Il 05/11/2013 13:23, Peter Maydell ha scritto:
>>> >> This looks really weird. Why should the memory subsystem
>>> >> care whether we're using TCG or KVM or Xen?
>> >
>> > Because only TCG stores the section number in the low bits of the iotlb
>> > entry. This is exactly what is explained in the comments.
> So presumably we still crash if there are more than
> 32 virtio-blk disks on TCG (and indeed if more than 256
> on KVM)? That doesn't seem very satisfactory...
It isn't, do you have any idea on how to make the threshold equal for
TCG and KVM?
I guess the code could be made clearer like this:
assert (... < SHRT_MAX);
if (tcg_enabled()) {
/* TCG has a stricter limit due to iotlb etc. etc. */
assert (... < TARGET_PAGE_SIZE);
}
but that's pretty much it...
Paolo
