xen: use libxendevice model to restrict operations

[qemu.git] / hw / xen / xen_pvdev.c

diff --git a/hw/xen/xen_pvdev.c b/hw/xen/xen_pvdev.c
index a1dc2bed4c0244a5439f35e1280a22ad9be9503c..aed783e844ea8b3ef1359d9c93cbdc596cba95f4 100644 (file)
--- a/hw/xen/xen_pvdev.c
+++ b/hw/xen/xen_pvdev.c
@@ -18,13 +18,69 @@
  */
 
 #include "qemu/osdep.h"
-
+#include "qemu/log.h"
+#include "hw/qdev-core.h"
 #include "hw/xen/xen_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_head, xs_dirs) xs_cleanup =
+    QTAILQ_HEAD_INITIALIZER(xs_cleanup);
+
+static QTAILQ_HEAD(XenDeviceHead, XenDevice) 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];
@@ -95,6 +151,29 @@ int xenstore_read_uint64(const char *base, const char *node, uint64_t *uval)
     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[] = {
@@ -116,7 +195,7 @@ const char *xenbus_strstate(enum xenbus_state state)
  *  2 == noisy debug messages (logfile only).
  *  3 == will flood your log (logfile only).
  */
-void xen_be_printf(struct XenDevice *xendev, int msg_level,
+void xen_pv_printf(struct XenDevice *xendev, int msg_level,
                    const char *fmt, ...)
 {
     va_list args;
@@ -148,3 +227,92 @@ void xen_be_printf(struct XenDevice *xendev, int msg_level,
     }
     qemu_log_flush();
 }
+
+void xen_pv_evtchn_event(void *opaque)
+{
+    struct XenDevice *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 XenDevice *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 XenDevice *xendev)
+{
+    return xenevtchn_notify(xendev->evtchndev, xendev->local_port);
+}
+
+/* ------------------------------------------------------------- */
+
+struct XenDevice *xen_pv_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;
+}
+
+/*
+ * release xen backend device.
+ */
+void xen_pv_del_xendev(struct XenDevice *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 XenDevice *xendev)
+{
+    QTAILQ_INSERT_TAIL(&xendevs, xendev, next);
+}