From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [RFC + Queries] Flow of PCI passthrough in ARM Date: Thu, 6 Nov 2014 14:41:48 -0500 Message-ID: <20141106194148.GD5906@laptop.dumpdata.com> References: <20141008124657.GB13391@laptop.dumpdata.com> <1412775916.24894.15.camel@citrix.com> <20141008145107.GC18573@laptop.dumpdata.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: manish jaggi Cc: Ryan Wilson , Ian Campbell , Vijay Kilari , Stefano Stabellini , Prasun Kapoor , manish.jaggi@caviumnetworks.com, Julien Grall , xen-devel , JBeulich@suse.com List-Id: xen-devel@lists.xenproject.org On Thu, Nov 06, 2014 at 08:58:18PM +0530, manish jaggi wrote: > On 20 October 2014 20:24, Stefano Stabellini > wrote: > > On Mon, 20 Oct 2014, manish jaggi wrote: > >> On 8 October 2014 20:21, Konrad Rzeszutek Wilk wrote: > >> > On Wed, Oct 08, 2014 at 07:17:48PM +0530, manish jaggi wrote: > >> >> On 8 October 2014 19:15, Ian Campbell wrote: > >> >> > On Wed, 2014-10-08 at 19:07 +0530, manish jaggi wrote: > >> >> >> Thanks for replying. As detailed in this thread, I need to create a > >> >> >> hypercall that would send the following information to Xen at the time > >> >> >> of PCI attach > >> >> >> { sbdf , domU sbdf, domainId }. > >> >> >> I am not able to find a way to get the domU sbdf from dom0 at the time > >> >> >> of pci-attach. > >> >> > > >> >> > I think it would need to be done by the pciback driver in the dom0 > >> >> > kernel, which AFAIK is the thing which consistently knows both physical > >> >> > and virtual sbdf for a given assigned device. > >> >> > > >> >> > Ian. > >> >> > > >> >> Correct, can you point out which data structure holds the domU sbdf > >> >> corresponding to the actual sbdf in pciback. > >> > > >> > See 'xen_pcibk_export_device' or 'xen_pcibk_publish_pci_root' > >> > is that what you are referring to? > >> > >> Xen docs also mention about xen-pciback.passthrough=1. If I set this > >> in dom0 i see that the device is enumerated as the same sbdf in domU, > >> but > >> a) it is not shown in lspci > >> b) no front-back communication is done for reading devices configuration space > >> . > >> Is option useful / fully implemented for ARM ? > > > > I don't think this option is very useful. I wouldn't worry about it for > > now. > > Stefano / Ian / Konard / Julien, > > Attached is a first raw code FYI RFC Patches of PCI passthrough support on ARM. > - Linux Patch (3.18) I would move the code that arch/arm64/xen/xen_pci.c introduces (which is also in arch/x86/pci/xen.c) in its own generic file - say to drivers/xen/pci.c. That way you share the code between those two platforms instead of copying it. > - Xen Patch (4.5 staging) > ---(Smmu changes not included, thats a separate patch altogether) > This patches show the logic, at places need of improvements in code > organization/quality. I wanted to share to get initial comments. > This is working with SRIOV as well. Fantastic! > > Please have a look and let me know your positive comments