hw/xen/xen_pvdev.c - third_party/qemu - Git at Google

 /*
  * Xen para-virtualization device
  *
  *  (c) 2008 Gerd Hoffmann <kraxel@redhat.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * This library 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
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, see <http://www.gnu.org/licenses/>
  */

 #include "qemu/osdep.h"
 #include "qemu/log.h"
 #include "qemu/main-loop.h"
 #include "hw/qdev-core.h"
 #include "hw/xen/xen-legacy-backend.h"
 #include "hw/xen/xen_pvdev.h"

 /* private */
 static int debug;

 struct xs_dirs {
     char *xs_dir;
     QTAILQ_ENTRY(xs_dirs) list;
 };

 static QTAILQ_HEAD(, xs_dirs) xs_cleanup =
     QTAILQ_HEAD_INITIALIZER(xs_cleanup);

 static QTAILQ_HEAD(, XenLegacyDevice) xendevs =
     QTAILQ_HEAD_INITIALIZER(xendevs);

 /* ------------------------------------------------------------- */

 static void xenstore_cleanup_dir(char *dir)
 {
     struct xs_dirs *d;

     d = g_malloc(sizeof(*d));
     d->xs_dir = dir;
     QTAILQ_INSERT_TAIL(&xs_cleanup, d, list);
 }

 void xen_config_cleanup(void)
 {
     struct xs_dirs *d;

     QTAILQ_FOREACH(d, &xs_cleanup, list) {
         xs_rm(xenstore, 0, d->xs_dir);
     }
 }

 int xenstore_mkdir(char *path, int p)
 {
     struct xs_permissions perms[2] = {
         {
             .id    = 0, /* set owner: dom0 */
         }, {
             .id    = xen_domid,
             .perms = p,
         }
     };

     if (!xs_mkdir(xenstore, 0, path)) {
         xen_pv_printf(NULL, 0, "xs_mkdir %s: failed\n", path);
         return -1;
     }
     xenstore_cleanup_dir(g_strdup(path));

     if (!xs_set_permissions(xenstore, 0, path, perms, 2)) {
         xen_pv_printf(NULL, 0, "xs_set_permissions %s: failed\n", path);
         return -1;
     }
     return 0;
 }

 int xenstore_write_str(const char *base, const char *node, const char *val)
 {
     char abspath[XEN_BUFSIZE];

     snprintf(abspath, sizeof(abspath), "%s/%s", base, node);
     if (!xs_write(xenstore, 0, abspath, val, strlen(val))) {
         return -1;
     }
     return 0;
 }

 char *xenstore_read_str(const char *base, const char *node)
 {
     char abspath[XEN_BUFSIZE];
     unsigned int len;
     char *str, *ret = NULL;

     snprintf(abspath, sizeof(abspath), "%s/%s", base, node);
     str = xs_read(xenstore, 0, abspath, &len);
     if (str != NULL) {
         /* move to qemu-allocated memory to make sure
          * callers can savely g_free() stuff. */
         ret = g_strdup(str);
         free(str);
     }
     return ret;
 }

 int xenstore_write_int(const char *base, const char *node, int ival)
 {
     char val[12];

     snprintf(val, sizeof(val), "%d", ival);
     return xenstore_write_str(base, node, val);
 }

 int xenstore_write_int64(const char *base, const char *node, int64_t ival)
 {
     char val[21];

     snprintf(val, sizeof(val), "%"PRId64, ival);
     return xenstore_write_str(base, node, val);
 }

 int xenstore_read_int(const char *base, const char *node, int *ival)
 {
     char *val;
     int rc = -1;

     val = xenstore_read_str(base, node);
     if (val && 1 == sscanf(val, "%d", ival)) {
         rc = 0;
     }
     g_free(val);
     return rc;
 }

 int xenstore_read_uint64(const char *base, const char *node, uint64_t *uval)
 {
     char *val;
     int rc = -1;

     val = xenstore_read_str(base, node);
     if (val && 1 == sscanf(val, "%"SCNu64, uval)) {
         rc = 0;
     }
     g_free(val);
     return rc;
 }

 void xenstore_update(void *unused)
 {
     char **vec = NULL;
     intptr_t type, ops, ptr;
     unsigned int dom, count;

     vec = xs_read_watch(xenstore, &count);
     if (vec == NULL) {
         goto cleanup;
     }

     if (sscanf(vec[XS_WATCH_TOKEN], "be:%" PRIxPTR ":%d:%" PRIxPTR,
                &type, &dom, &ops) == 3) {
         xenstore_update_be(vec[XS_WATCH_PATH], (void *)type, dom, (void*)ops);
     }
     if (sscanf(vec[XS_WATCH_TOKEN], "fe:%" PRIxPTR, &ptr) == 1) {
         xenstore_update_fe(vec[XS_WATCH_PATH], (void *)ptr);
     }

