *
+ * The third argument is a "struct hv_ops" containing the
+ * put_chars() get_chars(), notifier_add() and notifier_del()
+ * pointers. The final argument is the output buffer size: we
+ * can do any size, so we put PAGE_SIZE here.
+ */
+ port->cons.vtermno = pdrvdata.next_vtermno;
+
+ port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
+ if (IS_ERR(port->cons.hvc)) {
+ ret = PTR_ERR(port->cons.hvc);
+ dev_err(port->dev,
+ "error %d allocating hvc for port\n", ret);
+ port->cons.hvc = NULL;
+ return ret;
+ }
+ spin_lock_irq(&pdrvdata_lock);
+ pdrvdata.next_vtermno++;
+ list_add_tail(&port->cons.list, &pdrvdata.consoles);
+ spin_unlock_irq(&pdrvdata_lock);
+ port->guest_connected = true;
+
+ /* Notify host of port being opened */
+ send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
+
+ return 0;
+}
+
+static ssize_t show_port_name(struct device *dev,
+ struct device_attribute *attr, char *buffer)
+{
+ struct port *port;
+
+ port = dev_get_drvdata(dev);
+
+ return sprintf(buffer, "%s\n", port->name);
+}
+
+static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
+
+static struct attribute *port_sysfs_entries[] = {
+ &dev_attr_name.attr,
+ NULL
+};
+
+static struct attribute_group port_attribute_group = {
+ .name = NULL, /* put in device directory */
+ .attrs = port_sysfs_entries,
+};
+
+static int debugfs_open(struct inode *inode, struct file *filp)
+{
+ filp->private_data = inode->i_private;
+ return 0;
+}
+
+static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
+ size_t count, loff_t *offp)
+{
+ struct port *port;
+ char *buf;
+ ssize_t ret, out_offset, out_count;
+
+ out_count = 1024;
+ buf = kmalloc(out_count, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ port = filp->private_data;
+ out_offset = 0;
+ out_offset += snprintf(buf + out_offset, out_count,
+ "name: %s\n", port->name ? port->name : "");
+ out_offset += snprintf(buf + out_offset, out_count - out_offset,
+ "guest_connected: %d\n", port->guest_connected);
+ out_offset += snprintf(buf + out_offset, out_count - out_offset,
+ "host_connected: %d\n", port->host_connected);
+ out_offset += snprintf(buf + out_offset, out_count - out_offset,
+ "is_console: %s\n",
+ is_console_port(port) ? "yes" : "no");
+ out_offset += snprintf(buf + out_offset, out_count - out_offset,
+ "console_vtermno: %u\n", port->cons.vtermno);
+
+ ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
+ kfree(buf);
+ return ret;
+}
+
+static const struct file_operations port_debugfs_ops = {
+ .owner = THIS_MODULE,
+ .open = debugfs_open,
+ .read = debugfs_read,
+};
+
+/* Remove all port-specific data. */
+static int remove_port(struct port *port)
+{
+ spin_lock_irq(&port->portdev->ports_lock);
+ list_del(&port->list);
+ spin_unlock_irq(&port->portdev->ports_lock);
+
+ if (is_console_port(port)) {
+ spin_lock_irq(&pdrvdata_lock);
+ list_del(&port->cons.list);
+ spin_unlock_irq(&pdrvdata_lock);
+ hvc_remove(port->cons.hvc);
+ }
+ if (port->guest_connected)
+ send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
+
+ while (port->in_vq->vq_ops->detach_unused_buf(port->in_vq))
+ ;
+
+ sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
+ device_destroy(pdrvdata.class, port->dev->devt);
+ cdev_del(&port->cdev);
+
+ discard_port_data(port);
+ kfree(port->name);
+
+ debugfs_remove(port->debugfs_file);
+
+ kfree(port);
+ return 0;
+}
+
+/* Any private messages that the Host and Guest want to share */
+static void handle_control_message(struct ports_device *portdev,
+ struct port_buffer *buf)
+{
+ struct virtio_console_control *cpkt;
+ struct port *port;
+ size_t name_size;
+ int err;
+
+ cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
+
+ port = find_port_by_id(portdev, cpkt->id);
+ if (!port) {
+ /* No valid header at start of buffer. Drop it. */
+ dev_dbg(&portdev->vdev->dev,
+ "Invalid index %u in control packet\n", cpkt->id);
+ return;
+ }
+
+ switch (cpkt->event) {
+ case VIRTIO_CONSOLE_CONSOLE_PORT:
+ if (!cpkt->value)
+ break;
+ if (is_console_port(port))
+ break;
+
+ init_port_console(port);
+ /*
+ * Could remove the port here in case init fails - but
+ * have to notify the host first.
+ */
+ break;
+ case VIRTIO_CONSOLE_RESIZE:
+ if (!is_console_port(port))
+ break;
+ port->cons.hvc->irq_requested = 1;
+ resize_console(port);
+ break;
+ case VIRTIO_CONSOLE_PORT_OPEN:
+ port->host_connected = cpkt->value;
+ wake_up_interruptible(&port->waitqueue);
+ break;
+ case VIRTIO_CONSOLE_PORT_NAME:
+ /*
+ * Skip the size of the header and the cpkt to get the size
+ * of the name that was sent
+ */
+ name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
+
+ port->name = kmalloc(name_size, GFP_KERNEL);
+ if (!port->name) {
+ dev_err(port->dev,
+ "Not enough space to store port name\n");
+ break;
+ }
+ strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
+ name_size - 1);
+ port->name[name_size - 1] = 0;
+
+ /*
+ * Since we only have one sysfs attribute, 'name',
+ * create it only if we have a name for the port.
+ */
+ err = sysfs_create_group(&port->dev->kobj,
+ &port_attribute_group);
+ if (err)
+ dev_err(port->dev,
+ "Error %d creating sysfs device attributes\n",
+ err);
+
+ break;
+ case VIRTIO_CONSOLE_PORT_REMOVE:
+ /*
+ * Hot unplug the port. We don't decrement nr_ports
+ * since we don't want to deal with extra complexities
+ * of using the lowest-available port id: We can just
+ * pick up the nr_ports number as the id and not have
+ * userspace send it to us. This helps us in two
+ * ways:
+ *
+ * - We don't need to have a 'port_id' field in the
+ * config space when a port is hot-added. This is a
+ * good thing as we might queue up multiple hotplug
+ * requests issued in our workqueue.
+ *
+ * - Another way to deal with this would have been to
+ * use a bitmap of the active ports and select the
+ * lowest non-active port from that map. That
+ * bloats the already tight config space and we
+ * would end up artificially limiting the
+ * max. number of ports to sizeof(bitmap). Right
+ * now we can support 2^32 ports (as the port id is
+ * stored in a u32 type).
+ *
+ */
+ remove_port(port);
+ break;
+ }
+}
+
+static void control_work_handler(struct work_struct *work)
{
- if (hvc_poll(hvc))
+ struct ports_device *portdev;
+ struct virtqueue *vq;
+ struct port_buffer *buf;
+ unsigned int len;
+
+ portdev = container_of(work, struct ports_device, control_work);
+ vq = portdev->c_ivq;
+
+ spin_lock(&portdev->cvq_lock);
+ while ((buf = vq->vq_ops->get_buf(vq, &len))) {
+ spin_unlock(&portdev->cvq_lock);
+
+ buf->len = len;
+ buf->offset = 0;
+
+ handle_control_message(portdev, buf);
+
+ spin_lock(&portdev->cvq_lock);
+ if (add_inbuf(portdev->c_ivq, buf) < 0) {
+ dev_warn(&portdev->vdev->dev,
+ "Error adding buffer to queue\n");
+ free_buf(buf);
+ }
+ }
+ spin_unlock(&portdev->cvq_lock);
+}
+
+static void in_intr(struct virtqueue *vq)
+{
+ struct port *port;
+ unsigned long flags;
+
+ port = find_port_by_vq(vq->vdev->priv, vq);
+ if (!port)
+ return;
+
+ spin_lock_irqsave(&port->inbuf_lock, flags);
+ port->inbuf = get_inbuf(port);
+
+ /*
+ * Don't queue up data when port is closed. This condition
+ * can be reached when a console port is not yet connected (no
+ * tty is spawned) and the host sends out data to console
+ * ports. For generic serial ports, the host won't
+ * (shouldn't) send data till the guest is connected.
+ */
+ if (!port->guest_connected)
+ discard_port_data(port);
+
+ spin_unlock_irqrestore(&port->inbuf_lock, flags);
+
+ wake_up_interruptible(&port->waitqueue);
+
+ if (is_console_port(port) && hvc_poll(port->cons.hvc))
hvc_kick();
}
-/*D:370 Once we're further in boot, we get probed like any other virtio device.
