This patch adds infrastructure for xen backend drivers living in qemu,
so drivers don't need to implement common stuff on their own. It's
mostly xenbus management stuff: some functions to access xentore,
setting up xenstore watches, callbacks on device discovery and state
changes, handle event channel, ...
Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
---
Makefile.target | 2 +-
hw/list.h | 169 ++++++++++++++
hw/xen-backend.c | 663 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
hw/xen-backend.h | 116 ++++++++++
hw/xen-machine.c | 5 +-
5 files changed, 953 insertions(+), 2 deletions(-)
create mode 100644 hw/list.h
create mode 100644 hw/xen-backend.c
create mode 100644 hw/xen-backend.h
diff --git a/Makefile.target b/Makefile.target
index 4f42582..0451048 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -516,7 +516,7 @@ LIBS += $(CONFIG_VNC_TLS_LIBS)
endif
# xen backend driver support
-XEN_OBJS := xen-machine.o
+XEN_OBJS := xen-machine.o xen-backend.o
ifeq ($(CONFIG_XEN), yes)
OBJS += $(XEN_OBJS)
LIBS += $(XEN_LIBS)
diff --git a/hw/list.h b/hw/list.h
new file mode 100644
index 0000000..fa9f790
--- /dev/null
+++ b/hw/list.h
@@ -0,0 +1,169 @@
+#ifndef _LIST_H
+#define _LIST_H 1
+
+/*
+ * Simple doubly linked list implementation.
+ * -- shamelessly stolen from the linux kernel sources
+ *
+ * Some of the internal functions ("__xxx") are useful when
+ * manipulating whole lists rather than single entries, as
+ * sometimes we already know the next/prev entries and we can
+ * generate better code by using them directly rather than
+ * using the generic single-entry routines.
+ */
+
+struct list_head {
+ struct list_head *next, *prev;
+};
+
+#define LIST_HEAD_INIT(name) { &(name), &(name) }
+
+#define LIST_HEAD(name) \
+ struct list_head name = LIST_HEAD_INIT(name)
+
+#define INIT_LIST_HEAD(ptr) do { \
+ (ptr)->next = (ptr); (ptr)->prev = (ptr); \
+} while (0)
+
+/*
+ * Insert a item entry between two known consecutive entries.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static __inline__ void __list_add(struct list_head * item,
+ struct list_head * prev,
+ struct list_head * next)
+{
+ next->prev = item;
+ item->next = next;
+ item->prev = prev;
+ prev->next = item;
+}
+
+/**
+ * list_add - add a item entry
+ * @item: item entry to be added
+ * @head: list head to add it after
+ *
+ * Insert a item entry after the specified head.
+ * This is good for implementing stacks.
+ */
+static __inline__ void list_add(struct list_head *item, struct list_head *head)
+{
+ __list_add(item, head, head->next);
+}
+
+/**
+ * list_add_tail - add a item entry
+ * @item: item entry to be added
+ * @head: list head to add it before
+ *
+ * Insert a item entry before the specified head.
+ * This is useful for implementing queues.
+ */
+static __inline__ void list_add_tail(struct list_head *item, struct list_head
*head)
+{
+ __list_add(item, head->prev, head);
+}
+
+/*
+ * Delete a list entry by making the prev/next entries
+ * point to each other.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static __inline__ void __list_del(struct list_head * prev,
+ struct list_head * next)
+{
+ next->prev = prev;
+ prev->next = next;
+}
+
+/**
+ * list_del - deletes entry from list.
+ * @entry: the element to delete from the list.
+ * Note: list_empty on entry does not return true after this, the entry is in
an undefined state.
+ */
+static __inline__ void list_del(struct list_head *entry)
+{
+ __list_del(entry->prev, entry->next);
+}
+
+/**
+ * list_del_init - deletes entry from list and reinitialize it.
+ * @entry: the element to delete from the list.
+ */
+static __inline__ void list_del_init(struct list_head *entry)
+{
+ __list_del(entry->prev, entry->next);
+ INIT_LIST_HEAD(entry);
+}
+
+/**
+ * list_empty - tests whether a list is empty
+ * @head: the list to test.
+ */
+static __inline__ int list_empty(struct list_head *head)
+{
+ return head->next == head;
+}
+
+/**
+ * list_splice - join two lists
+ * @list: the item list to add.
+ * @head: the place to add it in the first list.
+ */
+static __inline__ void list_splice(struct list_head *list, struct list_head
*head)
+{
+ struct list_head *first = list->next;
+
+ if (first != list) {
+ struct list_head *last = list->prev;
+ struct list_head *at = head->next;
+
+ first->prev = head;
+ head->next = first;
+
+ last->next = at;
+ at->prev = last;
+ }
+}
+
+/**
+ * list_entry - get the struct for this entry
+ * @ptr: the &struct list_head pointer.
