On Mon, Sep 14, 2009 at 12:42:32AM +0900, TAKEDA, toshiya wrote:
Dear Stuart and members,
I'm still slightly concerned that for machines with
MAX_PHYSICAL_DRIVES
set to 2, guests would see drives 2 and 3 as present, but with no
disk
inserted. Previously, though, I expect they would have been
mirrors of
drives 0 and 1, which is obviously worse!
FD_DOR_SELMASK is not affected by MAX_PHYSICAL_DRIVES and is fixed
to 3,
so I think drive 2 and 3 are not recognized as the mirror of 0 and 1.
Agreed.
(Just to clarify, my comment about mirrors of drives 2 and 3 was
referring to the old code, when FD_DOR_SELMASK was affected by
MAX_FD.)
Well, I also think it is better the user can select the physical
drive
number, not only 2 but 0, 1 and 3.
But it will require the large scale patch, for example the block and
qemu option commands.
The user should really be able to attach drives individually, and have
only drive 3 connected, if they want... but that's a separate problem.
If this patch is acceptable for commit, I will reimplement PC-09
patch
based on it and in this time I hope I can fix the sence interrupt
status.
My only concern is that a guest OS might now reserve drive letters for
drives 2 and 3, whereas before, it might have ignored those drives
because it was not possible to select them.
In reality, it seems a greater concern that without this patch, a
guest OS might allow access to the mirrors of drives 0 and 1,
potentially causing filesystem corruption. :-(
Cheers,
--
Stuart Brady