- * At this stage we set up the output virtqueue.
- *
- * To set up and manage our virtual console, we call hvc_alloc(). Since we
- * never remove the console device we never need this pointer again.
- *
- * Finally we put our input buffer in the input queue, ready to receive. */
-static int __devinit virtcons_probe(struct virtio_device *dev)
+static void control_intr(struct virtqueue *vq)
{
- vq_callback_t *callbacks[] = { hvc_handle_input, NULL};
- const char *names[] = { "input", "output" };
- struct virtqueue *vqs[2];
+ struct ports_device *portdev;
+
+ portdev = vq->vdev->priv;
+ schedule_work(&portdev->control_work);
+}
+
+static void config_intr(struct virtio_device *vdev)
+{
+ struct ports_device *portdev;
+
+ portdev = vdev->priv;
+ if (use_multiport(portdev)) {
+ /* Handle port hot-add */
+ schedule_work(&portdev->config_work);
+ }
+ /*
+ * We'll use this way of resizing only for legacy support.
+ * For newer userspace (VIRTIO_CONSOLE_F_MULTPORT+), use
+ * control messages to indicate console size changes so that
+ * it can be done per-port
+ */
+ resize_console(find_port_by_id(portdev, 0));
+}
+
+static void fill_queue(struct virtqueue *vq, spinlock_t *lock)
+{
+ struct port_buffer *buf;
+ int ret;
+
+ do {
+ buf = alloc_buf(PAGE_SIZE);
+ if (!buf)
+ break;
+
+ spin_lock_irq(lock);
+ ret = add_inbuf(vq, buf);
+ if (ret < 0) {
+ spin_unlock_irq(lock);
+ free_buf(buf);
+ break;
+ }
+ spin_unlock_irq(lock);
+ } while (ret > 0);
+}
+
+static int add_port(struct ports_device *portdev, u32 id)
+{
+ char debugfs_name[16];
+ struct port *port;
+ struct port_buffer *inbuf;
+ dev_t devt;
int err;
- vdev = dev;
+ port = kmalloc(sizeof(*port), GFP_KERNEL);
+ if (!port) {
+ err = -ENOMEM;
+ goto fail;
+ }
+
+ port->portdev = portdev;
+ port->id = id;
+
+ port->name = NULL;
+ port->inbuf = NULL;
+ port->cons.hvc = NULL;
+
+ port->host_connected = port->guest_connected = false;
- /* This is the scratch page we use to receive console input */
- inbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ port->in_vq = portdev->in_vqs[port->id];
+ port->out_vq = portdev->out_vqs[port->id];
+
+ cdev_init(&port->cdev, &port_fops);
+
+ devt = MKDEV(portdev->chr_major, id);
+ err = cdev_add(&port->cdev, devt, 1);
+ if (err < 0) {
+ dev_err(&port->portdev->vdev->dev,
+ "Error %d adding cdev for port %u\n", err, id);
+ goto free_port;
+ }
+ port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
+ devt, port, "vport%up%u",
+ port->portdev->drv_index, id);
+ if (IS_ERR(port->dev)) {
+ err = PTR_ERR(port->dev);
+ dev_err(&port->portdev->vdev->dev,
+ "Error %d creating device for port %u\n",
+ err, id);
+ goto free_cdev;
+ }
+
+ spin_lock_init(&port->inbuf_lock);
+ init_waitqueue_head(&port->waitqueue);
+
+ inbuf = alloc_buf(PAGE_SIZE);
if (!inbuf) {
err = -ENOMEM;
+ goto free_device;
+ }
+
+ /* Register the input buffer the first time. */
+ add_inbuf(port->in_vq, inbuf);
+
+ /*
+ * If we're not using multiport support, this has to be a console port
+ */
+ if (!use_multiport(port->portdev)) {
+ err = init_port_console(port);
+ if (err)
+ goto free_inbuf;
+ }
+
+ spin_lock_irq(&portdev->ports_lock);
+ list_add_tail(&port->list, &port->portdev->ports);
+ spin_unlock_irq(&portdev->ports_lock);
+
+ /*
+ * Tell the Host we're set so that it can send us various
+ * configuration parameters for this port (eg, port name,
+ * caching, whether this is a console port, etc.)
