[PATCH v4 01/13] ui: Get the fd associated with udmabuf driver

[Vivek Kasireddy <vivek.kasireddy@intel.com>]

Try to open the udmabuf dev node for the first time or return the
fd if the device was previously opened.

Based-on-patch-by: Gerd Hoffmann <kraxel@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
---
 include/ui/console.h |  3 +++
 ui/meson.build       |  1 +
 ui/udmabuf.c         | 40 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 44 insertions(+)
 create mode 100644 ui/udmabuf.c

diff --git a/include/ui/console.h b/include/ui/console.h
index ca3c7af6a6..b30b63976a 100644
--- a/include/ui/console.h
+++ b/include/ui/console.h
@@ -471,4 +471,7 @@ bool vnc_display_reload_certs(const char *id,  Error **errp);
 /* input.c */
 int index_from_key(const char *key, size_t key_length);
 
+/* udmabuf.c */
+int udmabuf_fd(void);
+
 #endif
diff --git a/ui/meson.build b/ui/meson.build
index e8d3ff41b9..7a709ff548 100644
--- a/ui/meson.build
+++ b/ui/meson.build
@@ -11,6 +11,7 @@ softmmu_ss.add(files(
   'kbd-state.c',
   'keymaps.c',
   'qemu-pixman.c',
+  'udmabuf.c',
 ))
 softmmu_ss.add([spice_headers, files('spice-module.c')])
 
diff --git a/ui/udmabuf.c b/ui/udmabuf.c
new file mode 100644
index 0000000000..e6234fd86f
--- /dev/null
+++ b/ui/udmabuf.c
@@ -0,0 +1,40 @@
+/*
+ * udmabuf helper functions.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "ui/console.h"
+
+#ifdef CONFIG_LINUX
+
+#include <sys/fcntl.h>
+#include <sys/ioctl.h>
+
+int udmabuf_fd(void)
+{
+    static bool first = true;
+    static int udmabuf;
+
+    if (!first) {
+        return udmabuf;
+    }
+    first = false;
+
+    udmabuf = open("/dev/udmabuf", O_RDWR);
+    if (udmabuf < 0) {
+        warn_report("open /dev/udmabuf: %s", strerror(errno));
+    }
+    return udmabuf;
+}
+
+#else
+
+int udmabuf_fd(void)
+{
+    return -1;
+}
+
+#endif
-- 
2.30.2