--- /dev/null
+/*
+ * xen backend driver infrastructure
+ * (c) 2008 Gerd Hoffmann <kraxel@redhat.com>
+ *
+ * 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; under version 2 of the License.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ *
+ * Contributions after 2012-01-13 are licensed under the terms of the
+ * GNU GPL, version 2 or (at your option) any later version.
+ */
+
+/*
+ * TODO: add some xenbus / xenstore concepts overview here.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <sys/signal.h>
+
+#include "hw/hw.h"
+#include "sysemu/char.h"
+#include "qemu/log.h"
+#include "hw/xen/xen_backend.h"
+
+#include <xen/grant_table.h>
+
+/* ------------------------------------------------------------- */
+
+/* public */
+XenXC xen_xc = XC_HANDLER_INITIAL_VALUE;
+struct xs_handle *xenstore = NULL;
+const char *xen_protocol;
+
+/* private */
+static QTAILQ_HEAD(XenDeviceHead, XenDevice) xendevs = QTAILQ_HEAD_INITIALIZER(xendevs);
+static int debug = 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;
+}
+
+int xenstore_write_be_str(struct XenDevice *xendev, const char *node, const char *val)
+{
+ return xenstore_write_str(xendev->be, node, val);
+}
+
+int xenstore_write_be_int(struct XenDevice *xendev, const char *node, int ival)
+{
+ return xenstore_write_int(xendev->be, node, ival);
+}
+
+int xenstore_write_be_int64(struct XenDevice *xendev, const char *node, int64_t ival)
+{
+ return xenstore_write_int64(xendev->be, node, ival);
+}
+
+char *xenstore_read_be_str(struct XenDevice *xendev, const char *node)
+{
+ return xenstore_read_str(xendev->be, node);
+}
+
+int xenstore_read_be_int(struct XenDevice *xendev, const char *node, int *ival)
+{
+ return xenstore_read_int(xendev->be, node, ival);
+}
+
+char *xenstore_read_fe_str(struct XenDevice *xendev, const char *node)
+{
+ return xenstore_read_str(xendev->fe, node);
+}
+
+int xenstore_read_fe_int(struct XenDevice *xendev, const char *node, int *ival)
+{
+ return xenstore_read_int(xendev->fe, node, ival);
+}
+
+int xenstore_read_fe_uint64(struct XenDevice *xendev, const char *node, uint64_t *uval)
+{
+ return xenstore_read_uint64(xendev->fe, node, uval);
+}
+
+/* ------------------------------------------------------------- */
+
+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";
+}
+
+int xen_be_set_state(struct XenDevice *xendev, enum xenbus_state state)
+{
+ int rc;
+
+ rc = xenstore_write_be_int(xendev, "state", state);
+ if (rc < 0) {
+ return rc;
+ }
+ xen_be_printf(xendev, 1, "backend state: %s -> %s\n",
+ xenbus_strstate(xendev->be_state), xenbus_strstate(state));
+ xendev->be_state = state;
+ return 0;
+}
+
+/* ------------------------------------------------------------- */
+
+struct XenDevice *xen_be_find_xendev(const char *type, int dom, int dev)
+{
+ struct XenDevice *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;
+}
+
+/*
+ * get xen backend device, allocate a new one if it doesn't exist.
+ */
+static struct XenDevice *xen_be_get_xendev(const char *type, int dom, int dev,
+ struct XenDevOps *ops)
+{
+ struct XenDevice *xendev;
+
+ xendev = xen_be_find_xendev(type, dom, dev);
+ if (xendev) {
+ return xendev;
+ }
+
+ /* init new xendev */
+ xendev = g_malloc0(ops->size);
+ xendev->type = type;
+ xendev->dom = dom;
+ xendev->dev = dev;
+ xendev->ops = ops;
+
+ snprintf(xendev->be, sizeof(xendev->be), "backend/%s/%d/%d",
+ xendev->type, xendev->dom, xendev->dev);
+ snprintf(xendev->name, sizeof(xendev->name), "%s-%d",
+ xendev->type, xendev->dev);
+
+ xendev->debug = debug;
+ xendev->local_port = -1;
+
+ xendev->evtchndev = xen_xc_evtchn_open(NULL, 0);
+ if (xendev->evtchndev == XC_HANDLER_INITIAL_VALUE) {
+ xen_be_printf(NULL, 0, "can't open evtchn device\n");
+ g_free(xendev);
+ return NULL;
+ }
+ fcntl(xc_evtchn_fd(xendev->evtchndev), F_SETFD, FD_CLOEXEC);
+
+ if (ops->flags & DEVOPS_FLAG_NEED_GNTDEV) {
+ xendev->gnttabdev = xen_xc_gnttab_open(NULL, 0);
+ if (xendev->gnttabdev == XC_HANDLER_INITIAL_VALUE) {
+ xen_be_printf(NULL, 0, "can't open gnttab device\n");
+ xc_evtchn_close(xendev->evtchndev);
+ g_free(xendev);
+ return NULL;
+ }
+ } else {
+ xendev->gnttabdev = XC_HANDLER_INITIAL_VALUE;
+ }
+
+ QTAILQ_INSERT_TAIL(&xendevs, xendev, next);
+
+ if (xendev->ops->alloc) {
+ xendev->ops->alloc(xendev);
+ }
+
+ return xendev;
+}
+
+/*
+ * release xen backend device.
