From: Borislav Petkov <bp@alien8.de>
To: lijiang <lijiang@redhat.com>
Cc: Baoquan He <bhe@redhat.com>, Petr Tesarik <ptesarik@suse.cz>,
linux-kernel@vger.kernel.org, x86@kernel.org,
kexec@lists.infradead.org, mingo@redhat.com, tglx@linutronix.de,
dyoung@redhat.com
Subject: Re: [PATCH] kdump, vmcoreinfo: Export sme_me_mask value to vmcoreinfo
Date: Sat, 27 Oct 2018 16:51:51 +0200 [thread overview]
Message-ID: <20181027145151.GA7338@nazgul.tnic> (raw)
In-Reply-To: <c55bef2a-b972-7e6e-b698-6ac1bc736046@redhat.com>
On Sat, Oct 27, 2018 at 10:41:56PM +0800, lijiang wrote:
> Actually, the value of 'sme_me_mask' is 0x800000000000 when SME is
> enabled, otherwise it is 0. That is to say, if the bit 47 is set, the
> bit number is also 0x800000000000 (1 << 47UL);
Yes, and you can simply copy the mask into your variable and export
that. Thinking about it more, though, it might be better if you instead
export a smaller value - not an u64 - and construct the mask in
userspace. I.e., a u8 which should be enough for your current purposes.
I say current because if it turns out we need to export more SME-related
info to userspace, exporting an u64 and then OR-ing in more information
in it would allow that. u8 not so much. So doing something like:
[ misc ][ enc bit ][ other misc SME info ]
0000_0000_0000_0000_1000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000
63 59 55 51 47 43 39 35 31 27 23 19 15 11 7 3
would allow for exporting that additional info.
Especially if we want to use VMCOREINFO for more than kexec things.
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
--
next prev parent reply other threads:[~2018-10-27 14:51 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-26 9:36 [PATCH] kdump, vmcoreinfo: Export sme_me_mask value to vmcoreinfo Lianbo Jiang
2018-10-26 9:43 ` Boris Petkov
2018-10-26 12:32 ` lijiang
2018-10-26 16:24 ` Petr Tesarik
2018-10-26 22:25 ` Borislav Petkov
2018-10-27 2:57 ` lijiang
2018-10-27 8:13 ` Baoquan He
2018-10-27 9:10 ` Borislav Petkov
2018-10-27 9:39 ` Baoquan He
2018-10-27 10:12 ` Borislav Petkov
2018-10-27 11:08 ` Baoquan He
2018-10-27 13:17 ` Boris Petkov
2018-10-27 14:41 ` lijiang
2018-10-27 14:51 ` Borislav Petkov [this message]
2018-10-29 7:59 ` lijiang
2018-10-29 8:31 ` Baoquan He
2018-10-29 9:29 ` lijiang
2018-10-29 9:57 ` Borislav Petkov
2018-10-29 10:12 ` lijiang
2018-10-29 11:44 ` Baoquan He
2018-10-29 13:41 ` lijiang
2018-10-29 13:49 ` Borislav Petkov
2018-10-30 4:46 ` lijiang
2018-10-30 5:09 ` Dave Young
2018-10-30 9:15 ` Borislav Petkov
2018-10-30 9:23 ` Baoquan He
2018-10-31 2:26 ` lijiang
2018-10-31 2:47 ` Dave Young
2018-10-31 7:43 ` lijiang
2018-10-31 10:10 ` Borislav Petkov
2018-11-01 15:01 ` Kazuhito Hagio
2018-10-26 16:35 ` Borislav Petkov
2018-10-27 2:19 ` lijiang
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=20181027145151.GA7338@nazgul.tnic \
--to=bp@alien8.de \
--cc=bhe@redhat.com \
--cc=dyoung@redhat.com \
--cc=kexec@lists.infradead.org \
--cc=lijiang@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=ptesarik@suse.cz \
--cc=tglx@linutronix.de \
--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;
as well as URLs for NNTP newsgroup(s).