 cleanup:
     free(vec);
 }

 const char *xenbus_strstate(enum xenbus_state state)
 {
     static const char *const name[] = {
         [XenbusStateUnknown]       = "Unknown",
         [XenbusStateInitialising]  = "Initialising",
         [XenbusStateInitWait]      = "InitWait",
         [XenbusStateInitialised]   = "Initialised",
         [XenbusStateConnected]     = "Connected",
         [XenbusStateClosing]       = "Closing",
         [XenbusStateClosed]        = "Closed",
     };
     return (state < ARRAY_SIZE(name)) ? name[state] : "INVALID";
 }

 /*
  * msg_level:
  *  0 == errors (stderr + logfile).
  *  1 == informative debug messages (logfile only).
  *  2 == noisy debug messages (logfile only).
  *  3 == will flood your log (logfile only).
  */
 static void xen_pv_output_msg(struct XenLegacyDevice *xendev,
                               FILE *f, const char *fmt, va_list args)
 {
     if (xendev) {
         fprintf(f, "xen be: %s: ", xendev->name);
     } else {
         fprintf(f, "xen be core: ");
     }
     vfprintf(f, fmt, args);
 }

 void xen_pv_printf(struct XenLegacyDevice *xendev, int msg_level,
                    const char *fmt, ...)
 {
     FILE *logfile;
     va_list args;

     if (msg_level > (xendev ? xendev->debug : debug)) {
         return;
     }

     logfile = qemu_log_trylock();
     if (logfile) {
         va_start(args, fmt);
         xen_pv_output_msg(xendev, logfile, fmt, args);
         va_end(args);
         qemu_log_unlock(logfile);
     }

     if (msg_level == 0) {
         va_start(args, fmt);
         xen_pv_output_msg(xendev, stderr, fmt, args);
         va_end(args);
     }
 }

 void xen_pv_evtchn_event(void *opaque)
 {
     struct XenLegacyDevice *xendev = opaque;
     evtchn_port_t port;

     port = xenevtchn_pending(xendev->evtchndev);
     if (port != xendev->local_port) {
         xen_pv_printf(xendev, 0,
                       "xenevtchn_pending returned %d (expected %d)\n",
                       port, xendev->local_port);
         return;
     }
     xenevtchn_unmask(xendev->evtchndev, port);

     if (xendev->ops->event) {
         xendev->ops->event(xendev);
     }
 }

 void xen_pv_unbind_evtchn(struct XenLegacyDevice *xendev)
 {
     if (xendev->local_port == -1) {
         return;
     }
     qemu_set_fd_handler(xenevtchn_fd(xendev->evtchndev), NULL, NULL, NULL);
     xenevtchn_unbind(xendev->evtchndev, xendev->local_port);
     xen_pv_printf(xendev, 2, "unbind evtchn port %d\n", xendev->local_port);
     xendev->local_port = -1;
 }

 int xen_pv_send_notify(struct XenLegacyDevice *xendev)
 {
     return xenevtchn_notify(xendev->evtchndev, xendev->local_port);
 }

 /* ------------------------------------------------------------- */

 struct XenLegacyDevice *xen_pv_find_xendev(const char *type, int dom, int dev)
 {
     struct XenLegacyDevice *xendev;

     QTAILQ_FOREACH(xendev, &xendevs, next) {
         if (xendev->dom != dom) {
             continue;
         }
         if (xendev->dev != dev) {
             continue;
         }
         if (strcmp(xendev->type, type) != 0) {
             continue;
         }
         return xendev;
     }
     return NULL;
 }

 /*
  * release xen backend device.
  */
 void xen_pv_del_xendev(struct XenLegacyDevice *xendev)
 {
     if (xendev->ops->free) {
         xendev->ops->free(xendev);
     }

     if (xendev->fe) {
         char token[XEN_BUFSIZE];
         snprintf(token, sizeof(token), "fe:%p", xendev);
         xs_unwatch(xenstore, xendev->fe, token);
         g_free(xendev->fe);
     }

     if (xendev->evtchndev != NULL) {
         xenevtchn_close(xendev->evtchndev);
     }
     if (xendev->gnttabdev != NULL) {
         xengnttab_close(xendev->gnttabdev);
     }

