From: "H. Peter Anvin" <hpa@zytor.com>
To: Kyle Huey <me@kylehuey.com>
Cc: "Robert O'Callahan" <robert@ocallahan.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Andy Lutomirski" <luto@kernel.org>,
"Ingo Molnar" <mingo@redhat.com>,
"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<x86@kernel.org>, "Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
"Jeff Dike" <jdike@addtoit.com>,
"Richard Weinberger" <richard@nod.at>,
"Alexander Viro" <viro@zeniv.linux.org.uk>,
"Shuah Khan" <shuah@kernel.org>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
"Borislav Petkov" <bp@suse.de>,
"Peter Zijlstra" <peterz@infradead.org>,
"Boris Ostrovsky" <boris.ostrovsky@oracle.com>,
"Len Brown" <len.brown@intel.com>,
"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
"Dmitry Safonov" <dsafonov@virtuozzo.com>
Subject: Re: [PATCH v10 6/7] x86/arch_prctl: Add ARCH_[GET|SET]_CPUID
Date: Tue, 14 Mar 2017 13:06:53 -0700 [thread overview]
Message-ID: <1acdafa1-4557-b147-ef67-069886255e6c@zytor.com> (raw)
In-Reply-To: <CAP045AqLAQSu3nsQUuv8v1o_8GP_eTJ1U+JKQM==mDLJa_1J2A@mail.gmail.com>
On 03/14/17 12:08, Kyle Huey wrote:
>
> That's largely what we ended up doing. See
> https://lkml.org/lkml/2017/2/14/80 and the latest version of this
> patch, https://lkml.org/lkml/2017/3/11/197.
>
Yes, as I said, my mistake.
I would still like to see an early-out when none of these flags are set
(I just discussed this with tglx on IRC):
if (likely(!((tifp|tifn) &
(_TIF_BLOCKSTEP|_TIF_NOTSC|_TIF_IO_BITMAP|
_TIF_NOCPUID|_TIF_USER_RETURN_NOTIFY))))
return;
The USER_RETURN_NOTIFY could really use some sanity: it is a notifier
chain with a single in-kernel user, which is KVM on x86 only, but we
most likely will need to propagate the flag even if it ends up getting
specialized.
-hpa
next prev parent reply other threads:[~2017-03-14 20:06 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-08 18:39 [PATCH v10 0/7] x86/arch_prctl Add ARCH_[GET|SET]_CPUID for controlling the CPUID instruction Kyle Huey
2016-11-08 18:39 ` [PATCH v10 1/7] x86/arch_prctl/64: Use SYSCALL_DEFINE2 to define sys_arch_prctl Kyle Huey
2016-11-09 9:47 ` Borislav Petkov
2016-11-10 18:17 ` Kyle Huey
2016-11-08 18:39 ` [PATCH v10 2/7] x86/arch_prctl/64: Rename do_arch_prctl to do_arch_prctl_64 Kyle Huey
2016-11-09 9:58 ` Borislav Petkov
2016-11-08 18:39 ` [PATCH v10 3/7] x86/arch_prctl: Add do_arch_prctl_common Kyle Huey
2016-11-09 10:31 ` Borislav Petkov
2016-11-08 18:39 ` [PATCH v10 4/7] x86/syscalls/32: Wire up arch_prctl on x86-32 Kyle Huey
2016-11-09 11:04 ` Borislav Petkov
2016-11-08 18:39 ` [PATCH v10 5/7] x86/cpufeature: Detect CPUID faulting support Kyle Huey
2016-11-08 19:06 ` Thomas Gleixner
2016-11-08 19:38 ` Kyle Huey
2016-11-09 11:14 ` Borislav Petkov
2016-11-08 18:39 ` [PATCH v10 6/7] x86/arch_prctl: Add ARCH_[GET|SET]_CPUID Kyle Huey
2016-11-08 20:06 ` Thomas Gleixner
2016-11-09 13:21 ` Borislav Petkov
2016-11-09 13:34 ` Thomas Gleixner
2016-11-10 23:38 ` Kyle Huey
2016-11-10 23:26 ` Kyle Huey
2016-11-09 13:12 ` Borislav Petkov
2017-03-14 19:01 ` H. Peter Anvin
2017-03-14 19:08 ` Kyle Huey
2017-03-14 20:06 ` H. Peter Anvin [this message]
2017-03-14 19:17 ` H. Peter Anvin
2017-03-14 19:23 ` Andy Lutomirski
2017-03-15 9:11 ` H. Peter Anvin
2016-11-08 18:39 ` [PATCH v10 7/7] KVM: x86: virtualize cpuid faulting Kyle Huey
2016-11-08 22:12 ` David Matlack
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=1acdafa1-4557-b147-ef67-069886255e6c@zytor.com \
--to=hpa@zytor.com \
--cc=boris.ostrovsky@oracle.com \
--cc=bp@suse.de \
--cc=dave.hansen@linux.intel.com \
--cc=dsafonov@virtuozzo.com \
--cc=jdike@addtoit.com \
--cc=len.brown@intel.com \
--cc=luto@kernel.org \
--cc=me@kylehuey.com \
--cc=mingo@redhat.com \
--cc=pbonzini@redhat.com \
--cc=peterz@infradead.org \
--cc=rafael.j.wysocki@intel.com \
--cc=richard@nod.at \
--cc=rkrcmar@redhat.com \
--cc=robert@ocallahan.org \
--cc=shuah@kernel.org \
--cc=tglx@linutronix.de \
--cc=viro@zeniv.linux.org.uk \
--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