"K.Prasad" <email@example.com> wrote on 17/12/2008 03:47:03:
I think you need to cater for an arch-specific filter that validates the
appearance of breakpoint interrupt. On the System Z, for example, one
specifies a range using the pair of control registers, one for the start
and the other of the end. You might think that this limits you to having
only one contiguous range of addresses which generate a h/w bp interrupt.
Not so. We use an algorithm, which employes a wrapping range
(i.e start addr > end addr) and we continually resize the gap, whenever we
take a BP interrupt, to begin at the next valid BP. That way we avoid too
many erroneous interrupts and we also benignly filter the erroneous ones.
Other architectures that employ a variable range could do something
I'm thinking here of IA64 for example.
The other thing that occurs to me is whether you should also include
HW_BREAKPOINT_IO for completeness. Of course not everyone supports
breakpointing the I/O address space, but some do, so it ought to be catered
zVM CP Development