From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: "jeremy@goop.org" <jeremy@goop.org>,
"xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Ian Campbell <Ian.Campbell@eu.citrix.com>,
"hpa@zytor.com" <hpa@zytor.com>,
"hpa@linux.intel.com" <hpa@linux.intel.com>,
"yinghai@kernel.org" <yinghai@kernel.org>
Subject: Re: Xen MMU's requirement to pin pages RO and initial_memory_mapping.
Date: Tue, 17 May 2011 14:17:16 -0400 [thread overview]
Message-ID: <20110517181716.GA4490@dumpdata.com> (raw)
In-Reply-To: <20110517180520.GC13706@dumpdata.com>
> > xen_alloc_pte_init and xen_alloc_pmd_init are the ones that mark the
> > pagetable pages RO and pin them, calling make_lowmem_page_readonly and
> > pin_pagetable_pfn.
> >
> > alloc_pte/pmd are called right before hooking them into the pagetable;
> > unfortunately that means that they fail at marking the pagetable pages
> > RO: make_lowmem_page_readonly uses lookup_address to find the pte
> > corresponding to a page, however at this point the pagetable pages are
> > not mapped yet (usually they are not hooked but when they are hooked, the
> > upper level pagetable page is not hooked), so lookup_address fails.
>
> Right. We don't have to walk the hooked pagetable, I think. We are passed
> in the PMD/PGD of the PFN and we could look at the content of that PFN.
err, got that backwards. "passed in the PFN of the PMD/PGD".
next prev parent reply other threads:[~2011-05-17 18:17 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-13 15:30 Xen MMU's requirement to pin pages RO and initial_memory_mapping Konrad Rzeszutek Wilk
2011-05-16 10:23 ` Stefano Stabellini
2011-05-16 15:41 ` Konrad Rzeszutek Wilk
2011-05-16 21:54 ` H. Peter Anvin
2011-05-17 17:51 ` Stefano Stabellini
2011-05-17 18:07 ` Konrad Rzeszutek Wilk
2011-05-17 17:50 ` Stefano Stabellini
2011-05-17 18:05 ` Konrad Rzeszutek Wilk
2011-05-17 18:17 ` Konrad Rzeszutek Wilk [this message]
2011-05-23 15:20 ` Stefano Stabellini
2011-05-24 13:06 ` Konrad Rzeszutek Wilk
2011-05-24 16:24 ` Stefano Stabellini
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=20110517181716.GA4490@dumpdata.com \
--to=konrad.wilk@oracle.com \
--cc=Ian.Campbell@eu.citrix.com \
--cc=hpa@linux.intel.com \
--cc=hpa@zytor.com \
--cc=jeremy@goop.org \
--cc=linux-kernel@vger.kernel.org \
--cc=stefano.stabellini@eu.citrix.com \
--cc=xen-devel@lists.xensource.com \
--cc=yinghai@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;
as well as URLs for NNTP newsgroup(s).