From: Andy Lutomirski <luto@kernel.org>
To: Richard Hughes <hughsient@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Borislav Petkov <bp@alien8.de>,
Daniel Gutson <daniel@eclypsium.com>,
Dave Hansen <dave.hansen@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, X86 ML <x86@kernel.org>,
"H. Peter Anvin" <hpa@zytor.com>, Arnd Bergmann <arnd@arndb.de>,
Peter Zijlstra <peterz@infradead.org>,
"David S. Miller" <davem@davemloft.net>,
Rob Herring <robh@kernel.org>, Tony Luck <tony.luck@intel.com>,
Rahul Tanwar <rahul.tanwar@linux.intel.com>,
Xiaoyao Li <xiaoyao.li@intel.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] Ability to read the MKTME status from userspace
Date: Fri, 19 Jun 2020 13:20:48 -0700 [thread overview]
Message-ID: <CALCETrVieskMnU5XHKHYm+qOfzc+o4yhsGw42pvBNhkv2zsQJA@mail.gmail.com> (raw)
In-Reply-To: <CAD2FfiGT5bsb0sd2k8NGNmShvW_q3UV9YXgn-EwxBCJjx6PSTw@mail.gmail.com>
On Fri, Jun 19, 2020 at 12:58 PM Richard Hughes <hughsient@gmail.com> wrote:
>
> On Fri, 19 Jun 2020 at 20:41, Andy Lutomirski <luto@kernel.org> wrote:
> > I don't object in principle to Linux giving userspace more visibility
> > into what's going on, but I'm not convinced that adding a new
> > must-support-for-a-long-time interface that only solves 5% of your
> > problem is worth it.
>
> At the moment the only visibility we have is "the CPU supports TME"
> and "the kernel printed a message in the journal". The sysfs/procfs
> file read allows us to notify the admin if the firmware is
> deliberately disabling TME for some reason, without resorting to
> `grep` on dmesg. I don't think perfect should be the enemy of the
> good.
I am unconvinced that this has hit the "good" bar, especially since
SME is completely missing here.
Boris, etc: would it be reasonable to add a list of CPU features that
are present but turned off by firmware? SME is far from the only
thing that's frequently in this category. x2apic, fast strings, and
virtualization come to mind.
>
> Richard.
next prev parent reply other threads:[~2020-06-19 20:21 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-18 21:02 [PATCH] Ability to read the MKTME status from userspace Daniel Gutson
2020-06-18 21:08 ` Dave Hansen
[not found] ` <CAFmMkTHNxSN_uWtm63TdkGxj44NXQQKEOmATXhjA=4DSCS92kQ@mail.gmail.com>
2020-06-18 22:01 ` Borislav Petkov
[not found] ` <CAFmMkTGMAu-huTnP1aeMb_W4NddbTD_b2jhbDVKBDrkwgB97wg@mail.gmail.com>
2020-06-19 7:40 ` Borislav Petkov
[not found] ` <CAFmMkTGV0ZR6C=EBGQAiz1vw1vrUXSLTnH5ZbBUvfhPLg_tF6g@mail.gmail.com>
2020-06-19 13:22 ` Borislav Petkov
2020-06-19 13:31 ` Richard Hughes
2020-06-19 13:44 ` Borislav Petkov
2020-06-19 13:50 ` Richard Hughes
2020-06-19 15:48 ` Andy Lutomirski
2020-06-19 16:17 ` Borislav Petkov
2020-06-19 16:28 ` Andy Lutomirski
2020-06-19 16:31 ` Richard Hughes
2020-06-19 16:10 ` Borislav Petkov
2020-06-19 16:33 ` Richard Hughes
2020-06-19 16:40 ` Greg Kroah-Hartman
2020-06-19 16:47 ` Richard Hughes
2020-06-19 19:41 ` Andy Lutomirski
2020-06-19 19:58 ` Richard Hughes
2020-06-19 20:20 ` Andy Lutomirski [this message]
2020-06-19 20:24 ` Dave Hansen
2020-06-22 9:34 ` Boris Petkov
2020-06-18 23:52 ` Dave Hansen
2020-06-19 7:41 ` Borislav Petkov
2020-06-19 13:25 ` Richard Hughes
2020-06-19 13:33 ` Dave Hansen
2020-06-19 13:37 ` Richard Hughes
2020-06-19 13:58 ` Dave Hansen
2020-06-19 14:09 ` Richard Hughes
2020-06-19 14:23 ` Dave Hansen
2020-06-19 14:36 ` Richard Hughes
2020-06-19 14:48 ` Dave Hansen
2020-06-19 15:02 ` Richard Hughes
2020-06-19 15:36 ` Dave Hansen
2020-06-19 7:20 ` Greg Kroah-Hartman
[not found] ` <CAFmMkTF7QBJQdKxhsPiUPifsxykyCVv=NYandpB0z8EccAxMXw@mail.gmail.com>
2020-06-19 14:02 ` Greg Kroah-Hartman
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=CALCETrVieskMnU5XHKHYm+qOfzc+o4yhsGw42pvBNhkv2zsQJA@mail.gmail.com \
--to=luto@kernel.org \
--cc=arnd@arndb.de \
--cc=bp@alien8.de \
--cc=daniel@eclypsium.com \
--cc=dave.hansen@intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=davem@davemloft.net \
--cc=gregkh@linuxfoundation.org \
--cc=hpa@zytor.com \
--cc=hughsient@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=rahul.tanwar@linux.intel.com \
--cc=robh@kernel.org \
--cc=sean.j.christopherson@intel.com \
--cc=tglx@linutronix.de \
--cc=tony.luck@intel.com \
--cc=x86@kernel.org \
--cc=xiaoyao.li@intel.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).