From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rusty Russell Subject: [PATCH 4/4] virtio: disable multiport console support. Date: Tue, 30 Mar 2010 15:49:43 +1030 Message-ID: <201003301549.43186.rusty@rustcorp.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Amit Shah Cc: "Michael S. Tsirkin" , virtualization@lists.linux-foundation.org List-Id: virtualization@lists.linuxfoundation.org Unfortunately there proved to be at least one bug which requires an ABI change, so we're best off not introducing multiport support until 2.6.35. While I generally left the multiport code paths intact, I really wanted to remove the ABI defines from the header, which meant some quite deep cuts. Signed-off-by: Rusty Russell To: Amit Shah --- drivers/char/virtio_console.c | 274 ----------------------------------------- include/linux/virtio_console.h | 19 -- 2 files changed, 4 insertions(+), 289 deletions(-) diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -252,15 +252,10 @@ static bool is_console_port(struct port return false; } +/* This is incomplete. */ 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); + return false; } static void free_buf(struct port_buffer *buf) @@ -373,31 +368,8 @@ out: return ret; } -static ssize_t send_control_msg(struct port *port, unsigned int event, - unsigned int value) -{ - struct scatterlist sg[1]; - struct virtio_console_control cpkt; - struct virtqueue *vq; - unsigned int len; - - if (!use_multiport(port->portdev)) - return 0; - - cpkt.id = port->id; - cpkt.event = event; - cpkt.value = value; - - 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; -} +/* For when we support control messages. */ +#define send_control_msg(port, event, value) 0 static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count) { @@ -882,142 +854,6 @@ static int remove_port(struct port *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); - } else { - /* - * Generate a udev event so that appropriate - * symlinks can be created based on udev - * rules. - */ - kobject_uevent(&port->dev->kobj, KOBJ_CHANGE); - } - 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) -{ - 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; @@ -1206,62 +1042,6 @@ 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; @@ -1385,7 +1165,6 @@ static int __devinit virtcons_probe(stru struct ports_device *portdev; u32 i; int err; - bool multiport; portdev = kmalloc(sizeof(*portdev), GFP_KERNEL); if (!portdev) { @@ -1411,32 +1190,8 @@ static int __devinit virtcons_probe(stru 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); @@ -1449,22 +1204,6 @@ static int __devinit virtcons_probe(stru spin_lock_init(&portdev->ports_lock); INIT_LIST_HEAD(&portdev->ports); - if (multiport) { - unsigned int nr_added_bufs; - - spin_lock_init(&portdev->cvq_lock); - INIT_WORK(&portdev->control_work, &control_work_handler); - INIT_WORK(&portdev->config_work, &config_work_handler); - - nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock); - if (!nr_added_bufs) { - dev_err(&vdev->dev, - "Error allocating buffers for control queue\n"); - err = -ENOMEM; - goto free_vqs; - } - } - for (i = 0; i < portdev->config.nr_ports; i++) add_port(portdev, i); @@ -1472,10 +1211,6 @@ static int __devinit virtcons_probe(stru early_put_chars = NULL; return 0; -free_vqs: - vdev->config->del_vqs(vdev); - kfree(portdev->in_vqs); - kfree(portdev->out_vqs); free_chrdev: unregister_chrdev(portdev->chr_major, "virtio-portsdev"); free: @@ -1521,7 +1256,6 @@ 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 = { diff --git a/include/linux/virtio_console.h b/include/linux/virtio_console.h --- a/include/linux/virtio_console.h +++ b/include/linux/virtio_console.h @@ -12,7 +12,6 @@ /* 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 */ @@ -25,24 +24,6 @@ struct virtio_console_config { __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)); #endif /* __KERNEL__ */