From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Vrabel Subject: Re: Status of FLR in Xen 4.4 Date: Thu, 26 Sep 2013 19:01:42 +0100 Message-ID: <52447686.7050601@citrix.com> References: <52445EC3.9020600@citrix.com> <52447375.60304@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <52447375.60304@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: Ross Philipson Cc: Matthias , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org On 26/09/13 18:48, Ross Philipson wrote: > On 09/26/2013 12:20 PM, David Vrabel wrote: >> On 26/09/13 17:05, Matthias wrote: >>> Hi everyone, >>> >>> I would like to ask what the current status of FLR, or better of FLR >>> emulation is in latest Xen and if we can expect better support in the >>> future. >> >> What are these cards, are they multi-function and do they actually >> support FLR? Many graphics cards do not. >> >> I have the following hack to pciback to fallback to a bus reset for >> multi-function devices without FLR. Does it help for your use case? >> You will need to ensure that all functions are co-assigned to the same >> domain. > > New kernels (e.g. 3.8) have full support for PCI-e and PCI AF FLRs as > well as fallback support for D0-D3 and secondary bus resets. This > functionality is also in the some of the last 2.6 kernels like 2.6.39. > If you are using an older kernel I guess you might need to patch it. It will only do a secondary bus reset iff the function to be reset is the only function on that bus. If you have a multi-function device secondary bus reset is not tried. David