[Qemu-devel] [PATCH] don't exit if cdrom media fails to open

[David Ahern <dsahern@gmail.com>]

This patch allows a VM to continue even if the cdrom image is not
accessible at VM boot time. It allows a boot progression similar to real
hardware (e.g., try cd, then disk).

For example,

qemu-system-x86_64 -cdrom /dev/dvd -hda disk.img -boot dc

If there is no media in the tray, qemu currently exits with the message:
qemu: could not open disk image /dev/dvd

With this patch, the message is still displayed, but qemu continues. It
first tries to boot from the cdrom and then falls back to the disk.

Signed-off-by: David Ahern <dsahern@gmail.com>

---

diff --git a/vl.c b/vl.c
index fcf8532..bd3709c 100644
--- a/vl.c
+++ b/vl.c
@@ -152,6 +152,7 @@ int main(int argc, char **argv)
 #include "qemu-char.h"
 #include "cache-utils.h"
 #include "block.h"
+#include "block_int.h"
 #include "dma.h"
 #include "audio/audio.h"
 #include "migration.h"
@@ -2551,7 +2552,8 @@ int drive_init(struct drive_opt *arg, int
snapshot, void *opaque)
     if (bdrv_open2(bdrv, file, bdrv_flags, drv) < 0) {
         fprintf(stderr, "qemu: could not open disk image %s\n",
                         file);
-        return -1;
+        if (bdrv->type != BDRV_TYPE_CDROM)
+            return -1;
     }
     if (bdrv_key_required(bdrv))
         autostart = 0;