This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


[Xen-devel] swiotlb and Xen query?

To: xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>, xenkernelnewbies@xxxxxxxxxxxxxxxx
Subject: [Xen-devel] swiotlb and Xen query?
From: "pradeep singh rautela" <rautelap@xxxxxxxxx>
Date: Wed, 2 May 2007 18:19:06 +0530
Delivery-date: Wed, 02 May 2007 05:47:50 -0700
Dkim-signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:mime-version:content-type; b=eG6TftVr3BqbuWOksmV1BghR8g90bEUeQyrWjtWkQeEkXsIACYEvXnw1dSXwqN9JIPD53YbPoJ9SZB+0zxhTCQq2PVJe0QWIP6dX+NUh7E3a8WLFLc9wZ6E8qQRPRCoGYBoZHdu07T8/9zW4Cody8jXMyhTRzYwEGmNA0KJa+k0=
Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:mime-version:content-type; b=mRrWnZgPv+7qTnH6oDyQdQotuQGefChIUdv/ANV6J0coRxVO/jvQcTGSvdKGtaaDemO1D1p3t9auwh/1VMybedtRhetkwvIzgql5sC3wChLV62sZs8CjK6Gju++bjMM54ZxIBSImr0px/yENB01H+4QmUIzi6lWVEVzVLuJI3Tk=
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Hi All,

dom0 and domU uses swiotlb mechanism to emulate hardware IOMMU, right?
And that so because the whole memory is visible to hypervisor only and not to other domains, am i right?

My doubt is once the translation table between virtual and physical addresses is set by the swiotlb.How does device becomes aware of this table which is emulated in hardware as a matter of fact using swiotlb.the device does not knows about this table when accessing physical memory, isnt it?

Another question is -
dom0 and domU they both have their swiotlb mappings.This means Xen also keeps record of a mapping between these two tables in dom0 and domU? Am i right? Doesnt this means wasting a lot of memory in allocating bounce buffers for swiotlb during booting of dom0 and then during booting of domUs?

Please bear as i am just starting with the Xen code .
Any pointers or links will be really helpful.

Thank you

pradeep singh rautela

"Genius is 1% inspiration, and 99% perspiration" - not me :)
Xen-devel mailing list
<Prev in Thread] Current Thread [Next in Thread>