From df660251eb534649f90f9dcfe1da1cef4ea48a3e Mon Sep 17 00:00:00 2001 From: Ian Campbell Date: Mon, 9 Feb 2009 12:05:51 -0800 Subject: xen: add backend driver support Impact: backend device support Add the basic machinery to support backend drivers. Signed-off-by: Ian Campbell Signed-off-by: Jeremy Fitzhardinge [corresponds to 79727b851bac in git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen.git] Signed-off-by: Konrad Rzeszutek Wilk --- drivers/xen/Kconfig | 8 + drivers/xen/xenbus/Makefile | 3 + drivers/xen/xenbus/xenbus_comms.c | 1 + drivers/xen/xenbus/xenbus_probe.c | 13 +- drivers/xen/xenbus/xenbus_probe.h | 1 - drivers/xen/xenbus/xenbus_probe_backend.c | 300 +++++++++++++++++++++++++++++ drivers/xen/xenbus/xenbus_probe_frontend.c | 39 +++- include/xen/xenbus.h | 2 +- 8 files changed, 345 insertions(+), 22 deletions(-) create mode 100644 drivers/xen/xenbus/xenbus_probe_backend.c diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig index 10b6bef2e217..84bf17bbb1cd 100644 --- a/drivers/xen/Kconfig +++ b/drivers/xen/Kconfig @@ -29,6 +29,14 @@ config XEN_DEV_EVTCHN firing. If in doubt, say yes. +config XEN_BACKEND + tristate "Backend driver support" + depends on XEN_DOM0 + default y + help + Support for backend device drivers that provide I/O services + to other virtual machines. + config XENFS tristate "Xen filesystem" default y diff --git a/drivers/xen/xenbus/Makefile b/drivers/xen/xenbus/Makefile index 33e8cf8149b3..8dca685358b4 100644 --- a/drivers/xen/xenbus/Makefile +++ b/drivers/xen/xenbus/Makefile @@ -6,4 +6,7 @@ xenbus-objs += xenbus_comms.o xenbus-objs += xenbus_xs.o xenbus-objs += xenbus_probe.o +xenbus-be-objs-$(CONFIG_XEN_BACKEND) += xenbus_probe_backend.o +xenbus-objs += $(xenbus-be-objs-y) + obj-$(CONFIG_XEN_XENBUS_FRONTEND) += xenbus_probe_frontend.o diff --git a/drivers/xen/xenbus/xenbus_comms.c b/drivers/xen/xenbus/xenbus_comms.c index 090c61ee8fd0..700dc7714838 100644 --- a/drivers/xen/xenbus/xenbus_comms.c +++ b/drivers/xen/xenbus/xenbus_comms.c @@ -49,6 +49,7 @@ static DECLARE_WAIT_QUEUE_HEAD(xb_waitq); static irqreturn_t wake_waiting(int irq, void *unused) { if (unlikely(xenstored_ready == 0)) { + printk(KERN_CRIT "xenbus_probe wake_waiting\n"); xenstored_ready = 1; schedule_work(&probe_work); } diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c index d46205868b88..b09eb17ba007 100644 --- a/drivers/xen/xenbus/xenbus_probe.c +++ b/drivers/xen/xenbus/xenbus_probe.c @@ -95,17 +95,6 @@ int xenbus_match(struct device *_dev, struct device_driver *_drv) EXPORT_SYMBOL_GPL(xenbus_match); -int xenbus_uevent(struct device *_dev, struct kobj_uevent_env *env) -{ - struct xenbus_device *dev = to_xenbus_device(_dev); - - if (add_uevent_var(env, "MODALIAS=xen:%s", dev->devicetype)) - return -ENOMEM; - - return 0; -} -EXPORT_SYMBOL_GPL(xenbus_uevent); - static void free_otherend_details(struct xenbus_device *dev) { kfree(dev->otherend); @@ -690,6 +679,8 @@ void xenbus_probe(struct work_struct *unused) { xenstored_ready = 1; + printk(KERN_CRIT "xenbus_probe wake_waiting\n"); + /* Notify others that xenstore is up */ blocking_notifier_call_chain(&xenstore_chain, 0, NULL); } diff --git a/drivers/xen/xenbus/xenbus_probe.h b/drivers/xen/xenbus/xenbus_probe.h index be390cef329f..0e5fc4c63eb2 100644 --- a/drivers/xen/xenbus/xenbus_probe.h +++ b/drivers/xen/xenbus/xenbus_probe.h @@ -60,7 +60,6 @@ extern int xenbus_probe_devices(struct