From: Wei Liu <wei.liu@kernel.org>
To: Uros Bizjak <ubizjak@gmail.com>
Cc: linux-hyperv@vger.kernel.org, x86@kernel.org,
linux-kernel@vger.kernel.org,
"K. Y. Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
Long Li <longli@microsoft.com>, Thomas Gleixner <tglx@kernel.org>,
Ingo Molnar <mingo@kernel.org>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH -hyperv 1/3] x86/hyperv: Save segment registers directly to memory in hv_hvcrash_ctxt_save()
Date: Thu, 12 Mar 2026 04:27:49 +0000 [thread overview]
Message-ID: <20260312042749.GH3612627@liuwe-devbox-debian-v2.local> (raw)
In-Reply-To: <20260311102658.215693-1-ubizjak@gmail.com>
On Wed, Mar 11, 2026 at 11:25:58AM +0100, Uros Bizjak wrote:
> hv_hvcrash_ctxt_save() in arch/x86/hyperv/hv_crash.c currently saves
> segment registers via a general-purpose register (%eax). Update the
> code to save segment registers (cs, ss, ds, es, fs, gs) directly to
> the crash context memory using movw. This avoids unnecessary use of
> a general-purpose register, making the code simpler and more efficient.
>
> The size of the corresponding object file improves as follows:
>
> text data bss dec hex filename
> 4167 176 200 4543 11bf hv_crash-old.o
> 4151 176 200 4527 11af hv_crash-new.o
>
> No functional change occurs to the saved context contents; this is
> purely a code-quality improvement.
>
> Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
> Cc: "K. Y. Srinivasan" <kys@microsoft.com>
> Cc: Haiyang Zhang <haiyangz@microsoft.com>
> Cc: Wei Liu <wei.liu@kernel.org>
> Cc: Dexuan Cui <decui@microsoft.com>
> Cc: Long Li <longli@microsoft.com>
> Cc: Thomas Gleixner <tglx@kernel.org>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: "H. Peter Anvin" <hpa@zytor.com>
Series applied to hyperv-fixes. Thanks.
prev parent reply other threads:[~2026-03-12 4:27 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-11 10:25 Uros Bizjak
2026-03-11 10:25 ` [PATCH -hyperv 2/3] x86/hyperv: Use current_stack_pointer to avoid asm() " Uros Bizjak
2026-03-11 10:26 ` [PATCH -hyperv 3/3] x86/hyperv: Use any general-purpose register when saving %cr2 and %cr8 Uros Bizjak
2026-03-12 4:27 ` Wei Liu [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=20260312042749.GH3612627@liuwe-devbox-debian-v2.local \
--to=wei.liu@kernel.org \
--cc=bp@alien8.de \
--cc=dave.hansen@linux.intel.com \
--cc=decui@microsoft.com \
--cc=haiyangz@microsoft.com \
--cc=hpa@zytor.com \
--cc=kys@microsoft.com \
--cc=linux-hyperv@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=longli@microsoft.com \
--cc=mingo@kernel.org \
--cc=tglx@kernel.org \
--cc=ubizjak@gmail.com \
--cc=x86@kernel.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
all inboxes | Powered by JetHome®