     QTAILQ_REMOVE(&xendevs, xendev, next);

     qdev_unplug(&xendev->qdev, NULL);
 }

 void xen_pv_insert_xendev(struct XenLegacyDevice *xendev)
 {
     QTAILQ_INSERT_TAIL(&xendevs, xendev, next);
 }
	/*
	* Xen para-virtualization device
	*
	* (c) 2008 Gerd Hoffmann <kraxel@redhat.com>
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2.1 of the License, or (at your option) any later version.
	*
	* This library 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
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General Public
	* License along with this library; if not, see <http://www.gnu.org/licenses/>
	*/

	#include "qemu/osdep.h"
	#include "qemu/log.h"
	#include "qemu/main-loop.h"
	#include "hw/qdev-core.h"
	#include "hw/xen/xen-legacy-backend.h"
	#include "hw/xen/xen_pvdev.h"

	/* private */
	static int debug;

	struct xs_dirs {
	char *xs_dir;
	QTAILQ_ENTRY(xs_dirs) list;
	};

	static QTAILQ_HEAD(, xs_dirs) xs_cleanup =
	QTAILQ_HEAD_INITIALIZER(xs_cleanup);

	static QTAILQ_HEAD(, XenLegacyDevice) xendevs =
	QTAILQ_HEAD_INITIALIZER(xendevs);

	/* ------------------------------------------------------------- */

	static void xenstore_cleanup_dir(char *dir)
	{
	struct xs_dirs *d;

	d = g_malloc(sizeof(*d));
	d->xs_dir = dir;
	QTAILQ_INSERT_TAIL(&xs_cleanup, d, list);
	}

	void xen_config_cleanup(void)
	{
	struct xs_dirs *d;

	QTAILQ_FOREACH(d, &xs_cleanup, list) {
	xs_rm(xenstore, 0, d->xs_dir);
	}
	}

	int xenstore_mkdir(char *path, int p)
	{
	struct xs_permissions perms[2] = {
	{
	.id = 0, /* set owner: dom0 */
	}, {
	.id = xen_domid,
	.perms = p,
	}
	};

	if (!xs_mkdir(xenstore, 0, path)) {
	xen_pv_printf(NULL, 0, "xs_mkdir %s: failed\n", path);
	return -1;
	}
	xenstore_cleanup_dir(g_strdup(path));

	if (!xs_set_permissions(xenstore, 0, path, perms, 2)) {
	xen_pv_printf(NULL, 0, "xs_set_permissions %s: failed\n", path);
	return -1;
	}
	return 0;
	}

	int xenstore_write_str(const char base, const char node, const char *val)
	{
	char abspath[XEN_BUFSIZE];

	snprintf(abspath, sizeof(abspath), "%s/%s", base, node);
	if (!xs_write(xenstore, 0, abspath, val, strlen(val))) {
	return -1;
	}
	return 0;
	}

	char xenstore_read_str(const char base, const char *node)
	{
	char abspath[XEN_BUFSIZE];
	unsigned int len;
	char str, ret = NULL;

	snprintf(abspath, sizeof(abspath), "%s/%s", base, node);
	str = xs_read(xenstore, 0, abspath, &len);
	if (str != NULL) {
	/* move to qemu-allocated memory to make sure
	* callers can savely g_free() stuff. */
	ret = g_strdup(str);
	free(str);
	}
	return ret;
	}

	int xenstore_write_int(const char base, const char node, int ival)
	{
	char val[12];

	snprintf(val, sizeof(val), "%d", ival);
	return xenstore_write_str(base, node, val);
	}

	int xenstore_write_int64(const char base, const char node, int64_t ival)
	{
	char val[21];

	snprintf(val, sizeof(val), "%"PRId64, ival);
	return xenstore_write_str(base, node, val);
	}

	int xenstore_read_int(const char base, const char node, int *ival)
	{
	char *val;
	int rc = -1;

	val = xenstore_read_str(base, node);
	if (val && 1 == sscanf(val, "%d", ival)) {
	rc = 0;
	}
	g_free(val);
	return rc;
	}

	int xenstore_read_uint64(const char base, const char node, uint64_t *uval)
	{
	char *val;
	int rc = -1;

	val = xenstore_read_str(base, node);
	if (val && 1 == sscanf(val, "%"SCNu64, uval)) {
	rc = 0;
	}
	g_free(val);
	return rc;
	}

	void xenstore_update(void *unused)
	{
	char **vec = NULL;
	intptr_t type, ops, ptr;
	unsigned int dom, count;

	vec = xs_read_watch(xenstore, &count);
	if (vec == NULL) {
	goto cleanup;
	}

	if (sscanf(vec[XS_WATCH_TOKEN], "be:%" PRIxPTR ":%d:%" PRIxPTR,
	&type, &dom, &ops) == 3) {
	xenstore_update_be(vec[XS_WATCH_PATH], (void )type, dom, (void)ops);
	}
	if (sscanf(vec[XS_WATCH_TOKEN], "fe:%" PRIxPTR, &ptr) == 1) {
	xenstore_update_fe(vec[XS_WATCH_PATH], (void *)ptr);
	}

