Initial import of qemu-2.4.1HEADmaster

1 files changed, 393 insertions, 0 deletions

diff --git a/roms/ipxe/src/interface/xen/xenbus.c b/roms/ipxe/src/interface/xen/xenbus.c
new file mode 100644
index 00000000..ffc8aba3
--- /dev/null
+++ b/roms/ipxe/src/interface/xen/xenbus.c
@@ -0,0 +1,393 @@
+/*
+ * 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.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdio.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 type		Device type
+ * @v instance		Device instance
+ * @ret rc		Return status code
+ */
+static int xenbus_probe_device ( struct xen_hypervisor *xen,
+				 struct device *parent, const char *type,
+				 const char *instance ) {
+	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 );
+
+	/* 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 );
+
+	/* Look for a driver */
+	xendev->driver = xenbus_find_driver ( type );
+	if ( ! xendev->driver ) {
+		DBGC ( xendev, "XENBUS %s has no driver\n", xendev->key );
+		/* Not a fatal error */
+		rc = 0;
+		goto err_no_driver;
+	}
+	xendev->dev.driver_name = xendev->driver->name;
+	DBGC ( xendev, "XENBUS %s has driver \"%s\"\n", xendev->key,
+	       xendev->driver->name );
+
+	/* 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_no_driver:
+ 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 ) {
+	char *children;
+	char *child;
+	size_t len;
+	int rc;
+
+	/* 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, type,
+						  child ) ) != 0 )
+			goto err_probe_device;
+	}
+
+	free ( children );
+	return 0;
+
+ err_probe_device:
+	free ( children );
+ err_directory:
+	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 );
+	}
+}