+ */
+static struct XenDevice *xen_be_del_xendev(int dom, int dev)
+{
+ struct XenDevice *xendev, *xnext;
+
+ /*
+ * This is pretty much like QTAILQ_FOREACH(xendev, &xendevs, next) but
+ * we save the next pointer in xnext because we might free xendev.
+ */
+ xnext = xendevs.tqh_first;
+ while (xnext) {
+ xendev = xnext;
+ xnext = xendev->next.tqe_next;
+
+ if (xendev->dom != dom) {
+ continue;
+ }
+ if (xendev->dev != dev && dev != -1) {
+ continue;
+ }
+
+ 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 != XC_HANDLER_INITIAL_VALUE) {
+ xc_evtchn_close(xendev->evtchndev);
+ }
+ if (xendev->gnttabdev != XC_HANDLER_INITIAL_VALUE) {
+ xc_gnttab_close(xendev->gnttabdev);
+ }
+
+ QTAILQ_REMOVE(&xendevs, xendev, next);
+ g_free(xendev);
+ }
+ return NULL;
+}
+
+/*
+ * Sync internal data structures on xenstore updates.
+ * Node specifies the changed field. node = NULL means
+ * update all fields (used for initialization).
+ */
+static void xen_be_backend_changed(struct XenDevice *xendev, const char *node)
+{
+ if (node == NULL || strcmp(node, "online") == 0) {
+ if (xenstore_read_be_int(xendev, "online", &xendev->online) == -1) {
+ xendev->online = 0;
+ }
+ }
+
+ if (node) {
+ xen_be_printf(xendev, 2, "backend update: %s\n", node);
+ if (xendev->ops->backend_changed) {
+ xendev->ops->backend_changed(xendev, node);
+ }
+ }
+}
+
+static void xen_be_frontend_changed(struct XenDevice *xendev, const char *node)
+{
+ int fe_state;
+
+ if (node == NULL || strcmp(node, "state") == 0) {
+ if (xenstore_read_fe_int(xendev, "state", &fe_state) == -1) {
+ fe_state = XenbusStateUnknown;
+ }
+ if (xendev->fe_state != fe_state) {
+ xen_be_printf(xendev, 1, "frontend state: %s -> %s\n",
+ xenbus_strstate(xendev->fe_state),
+ xenbus_strstate(fe_state));
+ }
+ xendev->fe_state = fe_state;
+ }
+ if (node == NULL || strcmp(node, "protocol") == 0) {
+ g_free(xendev->protocol);
+ xendev->protocol = xenstore_read_fe_str(xendev, "protocol");
+ if (xendev->protocol) {
+ xen_be_printf(xendev, 1, "frontend protocol: %s\n", xendev->protocol);
+ }
+ }
+
+ if (node) {
+ xen_be_printf(xendev, 2, "frontend update: %s\n", node);
+ if (xendev->ops->frontend_changed) {
+ xendev->ops->frontend_changed(xendev, node);
+ }
+ }
+}
+
+/* ------------------------------------------------------------- */
+/* Check for possible state transitions and perform them. */
+
+/*
+ * Initial xendev setup. Read frontend path, register watch for it.
+ * Should succeed once xend finished setting up the backend device.
+ *
+ * Also sets initial state (-> Initializing) when done. Which
+ * only affects the xendev->be_state variable as xenbus should
+ * already be put into that state by xend.