+ */
+ send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
+
+ if (pdrvdata.debugfs_dir) {
+ /*
+ * Finally, create the debugfs file that we can use to
+ * inspect a port's state at any time
+ */
+ sprintf(debugfs_name, "vport%up%u",
+ port->portdev->drv_index, id);
+ port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
+ pdrvdata.debugfs_dir,
+ port,
+ &port_debugfs_ops);
+ }
+ return 0;
+
+free_inbuf:
+ free_buf(inbuf);
+free_device:
+ device_destroy(pdrvdata.class, port->dev->devt);
+free_cdev:
+ cdev_del(&port->cdev);
+free_port:
+ kfree(port);
+fail:
+ return err;
+}
+
+/*
+ * The workhandler for config-space updates.
+ *
+ * This is called when ports are hot-added.
+ */
+static void config_work_handler(struct work_struct *work)
+{
+ struct virtio_console_config virtconconf;
+ struct ports_device *portdev;
+ struct virtio_device *vdev;
+ int err;
+
+ portdev = container_of(work, struct ports_device, config_work);
+
+ vdev = portdev->vdev;
+ vdev->config->get(vdev,
+ offsetof(struct virtio_console_config, nr_ports),
+ &virtconconf.nr_ports,
+ sizeof(virtconconf.nr_ports));
+
+ if (portdev->config.nr_ports == virtconconf.nr_ports) {
+ /*
+ * Port 0 got hot-added. Since we already did all the
+ * other initialisation for it, just tell the Host
+ * that the port is ready if we find the port. In
+ * case the port was hot-removed earlier, we call
+ * add_port to add the port.
+ */
+ struct port *port;
+
+ port = find_port_by_id(portdev, 0);
+ if (!port)
+ add_port(portdev, 0);
+ else
+ send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
+ return;
+ }
+ if (virtconconf.nr_ports > portdev->config.max_nr_ports) {
+ dev_warn(&vdev->dev,
+ "More ports specified (%u) than allowed (%u)",
+ portdev->config.nr_ports + 1,
+ portdev->config.max_nr_ports);
+ return;
+ }
+ if (virtconconf.nr_ports < portdev->config.nr_ports)
+ return;
+
+ /* Hot-add ports */
+ while (virtconconf.nr_ports - portdev->config.nr_ports) {
+ err = add_port(portdev, portdev->config.nr_ports);
+ if (err)
+ break;
+ portdev->config.nr_ports++;
+ }
+}
+
+static int init_vqs(struct ports_device *portdev)
+{
+ vq_callback_t **io_callbacks;
+ char **io_names;
+ struct virtqueue **vqs;
+ u32 i, j, nr_ports, nr_queues;
+ int err;
+
+ nr_ports = portdev->config.max_nr_ports;
+ nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
+
+ vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
+ if (!vqs) {
+ err = -ENOMEM;
goto fail;
}
+ io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
+ if (!io_callbacks) {
+ err = -ENOMEM;
+ goto free_vqs;
+ }
+ io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
+ if (!io_names) {
+ err = -ENOMEM;
+ goto free_callbacks;
+ }
+ portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
+ GFP_KERNEL);
+ if (!portdev->in_vqs) {
+ err = -ENOMEM;
+ goto free_names;
+ }
+ portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
+ GFP_KERNEL);
+ if (!portdev->out_vqs) {
+ err = -ENOMEM;
+ goto free_invqs;
+ }
+ /*
+ * For backward compat (newer host but older guest), the host
+ * spawns a console port first and also inits the vqs for port
+ * 0 before others.
