From patchwork Tue Aug 25 06:17:21 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Amit Shah X-Patchwork-Id: 43703 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n7P6InPb015897 for ; Tue, 25 Aug 2009 06:18:49 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754486AbZHYGSU (ORCPT ); Tue, 25 Aug 2009 02:18:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754494AbZHYGSU (ORCPT ); Tue, 25 Aug 2009 02:18:20 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52738 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754234AbZHYGST (ORCPT ); Tue, 25 Aug 2009 02:18:19 -0400 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id n7P6HkEp015137; Tue, 25 Aug 2009 02:17:46 -0400 Received: from localhost (vpn-12-87.rdu.redhat.com [10.11.12.87]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id n7P6Hge6031460; Tue, 25 Aug 2009 02:17:44 -0400 From: Amit Shah To: qemu-devel@nongnu.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org Cc: Amit Shah Subject: [PATCH] virtio_console: Add interface for guest and host communication Date: Tue, 25 Aug 2009 11:47:21 +0530 Message-Id: <1251181044-3696-2-git-send-email-amit.shah@redhat.com> In-Reply-To: <1251181044-3696-1-git-send-email-amit.shah@redhat.com> References: <1251181044-3696-1-git-send-email-amit.shah@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.11 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Expose multiple char devices ("ports") for simple communication between the host userspace and guest. Sample offline usages can be: poking around in a guest to find out the file systems used, applications installed, etc. Online usages can be sharing of clipboard data between the guest and the host, sending information about logged-in users to the host, locking the screen or session when a vnc session is closed, and so on. The interface presented to guest userspace is of a simple char device, so it can be used like this: fd = open("/dev/vcon2", O_RDWR); ret = read(fd, buf, 100); ret = write(fd, string, strlen(string)); Each port is to be assigned a unique function, for example, the first 4 ports may be reserved for libvirt usage, the next 4 for generic streaming data and so on. This port-function mapping isn't finalised yet. For requirements, use-cases and some history see http://www.linux-kvm.org/page/VMchannel_Requirements Signed-off-by: Amit Shah --- drivers/char/Kconfig | 4 +- drivers/char/virtio_console.c | 871 +++++++++++++++++++++++++++++++++++----- include/linux/virtio_console.h | 27 ++ 3 files changed, 791 insertions(+), 111 deletions(-) diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig index 6a06913..fe76627 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -678,7 +678,9 @@ config VIRTIO_CONSOLE select HVC_DRIVER 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/vconNN will + be created when corresponding ports are found. config HVCS tristate "IBM Hypervisor Virtual Console Server support" diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index c74dacf..3548bf6 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -13,6 +13,7 @@ * 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) 2009, Amit Shah, 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 @@ -28,100 +29,374 @@ * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ + +#include +#include #include +#include #include +#include #include #include +#include #include "hvc_console.h" -/*D:340 These represent our input and output console queues, and the virtio +/*D:340 FIXME 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; +struct virtio_console_struct { + struct work_struct rx_work; + struct work_struct tx_work; + struct work_struct config_work; + + struct list_head port_head; + struct list_head unused_read_head; + + struct virtio_device *vdev; + struct class *class; + struct virtqueue *in_vq, *out_vq; + + struct virtio_console_config *config; +}; + +/* This struct holds individual