From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: PCI Passthrough ARM Design : Draft1 Date: Tue, 16 Jun 2015 11:42:08 +0100 Message-ID: <557FFD80.1040506@citrix.com> References: <557549D7.5090407@caviumnetworks.com> <1433940302.30003.75.camel@citrix.com> <55788E1C.6080307@citrix.com> <5579FFC6.9070509@caviumnetworks.com> <1434097967.30003.181.camel@citrix.com> <557FB748.3050704@caviumnetworks.com> <557FC9FD.1030007@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; Format="flowed" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <557FC9FD.1030007@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: =?windows-1252?Q?Roger_Pau_Monn=E9?= , Manish Jaggi , Ian Campbell Cc: Vijay Kilari , Prasun Kapoor , "Kumar, Vijaya" , "xen-devel@lists.xen.org" , Stefano Stabellini , "Kulkarni, Ganapatrao" List-Id: xen-devel@lists.xenproject.org On 16/06/2015 08:02, Roger Pau Monn=E9 wrote: > Hello, > > El 16/06/15 a les 7.42, Manish Jaggi ha escrit: > [...] >>>>> Beware that the 1:1 mapping doesn't fit with the current guest memory >>>>> layout which is pre-defined at Xen build time. So you would also have >>>>> to make it dynamically or decide to use the same memory layout as the >>>>> host. >>>> If same layout as host used, would there be any issue? >>> I'm not sure that a 1:1 mapping is any different to the host layout. But >>> in any case, the host layout also doesn't match the guest layout, so it >>> has the same issues. >> There is a domctl on x86 DOMCTL_iomem_permission which looks doing the >> same thing as the map_mmio hypercall which I am proposing. I am not sure >> if it does a 1:1. Do you have more info on it? > > No, this hypercall only sets the permissions of IO memory ranges, but > AFAICT it doesn't touch the p2m at all. Correct. -- = Julien Grall