tools/guest-diag: guest frame capture + input driving for the two-VM GZDoom video (Xvfb XGetImage capture, SDL present shim, window resize, XTEST input, QGA range fetch)

1 files changed, 41 insertions, 0 deletions

diff --git a/tools/guest-diag/qga_snip.py b/tools/guest-diag/qga_snip.py
new file mode 100644
index 0000000..cd3b992
--- /dev/null
+++ b/tools/guest-diag/qga_snip.py
@@ -0,0 +1,41 @@
+#!/usr/bin/env python3
+# Fetch a byte range from a guest file via the QEMU guest agent.
+# Usage: qga_snip.py <guest_path> <offset> <length> <host_out>
+import base64
+import json
+import socket
+import sys
+
+GUEST, OFF, LEN, HOST = sys.argv[1], int(sys.argv[2]), int(sys.argv[3]), sys.argv[4]
+import os
+SOCK = os.environ.get("QGA_SOCK", "/tmp/qemu-guest-agent.sock")
+
+
+def recv_line(s):
+    buf = b""
+    while b"\n" not in buf:
+        c = s.recv(65536)
+        if not c:
+            break
+        buf += c
+    return buf.split(b"\n", 1)[0]
+
+
+def cmd(s, obj):
+    s.sendall((json.dumps(obj) + "\r\n").encode())
+    return json.loads(recv_line(s))
+
+
+s = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+s.settimeout(30.0)
+s.connect(SOCK)
+h = cmd(s, {"execute": "guest-file-open",
+            "arguments": {"path": GUEST, "mode": "r"}})["return"]
+cmd(s, {"execute": "guest-file-seek",
+        "arguments": {"handle": h, "offset": OFF, "whence": 0}})
+r = cmd(s, {"execute": "guest-file-read",
+            "arguments": {"handle": h, "count": LEN}})
+data = base64.b64decode(r["return"].get("buf-b64", ""))
+open(HOST, "wb").write(data)
+cmd(s, {"execute": "guest-file-close", "arguments": {"handle": h}})
+print(f"GOT {len(data)} bytes @ {OFF} -> {HOST}")