kvm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: "Radim Krčmář" <rkrcmar@redhat.com>
To: Nadav Amit <nadav.amit@gmail.com>
Cc: pbonzini@redhat.com, kvm@vger.kernel.org
Subject: Re: [PATCH] KVM: x86: avoid write-tearing of TDP
Date: Fri, 27 May 2016 18:34:37 +0200	[thread overview]
Message-ID: <20160527163437.GA14163@potion> (raw)
In-Reply-To: <1462979069-8275-1-git-send-email-nadav.amit@gmail.com>

2016-05-11 08:04-0700, Nadav Amit:
> In theory, nothing prevents the compiler from write-tearing PTEs, or
> split PTE writes. These partially-modified PTEs can be fetched by other
> cores and cause mayhem. I have not really encountered such case in
> real-life, but it does seem possible.
> 
> For example, the compiler may try to do something creative for
> kvm_set_pte_rmapp() and perform multiple writes to the PTE.
> 
> Signed-off-by: Nadav Amit <nadav.amit@gmail.com>
> ---

We don't lose anything by preventing tearing even if it wasn't possible.
Applied,

Thanks.

      parent reply	other threads:[~2016-05-27 16:34 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-11 15:04 [PATCH] KVM: x86: avoid write-tearing of TDP Nadav Amit
2016-05-26  7:34 ` Nadav Amit
2016-05-27 16:34 ` Radim Krčmář [this message]

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=20160527163437.GA14163@potion \
    --to=rkrcmar@redhat.com \
    --cc=kvm@vger.kernel.org \
    --cc=nadav.amit@gmail.com \
    --cc=pbonzini@redhat.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).