Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750905AbWCVGmt (ORCPT ); Wed, 22 Mar 2006 01:42:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750935AbWCVGmL (ORCPT ); Wed, 22 Mar 2006 01:42:11 -0500 Received: from 216-99-217-87.dsl.aracnet.com ([216.99.217.87]:1409 "EHLO sorel.sous-sol.org") by vger.kernel.org with ESMTP id S1750905AbWCVGin (ORCPT ); Wed, 22 Mar 2006 01:38:43 -0500 Message-Id: <20060322063807.597300000@sorel.sous-sol.org> References: <20060322063040.960068000@sorel.sous-sol.org> Date: Tue, 21 Mar 2006 22:31:13 -0800 From: Chris Wright To: linux-kernel@vger.kernel.org Cc: xen-devel@lists.xensource.com, virtualization@lists.osdl.org, Ian Pratt , Christian Limpach Subject: [RFC PATCH 33/35] Add the Xenbus sysfs and virtual device hotplug driver. Content-Disposition: inline; filename=32-xenbus Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 76932 Lines: 2919 This communicates with the machine control software via a registry residing in a controlling virtual machine. This allows dynamic creation, destruction and modification of virtual device configurations (network devices, block devices and CPUS, to name some examples). Signed-off-by: Ian Pratt Signed-off-by: Christian Limpach Signed-off-by: Chris Wright --- arch/i386/mach-xen/reboot.c | 6 drivers/xen/Makefile | 1 drivers/xen/xenbus/Makefile | 7 drivers/xen/xenbus/xenbus_client.c | 392 +++++++++++++ drivers/xen/xenbus/xenbus_comms.c | 201 ++++++ drivers/xen/xenbus/xenbus_comms.h | 40 + drivers/xen/xenbus/xenbus_probe.c | 1076 +++++++++++++++++++++++++++++++++++++ drivers/xen/xenbus/xenbus_xs.c | 827 ++++++++++++++++++++++++++++ include/xen/xenbus.h | 288 +++++++++ 9 files changed, 2832 insertions(+), 6 deletions(-) --- xen-subarch-2.6.orig/arch/i386/mach-xen/reboot.c +++ xen-subarch-2.6/arch/i386/mach-xen/reboot.c @@ -11,9 +11,7 @@ #include #include #include -#ifdef CONFIG_XEN_XENBUS #include -#endif #include #include #include @@ -71,14 +69,11 @@ EXPORT_SYMBOL(machine_power_off); * Stop/pickle callback handling. */ -#ifdef CONFIG_XEN_XENBUS /* Ignore multiple shutdown requests. */ static int shutting_down = SHUTDOWN_INVALID; static void __shutdown_handler(void *unused); static DECLARE_WORK(shutdown_work, __shutdown_handler, NULL); -#endif -#ifdef CONFIG_XEN_XENBUS static int shutdown_process(void *__unused) { static char *envp[] = { "HOME=/", "TERM=linux", @@ -262,4 +257,3 @@ static int __init setup_shutdown_event(v } subsys_initcall(setup_shutdown_event); -#endif --- xen-subarch-2.6.orig/drivers/xen/Makefile +++ xen-subarch-2.6/drivers/xen/Makefile @@ -2,3 +2,4 @@ obj-y += util.o obj-y += console/ +obj-y += xenbus/ --- /dev/null +++ xen-subarch-2.6/drivers/xen/xenbus/Makefile @@ -0,0 +1,7 @@ +obj-y += xenbus.o + +xenbus-objs = +xenbus-objs += xenbus_client.o +xenbus-objs += xenbus_comms.o +xenbus-objs += xenbus_xs.o +xenbus-objs += xenbus_probe.o --- /dev/null +++ xen-subarch-2.6/drivers/xen/xenbus/xenbus_client.c @@ -0,0 +1,392 @@ +/****************************************************************************** + * Client-facing interface for the Xenbus driver. In other words, the + * interface between the Xenbus and the device-specific code, be it the + * frontend or the backend of that driver. + * + * Copyright (C) 2005 XenSource Ltd + * + * This file may be 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. + */ + +#include +#include +#include +#include + +/* xenbus_probe.c */ +extern char *kasprintf(const char *fmt, ...); + +#define DPRINTK(fmt, args...) \ + pr_debug("xenbus_client (%s:%d) " fmt ".\n", __FUNCTION__, __LINE__, ##args) + +int xenbus_watch_path(struct xenbus_device *dev, const char *path, + struct xenbus_watch *watch, + void (*callback)(struct xenbus_watch *, + const char **, unsigned int)) +{ + int err; + + watch->node = path; + watch->callback = callback; + + err = register_xenbus_watch(watch); + + if (err) { + watch->node = NULL; + watch->callback = NULL; + xenbus_dev_fatal(dev, err, "adding watch on %s", path); + } + + return err; +} +EXPORT_SYMBOL(xenbus_watch_path); + + +int xenbus_watch_path2(struct xenbus_device *dev, const char *path, + const char *path2, struct xenbus_watch *watch, + void (*callback)(struct xenbus_watch *, + const char **, unsigned int)) +{ + int err; + char *state = kasprintf("%s/%s", path, path2); + if (!state) { + xenbus_dev_fatal(dev, -ENOMEM, "allocating path for watch"); + return -ENOMEM; + } + err = xenbus_watch_path(dev, state, watch, callback); + + if (err) + kfree(state); + return err; +} +EXPORT_SYMBOL(xenbus_watch_path2); + + +int xenbus_switch_state(struct xenbus_device *dev, + xenbus_transaction_t xbt, + XenbusState state) +{ + /* We check whether the state is currently set to the given value, and + if not, then the state is set. We don't want to unconditionally + write the given state, because we don't want to fire watches + unnecessarily. Furthermore, if the node has gone, we don't write + to it, as the device will be tearing down, and we don't want to + resurrect that directory. + */ + + int current_state; + int err; + + if (state == dev->state) + return 0; + + err = xenbus_scanf(xbt, dev->nodename, "state", "%d", + ¤t_state); + if (err != 1) + return 0; + + err = xenbus_printf(xbt, dev->nodename, "state", "%d", state); + if (err) { + if (state != XenbusStateClosing) /* Avoid looping */ + xenbus_dev_fatal(dev, err, "writing new state"); + return err; + } + + dev->state = state; + + return 0; +} +EXPORT_SYMBOL(xenbus_switch_state); + + +/** + * Return the path to the error node for the given device, or NULL on failure. + * If the value returned is non-NULL, then it is the caller's to kfree. + */ +static char *error_path(struct xenbus_device *dev) +{ + return kasprintf("error/%s", dev->nodename); +} + + +void _dev_error(struct xenbus_device *dev, int err, const char *fmt, + va_list ap) +{ + int ret; + unsigned int len; + char *printf_buffer = NULL, *path_buffer = NULL; + +#define PRINTF_BUFFER_SIZE 4096 + printf_buffer = kmalloc(PRINTF_BUFFER_SIZE, GFP_KERNEL); + if (printf_buffer == NULL) + goto fail; + + len = sprintf(printf_buffer, "%i ", -err); + ret = vsnprintf(printf_buffer+len, PRINTF_BUFFER_SIZE-len, fmt, ap); + + BUG_ON(len + ret > PRINTF_BUFFER_SIZE-1); + + dev_err(&dev->dev, "%s\n", printf_buffer); + + path_buffer = error_path(dev); + + if (path_buffer == NULL) { + printk("xenbus: failed to write error node for %s (%s)\n", + dev->nodename, printf_buffer); + goto fail; + } + + if (xenbus_write(XBT_NULL, path_buffer, "error", printf_buffer) != 0) { + printk("xenbus: failed to write error node for %s (%s)\n", + dev->nodename, printf_buffer); + goto fail; + } + +fail: + kfree(printf_buffer); + kfree(path_buffer); +} + + +void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, + ...) +{ + va_list ap; + + va_start(ap, fmt); + _dev_error(dev, err, fmt, ap); + va_end(ap); +} +EXPORT_SYMBOL(xenbus_dev_error); + + +void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, + ...) +{ + va_list ap; + + va_start(ap, fmt); + _dev_error(dev, err, fmt, ap); + va_end(ap); + + xenbus_switch_state(dev, XBT_NULL, XenbusStateClosing); +} +EXPORT_SYMBOL(xenbus_dev_fatal); + + +int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn) +{ + int err = gnttab_grant_foreign_access(dev->otherend_id, ring_mfn, 0); + if (err < 0) + xenbus_dev_fatal(dev, err, "granting access to ring page"); + return err; +} +EXPORT_SYMBOL(xenbus_grant_ring); + + +int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port) +{ + struct evtchn_op op = { + .cmd = EVTCHNOP_alloc_unbound, + .u.alloc_unbound.dom = DOMID_SELF, + .u.alloc_unbound.remote_dom = dev->otherend_id + }; + int err = HYPERVISOR_event_channel_op(&op); + if (err) + xenbus_dev_fatal(dev, err, "allocating event channel"); + else + *port = op.u.alloc_unbound.port; + return err; +} +EXPORT_SYMBOL(xenbus_alloc_evtchn); + + +int xenbus_bind_evtchn(struct xenbus_device *dev, int remote_port, int *port) +{ + struct evtchn_op op = { + .cmd = EVTCHNOP_bind_interdomain, + .u.bind_interdomain.remote_dom = dev->otherend_id, + .u.bind_interdomain.remote_port = remote_port, + }; + int err = HYPERVISOR_event_channel_op(&op); + if (err) + xenbus_dev_fatal(dev, err, + "binding to event channel %d from domain %d", + remote_port, dev->otherend_id); + else + *port = op.u.bind_interdomain.local_port; + return err; +} +EXPORT_SYMBOL(xenbus_bind_evtchn); + + +int xenbus_free_evtchn(struct