+ * @type: the type of the struct this is embedded in.
+ * @member: the name of the list_struct within the struct.
+ */
+#define list_entry(ptr, type, member) \
+ ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
+
+/**
+ * list_for_each - iterate over a list
+ * @pos: the &struct list_head to use as a loop counter.
+ * @head: the head for your list.
+ */
+#define list_for_each(pos, head) \
+ for (pos = (head)->next; pos != (head); pos = pos->next)
+
+/**
+ * list_for_each_safe - iterate over a list safe against removal of
list entry
+ * @pos: the &struct list_head to use as a loop counter.
+ * @n: another &struct list_head to use as temporary storage
+ * @head: the head for your list.
+ */
+#define list_for_each_safe(pos, n, head) \
+ for (pos = (head)->next, n = pos->next; pos != (head); \
+ pos = n, n = pos->next)
+
+/**
+ * list_for_each_prev - iterate over a list in reverse order
+ * @pos: the &struct list_head to use as a loop counter.
+ * @head: the head for your list.
+ */
+#define list_for_each_prev(pos, head) \
+ for (pos = (head)->prev; pos != (head); pos = pos->prev)
+
+#endif /* _LIST_H */
diff --git a/hw/xen-backend.c b/hw/xen-backend.c
new file mode 100644
index 0000000..4819624
--- /dev/null
+++ b/hw/xen-backend.c
@@ -0,0 +1,663 @@
+/*
+ * xen backend driver infrastructure
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#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 <xs.h>
+#include <xenctrl.h>
+#include <xen/grant_table.h>
+
+#include "hw.h"
+#include "qemu-char.h"
+#include "xen-backend.h"
+
+/* ------------------------------------------------------------- */
+
+/* public */
+int xen_xc;
+struct xs_handle *xenstore = NULL;
+
+/* private */
+static LIST_HEAD(xendevs);
+static const char *root = "/local/domain/0/backend";
+static int debug = 0;
+
+/* ------------------------------------------------------------- */
+
+int xenstore_write_str(const char *base, const char *node, const char *val)
+{
+ char abspath[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[BUFSIZE];
+ unsigned int len;
+
+ snprintf(abspath, sizeof(abspath), "%s/%s", base, node);
+ return xs_read(xenstore, 0, abspath, &len);
+}
+
+int xenstore_write_int(const char *base, const char *node, int ival)
+{
+ char val[32];
+
+ snprintf(val, sizeof(val), "%d", 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;
+ free(val);
+ return rc;
+}
+
+int xenstore_write_be_str(struct xendev *xendev, const char *node, const char
*val)
+{
+ return xenstore_write_str(xendev->be, node, val);
+}
+
+int xenstore_write_be_int(struct xendev *xendev, const char *node, int ival)
+{
+ return xenstore_write_int(xendev->be, node, ival);
+}
+
+char *xenstore_read_be_str(struct xendev *xendev, const char *node)
+{
+ return xenstore_read_str(xendev->be, node);
+}
+
+int xenstore_read_be_int(struct xendev *xendev, const char *node, int *ival)
+{
+ return xenstore_read_int(xendev->be, node, ival);
+}
+
+char *xenstore_read_fe_str(struct xendev *xendev, const char *node)
+{
+ return xenstore_read_str(xendev->fe, node);
+}
+
+int xenstore_read_fe_int(struct xendev *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 xendev *xendev, enum xenbus_state state)
+{
+ int rc;
+
+ rc = xenstore_write_be_int(xendev, "state", state);
+ if (0 != rc)
+ 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 xendev *xen_be_find_xendev(char *type, int dom, int dev)
+{
+ struct xendev *xendev;
+ struct list_head *item;
+
+ list_for_each(item, &xendevs) {
+ xendev = list_entry(item, struct xendev, next);
+ if (xendev->dom != dom)
+ continue;
+ if (xendev->dev != dev)
+ continue;
+ if (0 != strcmp(xendev->type, type))
+ continue;
+ return xendev;
+ }
+ return NULL;
+}
+
+/*
+ * get xen backend device, allocate a new one if it doesn't exist.
