/
githubmirror
/
ipxe
Обзор
Документация
Войти
/
githubmirror
/
ipxe
Код
Запросы
0
Пакеты
0
Релизы
0
Аналитика
Безопасность
master
src/interface/xen/xenbus.c
408 строк
11 KB
Michael Brown
[build] Drag in Xen and Hyper-V support via network device drivers
12 фев 2026, 01:02
12 фев 2026, 01:02
7a2817b
Код
Авторство
О чём код?
/* * Copyright (C) 2014 Michael Brown <mbrown@fensystems.co.uk>. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of the * License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA * 02110-1301, USA. * * You can also choose to distribute this program under the terms of * the Unmodified Binary Distribution Licence (as given in the file * COPYING.UBDL), provided that you have satisfied its requirements. */ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); FILE_SECBOOT ( PERMITTED ); #include <stdio.h> #include <string.h> #include <errno.h> #include <ipxe/malloc.h> #include <ipxe/device.h> #include <ipxe/timer.h> #include <ipxe/nap.h> #include <ipxe/xen.h> #include <ipxe/xenstore.h> #include <ipxe/xenbus.h> /** @file * * Xen device bus * */ /* Disambiguate the various error causes */ #define ETIMEDOUT_UNKNOWN \ __einfo_error ( EINFO_ETIMEDOUT_UNKNOWN ) #define EINFO_ETIMEDOUT_UNKNOWN \ __einfo_uniqify ( EINFO_ETIMEDOUT, XenbusStateUnknown, \ "Unknown" ) #define ETIMEDOUT_INITIALISING \ __einfo_error ( EINFO_ETIMEDOUT_INITIALISING ) #define EINFO_ETIMEDOUT_INITIALISING \ __einfo_uniqify ( EINFO_ETIMEDOUT, XenbusStateInitialising, \ "Initialising" ) #define ETIMEDOUT_INITWAIT \ __einfo_error ( EINFO_ETIMEDOUT_INITWAIT ) #define EINFO_ETIMEDOUT_INITWAIT \ __einfo_uniqify ( EINFO_ETIMEDOUT, XenbusStateInitWait, \ "InitWait" ) #define ETIMEDOUT_INITIALISED \ __einfo_error ( EINFO_ETIMEDOUT_INITIALISED ) #define EINFO_ETIMEDOUT_INITIALISED \ __einfo_uniqify ( EINFO_ETIMEDOUT, XenbusStateInitialised, \ "Initialised" ) #define ETIMEDOUT_CONNECTED \ __einfo_error ( EINFO_ETIMEDOUT_CONNECTED ) #define EINFO_ETIMEDOUT_CONNECTED \ __einfo_uniqify ( EINFO_ETIMEDOUT, XenbusStateConnected, \ "Connected" ) #define ETIMEDOUT_CLOSING \ __einfo_error ( EINFO_ETIMEDOUT_CLOSING ) #define EINFO_ETIMEDOUT_CLOSING \ __einfo_uniqify ( EINFO_ETIMEDOUT, XenbusStateClosing, \ "Closing" ) #define ETIMEDOUT_CLOSED \ __einfo_error ( EINFO_ETIMEDOUT_CLOSED ) #define EINFO_ETIMEDOUT_CLOSED \ __einfo_uniqify ( EINFO_ETIMEDOUT, XenbusStateClosed, \ "Closed" ) #define ETIMEDOUT_RECONFIGURING \ __einfo_error ( EINFO_ETIMEDOUT_RECONFIGURING ) #define EINFO_ETIMEDOUT_RECONFIGURING \ __einfo_uniqify ( EINFO_ETIMEDOUT, XenbusStateReconfiguring, \ "Reconfiguring" ) #define ETIMEDOUT_RECONFIGURED \ __einfo_error ( EINFO_ETIMEDOUT_RECONFIGURED ) #define EINFO_ETIMEDOUT_RECONFIGURED \ __einfo_uniqify ( EINFO_ETIMEDOUT, XenbusStateReconfigured, \ "Reconfigured" ) #define ETIMEDOUT_STATE( state ) \ EUNIQ ( EINFO_ETIMEDOUT, (state), ETIMEDOUT_UNKNOWN, \ ETIMEDOUT_INITIALISING, ETIMEDOUT_INITWAIT, \ ETIMEDOUT_INITIALISED, ETIMEDOUT_CONNECTED, \ ETIMEDOUT_CLOSING, ETIMEDOUT_CLOSED, \ ETIMEDOUT_RECONFIGURING, ETIMEDOUT_RECONFIGURED ) /** Maximum time to wait for backend to reach a given state, in ticks */ #define XENBUS_BACKEND_TIMEOUT ( 5 * TICKS_PER_SEC ) /** * Set device state * * @v xendev Xen device * @v state New state * @ret rc Return status code */ int xenbus_set_state ( struct xen_device *xendev, int state ) { int rc; /* Attempt to set state */ if ( ( rc = xenstore_write_num ( xendev->xen, state, xendev->key, "state", NULL ) ) != 0 ) { DBGC ( xendev, "XENBUS %s could not set state=\"%d\": %s\n", xendev->key, state, strerror ( rc ) ); return rc; } return 0; } /** * Get backend state * * @v xendev Xen device * @ret state Backend state, or negative error */ int xenbus_backend_state ( struct xen_device *xendev ) { unsigned long state; int rc; /* Attempt to get backend state */ if ( ( rc = xenstore_read_num ( xendev->xen, &state, xendev->backend, "state", NULL ) ) != 0 ) { DBGC ( xendev, "XENBUS %s could not read %s/state: %s\n", xendev->key, xendev->backend, strerror ( rc ) ); return rc; } return state; } /** * Wait for backend to reach a given state * * @v xendev Xen device * @v state Desired backend state * @ret rc Return status code */ int xenbus_backend_wait ( struct xen_device *xendev, int state ) { unsigned long started = currticks(); unsigned long elapsed; unsigned int attempts = 0; int current_state; int rc; /* Wait for backend to reach this state */ do { /* Get current backend state */ current_state = xenbus_backend_state ( xendev ); if ( current_state < 0 ) { rc = current_state; return rc; } if ( current_state == state ) return 0; /* Allow time for backend to react */ cpu_nap(); /* XenStore is a very slow interface; any fixed delay * time would be dwarfed by the XenStore access time. * We therefore use wall clock to time out this * operation. */ elapsed = ( currticks() - started ); attempts++; } while ( elapsed < XENBUS_BACKEND_TIMEOUT ); /* Construct status code from current backend state */ rc = -ETIMEDOUT_STATE ( current_state ); DBGC ( xendev, "XENBUS %s timed out after %d attempts waiting for " "%s/state=\"%d\": %s\n", xendev->key, attempts, xendev->backend, state, strerror ( rc ) ); return rc; } /** * Find driver for Xen device * * @v type Device type * @ret driver Driver, or NULL */ static struct xen_driver * xenbus_find_driver ( const char *type ) { struct xen_driver *xendrv; for_each_table_entry ( xendrv, XEN_DRIVERS ) { if ( strcmp ( xendrv->type, type ) == 0 ) return xendrv; } return NULL; } /** * Probe Xen device * * @v xen Xen hypervisor * @v parent Parent device * @v instance Device instance * @v driver Device driver * @ret rc Return status code */ static int xenbus_probe_device ( struct xen_hypervisor *xen, struct device *parent, const char *instance, struct xen_driver *driver ) { const char *type = driver->type; struct xen_device *xendev; size_t key_len; int rc; /* Allocate and initialise structure */ key_len = ( 7 /* "device/" */ + strlen ( type ) + 1 /* "/" */ + strlen ( instance ) + 1 /* NUL */ ); xendev = zalloc ( sizeof ( *xendev ) + key_len ); if ( ! xendev ) { rc = -ENOMEM; goto err_alloc; } snprintf ( xendev->dev.name, sizeof ( xendev->dev.name ), "%s/%s", type, instance ); xendev->dev.desc.bus_type = BUS_TYPE_XEN; INIT_LIST_HEAD ( &xendev->dev.children ); list_add_tail ( &xendev->dev.siblings, &parent->children ); xendev->dev.parent = parent; xendev->xen = xen; xendev->key = ( ( void * ) ( xendev + 1 ) ); snprintf ( xendev->key, key_len, "device/%s/%s", type, instance ); xendev->driver = driver; xendev->dev.driver_name = driver->name; DBGC ( xendev, "XENBUS %s has driver \"%s\"\n", xendev->key, xendev->driver->name ); /* Read backend key */ if ( ( rc = xenstore_read ( xen, &xendev->backend, xendev->key, "backend", NULL ) ) != 0 ) { DBGC ( xendev, "XENBUS %s