xenbus_device *dev, int port) +{ + struct evtchn_op op = { + .cmd = EVTCHNOP_close, + .u.close.port = port, + }; + int err = HYPERVISOR_event_channel_op(&op); + if (err) + xenbus_dev_error(dev, err, "freeing event channel %d", port); + return err; +} + + +/* Based on Rusty Russell's skeleton driver's map_page */ +int xenbus_map_ring_valloc(struct xenbus_device *dev, int gnt_ref, void **vaddr) +{ + struct gnttab_map_grant_ref op = { + .flags = GNTMAP_host_map, + .ref = gnt_ref, + .dom = dev->otherend_id, + }; + struct vm_struct *area; + + *vaddr = NULL; + + area = alloc_vm_area(PAGE_SIZE); + if (!area) + return -ENOMEM; + + op.host_addr = (unsigned long)area->addr; + + lock_vm_area(area); + BUG_ON(HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1)); + unlock_vm_area(area); + + if (op.status != GNTST_okay) { + free_vm_area(area); + xenbus_dev_fatal(dev, op.status, + "mapping in shared page %d from domain %d", + gnt_ref, dev->otherend_id); + return op.status; + } + + /* Stuff the handle in an unused field */ + area->phys_addr = (unsigned long)op.handle; + + *vaddr = area->addr; + return 0; +} +EXPORT_SYMBOL(xenbus_map_ring_valloc); + + +int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref, + grant_handle_t *handle, void *vaddr) +{ + struct gnttab_map_grant_ref op = { + .host_addr = (unsigned long)vaddr, + .flags = GNTMAP_host_map, + .ref = gnt_ref, + .dom = dev->otherend_id, + }; + + BUG_ON(HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1)); + + if (op.status != GNTST_okay) { + xenbus_dev_fatal(dev, op.status, + "mapping in shared page %d from domain %d", + gnt_ref, dev->otherend_id); + } else + *handle = op.handle; + + return op.status; +} +EXPORT_SYMBOL(xenbus_map_ring); + + +/* Based on Rusty Russell's skeleton driver's unmap_page */ +int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr) +{ + struct vm_struct *area; + struct gnttab_unmap_grant_ref op = { + .host_addr = (unsigned long)vaddr, + }; + + /* It'd be nice if linux/vmalloc.h provided a find_vm_area(void *addr) + * method so that we don't have to muck with vmalloc internals here. + * We could force the user to hang on to their struct vm_struct from + * xenbus_map_ring_valloc, but these 6 lines considerably simplify + * this API. + */ + read_lock(&vmlist_lock); + for (area = vmlist; area != NULL; area = area->next) { + if (area->addr == vaddr) + break; + } + read_unlock(&vmlist_lock); + + if (!area) { + xenbus_dev_error(dev, -ENOENT, + "can't find mapped virtual address %p", vaddr); + return GNTST_bad_virt_addr; + } + + op.handle = (grant_handle_t)area->phys_addr; + + lock_vm_area(area); + BUG_ON(HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1)); + unlock_vm_area(area); + + if (op.status == GNTST_okay) + free_vm_area(area); + else + xenbus_dev_error(dev, op.status, + "unmapping page at handle %d error %d", + (int16_t)area->phys_addr, op.status); + + return op.status; +} +EXPORT_SYMBOL(xenbus_unmap_ring_vfree); + + +int xenbus_unmap_ring(struct xenbus_device *dev, + grant_handle_t handle, void *vaddr) +{ + struct gnttab_unmap_grant_ref op = { + .host_addr = (unsigned long)vaddr, + .handle = handle, + }; + + BUG_ON(HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1)); + + if (op.status != GNTST_okay) + xenbus_dev_error(dev, op.status, + "unmapping page at handle %d error %d", + handle, op.status); + + return op.status; +} +EXPORT_SYMBOL(xenbus_unmap_ring); + + +XenbusState xenbus_read_driver_state(const char *path) +{ + XenbusState result; + int err = xenbus_gather(XBT_NULL, path, "state", "%d", &result, NULL); + if (err) + result = XenbusStateClosed; + + return result; +} +EXPORT_SYMBOL(xenbus_read_driver_state); --- /dev/null +++ xen-subarch-2.6/drivers/xen/xenbus/xenbus_comms.c @@ -0,0 +1,201 @@ +/****************************************************************************** + * xenbus_comms.c + * + * Low level code to talks to Xen Store: ringbuffer and event channel. + * + * Copyright (C) 2005 Rusty Russell, IBM Corporation + * + * This file may be 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. + */ + +#include +#include +#include +#include +#include +#include +#include +#include "xenbus_comms.h" + +static int xenbus_irq; + +extern void xenbus_probe(void *); +extern int xenstored_ready; +static DECLARE_WORK(probe_work, xenbus_probe, NULL); + +DECLARE_WAIT_QUEUE_HEAD(xb_waitq); + +static inline struct xenstore_domain_interface *xenstore_domain_interface(void) +{ + return mfn_to_virt(xen_start_info->store_mfn); +} + +static irqreturn_t wake_waiting(int irq, void *unused, struct pt_regs *regs) +{ + if (unlikely(xenstored_ready == 0)) { + xenstored_ready = 1; + schedule_work(&probe_work); + } + + wake_up(&xb_waitq); + return IRQ_HANDLED; +} + +static int check_indexes(XENSTORE_RING_IDX cons, XENSTORE_RING_IDX prod) +{ + return ((prod - cons) <= XENSTORE_RING_SIZE); +} + +static void *get_output_chunk(XENSTORE_RING_IDX cons, + XENSTORE_RING_IDX prod, + char *buf, uint32_t *len) +{ + *len = XENSTORE_RING_SIZE - MASK_XENSTORE_IDX(prod); + if ((XENSTORE_RING_SIZE - (prod - cons)) < *len) + *len = XENSTORE_RING_SIZE - (prod - cons); + return buf + MASK_XENSTORE_IDX(prod); +} + +static const void *get_input_chunk(XENSTORE_RING_IDX cons, + XENSTORE_RING_IDX prod, + const char *buf, uint32_t *len) +{ + *len = XENSTORE_RING_SIZE - MASK_XENSTORE_IDX(cons); + if ((prod - cons) < *len) + *len = prod - cons; + return buf + MASK_XENSTORE_IDX(cons); +} + +int xb_write(const void *data, unsigned len) +{ + struct xenstore_domain_interface *intf = xenstore_domain_interface(); + XENSTORE_RING_IDX cons, prod; + int rc; + + while (len != 0) { + void *dst; + unsigned int avail; + + rc = wait_event_interruptible( + xb_waitq, + (intf->req_prod - intf->req_cons) != + XENSTORE_RING_SIZE); + if (rc < 0) + return rc; + + /* Read indexes, then verify. */ + cons = intf->req_cons; + prod = intf->req_prod; + mb(); + if (!check_indexes(cons, prod)) + return -EIO; + + dst = get_output_chunk(cons, prod, intf->req, &avail); + if (avail == 0) + continue; + if (avail > len) + avail = len; + + memcpy(dst, data, avail); + data += avail; + len -= avail; + + /* Other side must not see new header until data is there. */ + wmb(); + intf->req_prod += avail; + + /* This implies mb() before other side sees interrupt. */ + notify_remote_via_evtchn(xen_start_info->store_evtchn); + } + + return 0; +} + +int xb_read(void *data, unsigned len) +{ + struct xenstore_domain_interface *intf = xenstore_domain_interface(); + XENSTORE_RING_IDX cons, prod; + int rc; + + while (len != 0) { + unsigned int avail; + const char *src; + + rc = wait_event_interruptible( + xb_waitq, + intf->rsp_cons != intf->rsp_prod); + if (rc < 0) + return rc; + + /* Read indexes, then verify. */ + cons = intf->rsp_cons; + prod = intf->rsp_prod; + mb(); + if (!check_indexes(cons, prod)) + return -EIO; + + src = get_input_chunk(cons, prod, intf->rsp, &avail); + if (avail == 0) + continue; + if (avail > len) + avail = len; + + /* We must read header before we read data. */ + rmb(); + + memcpy(data, src, avail); + data += avail; + len -= avail; + + /* Other side must not see free space until we've copied out */ + mb(); + intf->rsp_cons += avail; + + pr_debug("Finished read of %i bytes (%i to go)\n", avail, len); + + /* Implies mb(): they will see new header. */ + notify_remote_via_evtchn(xen_start_info->store_evtchn); + } + + return 0; +} + +/* Set up interrupt handler off store event channel. */ +int xb_init_comms(void) +{ + int err; + + if (xenbus_irq) + unbind_from_irqhandler(xenbus_irq, &xb_waitq); + + err = bind_evtchn_to_irqhandler( + xen_start_info->store_evtchn, wake_waiting, + 0, "xenbus", &xb_waitq); + if (err <= 0) { + printk(KERN_ERR "XENBUS request irq failed %i\n", err); + return err; + } + + xenbus_irq = err; + + return 0; +} --- /dev/null +++ xen-subarch-2.6/drivers/xen/xenbus/xenbus_comms.h @@ -0,0 +1,40 @@ +/* + * Private include for xenbus communications. + * + * Copyright (C) 2005 Rusty Russell, IBM Corporation + * + * This file may be 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. + */ + +#ifndef _XENBUS_COMMS_H +#define _XENBUS_COMMS_H + +int xs_init(void); +int xb_init_comms(void); + +/* Low level routines. */ +int xb_write(const void *data, unsigned len); +int xb_read(void *data, unsigned len); +int xs_input_avail(void); +extern wait_queue_head_t xb_waitq; + +#endif /* _XENBUS_COMMS_H */ --- /dev/null +++ xen-subarch-2.6/drivers/xen/xenbus/xenbus_probe.c @@ -0,0 +1,1076 @@ +/****************************************************************************** + * Talks to Xen Store to figure out what devices we have. + * + * Copyright (C) 2005 Rusty Russell, IBM Corporation + * Copyright (C) 2005 Mike Wray, Hewlett-Packard + * Copyright (C) 2005 XenSource Ltd + * + * This file may be 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", __FUNCTION__, __LINE__, ##args) + +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#ifdef XEN_XENBUS_PROC_INTERFACE +#include +#endif +#include + +#include "xenbus_comms.h" + +extern struct semaphore xenwatch_mutex; + +#define streq(a, b) (strcmp((a), (b)) == 0) + +static struct notifier_block *xenstore_chain; + +/* If something in array of ids matches this device, return it. */ +static const struct xenbus_device_id * +match_device(const struct xenbus_device_id *arr, struct xenbus_device *dev) +{ + for (; !streq(arr->devicetype, ""); arr++) { + if (streq(arr->devicetype, dev->devicetype)) + return arr; + } + return NULL; +} + +static int xenbus_match(struct device *_dev, struct device_driver *_drv) +{ + struct xenbus_driver *drv = to_xenbus_driver(_drv); + + if (!drv->ids) + return 0; + + return match_device(drv->ids, to_xenbus_device(_dev)) != NULL; +} + +struct xen_bus_type +{ + char *root; + unsigned int levels; + int (*get_bus_id)(char bus_id[BUS_ID_SIZE], const char *nodename); + int (*probe)(const char *type, const char *dir); + struct bus_type bus; + struct device dev; +}; + + +/* device// => - */ +static int frontend_bus_id(char bus_id[BUS_ID_SIZE], const char *nodename) +{ + nodename = strchr(nodename, '/'); + if (!nodename || strlen(nodename + 1) >= BUS_ID_SIZE) { + printk(KERN_WARNING "XENBUS: bad frontend %s\n", nodename); + return -EINVAL; + } + + strlcpy(bus_id, nodename + 1, BUS_ID_SIZE); + if (!strchr(bus_id, '/')) { + printk(KERN_WARNING "XENBUS: bus_id %s no slash\n", bus_id); + return -EINVAL; + } + *strchr(bus_id, '/') = '-'; + return 0; +} + + +static int read_otherend_details(struct xenbus_device *xendev, + char *id_node, char *path_node) +{ + int err = xenbus_gather(XBT_NULL, xendev->nodename, + id_node, "%i", &xendev->otherend_id, + path_node, NULL, &xendev->otherend, + NULL); + if (err) { + xenbus_dev_fatal(xendev, err, + "reading other end details from %s", + xendev->nodename); + return err; + } + if (strlen(xendev->otherend) == 0 || + !xenbus_exists(XBT_NULL, xendev->otherend, "")) { + xenbus_dev_fatal(xendev, -ENOENT, "missing other end from %s", + xendev->nodename); + kfree(xendev->otherend); + xendev->otherend = NULL; + return -ENOENT; + } + + return 0; +} + + +static int read_backend_details(struct xenbus_device *xendev) +{ + return read_otherend_details(xendev, "backend-id", "backend"); +} + + +static int read_frontend_details(struct xenbus_device *xendev) +{ + return read_otherend_details(xendev, "frontend-id", "frontend"); +} + + +static void free_otherend_details(struct xenbus_device *dev) +{ + kfree(dev->otherend); + dev->otherend = NULL; +} + + +static void free_otherend_watch(struct xenbus_device *dev) +{ + if (dev->otherend_watch.node) { + unregister_xenbus_watch(&dev->otherend_watch); + kfree(dev->otherend_watch.node); + dev->otherend_watch.node = NULL; + } +} + + +/* Bus type for frontend drivers. */ +static int xenbus_probe_frontend(const char *type, const char *name); +static struct xen_bus_type xenbus_frontend = { + .root = "device", + .levels = 2, /* device/type/ */ + .get_bus_id = frontend_bus_id, + .probe = xenbus_probe_frontend, + .bus = { + .name = "xen", + .match = xenbus_match, + }, + .dev = { + .bus_id = "xen", + }, +}; + +/* backend/// => -- */ +static int backend_bus_id(char bus_id[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_NULL, nodename, "frontend-id", "%i", &domid, + "frontend", NULL, &frontend, + NULL); + if (err) + return err; + if (strlen(frontend) == 0) + err = -ERANGE; + if (!err && !xenbus_exists(XBT_NULL, frontend, "")) + err = -ENOENT; + + kfree(frontend); + + if (err) + return err; + + if (snprintf(bus_id, BUS_ID_SIZE, + "%.*s-%i-%s", typelen, type, domid, devid) >= BUS_ID_SIZE) + return -ENOSPC; + return 0; +} + +static int xenbus_uevent_backend(struct device *dev, char **envp, + int num_envp, char *buffer, int buffer_size); +static int xenbus_probe_backend(const char *type, const char *domid); +static struct xen_bus_type xenbus_backend = { + .root = "backend", + .levels = 3, /* backend/type// */ + .get_bus_id = backend_bus_id, + .probe = xenbus_probe_backend, + .bus = { + .name = "xen-backend", + .match = xenbus_match, + .uevent = xenbus_uevent_backend, + }, + .dev = { + .bus_id = "xen-backend", + }, +}; + +static int xenbus_uevent_backend(struct device *dev, char **envp, + int num_envp, char *buffer, int buffer_size) +{ + struct xenbus_device *xdev; + struct xenbus_driver *drv; + int i = 0; + int length = 0; + + DPRINTK(""); + + if (dev == NULL) + return -ENODEV; + + xdev = to_xenbus_device(dev); + if (xdev == NULL) + return -ENODEV; + + /* stuff we want to pass to /sbin/hotplug */ + add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, + "XENBUS_TYPE=%s", xdev->devicetype); + + add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, + "XENBUS_PATH=%s", xdev->nodename); + + add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, + "XENBUS_BASE_PATH=%s", xenbus_backend.root); + + /* terminate, set to next free slot, shrink available space */ + envp[i] = NULL; + envp = &envp[i]; + num_envp -= i; + buffer = &buffer[length]; + buffer_size -= length; + + if (dev->driver) { + drv = to_xenbus_driver(dev->driver); + if (drv && drv->uevent) + return drv->uevent(xdev, envp, num_envp, buffer, + buffer_size); + } + + return 0; +} + +static void otherend_changed(struct xenbus_watch *watch, + const char **vec, unsigned int len) +{ + struct xenbus_device *dev = + container_of(watch, struct xenbus_device, otherend_watch); + struct xenbus_driver *drv = to_xenbus_driver(dev->dev.driver); + XenbusState state; + + /* Protect us against watches firing on old details when the otherend + details change, say immediately after a resume. */ + if (!dev->otherend || + strncmp(dev->otherend, vec[XS_WATCH_PATH], + strlen(dev->otherend))) { + DPRINTK("Ignoring watch at %s", vec[XS_WATCH_PATH]); + return; + } + + state = xenbus_read_driver_state(dev->otherend); + + DPRINTK("state is %d, %s, %s", + state, dev->otherend_watch.node, vec[XS_WATCH_PATH]); + if (drv->otherend_changed) + drv->otherend_changed(dev, state); +} + + +static int talk_to_otherend(struct xenbus_device *dev) +{ + struct xenbus_driver *drv = to_xenbus_driver(dev->dev.driver); + + free_otherend_watch(dev); + free_otherend_details(dev); + + return drv->read_otherend_details(dev); +} + + +static int watch_otherend(struct xenbus_device *dev) +{ + return xenbus_watch_path2(dev, dev->otherend, "state", + &dev->otherend_watch, otherend_changed); +} + + +static int xenbus_dev_probe(struct device *_dev) +{ + struct xenbus_device *dev = to_xenbus_device(_dev); + struct xenbus_driver *drv = to_xenbus_driver(_dev->driver); + const struct xenbus_device_id *id; + int err; + + DPRINTK(""); + + if (!drv->probe) { + err = -ENODEV; + goto fail; + } + + id = match_device(drv->ids, dev); + if (!id) { + err = -ENODEV; + goto fail; + } + + err = talk_to_otherend(dev); + if (err) { + printk(KERN_WARNING + "xenbus_probe: talk_to_otherend on %s failed.\n", + dev->nodename); + return err; + } + + err = drv->probe(dev, id); + if (err) + goto fail; + + err = watch_otherend(dev); + if (err) { + printk(KERN_WARNING + "xenbus_probe: watch_otherend on %s failed.