+ */
+static int xen_be_try_setup(struct XenDevice *xendev)
+{
+ char token[XEN_BUFSIZE];
+ int be_state;
+
+ if (xenstore_read_be_int(xendev, "state", &be_state) == -1) {
+ xen_be_printf(xendev, 0, "reading backend state failed\n");
+ return -1;
+ }
+
+ if (be_state != XenbusStateInitialising) {
+ xen_be_printf(xendev, 0, "initial backend state is wrong (%s)\n",
+ xenbus_strstate(be_state));
+ return -1;
+ }
+
+ xendev->fe = xenstore_read_be_str(xendev, "frontend");
+ if (xendev->fe == NULL) {
+ xen_be_printf(xendev, 0, "reading frontend path failed\n");
+ return -1;
+ }
+
+ /* setup frontend watch */
+ snprintf(token, sizeof(token), "fe:%p", xendev);
+ if (!xs_watch(xenstore, xendev->fe, token)) {
+ xen_be_printf(xendev, 0, "watching frontend path (%s) failed\n",
+ xendev->fe);
+ return -1;
+ }
+ xen_be_set_state(xendev, XenbusStateInitialising);
+
+ xen_be_backend_changed(xendev, NULL);
+ xen_be_frontend_changed(xendev, NULL);
+ return 0;
+}
+
+/*
+ * Try initialize xendev. Prepare everything the backend can do
+ * without synchronizing with the frontend. Fakes hotplug-status. No
+ * hotplug involved here because this is about userspace drivers, thus
+ * there are kernel backend devices which could invoke hotplug.
+ *
+ * Goes to InitWait on success.
+ */
+static int xen_be_try_init(struct XenDevice *xendev)
+{
+ int rc = 0;
+
+ if (!xendev->online) {
+ xen_be_printf(xendev, 1, "not online\n");
+ return -1;
+ }
+
+ if (xendev->ops->init) {
+ rc = xendev->ops->init(xendev);
+ }
+ if (rc != 0) {
+ xen_be_printf(xendev, 1, "init() failed\n");
+ return rc;
+ }
+
+ xenstore_write_be_str(xendev, "hotplug-status", "connected");
+ xen_be_set_state(xendev, XenbusStateInitWait);
+ return 0;
+}
+
+/*
+ * Try to initialise xendev. Depends on the frontend being ready
+ * for it (shared ring and evtchn info in xenstore, state being
+ * Initialised or Connected).
+ *
+ * Goes to Connected on success.
+ */
+static int xen_be_try_initialise(struct XenDevice *xendev)
+{
+ int rc = 0;
+
+ if (xendev->fe_state != XenbusStateInitialised &&
+ xendev->fe_state != XenbusStateConnected) {
+ if (xendev->ops->flags & DEVOPS_FLAG_IGNORE_STATE) {
+ xen_be_printf(xendev, 2, "frontend not ready, ignoring\n");
+ } else {
+ xen_be_printf(xendev, 2, "frontend not ready (yet)\n");
+ return -1;
+ }
+ }
+
+ if (xendev->ops->initialise) {
+ rc = xendev->ops->initialise(xendev);
+ }
+ if (rc != 0) {
+ xen_be_printf(xendev, 0, "initialise() failed\n");
+ return rc;
+ }
+
+ xen_be_set_state(xendev, XenbusStateConnected);
+ return 0;
+}
+
+/*
+ * Try to let xendev know that it is connected. Depends on the
+ * frontend being Connected. Note that this may be called more
+ * than once since the backend state is not modified.
+ */
+static void xen_be_try_connected(struct XenDevice *xendev)
+{
+ if (!xendev->ops->connected) {
+ return;
+ }
+
+ if (xendev->fe_state != XenbusStateConnected) {
+ if (xendev->ops->flags & DEVOPS_FLAG_IGNORE_STATE) {
+ xen_be_printf(xendev, 2, "frontend not ready, ignoring\n");
+ } else {
+ xen_be_printf(xendev, 2, "frontend not ready (yet)\n");
+ return;
+ }
+ }
+
+ xendev->ops->connected(xendev);
+}
+
+/*
+ * Teardown connection.
+ *
+ * Goes to Closed when done.
