From: Catalin Marinas <catalin.marinas@arm.com>
To: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>, Shuah Khan <shuah@kernel.org>,
Marc Zyngier <maz@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Zhang Lei <zhang.lei@jp.fujitsu.com>,
linux-kselftest@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v1 0/3] arm64/sve: Document our actual SVE syscall ABI
Date: Thu, 21 Jul 2022 16:25:17 +0100 [thread overview]
Message-ID: <Ytlv3e4WPrNvBYWN@arm.com> (raw)
In-Reply-To: <20220720205013.890942-1-broonie@kernel.org>
On Wed, Jul 20, 2022 at 09:50:10PM +0100, Mark Brown wrote:
> Currently our SVE syscall ABI documentation does not reflect the actual
> implemented ABI, it says that register state not shared with FPSIMD
> becomes undefined on syscall when in reality we always clear it. Since
> changing this would cause a change in the observed kernel behaviour
> there is a substantial desire to avoid taking advantage of the
> documented ABI so instead let's document what we actually do so it's
> clear that it is in reality an ABI.
>
> There has been some pushback on tightening the documentation in the past
> but it is hard to see who that helps, it makes the implementation
> decisions less clear and makes it harder for people to discover and make
> use of the actual ABI. The main practical concern is that qemu's user
> mode does not currently flush the registers.
>
> Mark Brown (3):
> kselftest/arm64: Correct buffer allocation for SVE Z registers
> arm64/sve: Document our actual ABI for clearing registers on syscall
> kselftest/arm64: Enforce actual ABI for SVE syscalls
For the series:
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
prev parent reply other threads:[~2022-07-21 15:25 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-20 20:50 [PATCH v1 0/3] arm64/sve: Document our actual SVE syscall ABI Mark Brown
2022-07-20 20:50 ` [PATCH v1 1/3] kselftest/arm64: Correct buffer allocation for SVE Z registers Mark Brown
2022-07-20 20:50 ` [PATCH v1 2/3] arm64/sve: Document our actual ABI for clearing registers on syscall Mark Brown
2022-07-20 20:50 ` [PATCH v1 3/3] kselftest/arm64: Enforce actual ABI for SVE syscalls Mark Brown
2022-07-21 15:25 ` Catalin Marinas [this message]
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=Ytlv3e4WPrNvBYWN@arm.com \
--to=catalin.marinas@arm.com \
--cc=broonie@kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=maz@kernel.org \
--cc=shuah@kernel.org \
--cc=will@kernel.org \
--cc=zhang.lei@jp.fujitsu.com \
/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;
as well as URLs for NNTP newsgroup(s).