buffers received for each port */ +struct virtio_console_port_buffer { + struct list_head next; -/* This is our input buffer, and how much data is left in it. */ -static unsigned int in_len; -static char *in, *inbuf; + char *buf; + + size_t len; /* length of the buffer */ + size_t offset; /* offset in the buf from which to consume data */ +}; + +struct virtio_console_port { + /* Next port in the list */ + struct list_head next; + + /* Buffer management */ + struct virtio_console_port_buffer read_buf; + struct list_head readbuf_head; + wait_queue_head_t waitqueue; + + /* Each port associates with a separate char device */ + struct cdev cdev; + struct device *dev; + + bool host_connected; /* Is the host device open */ +}; + +static struct virtio_console_struct virtconsole; + +static int major = 60; /* from the experimental range */ /* The operations for our console. */ +/* FIXME: this should go into the per-port struct */ static struct hv_ops virtio_cons; /* The hvc device */ static struct hvc_struct *hvc; -/*D:310 The put_chars() callback is pretty straightforward. +static struct virtio_console_port *get_port_from_id(u32 id) +{ + struct virtio_console_port *port; + + list_for_each_entry(port, &virtconsole.port_head, next) { + if (MINOR(port->dev->devt) == id) + return port; + } + return NULL; +} + +static int get_id_from_port(struct virtio_console_port *port) +{ + return MINOR(port->dev->devt); +} + +static inline bool use_multiport(void) +{ + return virtconsole.vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT); +} + +static ssize_t fill_readbuf(struct virtio_console_port *port, + char *out_buf, size_t out_count, bool to_user) +{ + struct virtio_console_port_buffer *buf, *buf2; + ssize_t out_offset, ret; + + out_offset = 0; + list_for_each_entry_safe(buf, buf2, &port->readbuf_head, next) { + size_t copy_size; + + copy_size = out_count; + if (copy_size > buf->len - buf->offset) + copy_size = buf->len - buf->offset; + + if (to_user) { + ret = copy_to_user(out_buf + out_offset, + buf->buf + buf->offset, + copy_size); + /* FIXME: Deal with ret != 0 */ + } else { + memcpy(out_buf + out_offset, + buf->buf + buf->offset, + copy_size); + ret = 0; /* Emulate copy_to_user behaviour */ + } + + /* Return the number of bytes actually copied */ + ret = copy_size - ret; + buf->offset += ret; + out_offset += ret; + out_count -= ret; + + if (buf->len - buf->offset == 0) { + list_del(&buf->next); + kfree(buf->buf); + kfree(buf); + } + if (!out_count) + break; + } + return out_offset; +} + +static ssize_t virtconsole_read(struct file *filp, char __user *ubuf, + size_t count, loff_t *offp) +{ + struct virtio_console_port *port; + ssize_t ret; + + port = filp->private_data; + + ret = 0; + if (list_empty(&port->readbuf_head)) { + if (filp->f_flags & O_NONBLOCK) + return -EAGAIN; + + ret = wait_event_interruptible(port->waitqueue, + !list_empty(&port->readbuf_head)); + } + if (ret < 0) + return ret; + + return fill_readbuf(port, ubuf, count, true); +} + +/* For data that exceeds PAGE_SIZE in size we should send it all in + * one sg to not unnecessarily split up the data. Also some (all?) + * vnc clients don't consume split data. * - * 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) + * If we are to keep PAGE_SIZE sized buffers, we then have to stack + * multiple of those in one virtio request. virtio-ring returns to us + * just one pointer for all the buffers. So use this struct to + * allocate the bufs in so that freeing this up later is easier. + */ +struct vbuf { + char **bufs; + struct scatterlist *sg; + unsigned int nent; +}; + +static ssize_t send_buf(struct virtio_console_port *port, + const char *in_buf, size_t in_count, + bool from_user, bool internal) { - struct scatterlist sg[1]; - unsigned int len; - - /* This is a convenient routine to initialize a single-elem sg list */ - sg_init_one(sg, buf, count); - - /* 