xen_bus_type *bus); extern void xenbus_dev_changed(const char *node, struct xen_bus_type *bus); -extern int xenbus_uevent(struct device *_dev, struct kobj_uevent_env *env); extern void xenbus_dev_shutdown(struct device *_dev); extern int xenbus_dev_suspend(struct device *dev, pm_message_t state); diff --git a/drivers/xen/xenbus/xenbus_probe_backend.c b/drivers/xen/xenbus/xenbus_probe_backend.c new file mode 100644 index 000000000000..7459ccee3c8b --- /dev/null +++ b/drivers/xen/xenbus/xenbus_probe_backend.c @@ -0,0 +1,300 @@ +/****************************************************************************** + * Talks to Xen Store to figure out what devices we have (backend half). + * + * Copyright (C) 2005 Rusty Russell, IBM Corporation + * Copyright (C) 2005 Mike Wray, Hewlett-Packard + * Copyright (C) 2005, 2006 XenSource Ltd + * Copyright (C) 2007 Solarflare Communications, Inc. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation; or, when distributed + * separately from the Linux kernel or incorporated into other + * software packages, subject to the following license: + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this source file (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, modify, + * merge, publish, distribute, sublicense, and/or sell copies of the Software, + * and to permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#define DPRINTK(fmt, args...) \ + pr_debug("xenbus_probe (%s:%d) " fmt ".\n", \ + __func__, __LINE__, ##args) + +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include + +#include "xenbus_comms.h" +#include "xenbus_probe.h" + +/* backend/// => -- */ +static int backend_bus_id(char bus_id[XEN_BUS_ID_SIZE], const char *nodename) +{ + int domid, err; + const char *devid, *type, *frontend; + unsigned int typelen; + + type = strchr(nodename, '/'); + if (!type) + return -EINVAL; + type++; + typelen = strcspn(type, "/"); + if (!typelen || type[typelen] != '/') + return -EINVAL; + + devid = strrchr(nodename, '/') + 1; + + err = xenbus_gather(XBT_NIL, nodename, "frontend-id", "%i", &domid, + "frontend", NULL, &frontend, + NULL); + if (err) + return err; + if (strlen(frontend) == 0) + err = -ERANGE; + if (!err && !xenbus_exists(XBT_NIL, frontend, "")) + err = -ENOENT; + kfree(frontend); + + if (err) + return err; + + if (snprintf(bus_id, XEN_BUS_ID_SIZE, + "%.*s-%i-%s", typelen, type, domid, devid) >= XEN_BUS_ID_SIZE) + return -ENOSPC; + return 0; +} + +static int xenbus_uevent_backend(struct device *dev, + struct kobj_uevent_env *env) +{ + struct xenbus_device *xdev; + struct xenbus_driver *drv; + struct xen_bus_type *bus; + + DPRINTK(""); + + if (dev == NULL) + return -ENODEV; + + xdev = to_xenbus_device(dev); + bus = container_of(xdev->dev.bus, struct xen_bus_type, bus); + if (xdev == NULL) + return -ENODEV; + + /* stuff we want to pass to /sbin/hotplug */ + if (add_uevent_var(env, "XENBUS_TYPE=%s", xdev->devicetype)) + return -ENOMEM; + + if (add_uevent_var(env, "XENBUS_PATH=%s", xdev->nodename)) + return -ENOMEM; + + if (add_uevent_var(env, "XENBUS_BASE_PATH=%s", bus->root)) + return -ENOMEM; + + if (dev->driver) { + drv = to_xenbus_driver(dev->driver); + if (drv && drv->uevent) + return drv->uevent(xdev, env); + } + + return 0; +} + +/* backend/// */ +static int xenbus_probe_backend_unit(struct xen_bus_type *bus, + const char *dir, + const char *type, + const char *name) +{ + char *nodename; + int