\n", + dev->nodename); + return err; + } + + return 0; +fail: + xenbus_dev_error(dev, err, "xenbus_dev_probe on %s", dev->nodename); + xenbus_switch_state(dev, XBT_NULL, XenbusStateClosed); + return -ENODEV; +} + +static int xenbus_dev_remove(struct device *_dev) +{ + struct xenbus_device *dev = to_xenbus_device(_dev); + struct xenbus_driver *drv = to_xenbus_driver(_dev->driver); + + DPRINTK(""); + + free_otherend_watch(dev); + free_otherend_details(dev); + + if (drv->remove) + drv->remove(dev); + + xenbus_switch_state(dev, XBT_NULL, XenbusStateClosed); + return 0; +} + +static int xenbus_register_driver_common(struct xenbus_driver *drv, + struct xen_bus_type *bus) +{ + int ret; + + drv->driver.name = drv->name; + drv->driver.bus = &bus->bus; + drv->driver.owner = drv->owner; + drv->driver.probe = xenbus_dev_probe; + drv->driver.remove = xenbus_dev_remove; + + down(&xenwatch_mutex); + ret = driver_register(&drv->driver); + up(&xenwatch_mutex); + return ret; +} + +int xenbus_register_frontend(struct xenbus_driver *drv) +{ + drv->read_otherend_details = read_backend_details; + + return xenbus_register_driver_common(drv, &xenbus_frontend); +} +EXPORT_SYMBOL(xenbus_register_frontend); + +int xenbus_register_backend(struct xenbus_driver *drv) +{ + drv->read_otherend_details = read_frontend_details; + + return xenbus_register_driver_common(drv, &xenbus_backend); +} +EXPORT_SYMBOL(xenbus_register_backend); + +void xenbus_unregister_driver(struct xenbus_driver *drv) +{ + driver_unregister(&drv->driver); +} +EXPORT_SYMBOL(xenbus_unregister_driver); + +struct xb_find_info +{ + struct xenbus_device *dev; + const char *nodename; +}; + +static int cmp_dev(struct device *dev, void *data) +{ + struct xenbus_device *xendev = to_xenbus_device(dev); + struct xb_find_info *info = data; + + if (streq(xendev->nodename, info->nodename)) { + info->dev = xendev; + get_device(dev); + return 1; + } + return 0; +} + +struct xenbus_device *xenbus_device_find(const char *nodename, + struct bus_type *bus) +{ + struct xb_find_info info = { .dev = NULL, .nodename = nodename }; + + bus_for_each_dev(bus, NULL, &info, cmp_dev); + return info.dev; +} + +static int cleanup_dev(struct device *dev, void *data) +{ + struct xenbus_device *xendev = to_xenbus_device(dev); + struct xb_find_info *info = data; + int len = strlen(info->nodename); + + DPRINTK("%s", info->nodename); + + /* Match the info->nodename path, or any subdirectory of that path. */ + if (strncmp(xendev->nodename, info->nodename, len)) + return 0; + + /* If the node name is longer, ensure it really is a subdirectory. */ + if ((strlen(xendev->nodename) > len) && (xendev->nodename[len] != '/')) + return 0; + + info->dev = xendev; + get_device(dev); + return 1; +} + +static void xenbus_cleanup_devices(const char *path, struct bus_type *bus) +{ + struct xb_find_info info = { .nodename = path }; + + do { + info.dev = NULL; + bus_for_each_dev(bus, NULL, &info, cleanup_dev); + if (info.dev) { + device_unregister(&info.dev->dev); + put_device(&info.dev->dev); + } + } while (info.dev); +} + +static void xenbus_dev_free(struct xenbus_device *xendev) +{ + kfree(xendev); +} + +static void xenbus_dev_release(struct device *dev) +{ + if (dev) + xenbus_dev_free(to_xenbus_device(dev)); +} + +/* Simplified asprintf. */ +char *kasprintf(const char *fmt, ...) +{ + va_list ap; + unsigned int len; + char *p, dummy[1]; + + va_start(ap, fmt); + /* FIXME: vsnprintf has a bug, NULL should work */ + len = vsnprintf(dummy, 0, fmt, ap); + va_end(ap); + + p = kmalloc(len + 1, GFP_KERNEL); + if (!p) + return NULL; + va_start(ap, fmt); + vsprintf(p, fmt, ap); + va_end(ap); + return p; +} + +static ssize_t xendev_show_nodename(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "%s\n", to_xenbus_device(dev)->nodename); +} +DEVICE_ATTR(nodename, S_IRUSR | S_IRGRP | S_IROTH, xendev_show_nodename, NULL); + +static ssize_t xendev_show_devtype(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "%s\n", to_xenbus_device(dev)->devicetype); +} +DEVICE_ATTR(devtype, S_IRUSR | S_IRGRP | S_IROTH, xendev_show_devtype, NULL); + + +static int xenbus_probe_node(struct xen_bus_type *bus, + const char *type, + const char *nodename) +{ + int err; + struct xenbus_device *xendev; + size_t stringlen; + char *tmpstring; + + XenbusState state = xenbus_read_driver_state(nodename); + + if (state != XenbusStateInitialising) { + /* Device is not new, so ignore it. This can happen if a + device is going away after switching to Closed. */ + return 0; + } + + stringlen = strlen(nodename) + 1 + strlen(type) + 1; + xendev = kmalloc(sizeof(*xendev) + stringlen, GFP_KERNEL); + if (!xendev) + return -ENOMEM; + memset(xendev, 0, sizeof(*xendev)); + + /* Copy the strings into the extra space. */ + + tmpstring = (char *)(xendev + 1); + strcpy(tmpstring, nodename); + xendev->nodename = tmpstring; + + tmpstring += strlen(tmpstring) + 1; + strcpy(tmpstring, type); + xendev->devicetype = tmpstring; + + xendev->dev.parent = &bus->dev; + xendev->dev.bus = &bus->bus; + xendev->dev.release = xenbus_dev_release; + + err = bus->get_bus_id(xendev->dev.bus_id, xendev->nodename); + if (err) + goto fail; + + /* Register with generic device framework. */ + err = device_register(&xendev->dev); + if (err) + goto fail; + + device_create_file(&xendev->dev, &dev_attr_nodename); + device_create_file(&xendev->dev, &dev_attr_devtype); + + return 0; +fail: + xenbus_dev_free(xendev); + return err; +} + +/* device// */ +static int xenbus_probe_frontend(const char *type, const char *name) +{ + char *nodename; + int err; + + nodename = kasprintf("%s/%s/%s", xenbus_frontend.root, type, name); + if (!nodename) + return -ENOMEM; + + DPRINTK("%s", nodename); + + err = xenbus_probe_node(&xenbus_frontend, type, nodename); + kfree(nodename); + return err; +} + +/* backend/// */ +static int xenbus_probe_backend_unit(const char *dir, + const char *type, + const char *name) +{ + char *nodename; + int err; + + nodename = kasprintf("%s/%s", dir, name); + if (!nodename) + return -ENOMEM; + + DPRINTK("%s\n", nodename); + + err = xenbus_probe_node(&xenbus_backend, type, nodename); + kfree(nodename); + return err; +} + +/* backend// */ +static int xenbus_probe_backend(const char *type, const char *domid) +{ + char *nodename; + int err = 0; + char **dir; + unsigned int i, dir_n = 0; + + DPRINTK(""); + + nodename = kasprintf("%s/%s/%s", xenbus_backend.root, type, domid); + if (!nodename) + return -ENOMEM; + + dir = xenbus_directory(XBT_NULL, 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(nodename, type, dir[i]); + if (err) + break; + } + kfree(dir); + kfree(nodename); + return err; +} + +static int xenbus_probe_device_type(struct xen_bus_type *bus, const char *type) +{ + int err = 0; + char **dir; + unsigned int dir_n = 0; + int i; + + dir = xenbus_directory(XBT_NULL, bus->root, type, &dir_n); + if (IS_ERR(dir)) + return PTR_ERR(dir); + + for (i = 0; i < dir_n; i++) { + err = bus->probe(type, dir[i]); + if (err) + break; + } + kfree(dir); + return err; +} + +static int xenbus_probe_devices(struct xen_bus_type *bus) +{ + int err = 0; + char **dir; + unsigned int i, dir_n; + + dir = xenbus_directory(XBT_NULL, bus->root, "", &dir_n); + if (IS_ERR(dir)) + return PTR_ERR(dir); + + for (i = 0; i < dir_n; i++) { + err = xenbus_probe_device_type(bus, dir[i]); + if (err) + break; + } + kfree(dir); + return err; +} + +static unsigned int char_count(const char *str, char c) +{ + unsigned int i, ret = 0; + + for (i = 0; str[i]; i++) + if (str[i] == c) + ret++; + return ret; +} + +static int strsep_len(const char *str, char c, unsigned int len) +{ + unsigned int i; + + for (i = 0; str[i]; i++) + if (str[i] == c) { + if (len == 0) + return i; + len--; + } + return (len == 0) ? i : -ERANGE; +} + +static void dev_changed(const char *node, struct xen_bus_type *bus) +{ + int exists, rootlen; + struct xenbus_device *dev; + char type[BUS_ID_SIZE]; + const char *p, *root; + + if (char_count(node, '/') < 2) + return; + + exists = xenbus_exists(XBT_NULL, node, ""); + if (!exists) { + xenbus_cleanup_devices(node, &bus->bus); + return; + } + + /* backend//... or device//... */ + p = strchr(node, '/') + 1; + snprintf(type, BUS_ID_SIZE, "%.*s", (int)strcspn(p, "/"), p); + type[BUS_ID_SIZE-1] = '\0'; + + rootlen = strsep_len(node, '/', bus->levels); + if (rootlen < 0) + return; + root = kasprintf("%.