Re: [PATCH v9 0/2] target/arm: kvm: Support for KVM DABT with no valid ISS

[Peter Maydell]

On Mon, 29 Jun 2020 at 12:41, Beata Michalska
<beata.michalska@linaro.org> wrote:
>
> Some of the ARMv7 & ARMv8 load/store instructions might trigger a data abort
> exception with no valid ISS info to be decoded. The lack of decode info
> makes it at least tricky to emulate the instruction which is one of the
> (many) reasons why KVM will not even try to do so.
>
> So far, if a guest made an attempt to access memory outside the memory slot,
> KVM reported vague ENOSYS. As a result QEMU exited with no useful information
> being provided or even a clue on what has just happened.
>
> ARM KVM introduced support for notifying of an attempt to execute
> an instruction that resulted in dabt with no valid ISS decoding info.
> This still leaves QEMU to handle the case, but at least now it gives more
> control and a start point for more meaningful handling of such cases.
>
> This patchset relies on KVM to insert the external data abort into the guest.



Applied to target-arm.next, thanks.

-- PMM