public inbox for qemu-arm@nongnu.org
 help / color / mirror / Atom feed
From: Zenghui Yu <zenghui.yu@linux.dev>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: qemu-arm@nongnu.org, qemu-devel@nongnu.org, richard.henderson@linaro.org
Subject: Re: [PATCH] target/arm: Don't skip access flag fault for AccessType_AT
Date: Fri, 20 Mar 2026 09:56:27 +0800	[thread overview]
Message-ID: <ec871f3f-58f2-4165-a673-b0a45f87b89e@linux.dev> (raw)
In-Reply-To: <CAFEAcA9bGVuWXAPA0=EaAWXhSigm_yf5OYfnYoTjaQ8x1qXKYg@mail.gmail.com>

Hi Peter,

On 3/20/26 1:17 AM, Peter Maydell wrote:
> On Tue, 17 Mar 2026 at 12:25, Zenghui Yu <zenghui.yu@linux.dev> wrote:
> >
> > As per the pseudo code from DDI0487 M.a.a (on J1-16021) AArch64.S1Walk():
> >
> >   // Check descriptor AF bit
> >   elsif (descriptor<10> == '0' && walkparams.ha == '0' &&
> >           (!accdesc.acctype IN {AccessType_DC, AccessType_IC} ||
> >            boolean IMPLEMENTATION_DEFINED "Generate access flag fault on IC/DC operations")) then
> >       fault.statuscode = Fault_AccessFlag;
> >
> > an access flag fault should be generated for AccessType_AT, if the AF bit
> > is 0 and !param.ha.
> 
> Did you find this by code inspection, or because it caused
> a guest to go wrong?

This was noticed when I was fixing the AT selftest on KVM side [*].

[*] https://lore.kernel.org/r/d58819b9-c745-4551-8ea4-e15af3fe63be@linux.dev

Thanks,
Zenghui


  reply	other threads:[~2026-03-20  1:57 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-17 12:25 [PATCH] target/arm: Don't skip access flag fault for AccessType_AT Zenghui Yu
2026-03-19 17:17 ` Peter Maydell
2026-03-20  1:56   ` Zenghui Yu [this message]
2026-03-24 13:38   ` Peter Maydell
2026-03-24 16:07     ` Zenghui Yu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=ec871f3f-58f2-4165-a673-b0a45f87b89e@linux.dev \
    --to=zenghui.yu@linux.dev \
    --cc=peter.maydell@linaro.org \
    --cc=qemu-arm@nongnu.org \
    --cc=qemu-devel@nongnu.org \
    --cc=richard.henderson@linaro.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox