1 files changed, 49 insertions, 0 deletions

diff --git a/gitlab/issues/target_missing/host_missing/accel_missing/2307.toml b/gitlab/issues/target_missing/host_missing/accel_missing/2307.toml
new file mode 100644
index 00000000..8b81b227
--- /dev/null
+++ b/gitlab/issues/target_missing/host_missing/accel_missing/2307.toml
@@ -0,0 +1,49 @@
+id = 2307
+title = "QEMU Windows COM port filenames not recognized i.e. \\\\.\\COM19 or \\\\.\\CNCA0"
+state = "opened"
+created_at = "2024-04-24T12:54:33.755Z"
+closed_at = "n/a"
+labels = ["Chardev", "hostos: Windows"]
+url = "https://gitlab.com/qemu-project/qemu/-/issues/2307"
+host-os = "Windows 10"
+host-arch = "x64"
+qemu-version = "QEMU emulator version 8.1.0 (v8.1.0-12034-g129566d84e)"
+guest-os = "n/a"
+guest-arch = "n/a"
+description = "n/a"
+reproduce = """1. Run qemu-system-arm with the comand line above.
+2. QEMU fails with `qemu-system-arm.exe: -gdb \\\\.\\CNCA8: '\\\\.\\CNCA8' is not a valid char driver`
+3. ```qemu-system-arm.exe -machine mps2-an500 -gdb \\\\.\\COM19
+qemu-system-arm.exe: -gdb \\\\.\\COM19: '\\\\.\\COM19' is not a valid char driver
+```"""
+additional = """Windows allows COM ports numbered 10 and higher to be prefixed with a `\\\\.\\` escape as in `\\\\.\\COM17`. Such COM port assignments are not uncommon when a plurality of USB serial adapters.
+Equally problematic are virtual COM port designations such as `\\\\.\\CNCA8` created by the Windows 10x64 driver package known as `com0com`: https://pete.akeo.ie/2011/07/com0com-signed-drivers.html
+
+Upon checking the source pulled from the Github mirror an initial fix was to simply modify /chardev/char.c, but this appears insufficient. Sadly.
+
+Please ask if more information is required. I am actively working on extending an existing QEMU machine emulation. A patch to fix this problem is below. Please comment if applicable.
+
+Jerry.
+
+```
+diff --git a/chardev/char.c b/chardev/char.c
+index 3c43fb1278..7a3f342c72 100644
+--- a/chardev/char.c
++++ b/chardev/char.c
+@@ -418,6 +418,13 @@ QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename,
+         qemu_opt_set(opts, "path", filename, &error_abort);
+         return opts;
+     }
++       // JME
++    if (strstart(filename, "\\\\\\\\.\\\\", NULL)) {
++        qemu_opt_set(opts, "backend", "serial", &error_abort);
++        qemu_opt_set(opts, "path", filename, &error_abort);
++        return opts;
++    }
++
+     if (strstart(filename, "file:", &p)) {
+         qemu_opt_set(opts, "backend", "file", &error_abort);
+         qemu_opt_set(opts, "path", p, &error_abort);
+
+```
+/label ~"kind::Bug""""