+ */
+static struct xendev *xen_be_get_xendev(char *type, int dom, int dev,
+ struct devops *ops)
+{
+ struct xendev *xendev;
+
+ xendev = xen_be_find_xendev(type, dom, dev);
+ if (xendev)
+ return xendev;
+
+ /* init new xendev */
+ xendev = malloc(ops->size);
+ memset(xendev,0,ops->size);
+ xendev->type = type;
+ xendev->dom = dom;
+ xendev->dev = dev;
+ xendev->ops = ops;
+ snprintf(xendev->be, sizeof(xendev->be), "%s/%s/%d/%d",
+ root, 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 = xc_evtchn_open();
+ if (xendev->evtchndev < 0) {
+ fprintf(stderr, "can't open evtchn device\n");
+ free(xendev);
+ return NULL;
+ }
+ fcntl(xc_evtchn_fd(xendev->evtchndev), F_SETFD, FD_CLOEXEC);
+
+ if (ops->flags & DEVOPS_FLAG_NEED_GNTDEV) {
+ xendev->gnttabdev = xc_gnttab_open();
+ if (xendev->gnttabdev < 0) {
+ fprintf(stderr, "can't open gnttab device\n");
+ xc_evtchn_close(xendev->evtchndev);
+ free(xendev);
+ return NULL;
+ }
+ } else {
+ xendev->gnttabdev = -1;
+ }
+
+ list_add_tail(&xendev->next, &xendevs);
+
+ if (xendev->ops->alloc)
+ xendev->ops->alloc(xendev);
+
+ return xendev;
+}
+
+/*
+ * release xen backend device.
+ */
+static struct xendev *xen_be_del_xendev(int dom, int dev)
+{
+ struct xendev *xendev;
+ struct list_head *item, *tmp;
+
+ list_for_each_safe(item, tmp, &xendevs) {
+ xendev = list_entry(item, struct xendev, 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[BUFSIZE];
+ snprintf(token, sizeof(token), "fe:%p", xendev);
+ xs_unwatch(xenstore, xendev->fe, token);
+ free(xendev->fe);
+ }
+
+ if (xendev->evtchndev >= 0)
+ xc_evtchn_close(xendev->evtchndev);
+ if (xendev->gnttabdev >= 0)
+ xc_gnttab_close(xendev->gnttabdev);
+
+ list_del(&xendev->next);
+ 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 xendev *xendev, const char *node)
+{
+ if (NULL == node || 0 == strcmp(node, "online")) {
+ if (-1 == xenstore_read_be_int(xendev, "online", &xendev->online))
+ 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 xendev *xendev, const char *node)
+{
+ int fe_state;
+
+ if (NULL == node || 0 == strcmp(node, "state")) {
+ if (-1 == xenstore_read_fe_int(xendev, "state", &fe_state))
+ 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 (NULL == node || 0 == strcmp(node, "protocol")) {
+ 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 xendev *xendev)
+{
+ char token[BUFSIZE];
+ int be_state;
+
+ if (-1 == xenstore_read_be_int(xendev, "state", &be_state)) {
+ 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 (NULL == xendev->fe) {
+ 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 xendev *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 (0 != rc) {
+ 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 connect 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_connect(struct xendev *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->connect)
+ rc = xendev->ops->connect(xendev);
+ if (0 != rc) {
+ xen_be_printf(xendev, 0, "connect() failed\n");
+ return rc;
+ }
+
+ xen_be_set_state(xendev, XenbusStateConnected);
+
+#if 0
+ if (xendev->ops->event)
+ xendev->ops->event(xendev);
+#endif
+ return 0;
+}
+
+/*
+ * Teardown connection.
+ *
+ * Goes to Closed when done.