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(); + struct virtqueue *out_vq; + struct virtio_console_header header; + struct vbuf *vbuf; + size_t in_offset, copy_size; + ssize_t ret; + unsigned int i, header_len; + + if (!in_count) + return 0; + + out_vq = virtconsole.out_vq; + + /* We can't send internal messages to a host that won't understand it */ + if (!use_multiport() && internal) { + return 0; + } + header_len = 0; + if (use_multiport()) { + header.id = get_id_from_port(port); + header.internal_message = internal; + header_len = sizeof(header); + } + ret = -ENOMEM; + vbuf = kzalloc(sizeof(struct vbuf), GFP_KERNEL); + if (!vbuf) + return ret; + + /* Max. number of buffers clubbed together in one message */ + vbuf->nent = (in_count + header_len + PAGE_SIZE - 1) / PAGE_SIZE; + + vbuf->bufs = kzalloc(sizeof(char *) * vbuf->nent, GFP_KERNEL); + if (!vbuf->bufs) + goto free_vbuf; + + vbuf->sg = kzalloc(sizeof(struct scatterlist) * vbuf->nent, GFP_KERNEL); + if (!vbuf->sg) + goto free_bufs; + sg_init_table(vbuf->sg, vbuf->nent); + + i = 0; /* vbuf->bufs[i] */ + in_offset = 0; /* offset in the user buffer */ + while (in_count - in_offset) { + copy_size = min(in_count - in_offset + header_len, PAGE_SIZE); + vbuf->bufs[i] = kzalloc(copy_size, GFP_KERNEL); + if (!vbuf->bufs[i]) { + ret = -ENOMEM; + if (!i) + goto free_sg; + goto free_buffers; + } + if (header_len) { + memcpy(vbuf->bufs[i], &header, header_len); + copy_size -= header_len; + } + if (from_user) + ret = copy_from_user(vbuf->bufs[i] + header_len, + in_buf + in_offset, copy_size); + else { + /* Since we're not sure when the host will actually + * consume the data and tell us about it, we have + * to copy the data here in case the caller + * frees the in_buf + */ + memcpy(vbuf->bufs[i] + header_len, + in_buf + in_offset, copy_size); + ret = 0; /* Emulate copy_from_user */ + } + in_offset += copy_size - ret; + + sg_set_buf(&vbuf->sg[i], vbuf->bufs[i], + copy_size - ret + header_len); + header_len = 0; /* Pass the header only in the first buffer */ + i++; + } + if (out_vq->vq_ops->add_buf(out_vq, vbuf->sg, i, 0, vbuf)) { + ret = -EIO; + goto free_buffers; } + /* Tell Host to go! */ + out_vq->vq_ops->kick(out_vq); + + /* We're expected to return the amount of data we wrote */ + return in_offset; +free_buffers: + while (--i >= 0) + kfree(vbuf->bufs[i]); +free_sg: + kfree(vbuf->sg); +free_bufs: + kfree(vbuf->bufs); +free_vbuf: + kfree(vbuf); + return ret; +} + +static ssize_t virtconsole_write(struct file *filp, const char __user *ubuf, + size_t count, loff_t *offp) +{ + struct virtio_console_port *port; - /* We're expected to return the amount of data we wrote: all of it. */ - return count; + port = filp->private_data; + + return send_buf(port, ubuf, count, 1, 0); } -/* Create a scatter-gather list representing our input buffer and put it in the - * queue. */ -static void add_inbuf(void) +static unsigned int virtconsole_poll(struct file *filp, poll_table *wait) { - struct scatterlist sg[1]; - sg_init_one(sg, inbuf, PAGE_SIZE); + struct virtio_console_port *port; + unsigned int ret; + + port = filp->private_data; + poll_wait(filp, &port->waitqueue, wait); - /* 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); + ret = 0; + if (!list_empty(&port->readbuf_head)) + ret |= POLLIN | POLLRDNORM; + + return ret; } -/*D:350 get_chars() is the callback from the hvc_console infrastructure when - * an interrupt is received. +static int virtconsole_release(struct inode *inode, struct file *filp) +{ + struct virtio_console_control cpkt; + + /* Notify host of port being closed */ + cpkt.event = VIRTIO_CONSOLE_PORT_OPEN; + cpkt.value = 0; + send_buf(filp->private_data, (char *)&cpkt, sizeof(cpkt), false, true); + + return 0; +} + +static int virtconsole_open(struct inode *inode, struct file *filp) +{ + struct cdev *cdev = inode->i_cdev; + struct virtio_console_port *port; + struct virtio_console_control cpkt; + + port = container_of(cdev, struct virtio_console_port, cdev); + filp->private_data = port; + + /* Notify host of port being opened */ + cpkt.event = VIRTIO_CONSOLE_PORT_OPEN; + cpkt.value = 1; + send_buf(filp->private_data, (char *)&cpkt, sizeof(cpkt), false, true); + + return 0; +} + +static const struct file_operations virtconsole_fops = { + .owner = THIS_MODULE, + .open = virtconsole_open, + .read = virtconsole_read, + .write = virtconsole_write, + .poll = virtconsole_poll, + .release = virtconsole_release, +}; + +/*D:310 The cons_put_chars() callback is pretty straightforward. + * + * 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 cons_put_chars(u32 vtermno, const char *buf, int count) +{ + struct virtio_console_port *port; + + port = get_port_from_id(vtermno); + if (!port) + return 0; + + return send_buf(port, buf, count, false, false); +} + +/*D:350 cons_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 int cons_get_chars(u32 vtermno, char *buf, int count) { - /* If we don't have an input queue yet, we can't get input. */ - BUG_ON(!in_vq); + struct virtio_console_port *port; - /* No buffer? Try to get one. */ - if (!in_len) { - in = in_vq->vq_ops->get_buf(in_vq, &in_len); - if (!in) - return 0; - } + /* If we don't have an input queue yet, we can't get input. */ + BUG_ON(!virtconsole.in_vq); - /* You want more than we have to give? Well, try wanting less! */ - if (in_len < count) - count = in_len; + port = get_port_from_id(vtermno); + if (!port) + return 0; - /* Copy across to their buffer and increment offset. */ - memcpy(buf, in, count); - in += count; - in_len -= count; + if (list_empty(&port->readbuf_head)) + return 0; - /* Finished? Re-register buffer so Host will use it again. */ - if (in_len == 0) - add_inbuf(); + return fill_readbuf(port, buf, count, false); - return count; } /*:*/ @@ -160,23 +435,317 @@ static void virtcons_apply_config(struct virtio_device *dev) * 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 */ -static int notifier_add_vio(struct hvc_struct *hp, int data) +static int cons_notifier_add_vio(struct hvc_struct *hp, int data) { hp->irq_requested = 1; - virtcons_apply_config(vdev); + virtcons_apply_config(virtconsole.vdev); return 0; } -static void notifier_del_vio(struct hvc_struct *hp, int data) +static void cons_notifier_del_vio(struct hvc_struct *hp, int data) { hp->irq_requested = 0; } -static void hvc_handle_input(struct virtqueue *vq) +static void fill_queue(struct virtqueue *vq, size_t buf_size, + struct list_head *unused_head) { - if (hvc_poll(hvc)) + struct scatterlist sg[1]; + struct virtio_console_port_buffer *buf; + + while (1) { + /* We have to keep track of the unused buffers + * so that they can be freed when the module + * is being removed + */ + buf = kzalloc(sizeof(*buf), GFP_KERNEL); + if (!buf) + break; + buf->buf = kzalloc(buf_size, GFP_KERNEL); + if (!buf->buf) { + kfree(buf); + break; + } + sg_init_one(sg, buf->buf, buf_size); + + if (vq->vq_ops->add_buf(vq, sg, 0, 1, buf->buf) < 0) { + kfree(buf->buf); + kfree(buf); + break; + } + list_add_tail(&buf->next, unused_head); + } + vq->vq_ops->kick(vq); +} + +static void fill_receive_queue(void) +{ + fill_queue(virtconsole.in_vq, PAGE_SIZE, &virtconsole.unused_read_head); +} + +static void handle_control_message(struct virtio_console_port *port, + struct virtio_console_control *cpkt) +{ + switch (cpkt->event) { + case VIRTIO_CONSOLE_PORT_OPEN: + port->host_connected = cpkt->value; + break; + } +} + +static void virtio_console_rx_work_handler(struct work_struct *work) +{ + struct virtio_console_port *port = NULL; + struct virtio_console_port_buffer *buf; + struct virtio_console_header header; + struct virtqueue *vq; + char *tmpbuf; + unsigned int tmplen, header_len; + + header_len = use_multiport() ? sizeof(header) : 0; + + vq = virtconsole.in_vq; + while ((tmpbuf = vq->vq_ops->get_buf(vq, &tmplen))) { + list_for_each_entry(buf, &virtconsole.unused_read_head, next) { + if (tmpbuf == buf->buf) + break; + } + BUG_ON(!buf); + /* The buffer is no longer unused */ + list_del(&buf->next); + + if (use_multiport()) { + memcpy(&header, buf->buf, header_len); + port = get_port_from_id(header.id); + } else + port = get_port_from_id(VIRTIO_CONSOLE_CONSOLE_PORT); + if (!port) { + /* No valid index at start of + * buffer. Drop it. + */ + pr_debug("%s: invalid index in buffer, %c %d\n", + __func__, buf->buf[0], buf->buf[0]); + kfree(buf->buf); + kfree(buf); + break; + } + if (use_multiport() && header.internal_message) { + handle_control_message(port, + (struct virtio_console_control *) + (tmpbuf + header_len)); + + /* FIXME: This buffer can be added to the + * unused list to avoid free/alloc + */ + kfree(buf->buf); + kfree(buf); + } else { + buf->len = tmplen; + buf->offset = header_len; + list_add_tail(&buf->next, &port->readbuf_head); + } + wake_up_interruptible(&port->waitqueue); + } + + if (get_id_from_port(port) == VIRTIO_CONSOLE_CONSOLE_PORT && hvc_poll(hvc)) hvc_kick(); + + /* Allocate buffers for all the ones that got used up */ + fill_receive_queue(); +} + +static void virtio_console_tx_work_handler(struct work_struct *work) +{ + struct virtqueue *vq; + struct vbuf *vbuf; + unsigned int tmplen; + unsigned int i; + + vq = virtconsole.out_vq; + while ((vbuf = vq->vq_ops->get_buf(vq, &tmplen))) { + for (i = 0; i < vbuf->nent; i++) { + kfree(vbuf->bufs[i]); + } + kfree(vbuf->bufs); + kfree(vbuf->sg); + kfree(vbuf); + } +} + +static void rx_intr(struct virtqueue *vq) +{ + schedule_work(&virtconsole.rx_work); +} + +static void tx_intr(struct virtqueue *vq) +{ + schedule_work(&virtconsole.tx_work); +} + +static void config_intr(struct virtio_device *vdev) +{ + /* Handle port hot-add */ + schedule_work(&virtconsole.config_work); + + /* Handle console size changes */ + virtcons_apply_config(vdev); +} + +static u32 virtconsole_get_hot_add_port(struct virtio_console_config *config) +{ + u32 i; + u32 port_nr; + + for (i = 0; i < virtconsole.config->max_nr_ports / 32; i++) { + port_nr = ffs(config->ports_map[i] ^ virtconsole.config->ports_map[i]); + if (port_nr) + break; + } + if (unlikely(!port_nr)) + return VIRTIO_CONSOLE_BAD_ID; + + /* We used ffs above */ + port_nr--; + + /* FIXME: Do this only when add_port is successful */ + virtconsole.config->ports_map[i] |= 1U << port_nr; + + port_nr += i * 32; + return port_nr; +} + +static u32 virtconsole_find_next_port(u32 *map, int *map_i) +{ + u32 port_nr; + + while (1) { + port_nr = ffs(*map); + if (port_nr) + break; + + if (unlikely(*map_i >= virtconsole.config->max_nr_ports / 32)) + return VIRTIO_CONSOLE_BAD_ID; + ++*map_i; + *map = virtconsole.config->ports_map[*map_i]; + } + /* We used ffs above */ + port_nr--; + + /* FIXME: Do this only when add_port is successful / reset bit + * in config space if add_port was unsuccessful + */ + *map &= ~(1U << port_nr); + + port_nr += *map_i * 32; + return port_nr; +} + +static int virtconsole_add_port(u32 port_nr) +{ + struct virtio_console_port *port; + dev_t devt; + int ret; + + port = kzalloc(sizeof(*port), GFP_KERNEL); + if (!port) + return -ENOMEM; + + devt = MKDEV(major, port_nr); + cdev_init(&port->cdev, &virtconsole_fops); + + ret = register_chrdev_region(devt, 1, "virtio-console"); + if (ret < 0) { + pr_err("%s: error registering chrdev region, ret = %d\n", + __func__, ret); + goto free_cdev; + } + ret = cdev_add(&port->cdev, devt, 1); + if (ret < 0) { + pr_err("%s: error adding cdev, ret = %d\n", __func__, ret); + goto free_cdev; + } + port->dev = device_create(virtconsole.class, NULL, devt, NULL, + "vcon%u", port_nr); + if (IS_ERR(port->dev)) { + ret = PTR_ERR(port->dev); + pr_err("%s: Error creating device, ret = %d\n", __func__, ret); + goto free_cdev; + } + INIT_LIST_HEAD(&port->readbuf_head); + init_waitqueue_head(&port->waitqueue); + + list_add_tail(&port->next, &virtconsole.port_head); + + if (port_nr == VIRTIO_CONSOLE_CONSOLE_PORT) { + /* Start using the new console output. */ + virtio_cons.get_chars = cons_get_chars; + virtio_cons.put_chars = cons_put_chars; + virtio_cons.notifier_add = cons_notifier_add_vio; + virtio_cons.notifier_del = cons_notifier_del_vio; + virtio_cons.notifier_hangup = cons_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)) { + ret = PTR_ERR(hvc); + goto free_cdev; + } + } + pr_info("virtio-console port found at id %u\n", port_nr); + + return 0; +free_cdev: + unregister_chrdev(major, "virtio-console"); + return ret; +} + +static u32 get_ports_map_size(u32 max_ports) +{ + return sizeof(u32) * ((max_ports + 31) / 32); +} + +static void virtio_console_config_work_handler(struct work_struct *work) +{ + struct virtio_console_config *virtconconf; + struct virtio_device *vdev = virtconsole.vdev; + u32 i, port_nr; + int ret; + + virtconconf = kzalloc(sizeof(*virtconconf) + + get_ports_map_size(virtconsole.config->max_nr_ports), + GFP_KERNEL); + vdev->config->get(vdev, + offsetof(struct virtio_console_config, nr_active_ports), + &virtconconf->nr_active_ports, + sizeof(virtconconf->nr_active_ports)); + vdev->config->get(vdev, + offsetof(struct virtio_console_config, ports_map), + virtconconf->ports_map, + get_ports_map_size(virtconsole.config->max_nr_ports)); + + /* Hot-add ports */ + for (i = virtconsole.config->nr_active_ports; + i < virtconconf->nr_active_ports; i++) { + port_nr = virtconsole_get_hot_add_port(virtconconf); + if (port_nr == VIRTIO_CONSOLE_BAD_ID) + continue; + ret = virtconsole_add_port(port_nr); + if (!ret) + virtconsole.config->nr_active_ports++; + } + kfree(virtconconf); } /*D:370 Once we're further in boot, we get probed like any other virtio device. @@ -186,64 +755,132 @@ static void hvc_handle_input(struct virtqueue *vq) * 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 int __devinit virtcons_probe(struct virtio_device *vdev) { - vq_callback_t *callbacks[] = { hvc_handle_input, NULL}; + vq_callback_t *callbacks[] = { rx_intr, tx_intr }; const char *names[] = { "input", "output" }; struct virtqueue *vqs[2]; - int err; - - vdev = dev; - - /* This is the scratch page we use to receive console input */ - inbuf = kmalloc(PAGE_SIZE, GFP_KERNEL); - if (!inbuf) { - err = -ENOMEM; - goto fail; + u32 i, map; + int ret, map_i; + u32 max_nr_ports; + bool multiport; + + virtconsole.vdev = vdev; + + multiport = false; + if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) { + multiport = true; + vdev->features[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT; + vdev->config->finalize_features(vdev); + + vdev->config->get(vdev, + offsetof(struct virtio_console_config, + max_nr_ports), + &max_nr_ports, + sizeof(max_nr_ports)); + virtconsole.config = kzalloc(sizeof(struct virtio_console_config) + + get_ports_map_size(max_nr_ports), + GFP_KERNEL); + if (!virtconsole.config) + return -ENOMEM; + virtconsole.config->max_nr_ports = max_nr_ports; + + vdev->config->get(vdev, offsetof(struct virtio_console_config, + nr_active_ports), + &virtconsole.config->nr_active_ports, + sizeof(virtconsole.config->nr_active_ports)); + vdev->config->get(vdev, + offsetof(struct virtio_console_config, + ports_map), + virtconsole.config->ports_map, + get_ports_map_size(max_nr_ports)); } /* 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); - if (err) - goto free; + ret = vdev->config->find_vqs(vdev, 2, vqs, callbacks, names); + if (ret) + goto fail; - in_vq = vqs[0]; - out_vq = vqs[1]; + virtconsole.in_vq = vqs[0]; + virtconsole.out_vq = vqs[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; - } + INIT_LIST_HEAD(&virtconsole.port_head); + INIT_LIST_HEAD(&virtconsole.unused_read_head); + + if (multiport) { + map_i = 0; + map = virtconsole.config->ports_map[map_i]; + for (i = 0; i < virtconsole.config->nr_active_ports; i++) { + u32 port_nr; + + port_nr = virtconsole_find_next_port(&map, &map_i); + if (unlikely(port_nr == VIRTIO_CONSOLE_BAD_ID)) + continue; + virtconsole_add_port(port_nr); + } + } else + virtconsole_add_port(VIRTIO_CONSOLE_CONSOLE_PORT); + + INIT_WORK(&virtconsole.rx_work, &virtio_console_rx_work_handler); + INIT_WORK(&virtconsole.tx_work, &virtio_console_tx_work_handler); + INIT_WORK(&virtconsole.config_work, &virtio_console_config_work_handler); - /* Register the input buffer the first time. */ - add_inbuf(); + fill_receive_queue(); return 0; -free_vqs: - vdev->config->del_vqs(vdev); -free: - kfree(inbuf); fail: - return err; + return ret; +} + +static void virtconsole_remove_port_data(struct virtio_console_port *port) +{ + struct virtio_console_port_buffer *buf, *buf2; + + device_destroy(virtconsole.class, port->dev->devt); + unregister_chrdev_region(port->dev->devt, 1); + cdev_del(&port->cdev); + + /* Remove the buffers in which we have unconsumed data */ + list_for_each_entry_safe(buf, buf2, &port->readbuf_head, next) { + list_del(&buf->next); + kfree(buf->buf); + kfree(buf); + } +} + +static void virtconsole_remove(struct virtio_device *vdev) +{ + struct virtio_console_port *port, *port2; + struct virtio_console_port_buffer *buf, *buf2; + char *tmpbuf; + int len; + + unregister_chrdev(major, "virtio-console"); + class_destroy(virtconsole.class); + + cancel_work_sync(&virtconsole.rx_work); + + /* Free up the buffers in the 'received' queue */ + while ((tmpbuf = virtconsole.in_vq->vq_ops->get_buf(virtconsole.in_vq, + &len))) + kfree(tmpbuf); + + vdev->config->del_vqs(vdev); + + /* Free up the buffers that were unused */ + list_for_each_entry_safe(buf, buf2, &virtconsole.unused_read_head, next) { + list_del(&buf->next); + kfree(buf->buf); + kfree(buf); + } + list_for_each_entry_safe(port, port2, &virtconsole.port_head, next) { + list_del(&port->next); + virtconsole_remove_port_data(port); + kfree(port); + } + kfree(virtconsole.config); } static struct virtio_device_id id_table[] = { @@ -253,6 +890,7 @@ 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 = { @@ -262,12 +900,25 @@ 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) { - return register_virtio_driver(&virtio_console); + int ret; + + virtconsole.class = class_create(THIS_MODULE, "virtio-console"); + if (IS_ERR(virtconsole.class)) { + pr_err("Error creating virtio-console class\n"); + ret = PTR_ERR(virtconsole.class); + return ret; + } + ret = register_virtio_driver(&virtio_console); + if (ret) { + class_destroy(virtconsole.class); + return ret; + } + return 0; } module_init(init); diff --git a/include/linux/virtio_console.h b/include/linux/virtio_console.h index dc16111..2197e37 100644 --- a/include/linux/virtio_console.h +++ b/include/linux/virtio_console.h @@ -10,14 +10,41 @@ /* Feature bits */ #define VIRTIO_CONSOLE_F_SIZE 0 /* Does host provide console size? */ +#define VIRTIO_CONSOLE_F_MULTIPORT 1 /* Does host provide multiple ports? */ + +#define VIRTIO_CONSOLE_BAD_ID (~(u32)0) /* Invalid port number */ + +/* Port at which the virtio console is spawned */ +#define VIRTIO_CONSOLE_CONSOLE_PORT 0 struct virtio_console_config { /* colums of the screens */ __u16 cols; /* rows of the screens */ __u16 rows; + /* max. number of ports supported for each PCI device */ + __u32 max_nr_ports; + /* number of ports in use */ + __u32 nr_active_ports; + /* locations of the ports in use */ + __u32 ports_map[0 /* (max_nr_ports + 31) / 32 */]; +} __attribute__((packed)); + +struct virtio_console_control { + __u16 event; + __u16 value; +}; + +/* This struct is put in each buffer that gets passed to userspace and + * vice-versa + */ +struct virtio_console_header { + u32 id; /* Port number */ + bool internal_message; /* Some message between host and guest */ } __attribute__((packed)); +/* Some events for internal messages */ +#define VIRTIO_CONSOLE_PORT_OPEN 0 #ifdef __KERNEL__ int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int));