could not read backend: %s\n", xendev->key, strerror ( rc ) ); goto err_read_backend; } /* Read backend domain ID */ if ( ( rc = xenstore_read_num ( xen, &xendev->backend_id, xendev->key, "backend-id", NULL ) ) != 0 ) { DBGC ( xendev, "XENBUS %s could not read backend-id: %s\n", xendev->key, strerror ( rc ) ); goto err_read_backend_id; } DBGC ( xendev, "XENBUS %s backend=\"%s\" in domain %ld\n", xendev->key, xendev->backend, xendev->backend_id ); /* Probe driver */ if ( ( rc = xendev->driver->probe ( xendev ) ) != 0 ) { DBGC ( xendev, "XENBUS could not probe %s: %s\n", xendev->key, strerror ( rc ) ); goto err_probe; } return 0; xendev->driver->remove ( xendev ); err_probe: err_read_backend_id: free ( xendev->backend ); err_read_backend: list_del ( &xendev->dev.siblings ); free ( xendev ); err_alloc: return rc; } /** * Remove Xen device * * @v xendev Xen device */ static void xenbus_remove_device ( struct xen_device *xendev ) { /* Remove device */ xendev->driver->remove ( xendev ); free ( xendev->backend ); list_del ( &xendev->dev.siblings ); free ( xendev ); } /** * Probe Xen devices of a given type * * @v xen Xen hypervisor * @v parent Parent device * @v type Device type * @ret rc Return status code */ static int xenbus_probe_type ( struct xen_hypervisor *xen, struct device *parent, const char *type ) { struct xen_driver *driver; char *children; char *child; size_t len; int rc; /* Look for a driver */ driver = xenbus_find_driver ( type ); if ( ! driver ) { DBGC ( xen, "XENBUS has no driver for \"%s\" devices\n", type ); /* Not a fatal error */ rc = 0; goto err_no_driver; } /* Get children of this key */ if ( ( rc = xenstore_directory ( xen, &children, &len, "device", type, NULL ) ) != 0 ) { DBGC ( xen, "XENBUS could not list \"%s\" devices: %s\n", type, strerror ( rc ) ); goto err_directory; } /* Probe each child */ for ( child = children ; child < ( children + len ) ; child += ( strlen ( child ) + 1 /* NUL */ ) ) { if ( ( rc = xenbus_probe_device ( xen, parent, child, driver ) ) != 0 ) goto err_probe_device; } free ( children ); return 0; err_probe_device: free ( children ); err_directory: err_no_driver: return rc; } /** * Probe Xen bus * * @v xen Xen hypervisor * @v parent Parent device * @ret rc Return status code */ int xenbus_probe ( struct xen_hypervisor *xen, struct device *parent ) { char *types; char *type; size_t len; int rc; /* Get children of "device" key */ if ( ( rc = xenstore_directory ( xen, &types, &len, "device", NULL ) ) != 0 ) { DBGC ( xen, "XENBUS could not list device types: %s\n", strerror ( rc ) ); goto err_directory; } /* Probe each child type */ for ( type = types ; type < ( types + len ) ; type += ( strlen ( type ) + 1 /* NUL */ ) ) { if ( ( rc = xenbus_probe_type ( xen, parent, type ) ) != 0 ) goto err_probe_type; } free ( types ); return 0; xenbus_remove ( xen, parent ); err_probe_type: free ( types ); err_directory: return rc; } /** * Remove Xen bus * * @v xen Xen hypervisor * @v parent Parent device */ void xenbus_remove ( struct xen_hypervisor *xen __unused, struct device *parent ) { struct xen_device *xendev; struct xen_device *tmp; /* Remove devices */ list_for_each_entry_safe ( xendev, tmp, &parent->children, dev.siblings ) { xenbus_remove_device ( xendev ); } } /* Drag in objects via xenbus_set_state() */ REQUIRING_SYMBOL ( xenbus_set_state ); /* Drag in backing hardware device */ REQUIRE_OBJECT ( hvm );