*s", rootlen, node); + if (!root) + return; + + dev = xenbus_device_find(root, &bus->bus); + if (!dev) + xenbus_probe_node(bus, type, root); + else + put_device(&dev->dev); + + kfree(root); +} + +static void frontend_changed(struct xenbus_watch *watch, + const char **vec, unsigned int len) +{ + DPRINTK(""); + + dev_changed(vec[XS_WATCH_PATH], &xenbus_frontend); +} + +static void backend_changed(struct xenbus_watch *watch, + const char **vec, unsigned int len) +{ + DPRINTK(""); + + dev_changed(vec[XS_WATCH_PATH], &xenbus_backend); +} + +/* We watch for devices appearing and vanishing. */ +static struct xenbus_watch fe_watch = { + .node = "device", + .callback = frontend_changed, +}; + +static struct xenbus_watch be_watch = { + .node = "backend", + .callback = backend_changed, +}; + +static int suspend_dev(struct device *dev, void *data) +{ + int err = 0; + struct xenbus_driver *drv; + struct xenbus_device *xdev; + + DPRINTK(""); + + if (dev->driver == NULL) + return 0; + drv = to_xenbus_driver(dev->driver); + xdev = container_of(dev, struct xenbus_device, dev); + if (drv->suspend) + err = drv->suspend(xdev); + if (err) + printk(KERN_WARNING + "xenbus: suspend %s failed: %i\n", dev->bus_id, err); + return 0; +} + +static int resume_dev(struct device *dev, void *data) +{ + int err; + struct xenbus_driver *drv; + struct xenbus_device *xdev; + + DPRINTK(""); + + if (dev->driver == NULL) + return 0; + drv = to_xenbus_driver(dev->driver); + xdev = container_of(dev, struct xenbus_device, dev); + + err = talk_to_otherend(xdev); + if (err) { + printk(KERN_WARNING + "xenbus: resume (talk_to_otherend) %s failed: %i\n", + dev->bus_id, err); + return err; + } + + err = watch_otherend(xdev); + if (err) { + printk(KERN_WARNING + "xenbus_probe: resume (watch_otherend) %s failed: " + "%d.\n", dev->bus_id, err); + return err; + } + + if (drv->resume) + err = drv->resume(xdev); + if (err) + printk(KERN_WARNING + "xenbus: resume %s failed: %i\n", dev->bus_id, err); + return err; +} + +void xenbus_suspend(void) +{ + DPRINTK(""); + + bus_for_each_dev(&xenbus_frontend.bus, NULL, NULL, suspend_dev); + bus_for_each_dev(&xenbus_backend.bus, NULL, NULL, suspend_dev); + xs_suspend(); +} +EXPORT_SYMBOL(xenbus_suspend); + +void xenbus_resume(void) +{ + xb_init_comms(); + xs_resume(); + bus_for_each_dev(&xenbus_frontend.bus, NULL, NULL, resume_dev); + bus_for_each_dev(&xenbus_backend.bus, NULL, NULL, resume_dev); +} +EXPORT_SYMBOL(xenbus_resume); + + +/* A flag to determine if xenstored is 'ready' (i.e. has started) */ +int xenstored_ready = 0; + + +int register_xenstore_notifier(struct notifier_block *nb) +{ + int ret = 0; + + if (xenstored_ready > 0) + ret = nb->notifier_call(nb, 0, NULL); + else + notifier_chain_register(&xenstore_chain, nb); + + return ret; +} +EXPORT_SYMBOL(register_xenstore_notifier); + +void unregister_xenstore_notifier(struct notifier_block *nb) +{ + notifier_chain_unregister(&xenstore_chain, nb); +} +EXPORT_SYMBOL(unregister_xenstore_notifier); + + +static int all_devices_ready_(struct device *dev, void *data) +{ + struct xenbus_device *xendev = to_xenbus_device(dev); + int *result = data; + + if (xendev->state != XenbusStateConnected) { + result = 0; + return 1; + } + + return 0; +} + + +static int all_devices_ready(void) +{ + int ready = 1; + bus_for_each_dev(&xenbus_frontend.bus, NULL, &ready, + all_devices_ready_); + return ready; +} + + +void xenbus_probe(void *unused) +{ + int i; + + BUG_ON((xenstored_ready <= 0)); + + /* Enumerate devices in xenstore. */ + xenbus_probe_devices(&xenbus_frontend); + xenbus_probe_devices(&xenbus_backend); + + /* Watch for changes. */ + register_xenbus_watch(&fe_watch); + register_xenbus_watch(&be_watch); + + /* Notify others that xenstore is up */ + notifier_call_chain(&xenstore_chain, 0, NULL); + + /* On a 10 second timeout, waiting for all devices currently + configured. We need to do this to guarantee that the filesystems + and / or network devices needed for boot are available, before we + can allow the boot to proceed. + + A possible improvement here would be to have the tools add a + per-device flag to the store entry, indicating whether it is needed + at boot time. This would allow people who knew what they were + doing to accelerate their boot slightly, but of course needs tools + or manual intervention to set up those flags correctly. + */ + for (i = 0; i < 10 * HZ; i++) { + if (all_devices_ready()) + return; + + set_current_state(TASK_INTERRUPTIBLE); + schedule_timeout(1); + } + + printk(KERN_WARNING + "XENBUS: Timeout connecting to devices!\n"); +} + + +#ifdef XEN_XENBUS_PROC_INTERFACE +static struct file_operations xsd_kva_fops; +static struct proc_dir_entry *xsd_kva_intf; +static struct proc_dir_entry *xsd_port_intf; + +static int xsd_kva_mmap(struct file *file, struct vm_area_struct *vma) +{ + size_t size = vma->vm_end - vma->vm_start; + + if ((size > PAGE_SIZE) || (vma->vm_pgoff != 0)) + return -EINVAL; + + if (remap_pfn_range(vma, vma->vm_start, + mfn_to_pfn(xen_start_info->store_mfn), + size, vma->vm_page_prot)) + return -EAGAIN; + + return 0; +} + +static int xsd_kva_read(char *page, char **start, off_t off, + int count, int *eof, void *data) +{ + int len; + + len = sprintf(page, "0x%p", mfn_to_virt(xen_start_info->store_mfn)); + *eof = 1; + return len; +} + +static int xsd_port_read(char *page, char **start, off_t off, + int count, int *eof, void *data) +{ + int len; + + len = sprintf(page, "%d", xen_start_info->store_evtchn); + *eof = 1; + return len; +} +#endif + + +static int __init xenbus_probe_init(void) +{ + int err = 0, dom0; + + DPRINTK(""); + + if (xen_init() < 0) { + DPRINTK("failed"); + return -ENODEV; + } + + /* Register ourselves with the kernel bus & device subsystems */ + bus_register(&xenbus_frontend.bus); + bus_register(&xenbus_backend.bus); + device_register(&xenbus_frontend.dev); + device_register(&xenbus_backend.dev); + + /* + * Domain0 doesn't have a store_evtchn or store_mfn yet. + */ + dom0 = (xen_start_info->store_evtchn == 0); + +#ifdef XEN_XENBUS_PROC_INTERFACE + if (dom0) { + + unsigned long page; + evtchn_op_t op = { 0 }; + int ret; + + + /* Allocate page. */ + page = get_zeroed_page(GFP_KERNEL); + if (!page) + return -ENOMEM; + + /* We don't refcnt properly, so set reserved on page. + * (this allocation is permanent) */ + SetPageReserved(virt_to_page(page)); + + xen_start_info->store_mfn = + pfn_to_mfn(virt_to_phys((void *)page) >> + PAGE_SHIFT); + + /* Next allocate a local port which xenstored can bind to */ + op.cmd = EVTCHNOP_alloc_unbound; + op.u.alloc_unbound.dom = DOMID_SELF; + op.u.alloc_unbound.remote_dom = 0; + + ret = HYPERVISOR_event_channel_op(&op); + BUG_ON(ret); + xen_start_info->store_evtchn = op.u.alloc_unbound.port; + + /* And finally publish the above info in /proc/xen */ + xsd_kva_intf = create_xen_proc_entry("xsd_kva", 0600); + if (xsd_kva_intf) { + memcpy(&xsd_kva_fops, xsd_kva_intf->proc_fops, + sizeof(xsd_kva_fops)); + xsd_kva_fops.mmap = xsd_kva_mmap; + xsd_kva_intf->proc_fops = &xsd_kva_fops; + xsd_kva_intf->read_proc = xsd_kva_read; + } + xsd_port_intf = create_xen_proc_entry("xsd_port", 0400); + if (xsd_port_intf) + xsd_port_intf->read_proc = xsd_port_read; + } +#endif + + /* Initialize the interface to xenstore. */ + err = xs_init(); + if (err) { + printk(KERN_WARNING + "XENBUS: Error initializing xenstore comms: %i\n", err); + return err; + } + + if (!dom0) { + xenstored_ready = 1; + xenbus_probe(NULL); + } + + return 0; +} + +postcore_initcall(xenbus_probe_init); --- /dev/null +++ xen-subarch-2.6/drivers/xen/xenbus/xenbus_xs.c @@ -0,0 +1,827 @@ +/****************************************************************************** + * xenbus_xs.c + * + * This is the kernel equivalent of the "xs" library. We don't need everything + * and we use xenbus_comms for communication. + * + * Copyright (C) 2005 Rusty Russell, IBM Corporation + * + * This file may be 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. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "xenbus_comms.h" + +/* xenbus_probe.c */ +extern char *kasprintf(const char *fmt, ...); + +#define streq(a, b) (strcmp((a), (b)) == 0) + +struct xs_stored_msg { + struct list_head list; + + struct xsd_sockmsg hdr; + + union { + /* Queued replies. */ + struct { + char *body; + } reply; + + /* Queued watch events. */ + struct { + struct xenbus_watch *handle; + char **vec; + unsigned int vec_size; + } watch; + } u; +}; + +struct xs_handle { + /* A list of replies. Currently only one will ever be outstanding. */ + struct list_head reply_list; + spinlock_t reply_lock; + wait_queue_head_t reply_waitq; + + /* One request at a time. */ + struct semaphore request_mutex; + + /* Protect transactions against save/restore. */ + struct rw_semaphore suspend_mutex; +}; + +static struct xs_handle xs_state; + +/* List of registered watches, and a lock to protect it. */ +static LIST_HEAD(watches); +static DEFINE_SPINLOCK(watches_lock); + +/* List of pending watch callback events, and a lock to protect it. */ +static LIST_HEAD(watch_events); +static DEFINE_SPINLOCK(watch_events_lock); + +/* + * Details of the xenwatch callback kernel thread. The thread waits on the + * watch_events_waitq for work to do (queued on watch_events