err; + + nodename = kasprintf(GFP_KERNEL, "%s/%s", dir, name); + if (!nodename) + return -ENOMEM; + + DPRINTK("%s\n", nodename); + + err = xenbus_probe_node(bus, type, nodename); + kfree(nodename); + return err; +} + +/* backend// */ +static int xenbus_probe_backend(struct xen_bus_type *bus, const char *type, const char *domid) +{ + char *nodename; + int err = 0; + char **dir; + unsigned int i, dir_n = 0; + + DPRINTK(""); + + nodename = kasprintf(GFP_KERNEL, "%s/%s/%s", bus->root, type, domid); + if (!nodename) + return -ENOMEM; + + dir = xenbus_directory(XBT_NIL, nodename, "", &dir_n); + if (IS_ERR(dir)) { + kfree(nodename); + return PTR_ERR(dir); + } + + for (i = 0; i < dir_n; i++) { + err = xenbus_probe_backend_unit(bus, nodename, type, dir[i]); + if (err) + break; + } + kfree(dir); + kfree(nodename); + return err; +} + +static void frontend_changed(struct xenbus_watch *watch, + const char **vec, unsigned int len) +{ + xenbus_otherend_changed(watch, vec, len, 0); +} + +static struct device_attribute xenbus_backend_dev_attrs[] = { + __ATTR_NULL +}; + +static struct xen_bus_type xenbus_backend = { + .root = "backend", + .levels = 3, /* backend/type// */ + .get_bus_id = backend_bus_id, + .probe = xenbus_probe_backend, + .otherend_changed = frontend_changed, + .bus = { + .name = "xen-backend", + .match = xenbus_match, + .uevent = xenbus_uevent_backend, + .probe = xenbus_dev_probe, + .remove = xenbus_dev_remove, + .shutdown = xenbus_dev_shutdown, + .dev_attrs = xenbus_backend_dev_attrs, + }, +}; + +static void backend_changed(struct xenbus_watch *watch, + const char **vec, unsigned int len) +{ + DPRINTK(""); + + xenbus_dev_changed(vec[XS_WATCH_PATH], &xenbus_backend); +} + +static struct xenbus_watch be_watch = { + .node = "backend", + .callback = backend_changed, +}; + +static int read_frontend_details(struct xenbus_device *xendev) +{ + return xenbus_read_otherend_details(xendev, "frontend-id", "frontend"); +} + +//void xenbus_backend_suspend(int (*fn)(struct device *, void *)) +//{ +// DPRINTK(""); +// bus_for_each_dev(&xenbus_backend.bus, NULL, NULL, fn); +//} + +//void xenbus_backend_resume(int (*fn)(struct device *, void *)) +//{ +// DPRINTK(""); +// bus_for_each_dev(&xenbus_backend.bus, NULL, NULL, fn); +//} + +//int xenbus_for_each_backend(void *arg, int (*fn)(struct device *, void *)) +//{ +// return bus_for_each_dev(&xenbus_backend.bus, NULL, arg, fn); +//} +//EXPORT_SYMBOL_GPL(xenbus_for_each_backend); + +int xenbus_dev_is_online(struct xenbus_device *dev) +{ + int rc, val; + + rc = xenbus_scanf(XBT_NIL, dev->nodename, "online", "%d", &val); + if (rc != 1) + val = 0; /* no online node present */ + + return val; +} +EXPORT_SYMBOL_GPL(xenbus_dev_is_online); + +int __xenbus_register_backend(struct xenbus_driver *drv, + struct module *owner, const char *mod_name) +{ + drv->read_otherend_details = read_frontend_details; + + return xenbus_register_driver_common(drv, &xenbus_backend, + owner, mod_name); +} +EXPORT_SYMBOL_GPL(__xenbus_register_backend); + +static int backend_probe_and_watch(struct notifier_block *notifier, + unsigned long event, + void *data) +{ + /* Enumerate devices in xenstore and watch for changes. */ + xenbus_probe_devices(&xenbus_backend); + printk(KERN_CRIT "%s devices probed ok\n", __func__); + register_xenbus_watch(&be_watch); + printk(KERN_CRIT "%s watch add ok ok\n", __func__); + printk(KERN_CRIT "%s all done\n", __func__); + return NOTIFY_DONE; +} + +static int __init xenbus_probe_backend_init(void) +{ + static struct notifier_block xenstore_notifier = { + .notifier_call = backend_probe_and_watch + }; + int err; + + DPRINTK(""); + + /* Register ourselves with the kernel bus subsystem */ + err = bus_register(&xenbus_backend.bus); + if (err) { + printk(KERN_CRIT "%s didn't register bus!