	cleanup:
	free(vec);
	}

	const char *xenbus_strstate(enum xenbus_state state)
	{
	static const char *const name[] = {
	[XenbusStateUnknown] = "Unknown",
	[XenbusStateInitialising] = "Initialising",
	[XenbusStateInitWait] = "InitWait",
	[XenbusStateInitialised] = "Initialised",
	[XenbusStateConnected] = "Connected",
	[XenbusStateClosing] = "Closing",
	[XenbusStateClosed] = "Closed",
	};
	return (state < ARRAY_SIZE(name)) ? name[state] : "INVALID";
	}

	/*
	* msg_level:
	* 0 == errors (stderr + logfile).
	* 1 == informative debug messages (logfile only).
	* 2 == noisy debug messages (logfile only).
	* 3 == will flood your log (logfile only).
	*/
	static void xen_pv_output_msg(struct XenLegacyDevice *xendev,
	FILE f, const char fmt, va_list args)
	{
	if (xendev) {
	fprintf(f, "xen be: %s: ", xendev->name);
	} else {
	fprintf(f, "xen be core: ");
	}
	vfprintf(f, fmt, args);
	}

	void xen_pv_printf(struct XenLegacyDevice *xendev, int msg_level,
	const char *fmt, ...)
	{
	FILE *logfile;
	va_list args;

	if (msg_level > (xendev ? xendev->debug : debug)) {
	return;
	}

	logfile = qemu_log_trylock();
	if (logfile) {
	va_start(args, fmt);
	xen_pv_output_msg(xendev, logfile, fmt, args);
	va_end(args);
	qemu_log_unlock(logfile);
	}

	if (msg_level == 0) {
	va_start(args, fmt);
	xen_pv_output_msg(xendev, stderr, fmt, args);
	va_end(args);
	}
	}

	void xen_pv_evtchn_event(void *opaque)
	{
	struct XenLegacyDevice *xendev = opaque;
	evtchn_port_t port;

	port = xenevtchn_pending(xendev->evtchndev);
	if (port != xendev->local_port) {
	xen_pv_printf(xendev, 0,
	"xenevtchn_pending returned %d (expected %d)\n",
	port, xendev->local_port);
	return;
	}
	xenevtchn_unmask(xendev->evtchndev, port);

	if (xendev->ops->event) {
	xendev->ops->event(xendev);
	}
	}

	void xen_pv_unbind_evtchn(struct XenLegacyDevice *xendev)
	{
	if (xendev->local_port == -1) {
	return;
	}
	qemu_set_fd_handler(xenevtchn_fd(xendev->evtchndev), NULL, NULL, NULL);
	xenevtchn_unbind(xendev->evtchndev, xendev->local_port);
	xen_pv_printf(xendev, 2, "unbind evtchn port %d\n", xendev->local_port);
	xendev->local_port = -1;
	}

	int xen_pv_send_notify(struct XenLegacyDevice *xendev)
	{
	return xenevtchn_notify(xendev->evtchndev, xendev->local_port);
	}

	/* ------------------------------------------------------------- */

	struct XenLegacyDevice xen_pv_find_xendev(const char type, int dom, int dev)
	{
	struct XenLegacyDevice *xendev;

	QTAILQ_FOREACH(xendev, &xendevs, next) {
	if (xendev->dom != dom) {
	continue;
	}
	if (xendev->dev != dev) {
	continue;
	}
	if (strcmp(xendev->type, type) != 0) {
	continue;
	}
	return xendev;
	}
	return NULL;
	}

	/*
	* release xen backend device.
	*/
	void xen_pv_del_xendev(struct XenLegacyDevice *xendev)
	{
	if (xendev->ops->free) {
	xendev->ops->free(xendev);
	}

	if (xendev->fe) {
	char token[XEN_BUFSIZE];
	snprintf(token, sizeof(token), "fe:%p", xendev);
	xs_unwatch(xenstore, xendev->fe, token);
	g_free(xendev->fe);
	}

	if (xendev->evtchndev != NULL) {
	xenevtchn_close(xendev->evtchndev);
	}
	if (xendev->gnttabdev != NULL) {
	xengnttab_close(xendev->gnttabdev);
	}

	QTAILQ_REMOVE(&xendevs, xendev, next);

	qdev_unplug(&xendev->qdev, NULL);
	}

	void xen_pv_insert_xendev(struct XenLegacyDevice *xendev)
	{
	QTAILQ_INSERT_TAIL(&xendevs, xendev, next);
	}