diff options
Diffstat (limited to 'hw/xen_backend.c')
| -rw-r--r-- | hw/xen_backend.c | 800 |
1 files changed, 0 insertions, 800 deletions
diff --git a/hw/xen_backend.c b/hw/xen_backend.c deleted file mode 100644 index 02693d7565..0000000000 --- a/hw/xen_backend.c +++ /dev/null @@ -1,800 +0,0 @@ -/* - * 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 "char/char.h" -#include "qemu/log.h" -#include "hw/xen_backend.h" - -#include <xen/grant_table.h> - -/* ------------------------------------------------------------- */ - -/* public */ -XenXC xen_xc = XC_HANDLER_INITIAL_VALUE; -XenGnttab xen_xcg = 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_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); -} - -/* ------------------------------------------------------------- */ - -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; - char *dom0; - - 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; - - dom0 = xs_get_domain_path(xenstore, 0); - snprintf(xendev->be, sizeof(xendev->be), "%s/backend/%s/%d/%d", - dom0, xendev->type, xendev->dom, xendev->dev); - snprintf(xendev->name, sizeof(xendev->name), "%s-%d", - xendev->type, xendev->dev); - free(dom0); - - 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, *dom0; - unsigned int cdev, j; - - /* setup watch */ - dom0 = xs_get_domain_path(xenstore, 0); - snprintf(token, sizeof(token), "be:%p:%d:%p", type, dom, ops); - snprintf(path, sizeof(path), "%s/backend/%s/%d", dom0, type, dom); - free(dom0); - 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], *dom0, *bepath; - unsigned int len, dev; - - dom0 = xs_get_domain_path(xenstore, 0); - len = snprintf(path, sizeof(path), "%s/backend/%s/%d", dom0, type, dom); - free(dom0); - 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; - } - - if (qemu_set_fd_handler(xs_fileno(xenstore), xenstore_update, NULL, NULL) < 0) { - goto err; - } - - 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(); -} |