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>
diff --git a/include/hw/xen/xen_pvdev.h b/include/hw/xen/xen_pvdev.h
new file mode 100644
index 0000000..cd3d6bc
--- /dev/null
+++ b/include/hw/xen/xen_pvdev.h
@@ -0,0 +1,69 @@
+#ifndef QEMU_HW_XEN_PVDEV_H
+#define QEMU_HW_XEN_PVDEV_H
+
+#include "hw/xen/xen_common.h"
+/* ------------------------------------------------------------- */
+
+#define XEN_BUFSIZE 1024
+
+struct XenDevice;
+
+/* 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 XenDevOps {
+    size_t    size;
+    uint32_t  flags;
+    void      (*alloc)(struct XenDevice *xendev);
+    int       (*init)(struct XenDevice *xendev);
+    int       (*initialise)(struct XenDevice *xendev);
+    void      (*connected)(struct XenDevice *xendev);
+    void      (*event)(struct XenDevice *xendev);
+    void      (*disconnect)(struct XenDevice *xendev);
+    int       (*free)(struct XenDevice *xendev);
+    void      (*backend_changed)(struct XenDevice *xendev, const char *node);
+    void      (*frontend_changed)(struct XenDevice *xendev, const char *node);
+    int       (*backend_register)(void);
+};
+
+struct XenDevice {
+    const 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[XEN_BUFSIZE];
+    char               *fe;
+    char               *protocol;
+    int                remote_port;
+    int                local_port;
+
+    xenevtchn_handle   *evtchndev;
+    xengnttab_handle   *gnttabdev;
+
+    struct XenDevOps   *ops;
+    QTAILQ_ENTRY(XenDevice) next;
+};
+
+/* ------------------------------------------------------------- */
+
+/* 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);
+int xenstore_write_int64(const char *base, const char *node, int64_t 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_read_uint64(const char *base, const char *node, uint64_t *uval);
+
+const char *xenbus_strstate(enum xenbus_state state);
+
+void xen_be_printf(struct XenDevice *xendev, int msg_level,
+                   const char *fmt, ...)  GCC_FMT_ATTR(3, 4);
+
+#endif /* QEMU_HW_XEN_PVDEV_H */