From: Marcelo Tosatti <mtosatti@redhat.com>
To: Andrea Arcangeli <aarcange@redhat.com>
Cc: kvm@vger.kernel.org
Subject: Re: missing kvm smp tlb flush in invlpg
Date: Sun, 15 Mar 2009 16:23:42 -0300 [thread overview]
Message-ID: <20090315192342.GA6651@amt.cnet> (raw)
In-Reply-To: <20090312171843.GU27823@random.random>
On Thu, Mar 12, 2009 at 06:18:43PM +0100, Andrea Arcangeli wrote:
> From: Andrea Arcangeli <aarcange@redhat.com>
>
> While looking at invlpg out of sync code with Izik I think I noticed a
> missing smp tlb flush here. Without this the other cpu can still write
> to a freed host physical page. tlb smp flush must happen if
> rmap_remove is called always before mmu_lock is released because the
> VM will take the mmu_lock before it can finally add the page to the
> freelist after swapout. mmu notifier makes it safe to flush the tlb
> after freeing the page (otherwise it would never be safe) so we can do
> a single flush for multiple sptes invalidated.
I think this fix is more expensive than it needs to be, but better than
being unsafe for now.
Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
next prev parent reply other threads:[~2009-03-15 19:24 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-12 17:18 missing kvm smp tlb flush in invlpg Andrea Arcangeli
2009-03-15 10:35 ` Avi Kivity
2009-03-15 16:16 ` Andrea Arcangeli
2009-03-15 16:19 ` Avi Kivity
2009-03-15 16:30 ` Andrea Arcangeli
2009-03-15 16:35 ` Avi Kivity
2009-03-15 17:05 ` Andrea Arcangeli
2009-03-16 10:16 ` Avi Kivity
2009-03-15 19:23 ` Marcelo Tosatti [this message]
2009-03-15 20:11 ` Izik Eidus
2009-03-16 18:22 ` Marcelo Tosatti
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=20090315192342.GA6651@amt.cnet \
--to=mtosatti@redhat.com \
--cc=aarcange@redhat.com \
--cc=kvm@vger.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