\n", __func__); + return err; + } + printk(KERN_CRIT "%s bus registered ok\n", __func__); + + register_xenstore_notifier(&xenstore_notifier); + + return 0; +} + +module_init(xenbus_probe_backend_init); diff --git a/drivers/xen/xenbus/xenbus_probe_frontend.c b/drivers/xen/xenbus/xenbus_probe_frontend.c index 04c4f0123521..dd31d5a43b40 100644 --- a/drivers/xen/xenbus/xenbus_probe_frontend.c +++ b/drivers/xen/xenbus/xenbus_probe_frontend.c @@ -62,6 +62,17 @@ static int xenbus_probe_frontend(struct xen_bus_type *bus, const char *type, con return err; } +static int xenbus_uevent_frontend(struct device *_dev, struct kobj_uevent_env *env) +{ + struct xenbus_device *dev = to_xenbus_device(_dev); + + if (add_uevent_var(env, "MODALIAS=xen:%s", dev->devicetype)) + return -ENOMEM; + + return 0; +} + + static void backend_changed(struct xenbus_watch *watch, const char **vec, unsigned int len) { @@ -81,7 +92,7 @@ static struct xen_bus_type xenbus_frontend = { .bus = { .name = "xen", .match = xenbus_match, - .uevent = xenbus_uevent, + .uevent = xenbus_uevent_frontend, .probe = xenbus_dev_probe, .remove = xenbus_dev_remove, .shutdown = xenbus_dev_shutdown, @@ -232,8 +243,25 @@ int __xenbus_register_frontend(struct xenbus_driver *drv, } EXPORT_SYMBOL_GPL(__xenbus_register_frontend); +static int frontend_probe_and_watch(struct notifier_block *notifier, + unsigned long event, + void *data) +{ + /* Enumerate devices in xenstore and watch for changes. */ + xenbus_probe_devices(&xenbus_frontend); + printk(KERN_CRIT "%s devices probed ok\n", __func__); + register_xenbus_watch(&fe_watch); + printk(KERN_CRIT "%s watch add ok ok\n", __func__); + printk(KERN_CRIT "%s all done\n", __func__); + return NOTIFY_DONE; +} + + static int __init xenbus_probe_frontend_init(void) { + static struct notifier_block xenstore_notifier = { + .notifier_call = frontend_probe_and_watch + }; int err; DPRINTK(""); @@ -246,14 +274,7 @@ static int __init xenbus_probe_frontend_init(void) } printk(KERN_CRIT "%s bus registered ok\n", __func__); - if (!xen_initial_domain()) { - /* Enumerate devices in xenstore and watch for changes. */ - xenbus_probe_devices(&xenbus_frontend); - printk(KERN_CRIT "%s devices probed ok\n", __func__); - register_xenbus_watch(&fe_watch); - printk(KERN_CRIT "%s watch add ok ok\n", __func__); - printk(KERN_CRIT "%s all done\n", __func__); - } + register_xenstore_notifier(&xenstore_notifier); return 0; } diff --git a/include/xen/xenbus.h b/include/xen/xenbus.h index 43e2d7d33976..7a1d15ff19b7 100644 --- a/include/xen/xenbus.h +++ b/include/xen/xenbus.h @@ -94,7 +94,7 @@ struct xenbus_driver { int (*remove)(struct xenbus_device *dev); int (*suspend)(struct xenbus_device *dev, pm_message_t state); int (*resume)(struct xenbus_device *dev); - int (*uevent)(struct xenbus_device *, char **, int, char *, int); + int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *); struct device_driver driver; int (*read_otherend_details)(struct xenbus_device *dev); int (*is_ready)(struct xenbus_device *dev); -- cgit v1.2.3