hw/xen: Add xenstore operations to allow redirection to internal emulation

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>

1 files changed, 64 insertions, 55 deletions

diff --git a/hw/xen/xen-legacy-backend.c b/hw/xen/xen-legacy-backend.c
index a48a25aeb5..4ded3cec23 100644
--- a/hw/xen/xen-legacy-backend.c
+++ b/hw/xen/xen-legacy-backend.c
@@ -39,7 +39,7 @@ BusState *xen_sysbus;
 /* ------------------------------------------------------------- */
 
 /* public */
-struct xs_handle *xenstore;
+struct qemu_xs_handle *xenstore;
 const char *xen_protocol;
 
 /* private */
@@ -274,6 +274,25 @@ static void xen_be_frontend_changed(struct XenLegacyDevice *xendev,
     }
 }
 
+static void xenstore_update_fe(void *opaque, const char *watch)
+{
+    struct XenLegacyDevice *xendev = opaque;
+    const 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);
+}
+
 /* ------------------------------------------------------------- */
 /* Check for possible state transitions and perform them.        */
 
@@ -287,7 +306,6 @@ static void xen_be_frontend_changed(struct XenLegacyDevice *xendev,
  */
 static int xen_be_try_setup(struct XenLegacyDevice *xendev)
 {
-    char token[XEN_BUFSIZE];
     int be_state;
 
     if (xenstore_read_be_int(xendev, "state", &be_state) == -1) {
@@ -308,8 +326,9 @@ static int xen_be_try_setup(struct XenLegacyDevice *xendev)
     }
 
     /* setup frontend watch */
-    snprintf(token, sizeof(token), "fe:%p", xendev);
-    if (!xs_watch(xenstore, xendev->fe, token)) {
+    xendev->watch = qemu_xen_xs_watch(xenstore, xendev->fe, xenstore_update_fe,
+                                      xendev);
+    if (!xendev->watch) {
         xen_pv_printf(xendev, 0, "watching frontend path (%s) failed\n",
                       xendev->fe);
         return -1;
@@ -498,46 +517,20 @@ void xen_be_check_state(struct XenLegacyDevice *xendev)
 
 /* ------------------------------------------------------------- */
 
-static int xenstore_scan(const char *type, int dom, struct XenDevOps *ops)
-{
-    struct XenLegacyDevice *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_pv_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;
-}
+struct xenstore_be {
+    const char *type;
+    int dom;
+    struct XenDevOps *ops;
+};
 
-void xenstore_update_be(char *watch, char *type, int dom,
-                        struct XenDevOps *ops)
+static void xenstore_update_be(void *opaque, const char *watch)
 {
+    struct xenstore_be *be = opaque;
     struct XenLegacyDevice *xendev;
     char path[XEN_BUFSIZE], *bepath;
     unsigned int len, dev;
 
-    len = snprintf(path, sizeof(path), "backend/%s/%d", type, dom);
+    len = snprintf(path, sizeof(path), "backend/%s/%d", be->type, be->dom);
     if (strncmp(path, watch, len) != 0) {
         return;
     }
@@ -551,9 +544,9 @@ void xenstore_update_be(char *watch, char *type, int dom,
         return;
     }
 
-    xendev = xen_be_get_xendev(type, dom, dev, ops);
+    xendev = xen_be_get_xendev(be->type, be->dom, dev, be->ops);
     if (xendev != NULL) {
-        bepath = xs_read(xenstore, 0, xendev->be, &len);
+        bepath = qemu_xen_xs_read(xenstore, 0, xendev->be, &len);
         if (bepath == NULL) {
             xen_pv_del_xendev(xendev);
         } else {
@@ -564,23 +557,41 @@ void xenstore_update_be(char *watch, char *type, int dom,
     }
 }
 
-void xenstore_update_fe(char *watch, struct XenLegacyDevice *xendev)
+static int xenstore_scan(const char *type, int dom, struct XenDevOps *ops)
 {
-    char *node;
-    unsigned int len;
+    struct XenLegacyDevice *xendev;
+    char path[XEN_BUFSIZE];
+    struct xenstore_be *be = g_new0(struct xenstore_be, 1);
+    char **dev = NULL;
+    unsigned int cdev, j;
 
-    len = strlen(xendev->fe);
-    if (strncmp(xendev->fe, watch, len) != 0) {
-        return;
-    }
-    if (watch[len] != '/') {
-        return;
+    /* setup watch */
+    be->type = type;
+    be->dom = dom;
+    be->ops = ops;
+    snprintf(path, sizeof(path), "backend/%s/%d", type, dom);
+    if (!qemu_xen_xs_watch(xenstore, path, xenstore_update_be, be)) {
+        xen_pv_printf(NULL, 0, "xen be: watching backend path (%s) failed\n",
+                      path);
+        return -1;
     }
-    node = watch + len + 1;
 
-    xen_be_frontend_changed(xendev, node);
-    xen_be_check_state(xendev);
+    /* look for backends */
+    dev = qemu_xen_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 xen_set_dynamic_sysbus(void)
@@ -594,14 +605,12 @@ static void xen_set_dynamic_sysbus(void)
 
 void xen_be_init(void)
 {
-    xenstore = xs_daemon_open();
+    xenstore = qemu_xen_xs_open();
     if (!xenstore) {
         xen_pv_printf(NULL, 0, "can't connect to xenstored\n");
         exit(1);
     }
 
-    qemu_set_fd_handler(xs_fileno(xenstore), xenstore_update, NULL, NULL);
-
     if (xen_evtchn_ops == NULL || xen_gnttab_ops == NULL) {
         xen_pv_printf(NULL, 0, "Xen operations not set up\n");
         exit(1);