+ */
+static void xen_be_disconnect(struct XenDevice *xendev, enum xenbus_state state)
+{
+ if (xendev->be_state != XenbusStateClosing &&
+ xendev->be_state != XenbusStateClosed &&
+ xendev->ops->disconnect) {
+ xendev->ops->disconnect(xendev);
+ }
+ if (xendev->be_state != state) {
+ xen_be_set_state(xendev, state);
+ }
+}
+
+/*
+ * Try to reset xendev, for reconnection by another frontend instance.
+ */
+static int xen_be_try_reset(struct XenDevice *xendev)
+{
+ if (xendev->fe_state != XenbusStateInitialising) {
+ return -1;
+ }
+
+ xen_be_printf(xendev, 1, "device reset (for re-connect)\n");
+ xen_be_set_state(xendev, XenbusStateInitialising);
+ return 0;
+}
+
+/*
+ * state change dispatcher function
+ */
+void xen_be_check_state(struct XenDevice *xendev)
+{
+ int rc = 0;
+
+ /* frontend may request shutdown from almost anywhere */
+ if (xendev->fe_state == XenbusStateClosing ||
+ xendev->fe_state == XenbusStateClosed) {
+ xen_be_disconnect(xendev, xendev->fe_state);
+ return;
+ }
+
+ /* check for possible backend state transitions */
+ for (;;) {
+ switch (xendev->be_state) {
+ case XenbusStateUnknown:
+ rc = xen_be_try_setup(xendev);
+ break;
+ case XenbusStateInitialising:
+ rc = xen_be_try_init(xendev);
+ break;
+ case XenbusStateInitWait:
+ rc = xen_be_try_initialise(xendev);
+ break;
+ case XenbusStateConnected:
+ /* xendev->be_state doesn't change */
+ xen_be_try_connected(xendev);
+ rc = -1;
+ break;
+ case XenbusStateClosed:
+ rc = xen_be_try_reset(xendev);
+ break;
+ default:
+ rc = -1;
+ }
+ if (rc != 0) {
+ break;
+ }
+ }
+}
+
+/* ------------------------------------------------------------- */
+
+static int xenstore_scan(const char *type, int dom, struct XenDevOps *ops)
+{
+ struct XenDevice *xendev;
+ char path[XEN_BUFSIZE], token[XEN_BUFSIZE];
+ char **dev = NULL;
+ unsigned int cdev, j;
+
+ /* setup watch */
+ snprintf(token, sizeof(token), "be:%p:%d:%p", type, dom, ops);
+ snprintf(path, sizeof(path), "backend/%s/%d", type, dom);
+ if (!xs_watch(xenstore, path, token)) {
+ xen_be_printf(NULL, 0, "xen be: watching backend path (%s) failed\n", path);
+ return -1;
+ }
+
+ /* look for backends */
+ dev = xs_directory(xenstore, 0, path, &cdev);
+ if (!dev) {
+ return 0;
+ }
+ for (j = 0; j < cdev; j++) {
+ xendev = xen_be_get_xendev(type, dom, atoi(dev[j]), ops);
+ if (xendev == NULL) {
+ continue;
+ }
+ xen_be_check_state(xendev);
+ }
+ free(dev);
+ return 0;
+}
+
+static void xenstore_update_be(char *watch, char *type, int dom,
+ struct XenDevOps *ops)
+{
+ struct XenDevice *xendev;
+ char path[XEN_BUFSIZE], *bepath;
+ unsigned int len, dev;
+
+ len = snprintf(path, sizeof(path), "backend/%s/%d", type, dom);
+ if (strncmp(path, watch, len) != 0) {
+ return;
+ }
+ if (sscanf(watch+len, "/%u/%255s", &dev, path) != 2) {
+ strcpy(path, "");
+ if (sscanf(watch+len, "/%u", &dev) != 1) {
+ dev = -1;
+ }
+ }
+ if (dev == -1) {
+ return;
+ }
+
+ xendev = xen_be_get_xendev(type, dom, dev, ops);
+ if (xendev != NULL) {
+ bepath = xs_read(xenstore, 0, xendev->be, &len);
+ if (bepath == NULL) {
+ xen_be_del_xendev(dom, dev);
+ } else {
+ free(bepath);
+ xen_be_backend_changed(xendev, path);
+ xen_be_check_state(xendev);
+ }
+ }
+}
+