list). When it + * wakes up it acquires the xenwatch_mutex before reading the list and + * carrying out work. + */ +static pid_t xenwatch_pid; +/* static */ DECLARE_MUTEX(xenwatch_mutex); +static DECLARE_WAIT_QUEUE_HEAD(watch_events_waitq); + +static int get_error(const char *errorstring) +{ + unsigned int i; + + for (i = 0; !streq(errorstring, xsd_errors[i].errstring); i++) { + if (i == ARRAY_SIZE(xsd_errors) - 1) { + printk(KERN_WARNING + "XENBUS xen store gave: unknown error %s", + errorstring); + return EINVAL; + } + } + return xsd_errors[i].errnum; +} + +static void *read_reply(enum xsd_sockmsg_type *type, unsigned int *len) +{ + struct xs_stored_msg *msg; + char *body; + + spin_lock(&xs_state.reply_lock); + + while (list_empty(&xs_state.reply_list)) { + spin_unlock(&xs_state.reply_lock); + /* XXX FIXME: Avoid synchronous wait for response here. */ + wait_event(xs_state.reply_waitq, + !list_empty(&xs_state.reply_list)); + spin_lock(&xs_state.reply_lock); + } + + msg = list_entry(xs_state.reply_list.next, + struct xs_stored_msg, list); + list_del(&msg->list); + + spin_unlock(&xs_state.reply_lock); + + *type = msg->hdr.type; + if (len) + *len = msg->hdr.len; + body = msg->u.reply.body; + + kfree(msg); + + return body; +} + +/* Emergency write. */ +void xenbus_debug_write(const char *str, unsigned int count) +{ + struct xsd_sockmsg msg = { 0 }; + + msg.type = XS_DEBUG; + msg.len = sizeof("print") + count + 1; + + down(&xs_state.request_mutex); + xb_write(&msg, sizeof(msg)); + xb_write("print", sizeof("print")); + xb_write(str, count); + xb_write("", 1); + up(&xs_state.request_mutex); +} + +void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg) +{ + void *ret; + struct xsd_sockmsg req_msg = *msg; + int err; + + if (req_msg.type == XS_TRANSACTION_START) + down_read(&xs_state.suspend_mutex); + + down(&xs_state.request_mutex); + + err = xb_write(msg, sizeof(*msg) + msg->len); + if (err) { + msg->type = XS_ERROR; + ret = ERR_PTR(err); + } else + ret = read_reply(&msg->type, &msg->len); + + up(&xs_state.request_mutex); + + if ((msg->type == XS_TRANSACTION_END) || + ((req_msg.type == XS_TRANSACTION_START) && + (msg->type == XS_ERROR))) + up_read(&xs_state.suspend_mutex); + + return ret; +} + +/* Send message to xs, get kmalloc'ed reply. ERR_PTR() on error. */ +static void *xs_talkv(xenbus_transaction_t t, + enum xsd_sockmsg_type type, + const struct kvec *iovec, + unsigned int num_vecs, + unsigned int *len) +{ + struct xsd_sockmsg msg; + void *ret = NULL; + unsigned int i; + int err; + + msg.tx_id = t; + msg.req_id = 0; + msg.type = type; + msg.len = 0; + for (i = 0; i < num_vecs; i++) + msg.len += iovec[i].iov_len; + + down(&xs_state.request_mutex); + + err = xb_write(&msg, sizeof(msg)); + if (err) { + up(&xs_state.request_mutex); + return ERR_PTR(err); + } + + for (i = 0; i < num_vecs; i++) { + err = xb_write(iovec[i].iov_base, iovec[i].iov_len);; + if (err) { + up(&xs_state.request_mutex); + return ERR_PTR(err); + } + } + + ret = read_reply(&msg.type, len); + + up(&xs_state.request_mutex); + + if (IS_ERR(ret)) + return ret; + + if (msg.type == XS_ERROR) { + err = get_error(ret); + kfree(ret); + return ERR_PTR(-err); + } + + if (msg.type != type) { + if (printk_ratelimit()) + printk(KERN_WARNING + "XENBUS unexpected type [%d], expected [%d]\n", + msg.type, type); + kfree(ret); + return ERR_PTR(-EINVAL); + } + return ret; +} + +/* Simplified version of xs_talkv: single message. */ +static void *xs_single(xenbus_transaction_t t, + enum xsd_sockmsg_type type, + const char *string, + unsigned int *len) +{ + struct kvec iovec; + + iovec.iov_base = (void *)string; + iovec.iov_len = strlen(string) + 1; + return xs_talkv(t, type, &iovec, 1, len); +} + +/* Many commands only need an ack, don't care what it says. */ +static int xs_error(char *reply) +{ + if (IS_ERR(reply)) + return PTR_ERR(reply); + kfree(reply); + return 0; +} + +static unsigned int count_strings(const char *strings, unsigned int len) +{ + unsigned int num; + const char *p; + + for (p = strings, num = 0; p < strings + len; p += strlen(p) + 1) + num++; + + return num; +} + +/* Return the path to dir with /name appended. Buffer must be kfree()'ed. */ +static char *join(const char *dir, const char *name) +{ + char *buffer; + + if (strlen(name) == 0) + buffer = kasprintf("%s", dir); + else + buffer = kasprintf("%s/%s", dir, name); + return (!buffer) ? ERR_PTR(-ENOMEM) : buffer; +} + +static char **split(char *strings, unsigned int len, unsigned int *num) +{ + char *p, **ret; + + /* Count the strings. */ + *num = count_strings(strings, len); + + /* Transfer to one big alloc for easy freeing. */ + ret = kmalloc(*num * sizeof(char *) + len, GFP_KERNEL); + if (!ret) { + kfree(strings); + return ERR_PTR(-ENOMEM); + } + memcpy(&ret[*num], strings, len); + kfree(strings); + + strings = (char *)&ret[*num]; + for (p = strings, *num = 0; p < strings + len; p += strlen(p) + 1) + ret[(*num)++] = p; + + return ret; +} + +char **xenbus_directory(xenbus_transaction_t t, + const char *dir, const char *node, unsigned int *num) +{ + char *strings, *path; + unsigned int len; + + path = join(dir, node); + if (IS_ERR(path)) + return (char **)path; + + strings = xs_single(t, XS_DIRECTORY, path, &len); + kfree(path); + if (IS_ERR(strings)) + return (char **)strings; + + return split(strings, len, num); +} +EXPORT_SYMBOL(xenbus_directory); + +/* Check if a path exists. Return 1 if it does. */ +int xenbus_exists(xenbus_transaction_t t, + const char *dir, const char *node) +{ + char **d; + int dir_n; + + d = xenbus_directory(t, dir, node, &dir_n); + if (IS_ERR(d)) + return 0; + kfree(d); + return 1; +} +EXPORT_SYMBOL(xenbus_exists); + +/* Get the value of a single file. + * Returns a kmalloced value: call free() on it after use. + * len indicates length in bytes. + */ +void *xenbus_read(xenbus_transaction_t t, + const char *dir, const char *node, unsigned int *len) +{ + char *path; + void *ret; + + path = join(dir, node); + if (IS_ERR(path)) + return (void *)path; + + ret = xs_single(t, XS_READ, path, len); + kfree(path); + return ret; +} +EXPORT_SYMBOL(xenbus_read); + +/* Write the value of a single file. + * Returns -err on failure. + */ +int xenbus_write(xenbus_transaction_t t, + const char *dir, const char *node, const char *string) +{ + const char *path; + struct kvec iovec[2]; + int ret; + + path = join(dir, node); + if (IS_ERR(path)) + return PTR_ERR(path); + + iovec[0].iov_base = (void *)path; + iovec[0].iov_len = strlen(path) + 1; + iovec[1].iov_base = (void *)string; + iovec[1].iov_len = strlen(string); + + ret = xs_error(xs_talkv(t, XS_WRITE, iovec, ARRAY_SIZE(iovec), NULL)); + kfree(path); + return ret; +} +EXPORT_SYMBOL(xenbus_write); + +/* Create a new directory. */ +int xenbus_mkdir(xenbus_transaction_t t, + const char *dir, const char *node) +{ + char *path; + int ret; + + path = join(dir, node); + if (IS_ERR(path)) + return PTR_ERR(path); + + ret = xs_error(xs_single(t, XS_MKDIR, path, NULL)); + kfree(path); + return ret; +} +EXPORT_SYMBOL(xenbus_mkdir); + +/* Destroy a file or directory (directories must be empty). */ +int xenbus_rm(xenbus_transaction_t t, const char *dir, const char *node) +{ + char *path; + int ret; + + path = join(dir, node); + if (IS_ERR(path)) + return PTR_ERR(path); + + ret = xs_error(xs_single(t, XS_RM, path, NULL)); + kfree(path); + return ret; +} +EXPORT_SYMBOL(xenbus_rm); + +/* Start a transaction: changes by others will not be seen during this + * transaction, and changes will not be visible to others until end. + */ +int xenbus_transaction_start(xenbus_transaction_t *t) +{ + char *id_str; + + down_read(&xs_state.suspend_mutex); + + id_str = xs_single(XBT_NULL, XS_TRANSACTION_START, "", NULL); + if (IS_ERR(id_str)) { + up_read(&xs_state.suspend_mutex); + return PTR_ERR(id_str); + } + + *t = simple_strtoul(id_str, NULL, 0); + kfree(id_str); + return 0; +} +EXPORT_SYMBOL(xenbus_transaction_start); + +/* End a transaction. + * If abandon is true, transaction is discarded instead of committed. + */ +int xenbus_transaction_end(xenbus_transaction_t t, int abort) +{ + char abortstr[2]; + int err; + + if (abort) + strcpy(abortstr, "F"); + else + strcpy(abortstr, "T"); + + err = xs_error(xs_single(t, XS_TRANSACTION_END, abortstr, NULL)); + + up_read(&xs_state.suspend_mutex); + + return err; +} +EXPORT_SYMBOL(xenbus_transaction_end); + +/* Single read and scanf: returns -errno or