kvm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: David Laight <David.Laight@ACULAB.COM>
To: 'Xiaoyao Li' <xiaoyao.li@intel.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	"Sean Christopherson" <sean.j.christopherson@intel.com>
Cc: "x86@kernel.org" <x86@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>
Subject: RE: [PATCH 1/2] KVM: x86: Emulate split-lock access as a write
Date: Thu, 30 Jan 2020 12:31:44 +0000	[thread overview]
Message-ID: <db3b854fd03745738f46cfce451d9c98@AcuMS.aculab.com> (raw)
In-Reply-To: <20200130121939.22383-2-xiaoyao.li@intel.com>

From: Xiaoyao Li
> Sent: 30 January 2020 12:20
> If split lock detect is enabled (warn/fatal), #AC handler calls die()
> when split lock happens in kernel.
> 
> A sane guest should never tigger emulation on a split-lock access, but
> it cannot prevent malicous guest from doing this. So just emulating the
> access as a write if it's a split-lock access to avoid malicous guest
> polluting the kernel log.

That doesn't seem right if, for example, the locked access is addx.
ISTM it would be better to force an immediate fatal error of some
kind than just corrupt the guest memory.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)


  reply	other threads:[~2020-01-30 12:31 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-30 12:19 [PATCH 0/2] kvm: split_lock: Fix emulator and extend #AC handler Xiaoyao Li
2020-01-30 12:19 ` [PATCH 1/2] KVM: x86: Emulate split-lock access as a write Xiaoyao Li
2020-01-30 12:31   ` David Laight [this message]
2020-01-30 15:16     ` Andy Lutomirski
2020-01-31 20:01       ` Sean Christopherson
2020-02-04 14:47         ` Vitaly Kuznetsov
2020-02-10 21:59           ` Sean Christopherson
2020-01-30 12:19 ` [PATCH 2/2] KVM: VMX: Extend VMX's #AC handding Xiaoyao Li
2020-01-30 15:18   ` Andy Lutomirski
2020-01-30 16:29     ` Xiaoyao Li
2020-01-30 17:16       ` Andy Lutomirski
2020-01-31  7:22         ` Xiaoyao Li
2020-01-31 15:37           ` Andy Lutomirski
2020-01-31 17:47             ` Xiaoyao Li
2020-01-31 20:17               ` Sean Christopherson
2020-01-31 20:57                 ` Andy Lutomirski
2020-01-31 21:04                   ` Sean Christopherson
2020-01-31 21:33                     ` Andy Lutomirski
2020-02-01 16:58                       ` Xiaoyao Li
2020-02-01 17:56                         ` Andy Lutomirski
2020-02-02  4:33                           ` Xiaoyao Li
2020-02-03 18:49                             ` Andy Lutomirski
2020-02-04  6:03                               ` 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=db3b854fd03745738f46cfce451d9c98@AcuMS.aculab.com \
    --to=david.laight@aculab.com \
    --cc=bp@alien8.de \
    --cc=hpa@zytor.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=pbonzini@redhat.com \
    --cc=sean.j.christopherson@intel.com \
    --cc=tglx@linutronix.de \
    --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).