Re: [Qemu-devel] r6677 broke access to physical FDD on Win32

[Anthony Liguori]

Robert Riebisch wrote:
> Anthony Liguori wrote:
>
>   
> > block-raw-win32.c:raw_getlength():
> >
> >     case FTYPE_HARDDISK:
> >     
>
> A floppy disk drive is hard disk?
>   

I didn't write the code, but yeah, that confused me too.

> > Looking at the code, perhaps you should be saying -fda //./a.
> >     
>
> "-fda //./a" fails, but "-fda //./a:" works for the stable branch. It
> does NOT work for original qemu-0.10.0.tar.gz.
>
> Now we "just" need to allow the old syntax. :-)
>   

The patch that I wrote fixed a bug where a guest could send IO requests 
to a guest backend that were greater than the size of the device.  The 
size of the device is bdrv_getlength().  In this case, when you specify 
"a:" on Windows, it doesn't correctly detect that it is a physical 
device.  It cannot get the size of the device correctly because of 
this.  This wasn't an issue before because of the aforementioned bug.

Is "a:" a valid filename in Windows?  Is there a way in Windows to 
detect that a given file is actually a physical device?

Regards,

Anthony Liguori

> Robert Riebisch
>