Re: [Qemu-devel] [RFC 0/3] target/m68k: convert to transaction_failed hook

[Mark Cave-Ayland]

On 10/12/2018 16:56, Peter Maydell wrote:

> This patchset converts the m68k target from the deprecated
> unassigned_access hook to the new transaction_failed hook.
> It's RFC for a couple of reasons:
>  * it's untested, since I don't have an m68k test image
>  * the second patch just makes "bus error while trying to
>    read page tables" be treated as a page fault, when it
>    should probably cause a fault reporting it as a bus error
>    of some kind
>  * I don't understand why the old unassigned_access hook
>    set the ATC bit in the MMU SSW, since the docs I have say
>    this should be set if the fault happened during a table
>    search, but cleared if it's just an ordinary bus-errored
>    data or insn access. Probably this is a pre-existing bug?
> 
> Anyway, I send it out as a skeleton for comments, because
> it would be nice to get rid of the old unassigned_access
> hook, which is fundamentally broken (it's still used by m68k,
> microblaze, mips and sparc).

Laurent is really the expert here (my work on the q800 was purely on the device
side), however is this also a nudge to see if the unassigned_access hook can be
eliminated from sparc too? ;)


ATB,

Mark.