All of lore.kernel.org
 help / color / mirror / Atom feed
From: Christoph Hellwig <hch@infradead.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
	x86@kernel.org, "Kenneth R. Crudup" <kenny@panix.com>,
	"Peter Zijlstra (Intel)" <peterz@infradead.org>,
	Paolo Bonzini <pbonzini@redhat.com>, Jessica Yu <jeyu@kernel.org>,
	Fenghua Yu <fenghua.yu@intel.com>,
	Xiaoyao Li <xiaoyao.li@intel.com>, Nadav Amit <namit@vmware.com>,
	Thomas Hellstrom <thellstrom@vmware.com>,
	Sean Christopherson <sean.j.christopherson@intel.com>,
	Tony Luck <tony.luck@intel.com>,
	Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [patch 1/2] x86,module: Detect VMX modules and disable Split-Lock-Detect
Date: Mon, 6 Apr 2020 05:23:43 -0700	[thread overview]
Message-ID: <20200406122343.GA10683@infradead.org> (raw)
In-Reply-To: <20200402124205.242674296@linutronix.de>

On Thu, Apr 02, 2020 at 02:32:59PM +0200, Thomas Gleixner wrote:
> From: Peter Zijlstra <peterz@infradead.org>
> 
> It turns out that with Split-Lock-Detect enabled (default) any VMX
> hypervisor needs at least a little modification in order to not blindly
> inject the #AC into the guest without the guest being ready for it.
> 
> Since there is no telling which module implements a hypervisor, scan the
> module text and look for the VMLAUNCH instruction. If found, the module is
> assumed to be a hypervisor of some sort and SLD is disabled.
> 
> Hypervisors, which have been modified and are known to work correctly,
> can add:
> 
>   MODULE_INFO(sld_safe, "Y");
> 
> to explicitly tell the module loader they're good.
> 
> NOTE: it is unfortunate that struct load_info is not available to the
>       arch module code, this means CONFIG_CPU_SUP_INTEL gunk is needed
>       in generic code.
> 
> NOTE: while we can 'trivially' fix KVM, we're still stuck with stuff
>       like VMware and VirtualBox doing their own thing.

This is just crazy.  We have never cared about any out tree module, why
would we care here where it creates a real complexity.  Just fix KVM
and ignore anything else.

  parent reply	other threads:[~2020-04-06 12:23 UTC|newest]

Thread overview: 81+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-02 12:32 [patch 0/2] x86: Prevent Split-Lock-Detection wreckage on VMX hypervisors Thomas Gleixner
2020-04-02 12:32 ` [patch 1/2] x86,module: Detect VMX modules and disable Split-Lock-Detect Thomas Gleixner
2020-04-02 15:23   ` [patch v2 " Peter Zijlstra
2020-04-02 16:20     ` Xiaoyao Li
2020-04-02 16:25       ` Peter Zijlstra
2020-04-02 16:39         ` Nadav Amit
2020-04-02 16:41         ` Xiaoyao Li
2020-04-02 17:34           ` Thomas Gleixner
2020-04-02 17:51             ` Sean Christopherson
2020-04-02 18:51               ` Peter Zijlstra
2020-04-02 20:23                 ` Sean Christopherson
2020-04-02 21:04                   ` Thomas Gleixner
2020-04-02 21:16                     ` Sean Christopherson
2020-04-03  8:09     ` David Laight
2020-04-03 14:33       ` Peter Zijlstra
2020-04-02 23:42   ` [patch " Rasmus Villemoes
2020-04-03 14:35     ` Jessica Yu
2020-04-03 15:21       ` Peter Zijlstra
2020-04-03 16:01         ` Sean Christopherson
2020-04-03 16:12           ` Peter Zijlstra
2020-04-03 16:16             ` David Laight
2020-04-03 16:39               ` Peter Zijlstra
2020-04-03 16:25             ` Sean Christopherson
2020-04-03 16:40               ` Peter Zijlstra
2020-04-03 16:48                 ` Nadav Amit
2020-04-03 17:21                   ` Sean Christopherson
2020-04-03 18:53         ` Thomas Gleixner
2020-04-03 20:58           ` Andy Lutomirski
2020-04-03 21:49             ` Thomas Gleixner
2020-04-03 11:29   ` kbuild test robot
2020-04-03 11:29     ` [patch 1/2] x86, module: " kbuild test robot
2020-04-03 14:43   ` [patch 1/2] x86,module: " kbuild test robot
2020-04-03 14:43     ` [patch 1/2] x86, module: " kbuild test robot
2020-04-03 16:36   ` [patch 1/2] x86,module: " Sean Christopherson
2020-04-03 16:41     ` Peter Zijlstra
2020-04-03 18:35       ` Jessica Yu
2020-04-06 12:23   ` Christoph Hellwig [this message]
2020-04-06 14:40     ` Peter Zijlstra
2020-04-06 15:18       ` Christoph Hellwig
2020-04-06 15:22         ` Peter Zijlstra
2020-04-06 18:27           ` Steven Rostedt
2020-04-02 12:33 ` [patch 2/2] x86/kvm/vmx: Prevent split lock detection induced #AC wreckage Thomas Gleixner
2020-04-02 15:30   ` Sean Christopherson
2020-04-02 15:44     ` Nadav Amit
2020-04-02 16:04       ` Sean Christopherson
2020-04-02 16:56     ` Thomas Gleixner
2020-04-02 15:55   ` [PATCH 0/3] x86: KVM: VMX: Add basic split-lock #AC handling Sean Christopherson
2020-04-02 15:55     ` [PATCH 1/3] KVM: x86: Emulate split-lock access as a write in emulator Sean Christopherson
2020-04-02 15:55     ` [PATCH 2/3] x86/split_lock: Refactor and export handle_user_split_lock() for KVM Sean Christopherson
2020-04-02 17:01       ` Thomas Gleixner
2020-04-02 17:19         ` Sean Christopherson
2020-04-02 19:06           ` Thomas Gleixner
2020-04-10  4:39             ` Xiaoyao Li
2020-04-10 10:21               ` Paolo Bonzini
2020-04-02 15:55     ` [PATCH 3/3] KVM: VMX: Extend VMX's #AC interceptor to handle split lock #AC in guest Sean Christopherson
2020-04-02 17:19       ` Thomas Gleixner
2020-04-02 17:40         ` Sean Christopherson
2020-04-02 20:07           ` Thomas Gleixner
2020-04-02 20:36             ` Andy Lutomirski
2020-04-02 20:48             ` Peter Zijlstra
2020-04-02 20:51             ` Sean Christopherson
2020-04-02 22:27               ` Thomas Gleixner
2020-04-02 22:40                 ` Nadav Amit
2020-04-02 23:03                   ` Thomas Gleixner
2020-04-02 23:08                   ` Steven Rostedt
2020-04-02 23:16                     ` Kenneth R. Crudup
2020-04-02 23:18                       ` Jim Mattson
2020-04-03 12:16                         ` Thomas Gleixner
2020-04-10 10:23     ` [PATCH 0/3] x86: KVM: VMX: Add basic split-lock #AC handling Paolo Bonzini
2020-04-10 11:14       ` Thomas Gleixner
2020-04-02 13:43 ` [patch 0/2] x86: Prevent Split-Lock-Detection wreckage on VMX hypervisors Kenneth R. Crudup
2020-04-02 14:32   ` Peter Zijlstra
2020-04-02 14:41     ` Kenneth R. Crudup
2020-04-02 14:46       ` Peter Zijlstra
2020-04-02 14:53         ` Kenneth R. Crudup
2020-04-02 14:37   ` Thomas Gleixner
2020-04-02 14:47     ` Nadav Amit
2020-04-02 15:11       ` Peter Zijlstra
2020-04-02 14:53 [patch 1/2] x86,module: Detect VMX modules and disable Split-Lock-Detect Andy Lutomirski
2020-04-02 15:02 ` Kenneth R. Crudup
2020-04-02 16:46   ` Thomas Gleixner

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=20200406122343.GA10683@infradead.org \
    --to=hch@infradead.org \
    --cc=fenghua.yu@intel.com \
    --cc=jeyu@kernel.org \
    --cc=kenny@panix.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=namit@vmware.com \
    --cc=pbonzini@redhat.com \
    --cc=peterz@infradead.org \
    --cc=rostedt@goodmis.org \
    --cc=sean.j.christopherson@intel.com \
    --cc=tglx@linutronix.de \
    --cc=thellstrom@vmware.com \
    --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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.