From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH 0/2] Re-factoring passthrough/pci.c and adding place-holder code for ARM/PCI Date: Mon, 13 Apr 2015 11:19:04 +0100 Message-ID: <552B9818.7010702@gmail.com> References: <552B724A.8080400@caviumnetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <552B724A.8080400@caviumnetworks.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: Manish Jaggi , xen Devel , Stefano Stabellini , Julien Grall , Ian Campbell , "Kumar, Vijaya" , "Prasun.kapoor@cavium.com" List-Id: xen-devel@lists.xenproject.org Hi Manish, On 13/04/15 08:37, Manish Jaggi wrote: > Xen currently does not have PCI support for ARM builds. This patch set > makes the code compilable for ARM PCI and adds places-holder code > which would be replaced with PCI pass-through support patch series. May I ask why you did send directly all the code to support PCI on ARM? Without the rest it's hard to tell whether these patches make sense or not. > Re-factor MSI Handling > ------------- > There is a some x86 specific code which is found in common code: > xen/drivers/passthrough/pci.c which needs to be re factored. > > MSI/X are configured and handled by dom0 or domU code on ARM64 and is not > required to be part of common code. However there are functions which are > used as part of common code and calls to these functions cannot be easily > re factored like pci_cleanup_msi. On x86, the hypervisor is taking care of MSI (enabling/disabling in the config space) as long as doing sanity check on MSI used by a given domain. How do you plan to handle it on ARM? IHMO, the MSI code is very useful and would also help GIC MSI implement (ITS + V2M). FWIW, I've pointed out the same issue on the ITS series a couple of weeks ago. Regards, -- Julien Grall