From mboxrd@z Thu Jan 1 00:00:00 1970 From: konrad wilk Subject: Re: [Xen-devel] BUG: bad page map under Xen Date: Mon, 21 Oct 2013 08:59:32 -0400 Message-ID: <52652534.2040303@oracle.com> References: <20131021115740.GN20913@ics.muni.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-2; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20131021115740.GN20913-8qz54MUs51PtwjQa/ONI9g@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Lukas Hejtmanek Cc: xen-devel-GuqFBffKawuEi8DpZVb4nw@public.gmane.org, roland-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org On 10/21/2013 7:57 AM, Lukas Hejtmanek wrote: > Hello, > > I'm trying to get SR-IOV working under Xen (4.2). It almost works except > memory bug. This is easily reproducible just in Dom0. > > I have Connect-X3 card with the latest firmware. OFED 2.0-3 drivers. I tried > 3.2 kernel from Debian, 3.10 kernel from Debian and vanila 3.11.5 kernel. All > are the same. Ha! Funny you mention that. I had been looking at this. > As soon as I issue ibv_devinfo command, it produces the following messages > into dmesg. Problem is that with ib_rdma_bw command, I get more of those > messages and moreover, oom killer gets confused and kills almost all > processes. > > [23502.645455] mlx4_core 0000:06:00.0: mlx4_ib: Port 1 logical link is up > [23550.181907] check_flow_steering_support: Device managed flow steering is unavailable for IB port in multifunction env. > [23550.183822] swap_free: Unused swap offset entry 00000001 > [23550.183868] BUG: Bad page map in process ibv_devinfo pte:00000200 pmd:1b7df4067 > [23550.183939] addr:00007f7ef5e18000 vm_flags:400844fa anon_vma: (null) mapping:ffff8801b83c0480 index:380fe0882 > [23550.184022] vma->vm_file->f_op->mmap: ib_uverbs_mmap+0x0/0x2d [ib_uverbs] > [23550.195382] Pid: 13813, comm: ibv_devinfo Tainted: G O 3.2.0-0.bpo.4-amd64 #1 Debian 3.2.41-2+deb7u2~bpo60+1+zs4 > [23550.195461] Call Trace: > [23550.195508] [] ? print_bad_pte+0x1f5/0x20d > [23550.195553] [] ? unmap_vmas+0x5fe/0x814 > [23550.195601] [] ? __add_page_to_lru_list+0x53/0x53 > [23550.195647] [] ? unmap_region+0x9f/0x102 > [23550.195694] [] ? __switch_to+0x23b/0x2b1 > [23550.195741] [] ? pick_next_task_fair+0xfc/0x10c > [23550.195788] [] ? finish_task_switch+0x53/0xc7 > [23550.195832] [] ? do_munmap+0x281/0x2eb > [23550.195875] [] ? sys_munmap+0x3f/0x55 > [23550.195921] [] ? system_call_fastpath+0x16/0x1b > [23550.195965] Disabling lock debugging due to kernel taint > [23550.196412] check_flow_steering_support: Device managed flow steering is unavailable for IB port in multifunction env. > [23550.198303] swap_free: Unused swap offset entry 00000001 > [23550.198348] BUG: Bad page map in process ibv_devinfo pte:00000200 pmd:1b7df4067 > [23550.198424] addr:00007f7ef5e18000 vm_flags:400844fa anon_vma: (null) mapping:ffff8801b83c09a0 index:380fe0082 .. > this happens only if running under Xen. Native kernel in the same version is OK. > > Is it a known bug or is something wrong with BIOS/firmware? > It is a bug in the drivers I believe. The issue is that the mapping created for the second mmap call is done without VM_IO and on an PFN that is RAM (and not the BAR). But I am not entirely sure and hopefully this week will have a better idea and fix. Stay tuned. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html