xen: Create a new file xen_pvdev.c

The purpose of the new file is to store generic functions shared by frontend
and backends such as xenstore operations, xendevs.

Signed-off-by: Quan Xu <quan.xu@intel.com>
Signed-off-by: Emil Condrea <emilcondrea@gmail.com>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Quan Xu <xuquan8@huawei.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>

hw/xen/xen_pvdev.c

@@ -0,0 +1,150 @@
+/*
+ * Xen para-virtualization device
+ *
+ *  (c) 2008 Gerd Hoffmann <kraxel@redhat.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>
+ */
+
+#include "qemu/osdep.h"
+
+#include "hw/xen/xen_backend.h"
+#include "hw/xen/xen_pvdev.h"
+
+static int debug;
+/* ------------------------------------------------------------- */
+
+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;
+}
+
+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";
+}
+
+/*
+ * 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();
+}