From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mukesh Rathor Subject: Re: [PATCH v3] docs: add PVH specification Date: Mon, 22 Sep 2014 17:38:37 -0700 Message-ID: <20140922173837.1e069d63@mantra.us.oracle.com> References: <1411060764-4016-1-git-send-email-roger.pau@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1XWE80-0002U2-H0 for xen-devel@lists.xenproject.org; Tue, 23 Sep 2014 00:38:48 +0000 In-Reply-To: <1411060764-4016-1-git-send-email-roger.pau@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Roger Pau Monne Cc: xen-devel@lists.xenproject.org, David Vrabel , Jan Beulich List-Id: xen-devel@lists.xenproject.org On Thu, 18 Sep 2014 19:19:24 +0200 Roger Pau Monne wrote: > Introduce a document that describes the interfaces used on PVH. This > document has been designed from a guest OS point of view (i.e.: what > a guest needs to do in order to support PVH). ..... > + > +*TODO*: we need to figure out what to do with MMIO regions, right > now Xen +sets all the holes in the native e820 to MMIO regions for > Dom0 up to 4GB. We +need to decide what to do with MMIO regions above > 4GB on Dom0, and what to do +for PVH DomUs with pci-passthrough. My previous comment in earlier version on this: "We map all non-ram regions for dom0 1:1 till the highest non-ram e820 entry. If there is anything that is beyond the last e820 entry, it will remain unmapped." The 4GB comment in the function pvh_map_all_iomem() refers to when a BIOS may not report io space above ram when ram is less than 4GB. > +In the case of a guest started with memory != maxmem, the e820 > memory map +returned by Xen will contain the memory up to maxmem. The > guest has to be very +careful to only use the lower memory pages up > to the value contained in +`start_info->nr_pages` because any memory > page above that value will not be +populated. > + > +## Physical devices ## > + > +When running as Dom0 the guest OS has the ability to interact with > the physical +devices present in the system. A note should be made > that PVH guests require +a working IOMMU in order to interact with > physical devices. + > +The first step in order to manipulate the devices is to make Xen > aware of +them. Due to the fact that all the hardware description on > x86 comes from +ACPI, Dom0 is responsible of parsing the ACPI tables > and notify Xen about the +devices it finds. This is done with the Minor: Dom0 is responsible for parsing the ACPI tables and notifying Xen about... With that, thanks Roger, and : Acked-by: Mukesh Rathor Mukesh