From: "David P. Reed" <dpreed@deepplum.com>
To: "Sean Christopherson" <sean.j.christopherson@intel.com>
Cc: "Andy Lutomirski" <luto@amacapital.net>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"Borislav Petkov" <bp@alien8.de>, "X86 ML" <x86@kernel.org>,
"H. Peter Anvin" <hpa@zytor.com>,
"Allison Randal" <allison@lohutok.net>,
"Enrico Weigelt" <info@metux.net>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Kate Stewart" <kstewart@linuxfoundation.org>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
"Randy Dunlap" <rdunlap@infradead.org>,
"Martin Molnar" <martin.molnar.programming@gmail.com>,
"Andy Lutomirski" <luto@kernel.org>,
"Alexandre Chartre" <alexandre.chartre@oracle.com>,
"Jann Horn" <jannh@google.com>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] Fix undefined operation VMXOFF during reboot and crash
Date: Mon, 29 Jun 2020 18:46:41 -0400 (EDT) [thread overview]
Message-ID: <1593470801.608531492@apps.rackspace.com> (raw)
In-Reply-To: <20200629214956.GA12962@linux.intel.com>
On Monday, June 29, 2020 5:49pm, "Sean Christopherson" <sean.j.christopherson@intel.com> said:
> On Mon, Jun 29, 2020 at 02:22:45PM -0700, Andy Lutomirski wrote:
>>
>>
>> > On Jun 29, 2020, at 1:54 PM, David P. Reed <dpreed@deepplum.com> wrote:
>> >
>> > Simple question for those on the To: and CC: list here. Should I
>> > abandon any hope of this patch being accepted? It's been a long time.
>> >
>> > The non-response after I acknowledged that this was discovered by when
>> > working on a personal, non-commercial research project - which is
>> > "out-of-tree" (apparently dirty words on LKML) has me thinking my
>> > contribution is unwanted. That's fine, I suppose. I can maintain this patch
>> > out-of-tree as well. I did incorporate all the helpful suggestions I
>> > received in this second patch, and given some encouragement, will happily
>> > submit a revised v3 if there is any likelihood of acceptance. I'm wary of
>> > doing more radical changes (like combining emergency and normal paths).
>> >
>>
>> Sorry about being slow and less actively encouraging than we should be. We
>> absolutely welcome personal contributions. The actual problem is that
>> everyone is worked and we’re all slow. Also, you may be hitting a corner
>> case
>> in the process: is this a KVM patch or an x86 patch?
>
> It's an x86 patch as it's not KVM specific, e.g. this code also helps play
> nice with out of tree hypervisors.
>
> The code change is mostly good, but it needs to be split up as there are
> three separate fixes:
>
> 1. Handle #UD on VMXON due to a race.
> 2. Mark memory and flags as clobbered by VMXON.
> 3. Change emergency_vmx_disable_all() to not manually check cpu_vmx_enabled().
>
> Yes, the changes are tiny, but if for example #3 introduces a bug then we
> don't have to revert #1 and #2. Or perhaps older kernels are only subject
> to the #1 and #2 and thus dumping all three changes into a single patch makes
> it all harder to backport. In other words, all the usual "one change per
> patch" reasons.
>
Thanks. If no one else responds with additional suggestions, I will make it into 3 patches.
I'm happy to learn the nuances of the kernel patch regimen.
next prev parent reply other threads:[~2020-06-29 22:46 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-25 14:45 [PATCH v2] Fix undefined operation VMXOFF during reboot and crash David P. Reed
2020-06-25 14:59 ` David P. Reed
2020-06-29 20:54 ` David P. Reed
2020-06-29 21:22 ` Andy Lutomirski
2020-06-29 21:49 ` Sean Christopherson
2020-06-29 22:46 ` David P. Reed [this message]
2020-07-04 20:38 ` [PATCH v3 0/3] " David P. Reed
2020-07-04 20:38 ` [PATCH v3 1/3] Correct asm VMXOFF side effects David P. Reed
2020-07-05 5:46 ` Randy Dunlap
2020-07-04 20:38 ` [PATCH v3 2/3] Fix undefined operation fault that can hang a cpu on crash or panic David P. Reed
2020-07-05 18:22 ` Andy Lutomirski
2020-07-05 19:52 ` David P. Reed
2020-07-05 20:55 ` Andy Lutomirski
2020-07-05 22:07 ` David P. Reed
2020-07-07 5:09 ` Sean Christopherson
2020-07-07 19:09 ` David P. Reed
2020-07-07 19:24 ` Sean Christopherson
2020-07-07 19:52 ` David P. Reed
2020-07-04 20:38 ` [PATCH v3 3/3] Force all cpus to exit VMX root operation on crash/panic reliably David P. Reed
2020-07-05 18:26 ` Andy Lutomirski
2020-07-05 20:00 ` David P. Reed
2020-07-05 20:53 ` Andy Lutomirski
2020-07-07 5:29 ` Sean Christopherson
-- strict thread matches above, loose matches on Subject: below --
2020-06-11 17:02 [PATCH] Fix undefined operation VMXOFF during reboot and crash Andy Lutomirski
2020-06-11 19:45 ` [PATCH v2] " David P. Reed
2020-06-11 19:48 ` David P. Reed
2020-06-25 6:06 ` Sean Christopherson
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=1593470801.608531492@apps.rackspace.com \
--to=dpreed@deepplum.com \
--cc=alexandre.chartre@oracle.com \
--cc=allison@lohutok.net \
--cc=bp@alien8.de \
--cc=dave.hansen@linux.intel.com \
--cc=gregkh@linuxfoundation.org \
--cc=hpa@zytor.com \
--cc=info@metux.net \
--cc=jannh@google.com \
--cc=kstewart@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@amacapital.net \
--cc=luto@kernel.org \
--cc=martin.molnar.programming@gmail.com \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=rdunlap@infradead.org \
--cc=sean.j.christopherson@intel.com \
--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).