num scanned. */ +int xenbus_scanf(xenbus_transaction_t t, + const char *dir, const char *node, const char *fmt, ...) +{ + va_list ap; + int ret; + char *val; + + val = xenbus_read(t, dir, node, NULL); + if (IS_ERR(val)) + return PTR_ERR(val); + + va_start(ap, fmt); + ret = vsscanf(val, fmt, ap); + va_end(ap); + kfree(val); + /* Distinctive errno. */ + if (ret == 0) + return -ERANGE; + return ret; +} +EXPORT_SYMBOL(xenbus_scanf); + +/* Single printf and write: returns -errno or 0. */ +int xenbus_printf(xenbus_transaction_t t, + const char *dir, const char *node, const char *fmt, ...) +{ + va_list ap; + int ret; +#define PRINTF_BUFFER_SIZE 4096 + char *printf_buffer; + + printf_buffer = kmalloc(PRINTF_BUFFER_SIZE, GFP_KERNEL); + if (printf_buffer == NULL) + return -ENOMEM; + + va_start(ap, fmt); + ret = vsnprintf(printf_buffer, PRINTF_BUFFER_SIZE, fmt, ap); + va_end(ap); + + BUG_ON(ret > PRINTF_BUFFER_SIZE-1); + ret = xenbus_write(t, dir, node, printf_buffer); + + kfree(printf_buffer); + + return ret; +} +EXPORT_SYMBOL(xenbus_printf); + +/* Takes tuples of names, scanf-style args, and void **, NULL terminated. */ +int xenbus_gather(xenbus_transaction_t t, const char *dir, ...) +{ + va_list ap; + const char *name; + int ret = 0; + + va_start(ap, dir); + while (ret == 0 && (name = va_arg(ap, char *)) != NULL) { + const char *fmt = va_arg(ap, char *); + void *result = va_arg(ap, void *); + char *p; + + p = xenbus_read(t, dir, name, NULL); + if (IS_ERR(p)) { + ret = PTR_ERR(p); + break; + } + if (fmt) { + if (sscanf(p, fmt, result) == 0) + ret = -EINVAL; + kfree(p); + } else + *(char **)result = p; + } + va_end(ap); + return ret; +} +EXPORT_SYMBOL(xenbus_gather); + +static int xs_watch(const char *path, const char *token) +{ + struct kvec iov[2]; + + iov[0].iov_base = (void *)path; + iov[0].iov_len = strlen(path) + 1; + iov[1].iov_base = (void *)token; + iov[1].iov_len = strlen(token) + 1; + + return xs_error(xs_talkv(XBT_NULL, XS_WATCH, iov, + ARRAY_SIZE(iov), NULL)); +} + +static int xs_unwatch(const char *path, const char *token) +{ + struct kvec iov[2]; + + iov[0].iov_base = (char *)path; + iov[0].iov_len = strlen(path) + 1; + iov[1].iov_base = (char *)token; + iov[1].iov_len = strlen(token) + 1; + + return xs_error(xs_talkv(XBT_NULL, XS_UNWATCH, iov, + ARRAY_SIZE(iov), NULL)); +} + +static struct xenbus_watch *find_watch(const char *token) +{ + struct xenbus_watch *i, *cmp; + + cmp = (void *)simple_strtoul(token, NULL, 16); + + list_for_each_entry(i, &watches, list) + if (i == cmp) + return i; + + return NULL; +} + +/* Register callback to watch this node. */ +int register_xenbus_watch(struct xenbus_watch *watch) +{ + /* Pointer in ascii is the token. */ + char token[sizeof(watch) * 2 + 1]; + int err; + + sprintf(token, "%lX", (long)watch); + + down_read(&xs_state.suspend_mutex); + + spin_lock(&watches_lock); + BUG_ON(find_watch(token)); + list_add(&watch->list, &watches); + spin_unlock(&watches_lock); + + err = xs_watch(watch->node, token); + + /* Ignore errors due to multiple registration. */ + if ((err != 0) && (err != -EEXIST)) { + spin_lock(&watches_lock); + list_del(&watch->list); + spin_unlock(&watches_lock); + } + + up_read(&xs_state.suspend_mutex); + + return err; +} +EXPORT_SYMBOL(register_xenbus_watch); + +void unregister_xenbus_watch(struct xenbus_watch *watch) +{ + struct xs_stored_msg *msg, *tmp; + char token[sizeof(watch) * 2 + 1]; + int err; + + sprintf(token, "%lX", (long)watch); + + down_read(&xs_state.suspend_mutex); + + spin_lock(&watches_lock); + BUG_ON(!find_watch(token)); + list_del(&watch->list); + spin_unlock(&watches_lock); + + err = xs_unwatch(watch->node, token); + if (err) + printk(KERN_WARNING + "XENBUS Failed to release watch %s: %i\n", + watch->node, err); + + up_read(&xs_state.suspend_mutex); + + /* Cancel pending watch events. */ + spin_lock(&watch_events_lock); + list_for_each_entry_safe(msg, tmp, &watch_events, list) { + if (msg->u.watch.handle != watch) + continue; + list_del(&msg->list); + kfree(msg->u.watch.vec); + kfree(msg); + } + spin_unlock(&watch_events_lock); + + /* Flush any currently-executing callback, unless we are it. :-) */ + if (current->pid != xenwatch_pid) { + down(&xenwatch_mutex); + up(&xenwatch_mutex); + } +} +EXPORT_SYMBOL(unregister_xenbus_watch); + +void xs_suspend(void) +{ + down_write(&xs_state.suspend_mutex); + down(&xs_state.request_mutex); +} + +void xs_resume(void) +{ + struct xenbus_watch *watch; + char token[sizeof(watch) * 2 + 1]; + + up(&xs_state.request_mutex); + + /* No need for watches_lock: the suspend_mutex is sufficient. */ + list_for_each_entry(watch, &watches, list) { + sprintf(token, "%lX", (long)watch); + xs_watch(watch->node, token); + } + + up_write(&xs_state.suspend_mutex); +} + +static int xenwatch_thread(void *unused) +{ + struct list_head *ent; + struct xs_stored_msg *msg; + + for (;;) { + wait_event_interruptible(watch_events_waitq, + !list_empty(&watch_events)); + + if (kthread_should_stop()) + break; + + down(&xenwatch_mutex); + + spin_lock(&watch_events_lock); + ent = watch_events.next; + if (ent != &watch_events) + list_del(ent); + spin_unlock(&watch_events_lock); + + if (ent != &watch_events) { + msg = list_entry(ent, struct xs_stored_msg, list); + msg->u.watch.handle->callback( + msg->u.watch.handle, + (const char **)msg->u.watch.vec, + msg->u.watch.vec_size); + kfree(msg->u.watch.vec); + kfree(msg); + } + + up(&xenwatch_mutex); + } + + return 0; +} + +static int process_msg(void) +{ + struct xs_stored_msg *msg; + char *body; + int err; + + msg = kmalloc(sizeof(*msg), GFP_KERNEL); + if (msg == NULL) + return -ENOMEM; + + err = xb_read(&msg->hdr, sizeof(msg->hdr)); + if (err) { + kfree(msg); + return err; + } + + body = kmalloc(msg->hdr.len + 1, GFP_KERNEL); + if (body == NULL) { + kfree(msg); + return -ENOMEM; + } + + err = xb_read(body, msg->hdr.len); + if (err) { + kfree(body); + kfree(msg); + return err; + } + body[msg->hdr.len] = '\0'; + + if (msg->hdr.type == XS_WATCH_EVENT) { + msg->u.watch.vec = split(body, msg->hdr.len, + &msg->u.watch.vec_size); + if (IS_ERR(msg->u.watch.vec)) { + kfree(msg); + return PTR_ERR(msg->u.watch.vec); + } + + spin_lock(&watches_lock); + msg->u.watch.handle = find_watch( + msg->u.watch.vec[XS_WATCH_TOKEN]); + if (msg->u.watch.handle != NULL) { + spin_lock(&watch_events_lock); + list_add_tail(&msg->list, &watch_events); + wake_up(&watch_events_waitq); + spin_unlock(&watch_events_lock); + } else { + kfree(msg->u.watch.vec); + kfree(msg); + } + spin_unlock(&watches_lock); + } else { + msg->u.reply.body = body; + spin_lock(&xs_state.reply_lock); + list_add_tail(&msg->list, &xs_state.reply_list); + spin_unlock(&xs_state.reply_lock); + wake_up(&xs_state.reply_waitq); + } + + return 0; +} + +static int xenbus_thread(void *unused) +{ + int err; + + for (;;) { + err = process_msg(); + if (err) + printk(KERN_WARNING "XENBUS error %d while reading " + "message\n", err); + if (kthread_should_stop()) + break; + } + + return 0; +} + +int xs_init(void) +{ + int err; + struct task_struct *task; + + INIT_LIST_HEAD(&xs_state.reply_list); + spin_lock_init(&xs_state.reply_lock); + init_waitqueue_head(&xs_state.reply_waitq); + + init_MUTEX(&xs_state.request_mutex); + init_rwsem(&xs_state.suspend_mutex); + + /* Initialize the shared memory rings to talk to xenstored */ + err = xb_init_comms(); + if (err) + return err; + + task = kthread_run(xenwatch_thread, NULL, "xenwatch"); + if (IS_ERR(task)) + return PTR_ERR(task); + xenwatch_pid = task->pid; + + task = kthread_run(xenbus_thread, NULL, "xenbus"); + if (IS_ERR(task)) + return PTR_ERR(task); + + return 0; +} --- /dev/null +++ xen-subarch-2.6/include/xen/xenbus.h @@ -0,0 +1,288 @@ +/****************************************************************************** + * xenbus.h + * + * Talks to Xen Store to figure out what devices we have. + * + * Copyright (C) 2005 Rusty Russell, IBM Corporation + * Copyright (C) 2005 XenSource Ltd. + * + * This file may be 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. + */ + +#ifndef _XEN_XENBUS_H +#define _XEN_XENBUS_H + +#include +#include +#include +#include +#include +#include +#include + +#define XBT_NULL 0 + +/* Register callback to watch this node. */ +struct xenbus_watch +{ + struct list_head list; + + /* Path being watched. */ + const char *node; + + /* Callback (executed in a process context with no locks held). */ + void (*callback)(struct