+ */
+static void xen_be_disconnect(struct xendev *xendev)
+{
+ if (xendev->be_state == XenbusStateClosed)
+ return;
+ if (xendev->ops->disconnect)
+ xendev->ops->disconnect(xendev);
+ xen_be_set_state(xendev, XenbusStateClosed);
+}
+
+/*
+ * state change dispatcher function
+ */
+void xen_be_check_state(struct xendev *xendev)
+{
+ int rc = 0;
+
+ /* frontend may request shutdown from almost anywhere */
+ if (xendev->fe_state == XenbusStateClosing ||
+ xendev->fe_state == XenbusStateClosed) {
+ xen_be_disconnect(xendev);
+ 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_connect(xendev);
+ break;
+ default:
+ rc = -1;
+ }
+ if (0 != rc)
+ break;
+ }
+}
+
+/* ------------------------------------------------------------- */
+
+static int xenstore_scan(char *type, int dom, struct devops *ops)
+{
+ struct xendev *xendev;
+ char path[BUFSIZE], token[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), "%s/%s/%d", root, type, dom);
+ if (!xs_watch(xenstore, path, token)) {
+ fprintf(stderr, "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 (NULL == xendev)
+ continue;
+ xen_be_check_state(xendev);
+ }
+ free(dev);
+ return 0;
+}
+
+static void xenstore_update_be(char *watch, char *type, int dom,
+ struct devops *ops)
+{
+ struct xendev *xendev;
+ char path[BUFSIZE];
+ unsigned int len, dev;
+
+ len = snprintf(path, sizeof(path), "%s/%s/%d", root, type, dom);
+ if (0 != strncmp(path, watch, len))
+ return;
+ if (2 != sscanf(watch+len, "/%u/%255s", &dev, path)) {
+ strcpy(path, "");
+ if (1 != sscanf(watch+len, "/%u", &dev))
+ dev = -1;
+ }
+ if (-1 == dev)
+ return;
+
+ if (0) {
+ /* FIXME: detect devices being deleted from xenstore ... */
+ xen_be_del_xendev(dom, dev);
+ }
+
+ xendev = xen_be_get_xendev(type, dom, dev, ops);
+ if (NULL != xendev) {
+ xen_be_backend_changed(xendev, path);
+ xen_be_check_state(xendev);
+ }
+}
+
+static void xenstore_update_fe(char *watch, struct xendev *xendev)
+{
+ char *node;
+ unsigned int len;
+
+ len = strlen(xendev->fe);
+ if (0 != strncmp(xendev->fe, watch, len))
+ 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 (NULL == vec)
+ goto cleanup;
+
+ if (3 == sscanf(vec[XS_WATCH_TOKEN], "be:%" PRIxPTR ":%d:%" PRIxPTR,
+ &type, &dom, &ops))
+ xenstore_update_be(vec[XS_WATCH_PATH], (void*)type, dom, (void*)ops);
+ if (1 == sscanf(vec[XS_WATCH_TOKEN], "fe:%" PRIxPTR, &ptr))
+ xenstore_update_fe(vec[XS_WATCH_PATH], (void*)ptr);
+
+cleanup:
+ free(vec);
+}
+
+static void xen_be_evtchn_event(void *opaque)
+{
+ struct xendev *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) {
+ fprintf(stderr, "can't connect to xenstored\n");
+ return -1;
+ }
+
+ if (qemu_set_fd_handler(xs_fileno(xenstore), xenstore_update, NULL, NULL)
< 0)
+ goto err;
+
+ xen_xc = xc_interface_open();
+ if (-1 == xen_xc) {
+ fprintf(stderr, "can't open xen interface\n");
+ 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(char *type, struct devops *ops)
+{
+ return xenstore_scan(type, xen_domid, ops);
+}
+
+int xen_be_bind_evtchn(struct xendev *xendev)
+{
+ if (xendev->local_port != -1)
+ return 0;
+ xendev->local_port = xc_evtchn_bind_interdomain
+ (xendev->evtchndev, xendev->dom, xendev->remote_port);
+ if (-1 == xendev->local_port) {
+ xendev->local_port = 0;
+ return -1;
+ }
+ qemu_set_fd_handler(xc_evtchn_fd(xendev->evtchndev),
+ xen_be_evtchn_event, NULL, xendev);
+#if 0
+ xc_evtchn_unmask(xendev->evtchndev, xendev->local_port);
+#endif
+ return 0;
+}
+
+void xen_be_unbind_evtchn(struct xendev *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);
+ xendev->local_port = -1;
+}
+
+int xen_be_send_notify(struct xendev *xendev)
+{
+ return xc_evtchn_notify(xendev->evtchndev, xendev->local_port);
+}
+
+/*
+ * msg_level:
+ * 0 == errors.
+ * 1 == informative debug messages.
+ * 2 == noisy debug messages.
+ * 3 == will flood your log.
+ */
+void xen_be_printf(struct xendev *xendev, int msg_level, const char *fmt, ...)