+ */
+ j = 0;
+ io_callbacks[j] = in_intr;
+ io_callbacks[j + 1] = NULL;
+ io_names[j] = "input";
+ io_names[j + 1] = "output";
+ j += 2;
+
+ if (use_multiport(portdev)) {
+ io_callbacks[j] = control_intr;
+ io_callbacks[j + 1] = NULL;
+ io_names[j] = "control-i";
+ io_names[j + 1] = "control-o";
+
+ for (i = 1; i < nr_ports; i++) {
+ j += 2;
+ io_callbacks[j] = in_intr;
+ io_callbacks[j + 1] = NULL;
+ io_names[j] = "input";
+ io_names[j + 1] = "output";
+ }
+ }
/* Find the queues. */
- /* FIXME: This is why we want to wean off hvc: we do nothing
- * when input comes in. */
- err = vdev->config->find_vqs(vdev, 2, vqs, callbacks, names);
+ err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
+ io_callbacks,
+ (const char **)io_names);
if (err)
- goto free;
+ goto free_outvqs;
- in_vq = vqs[0];
- out_vq = vqs[1];
+ j = 0;
+ portdev->in_vqs[0] = vqs[0];
+ portdev->out_vqs[0] = vqs[1];
+ j += 2;
+ if (use_multiport(portdev)) {
+ portdev->c_ivq = vqs[j];
+ portdev->c_ovq = vqs[j + 1];
- /* Start using the new console output. */
- virtio_cons.get_chars = get_chars;
- virtio_cons.put_chars = put_chars;
- virtio_cons.notifier_add = notifier_add_vio;
- virtio_cons.notifier_del = notifier_del_vio;
- virtio_cons.notifier_hangup = notifier_del_vio;
-
- /* The first argument of hvc_alloc() is the virtual console number, so
- * we use zero. The second argument is the parameter for the
- * notification mechanism (like irq number). We currently leave this
- * as zero, virtqueues have implicit notifications.
- *
- * The third argument is a "struct hv_ops" containing the put_chars()
- * get_chars(), notifier_add() and notifier_del() pointers.
- * The final argument is the output buffer size: we can do any size,
- * so we put PAGE_SIZE here. */
- hvc = hvc_alloc(0, 0, &virtio_cons, PAGE_SIZE);
- if (IS_ERR(hvc)) {
- err = PTR_ERR(hvc);
- goto free_vqs;
+ for (i = 1; i < nr_ports; i++) {
+ j += 2;
+ portdev->in_vqs[i] = vqs[j];
+ portdev->out_vqs[i] = vqs[j + 1];
+ }
}
+ kfree(io_callbacks);
+ kfree(io_names);
+ kfree(vqs);
- /* Register the input buffer the first time. */
- add_inbuf();
return 0;
+free_names:
+ kfree(io_names);
+free_callbacks:
+ kfree(io_callbacks);
+free_outvqs:
+ kfree(portdev->out_vqs);
+free_invqs:
+ kfree(portdev->in_vqs);
free_vqs:
- vdev->config->del_vqs(vdev);
+ kfree(vqs);
+fail:
+ return err;
+}
+
+static const struct file_operations portdev_fops = {
+ .owner = THIS_MODULE,
+};
+
+/*
+ * Once we're further in boot, we get probed like any other virtio
+ * device.
+ *
+ * If the host also supports multiple console ports, we check the
+ * config space to see how many ports the host has spawned. We
+ * initialize each port found.
+ */
+static int __devinit virtcons_probe(struct virtio_device *vdev)
+{
+ struct ports_device *portdev;
+ u32 i;
+ int err;
+ bool multiport;
+
+ portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
+ if (!portdev) {
+ err = -ENOMEM;
+ goto fail;
+ }
+
+ /* Attach this portdev to this virtio_device, and vice-versa. */
+ portdev->vdev = vdev;
+ vdev->priv = portdev;
+
+ spin_lock_irq(&pdrvdata_lock);
+ portdev->drv_index = pdrvdata.index++;
+ spin_unlock_irq(&pdrvdata_lock);
+
+ portdev->chr_major = register_chrdev(0, "virtio-portsdev",
+ &portdev_fops);
+ if (portdev->chr_major < 0) {
+ dev_err(&vdev->dev,
+ "Error %d registering chrdev for device %u\n",
+ portdev->chr_major, portdev->drv_index);
+ err = portdev->chr_major;
+ goto free;
+ }
+
+ multiport = false;
+ portdev->config.nr_ports = 1;
+ portdev->config.max_nr_ports = 1;
+ if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) {
+ multiport = true;
+ vdev->features[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT;
+
+ vdev->config->get(vdev, offsetof(struct virtio_console_config,
+ nr_ports),
+ &portdev->config.nr_ports,
+ sizeof(portdev->config.nr_ports));
+ vdev->config->get(vdev, offsetof(struct virtio_console_config,
+ max_nr_ports),