+static void xenstore_update_fe(char *watch, struct XenDevice *xendev)
+{
+ char *node;
+ unsigned int len;
+
+ len = strlen(xendev->fe);
+ if (strncmp(xendev->fe, watch, len) != 0) {
+ return;
+ }
+ if (watch[len] != '/') {
+ return;
+ }
+ node = watch + len + 1;
+
+ xen_be_frontend_changed(xendev, node);
+ xen_be_check_state(xendev);
+}
+
+static 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);
+}
+
+static void xen_be_evtchn_event(void *opaque)
+{
+ struct XenDevice *xendev = opaque;
+ evtchn_port_t port;
+
+ port = xc_evtchn_pending(xendev->evtchndev);
+ if (port != xendev->local_port) {
+ xen_be_printf(xendev, 0, "xc_evtchn_pending returned %d (expected %d)\n",
+ port, xendev->local_port);
+ return;
+ }
+ xc_evtchn_unmask(xendev->evtchndev, port);
+
+ if (xendev->ops->event) {
+ xendev->ops->event(xendev);
+ }
+}
+
+/* -------------------------------------------------------------------- */
+
+int xen_be_init(void)
+{
+ xenstore = xs_daemon_open();
+ if (!xenstore) {
+ xen_be_printf(NULL, 0, "can't connect to xenstored\n");
+ return -1;
+ }
+
+ qemu_set_fd_handler(xs_fileno(xenstore), xenstore_update, NULL, NULL);
+
+ if (xen_xc == XC_HANDLER_INITIAL_VALUE) {
+ /* Check if xen_init() have been called */
+ goto err;
+ }
+ return 0;
+
+err:
+ qemu_set_fd_handler(xs_fileno(xenstore), NULL, NULL, NULL);
+ xs_daemon_close(xenstore);
+ xenstore = NULL;
+
+ return -1;
+}
+
+int xen_be_register(const char *type, struct XenDevOps *ops)
+{
+ return xenstore_scan(type, xen_domid, ops);
+}
+
+int xen_be_bind_evtchn(struct XenDevice *xendev)
+{
+ if (xendev->local_port != -1) {
+ return 0;
+ }
+ xendev->local_port = xc_evtchn_bind_interdomain
+ (xendev->evtchndev, xendev->dom, xendev->remote_port);
+ if (xendev->local_port == -1) {
+ xen_be_printf(xendev, 0, "xc_evtchn_bind_interdomain failed\n");
+ return -1;
+ }
+ xen_be_printf(xendev, 2, "bind evtchn port %d\n", xendev->local_port);
+ qemu_set_fd_handler(xc_evtchn_fd(xendev->evtchndev),
+ xen_be_evtchn_event, NULL, xendev);
+ return 0;
+}
+
+void xen_be_unbind_evtchn(struct XenDevice *xendev)
+{
+ if (xendev->local_port == -1) {
+ return;
+ }
+ qemu_set_fd_handler(xc_evtchn_fd(xendev->evtchndev), NULL, NULL, NULL);
+ xc_evtchn_unbind(xendev->evtchndev, xendev->local_port);
+ xen_be_printf(xendev, 2, "unbind evtchn port %d\n", xendev->local_port);
+ xendev->local_port = -1;
+}
+
+int xen_be_send_notify(struct XenDevice *xendev)
+{
+ return xc_evtchn_notify(xendev->evtchndev, xendev->local_port);
+}
+
+/*
+ * 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).
+ */
+void xen_be_printf(struct XenDevice *xendev, int msg_level, const char *fmt, ...)
+{
+ va_list args;
+
+ if (xendev) {
+ if (msg_level > xendev->debug) {
+ return;
+ }
+ qemu_log("xen be: %s: ", xendev->name);
+ if (msg_level == 0) {
+ fprintf(stderr, "xen be: %s: ", xendev->name);
+ }
+ } else {
+ if (msg_level > debug) {
+ return;
+ }
+ qemu_log("xen be core: ");
+ if (msg_level == 0) {
+ fprintf(stderr, "xen be core: ");
+ }
+ }
+ va_start(args, fmt);
+ qemu_log_vprintf(fmt, args);
+ va_end(args);
+ if (msg_level == 0) {
+ va_start(args, fmt);
+ vfprintf(stderr, fmt, args);
+ va_end(args);
+ }
+ qemu_log_flush();
+}
Code Review / kvmfornfv.git / blobdiff