From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Szwed, Maciej" Subject: Re: Problem with MMAP on Xen kernel Date: Wed, 21 Jan 2015 14:38:18 +0000 Message-ID: <122B872DCF83AB4DB816E25A2C1AD08D2D9C3CE9@IRSMSX102.ger.corp.intel.com> References: <6AF484C0160C61439DE06F17668F3BCB5348719C@ORSMSX114.amr.corp.intel.com> <54B95C26.8020805@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Language: en-US List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: David Vrabel , "Dugger, Donald D" , "xen-devel@lists.xen.org" Cc: "Ronciak, John" List-Id: xen-devel@lists.xenproject.org Hi again, Error that I'm getting is: EBUSY 16 /* Device or resource busy */ Kernel version is: Linux XXX 3.12.28-2-xen #1 SMP Mon Sep 8 11:15:37 UTC 2014 (aff039d) x86_64 x86_64 x86_64 GNU/Linux I'm trying to map the memory of NIC with our own driver. Regards, Maciej -----Original Message----- From: Szwed, Maciej Sent: Tuesday, January 20, 2015 2:49 PM To: David Vrabel; Dugger, Donald D; xen-devel@lists.xen.org Cc: Ronciak, John Subject: RE: [Xen-devel] Problem with MMAP on Xen kernel Hi, Sorry for late response. I will provide required information tomorrow. Regards, Maciej -----Original Message----- From: David Vrabel [mailto:david.vrabel@citrix.com] Sent: Friday, January 16, 2015 7:45 PM To: Dugger, Donald D; xen-devel@lists.xen.org Cc: Ronciak, John; Szwed, Maciej Subject: Re: [Xen-devel] Problem with MMAP on Xen kernel On 16/01/15 18:24, Dugger, Donald D wrote: > One of our engineers, Maciek, is working on a driver and stumbled upon > what looks like a bug in the Xen kernel. The report I got was: > > > > We recently started to provide mmap functionality in our driver for > Linux. Function for this: > > > > /int/ > > /NalMmap(/ > > / struct file* File,/ > > / struct vm_area_struct* Vma/ > > / )/ > > /{/ > > / if(remap_pfn_range(Vma,/ > > / Vma->vm_start,/ > > / Vma->vm_pgoff,/ > > / Vma->vm_end - Vma->vm_start,/ > > / Vma->vm_page_prot))/ > > / {/ > > / return -EAGAIN;/ > > / }/ > > / / > > / return 0;/ > > /}/ > > > > We discovered that this doesn't work for xen kernels (but it doesn't > return any error, just does not map). I found that it is suggested to > use io_remap_pfn_range instead of remap_pfn_range. After switching > function everything still works on standard kernel, but on xen this > time it returns error. Not a lot to go on here. What kernel version? What PFNs are you trying to map (RAM? MMIO?) What error do you get? Can you provide a minimal driver that shows the problem? David -------------------------------------------------------------------- Intel Technology Poland sp. z o.o. ul. Slowackiego 173 | 80-298 Gdansk | Sad Rejonowy Gdansk Polnoc | VII Wydzial Gospodarczy Krajowego Rejestru Sadowego - KRS 101882 | NIP 957-07-52-316 | Kapital zakladowy 200.000 PLN. Ta wiadomosc wraz z zalacznikami jest przeznaczona dla okreslonego adresata i moze zawierac informacje poufne. W razie przypadkowego otrzymania tej wiadomosci, prosimy o powiadomienie nadawcy oraz trwale jej usuniecie; jakiekolwiek przegladanie lub rozpowszechnianie jest zabronione. This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). If you are not the intended recipient, please contact the sender and delete all copies; any review or distribution by others is strictly prohibited.