[Qemu-stable] [PATCH for 2.11 0/2] QEMU crashes with CD device without media

[Denis V. Lunev]

There are 2 cases I have spotted so far:
1) IDE ATAPI read processing. Actually this was reported from field
2) QEMU IO hmp command (found during evaluation of (1))

SCSI code checks during access that blk_is_available(). These patches add
same checks on different code paths.

Pls decide whether these patches should go through sub-system trees or via
block tree.

Signed-off-by: Denis V. Lunev <address@hidden>
CC: "Dr. David Alan Gilbert" <address@hidden>
CC: John Snow <address@hidden>
CC: Kevin Wolf <address@hidden>
CC: Stefan Hajnoczi <address@hidden>