Re: [Qemu-devel] PATCH: v3 Allow control over drive file open mode

[Daniel P. Berrange]

On Fri, Aug 01, 2008 at 10:10:09AM -0500, Anthony Liguori wrote:
> Daniel P. Berrange wrote:
> >This is version 3 of the patch.
> >  
> 
> Allowing the user to specify what mode we use to open a file is IMHO not 
> a good interface for a user.  A user should only be concerned with how 
> we expose a disk to the guest, not the underlying implementation of how 
> we support this.  It has subtle side-effects that a user is not going to 
> expect unless they are intimately familiar with how QEMU is implemented 
> (like snapshotting breaking).

So if I'm understanding you correctly, you'd be OK with a mode=ro, which 
would make the emulated drive itself read-only - independant of what 
open() flags we use for opening the file on the host ?  

So my next question would be, what IDE / SCSI / USB drives have a
concept of 'read only' ? A CDROM clearly is clearly readonly, and
floppy disks probably be to but can you mark general disks as read
only ?

Daniel
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