From: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
To: Marcelo Tosatti <mtosatti@redhat.com>, kvm-devel <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: KVM: MMU: drop read-only large sptes when creating lower level sptes
Date: Tue, 25 Feb 2014 11:30:37 +0800 [thread overview]
Message-ID: <530C0E5D.4030308@linux.vnet.ibm.com> (raw)
In-Reply-To: <20140224165932.GA15971@amt.cnet>
On 02/25/2014 12:59 AM, Marcelo Tosatti wrote:
>
> Read-only large sptes can be created due to read-only faults as
> follows:
>
> - QEMU pagetable entry that maps guest memory is read-only
> due to COW.
> - Guest read faults such memory, COW is not broken, because
> it is a read-only fault.
> - Enable dirty logging, large spte not nuked because it is read-only.
> - Write-fault on such memory causes guest to loop endlessly
> (which must go down to level 1 because dirty logging is enabled).
Hi Marcelo,
It surprised me that the large-readonly mapping was not dropped
by mmu-notifer as this is write fault on readonly mapping in Qemu.
Hmm... i missed something?
next prev parent reply other threads:[~2014-02-25 3:30 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-24 16:59 KVM: MMU: drop read-only large sptes when creating lower level sptes Marcelo Tosatti
2014-02-25 3:30 ` Xiao Guangrong [this message]
2014-02-25 13:13 ` Marcelo Tosatti
2014-02-25 15:11 ` Xiao Guangrong
2014-02-25 22:52 ` Marcelo Tosatti
2014-02-25 8:23 ` Paolo Bonzini
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=530C0E5D.4030308@linux.vnet.ibm.com \
--to=xiaoguangrong@linux.vnet.ibm.com \
--cc=kvm@vger.kernel.org \
--cc=mtosatti@redhat.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 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.