xenbus_watch *, + const char **vec, unsigned int len); +}; + + +/* A xenbus device. */ +struct xenbus_device { + const char *devicetype; + const char *nodename; + const char *otherend; + int otherend_id; + struct xenbus_watch otherend_watch; + struct device dev; + XenbusState state; + void *data; +}; + +static inline struct xenbus_device *to_xenbus_device(struct device *dev) +{ + return container_of(dev, struct xenbus_device, dev); +} + +struct xenbus_device_id +{ + /* .../device// */ + char devicetype[32]; /* General class of device. */ +}; + +/* A xenbus driver. */ +struct xenbus_driver { + char *name; + struct module *owner; + const struct xenbus_device_id *ids; + int (*probe)(struct xenbus_device *dev, + const struct xenbus_device_id *id); + void (*otherend_changed)(struct xenbus_device *dev, + XenbusState backend_state); + int (*remove)(struct xenbus_device *dev); + int (*suspend)(struct xenbus_device *dev); + int (*resume)(struct xenbus_device *dev); + int (*uevent)(struct xenbus_device *, char **, int, char *, int); + struct device_driver driver; + int (*read_otherend_details)(struct xenbus_device *dev); +}; + +static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv) +{ + return container_of(drv, struct xenbus_driver, driver); +} + +int xenbus_register_frontend(struct xenbus_driver *drv); +int xenbus_register_backend(struct xenbus_driver *drv); +void xenbus_unregister_driver(struct xenbus_driver *drv); + +typedef u32 xenbus_transaction_t; + +char **xenbus_directory(xenbus_transaction_t t, + const char *dir, const char *node, unsigned int *num); +void *xenbus_read(xenbus_transaction_t t, + const char *dir, const char *node, unsigned int *len); +int xenbus_write(xenbus_transaction_t t, + const char *dir, const char *node, const char *string); +int xenbus_mkdir(xenbus_transaction_t t, + const char *dir, const char *node); +int xenbus_exists(xenbus_transaction_t t, + const char *dir, const char *node); +int xenbus_rm(xenbus_transaction_t t, const char *dir, const char *node); +int xenbus_transaction_start(xenbus_transaction_t *t); +int xenbus_transaction_end(xenbus_transaction_t t, int abort); + +/* Single read and scanf: returns -errno or num scanned if > 0. */ +int xenbus_scanf(xenbus_transaction_t t, + const char *dir, const char *node, const char *fmt, ...) + __attribute__((format(scanf, 4, 5))); + +/* Single printf and write: returns -errno or 0. */ +int xenbus_printf(xenbus_transaction_t t, + const char *dir, const char *node, const char *fmt, ...) + __attribute__((format(printf, 4, 5))); + +/* Generic read function: NULL-terminated triples of name, + * sprintf-style type string, and pointer. Returns 0 or errno.*/ +int xenbus_gather(xenbus_transaction_t t, const char *dir, ...); + +/* notifer routines for when the xenstore comes up */ +int register_xenstore_notifier(struct notifier_block *nb); +void unregister_xenstore_notifier(struct notifier_block *nb); + +int register_xenbus_watch(struct xenbus_watch *watch); +void unregister_xenbus_watch(struct xenbus_watch *watch); +void xs_suspend(void); +void xs_resume(void); + +/* Used by xenbus_dev to borrow kernel's store connection. */ +void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg); + +/* Called from xen core code. */ +void xenbus_suspend(void); +void xenbus_resume(void); + +#define XENBUS_IS_ERR_READ(str) ({ \ + if (!IS_ERR(str) && strlen(str) == 0) { \ + kfree(str); \ + str = ERR_PTR(-ERANGE); \ + } \ + IS_ERR(str); \ +}) + +#define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE) + + +/** + * Register a watch on the given path, using the given xenbus_watch structure + * for storage, and the given callback function as the callback. Return 0 on + * success, or -errno on error. On success, the given path will be saved as + * watch->node, and remains the caller's to free. On error, watch->node will + * be NULL, the device will switch to XenbusStateClosing, and the error will + * be saved in the store. + */ +int xenbus_watch_path(struct xenbus_device *dev, const char *path, + struct xenbus_watch *watch, + void (*callback)(struct xenbus_watch *, + const char **, unsigned int)); + + +/** + * Register a watch on the given path/path2, using the given xenbus_watch + * structure for storage, and the given callback function as the callback. + * Return 0 on success, or -errno on error. On success, the watched path + * (path/path2) will be saved as watch->node, and becomes the caller's to + * kfree(). On error, watch->node will be NULL, so the caller has nothing to + * free, the device will switch to XenbusStateClosing, and the error will be + * saved in the store. + */ +int xenbus_watch_path2(struct xenbus_device *dev, const char *path, + const char *path2, struct xenbus_watch *watch, + void (*callback)(struct xenbus_watch *, + const char **, unsigned int)); + + +/** + * Advertise in the store a change of the given driver to the given new_state. + * Perform the change inside the given transaction xbt. xbt may be NULL, in + * which case this is performed inside its own transaction. Return 0 on + * success, or -errno on error. On error, the device will switch to + * XenbusStateClosing, and the error will be saved in the store. + */ +int xenbus_switch_state(struct xenbus_device *dev, + xenbus_transaction_t xbt, + XenbusState new_state); + + +/** + * Grant access to the given ring_mfn to the peer of the given device. Return + * 0 on success, or -errno on error. On error, the device will switch to + * XenbusStateClosing, and the error will be saved in the store. + */ +int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn); + + +/** + * Map a page of memory into this domain from another domain's grant table. + * xenbus_map_ring_valloc allocates a page of virtual address space, maps the + * page to that address, and sets *vaddr to that address. + * xenbus_map_ring does not allocate the virtual address space (you must do + * this yourself!). It only maps in the page to the specified address. + * Returns 0 on success, and GNTST_* (see xen/include/interface/grant_table.h) + * or -ENOMEM on error. If an error is returned, device will switch to + * XenbusStateClosing and the error message will be saved in XenStore. + */ +int xenbus_map_ring_valloc(struct xenbus_device *dev, + int gnt_ref, void **vaddr); +int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref, + grant_handle_t *handle, void *vaddr); + + +/** + * Unmap a page of memory in this domain that was imported from another domain. + * Use xenbus_unmap_ring_vfree if you mapped in your memory with + * xenbus_map_ring_valloc (it will free the virtual address space). + * Returns 0 on success and returns GNTST_* on error + * (see xen/include/interface/grant_table.h). + */ +int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr); +int xenbus_unmap_ring(struct xenbus_device *dev, + grant_handle_t handle, void *vaddr); + + +/** + * Allocate an event channel for the given xenbus_device, assigning the newly + * created local port to *port. Return 0 on success, or -errno on error. On + * error, the device will switch to XenbusStateClosing, and the error will be + * saved in the store. + */ +int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port); + + +/** + * Bind to an existing interdomain event channel in another domain. Returns 0 + * on success and stores the local port in *port. On error, returns -errno, + * switches the device to XenbusStateClosing, and saves the error in XenStore. + */ +int xenbus_bind_evtchn(struct xenbus_device *dev, int remote_port, int *port); + + +/** + * Free an existing event channel. Returns 0 on success or -errno on error. + */ +int xenbus_free_evtchn(struct xenbus_device *dev, int port); + + +/** + * Return the state of the driver rooted at the given store path, or + * XenbusStateClosed if no state can be read. + */ +XenbusState xenbus_read_driver_state(const char *path); + + +/*** + * Report the given negative errno into the store, along with the given + * formatted message. + */ +void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, + ...); + + +/*** + * Equivalent to xenbus_dev_error(dev, err, fmt, args), followed by + * xenbus_switch_state(dev, NULL, XenbusStateClosing) to schedule an orderly + * closedown of this driver and its peer. + */ +void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, + ...); + + +#endif /* _XEN_XENBUS_H */ -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/