+ &portdev->config.max_nr_ports,
+ sizeof(portdev->config.max_nr_ports));
+ if (portdev->config.nr_ports > portdev->config.max_nr_ports) {
+ dev_warn(&vdev->dev,
+ "More ports (%u) specified than allowed (%u). Will init %u ports.",
+ portdev->config.nr_ports,
+ portdev->config.max_nr_ports,
+ portdev->config.max_nr_ports);
+
+ portdev->config.nr_ports = portdev->config.max_nr_ports;
+ }
+ }
+
+ /* Let the Host know we support multiple ports.*/
+ vdev->config->finalize_features(vdev);
+
+ err = init_vqs(portdev);
+ if (err < 0) {
+ dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
+ goto free_chrdev;
+ }
+
+ spin_lock_init(&portdev->ports_lock);
+ INIT_LIST_HEAD(&portdev->ports);
+
+ if (multiport) {
+ spin_lock_init(&portdev->cvq_lock);
+ INIT_WORK(&portdev->control_work, &control_work_handler);
+ INIT_WORK(&portdev->config_work, &config_work_handler);
+
+ fill_queue(portdev->c_ivq, &portdev->cvq_lock);
+ }
+
+ for (i = 0; i < portdev->config.nr_ports; i++)
+ add_port(portdev, i);
+
+ /* Start using the new console output. */
+ early_put_chars = NULL;
+ return 0;
+
+free_chrdev:
+ unregister_chrdev(portdev->chr_major, "virtio-portsdev");
free:
- kfree(inbuf);
+ kfree(portdev);
fail:
return err;
}
@@ -253,6 +1450,7 @@ static struct virtio_device_id id_table[] = {
static unsigned int features[] = {
VIRTIO_CONSOLE_F_SIZE,
+ VIRTIO_CONSOLE_F_MULTIPORT,
};
static struct virtio_driver virtio_console = {
@@ -262,11 +1460,27 @@ static struct virtio_driver virtio_console = {
.driver.owner = THIS_MODULE,
.id_table = id_table,
.probe = virtcons_probe,
- .config_changed = virtcons_apply_config,
+ .config_changed = config_intr,
};
static int __init init(void)
{
+ int err;
+
+ pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
+ if (IS_ERR(pdrvdata.class)) {
+ err = PTR_ERR(pdrvdata.class);
+ pr_err("Error %d creating virtio-ports class\n", err);
+ return err;
+ }
+
+ pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
+ if (!pdrvdata.debugfs_dir) {
+ pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
+ PTR_ERR(pdrvdata.debugfs_dir));
+ }
+ INIT_LIST_HEAD(&pdrvdata.consoles);
+
return register_virtio_driver(&virtio_console);
}
module_init(init);
diff --git a/include/linux/virtio_console.h b/include/linux/virtio_console.h
index fe88517..ae4f039 100644
--- a/include/linux/virtio_console.h
+++ b/include/linux/virtio_console.h
@@ -3,19 +3,45 @@
#include <linux/types.h>
#include <linux/virtio_ids.h>
#include <linux/virtio_config.h>
-/* This header, excluding the #ifdef __KERNEL__ part, is BSD licensed so
- * anyone can use the definitions to implement compatible drivers/servers. */
+/*
+ * This header, excluding the #ifdef __KERNEL__ part, is BSD licensed so
+ * anyone can use the definitions to implement compatible drivers/servers.
+ *
+ * Copyright (C) Red Hat, Inc., 2009, 2010
+ */
/* Feature bits */
#define VIRTIO_CONSOLE_F_SIZE 0 /* Does host provide console size? */
+#define VIRTIO_CONSOLE_F_MULTIPORT 1 /* Does host provide multiple ports? */
struct virtio_console_config {
/* colums of the screens */
__u16 cols;
/* rows of the screens */
__u16 rows;
+ /* max. number of ports this device can hold */
+ __u32 max_nr_ports;
+ /* number of ports added so far */
+ __u32 nr_ports;
} __attribute__((packed));
+/*
+ * A message that's passed between the Host and the Guest for a
+ * particular port.
+ */
+struct virtio_console_control {
+ __u32 id; /* Port number */
+ __u16 event; /* The kind of control event (see below) */
+ __u16 value; /* Extra information for the key */
+};
+
+/* Some events for control messages */
+#define VIRTIO_CONSOLE_PORT_READY 0
+#define VIRTIO_CONSOLE_CONSOLE_PORT 1
+#define VIRTIO_CONSOLE_RESIZE 2
+#define VIRTIO_CONSOLE_PORT_OPEN 3
+#define VIRTIO_CONSOLE_PORT_NAME 4
+#define VIRTIO_CONSOLE_PORT_REMOVE 5
#ifdef __KERNEL__
int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int));
--
1.6.2.5
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