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From:   Peter Maydell <peter.maydell@linaro.org>
Date:   Fri, 6 Sep 2019 14:50:34 +0100
Message-ID: <CAFEAcA8HH-JeMLZ29h6GidDcLpb_oUHqoyEMJ0buo3hyTBj5jA@mail.gmail.com>
Subject: Re: [PATCH 1/1] KVM: inject data abort if instruction cannot be decoded
To:     Alexander Graf <graf@amazon.com>
Cc:     Christoffer Dall <christoffer.dall@arm.com>,
        =?UTF-8?Q?Daniel_P=2E_Berrang=C3=A9?= <berrange@redhat.com>,
        Marc Zyngier <maz@kernel.org>,
        lkml - Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Stefan Hajnoczi <stefanha@redhat.com>,
        Heinrich Schuchardt <xypron.glpk@gmx.de>,
        kvmarm@lists.cs.columbia.edu,
        arm-mail-list <linux-arm-kernel@lists.infradead.org>
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On Fri, 6 Sep 2019 at 14:41, Alexander Graf <graf@amazon.com> wrote:
> On 06.09.19 15:31, Peter Maydell wrote:
> > (b) we try to reuse the code we already have that does TCG exception
> > injection, which might or might not be a design mistake, and
>
> That's probably a design mistake, correct :)

Well, conceptually it's not necessarily a bad idea, because
in both cases what we're doing is "change the system register
state (PC, ESR_EL1, ELR_EL1 etc) so that the CPU looks like
it's just taken an exception"; but some of what the
TCG code needs to do isn't necessary for KVM and all of it
was not written with the idea of KVM in mind at all...

thanks
-- PMM