On Wed, Jul 1, 2015 at 11:13 PM, Programmingkid
<programmingk...@gmail.com> wrote:
> Fix real cdrom access in Mac OS X so it can be used in QEMU.
> It simply removes the r from a device file's name. This
> allows for a real cdrom to be accessible to the guest.
> It has been successfully tested with a Windows XP guest
> in qemu-system-i386. The qemu-system-ppc emulator doesn't
> quit anymore, but there is another problem that prevents a
> real cdrom from working.
>
> Signed-off-by: John Arbuckle <programmingk...@gmail.com>
>
> ---
> block/raw-posix.c | 10 ++++++++++
> 1 files changed, 10 insertions(+), 0 deletions(-)
>
> diff --git a/block/raw-posix.c b/block/raw-posix.c
> index a967464..3585ed9 100644
> --- a/block/raw-posix.c
> +++ b/block/raw-posix.c
> @@ -2096,6 +2096,16 @@ static int hdev_open(BlockDriverState *bs, QDict
> *options, int flags,
> kernResult = FindEjectableCDMedia( &mediaIterator );
> kernResult = GetBSDPath( mediaIterator, bsdPath, sizeof( bsdPath )
> );
>
>
>
> + /*
> + * Remove the r from cdrom block device if needed.
> + * /dev/rdisk1 would become /dev/disk1.
> + * The r means raw access. It doesn't work well.
> + */
> + int sizeOfString = strlen("/dev/r");
> + if (strncmp("/dev/r", bsdPath, sizeOfString) == 0) {
> + sprintf(bsdPath, "/dev/%s", bsdPath + sizeOfString);
> + }
Why doesn't raw access "work well"?
This patch looks like a workaround but you haven't identified the root cause.
Perhaps because of request alignment requirements? Typically CD-ROMs
have 2 KB block size. You could test this by changing the following
in block_int.h:
#define BLOCK_PROBE_BUF_SIZE 512
In that case you need to fix raw-posix.c alignment detection code for
Mac OS X. Look at raw_probe_alignment().
Stefan