+{
+ va_list args;
+
+ if (msg_level > xendev->debug)
+ return;
+ fprintf(stderr, "xen be: %s: ", xendev->name);
+ va_start(args, fmt);
+ vfprintf(stderr, fmt, args);
+ va_end(args);
+}
diff --git a/hw/xen-backend.h b/hw/xen-backend.h
new file mode 100644
index 0000000..db36ae7
--- /dev/null
+++ b/hw/xen-backend.h
@@ -0,0 +1,116 @@
+#include <stddef.h>
+#include <xs.h>
+#include <xenctrl.h>
+#include <xen/elfnote.h>
+#include <xen/elfstructs.h>
+
+#include <xen/io/xenbus.h>
+
+#include "list.h"
+
+#include "hw.h"
+#include "xen.h"
+
+/*
+ * tweaks needed to build with different xen versions
+ * 0x00030205 -> 3.1.0
+ * 0x00030207 -> 3.2.0
+ * 0x00030208 -> unstable
+ */
+#include <xen/xen-compat.h>
+#if __XEN_LATEST_INTERFACE_VERSION__ < 0x00030207
+# define xc_map_foreign_pages xc_map_foreign_batch
+#endif
+#if __XEN_LATEST_INTERFACE_VERSION__ < 0x00030208
+# define xen_mb() mb()
+# define xen_rmb() rmb()
+# define xen_wmb() wmb()
+#endif
+
+/* ------------------------------------------------------------- */
+
+#define container_of(ptr, type, member) ({ \
+ const typeof( ((type *)0)->member ) *__mptr = (ptr); \
+ (type *)( (char *)__mptr - offsetof(type,member) );})
+
+/* ------------------------------------------------------------- */
+
+#define BUFSIZE 1024
+
+struct xendev;
+
+/* driver uses grant tables -> open gntdev device (xendev->gnttabdev) */
+#define DEVOPS_FLAG_NEED_GNTDEV 1
+/* don't expect frontend doing correct state transitions (aka console quirk) */
+#define DEVOPS_FLAG_IGNORE_STATE 2
+
+struct devops {
+ size_t size;
+ uint32_t flags;
+ void (*alloc)(struct xendev *xendev);
+ int (*init)(struct xendev *xendev);
+ int (*connect)(struct xendev *xendev);
+ void (*event)(struct xendev *xendev);
+ void (*disconnect)(struct xendev *xendev);
+ int (*free)(struct xendev *xendev);
+ void (*backend_changed)(struct xendev *xendev, const char *node);
+ void (*frontend_changed)(struct xendev *xendev, const char *node);
+};
+
+struct xendev {
+ char *type;
+ int dom;
+ int dev;
+ char name[64];
+ int debug;
+
+ enum xenbus_state be_state;
+ enum xenbus_state fe_state;
+ int online;
+ char be[BUFSIZE];
+ char *fe;
+ char *protocol;
+ int remote_port;
+ int local_port;
+
+ int evtchndev;
+ int gnttabdev;
+
+ struct devops *ops;
+ struct list_head next;
+};
+
+/* ------------------------------------------------------------- */
+
+/* variables */
+extern int xen_domid; /* set by cmd line option, in vl.c */
+extern int xen_xc;
+extern struct xs_handle *xenstore;
+
+/* xenstore helper functions */
+int xenstore_write_str(const char *base, const char *node, const char *val);
+int xenstore_write_int(const char *base, const char *node, int ival);
+char *xenstore_read_str(const char *base, const char *node);
+int xenstore_read_int(const char *base, const char *node, int *ival);
+
+int xenstore_write_be_str(struct xendev *xendev, const char *node, const char
*val);
+int xenstore_write_be_int(struct xendev *xendev, const char *node, int ival);
+char *xenstore_read_be_str(struct xendev *xendev, const char *node);
+int xenstore_read_be_int(struct xendev *xendev, const char *node, int *ival);
+char *xenstore_read_fe_str(struct xendev *xendev, const char *node);
+int xenstore_read_fe_int(struct xendev *xendev, const char *node, int *ival);
+
+const char *xenbus_strstate(enum xenbus_state state);
+struct xendev *xen_be_find_xendev(char *type, int dom, int dev);
+void xen_be_check_state(struct xendev *xendev);
+
+/* xen backend driver bits */
+int xen_be_init(void);
+int xen_be_register(char *type, struct devops *ops);
+int xen_be_set_state(struct xendev *xendev, enum xenbus_state state);
+int xen_be_bind_evtchn(struct xendev *xendev);
+void xen_be_unbind_evtchn(struct xendev *xendev);
+int xen_be_send_notify(struct xendev *xendev);
+void xen_be_printf(struct xendev *xendev, int msg_level, const char *fmt, ...)
+ __attribute__ ((format(printf, 3, 4)));
+
diff --git a/hw/xen-machine.c b/hw/xen-machine.c
index 88f0f6e..798c0a7 100644
--- a/hw/xen-machine.c
+++ b/hw/xen-machine.c
@@ -25,7 +25,7 @@
#include "hw.h"
#include "boards.h"
-#include "xen.h"
+#include "xen-backend.h"
/* -------------------------------------------------------------------- */
/* variables */
@@ -54,6 +54,9 @@ static void xenpv_init(ram_addr_t ram_size, int vga_ram_size,
}
env = cpu_init(cpu_model);
env->halted = 1;
+
+ /* setup xen backend handlers */
+ xen_be_init();
}
QEMUMachine xenpv_machine = {
--
1.5.4.1
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
Home