Hi Bjorn, Best regards, Liu Po > -----Original Message----- > From: Bjorn Helgaas [mailto:helgaas@xxxxxxxxxx] > Sent: Friday, August 26, 2016 2:10 AM > To: Po Liu > Cc: S?ren Brinkmann; Roy Zang; Arnd Bergmann; linux-pci@xxxxxxxxxxxxxxx; > Pratyush Anand; Stuart Yoder; Yang-Leo Li; Mingkai Hu; Jingoo Han; Bjorn > Helgaas; Ley Foon Tan; Michal Simek; linux-arm- > kernel@xxxxxxxxxxxxxxxxxxx > Subject: Re: [PATCH v1] arm64:pci: fix the IOV device enabled crash > issue in designware > > On Thu, Aug 25, 2016 at 04:53:19AM +0000, Po Liu wrote: > > > -----Original Message----- > > > From: Bjorn Helgaas [mailto:helgaas@xxxxxxxxxx] > > > Sent: Thursday, August 25, 2016 4:51 AM > > > To: Po Liu > > > Cc: linux-pci@xxxxxxxxxxxxxxx; Roy Zang; Arnd Bergmann; Stuart > > > Yoder; Yang-Leo Li; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; Bjorn > > > Helgaas; Mingkai Hu; Ley Foon Tan; Michal Simek; Sören Brinkmann; > > > Jingoo Han; Pratyush Anand > > > Subject: Re: [PATCH v1] arm64:pci: fix the IOV device enabled crash > > > issue in designware > > > > > > [+cc Jingoo, Pratyush, Michal, Sören, Ley] > > > > > > On Tue, Aug 23, 2016 at 02:01:12PM +0800, Po Liu wrote: > > > > When echo a number to /sys/bus/pci/devices/xxx/sriov_numvfs to > > > enable > the VF devices. A crash log occurred. This found to be > > > access the IOV > devices config space failure issue. > > > > > > What was the actual crash? The mere fact that we made a config > > > read fail should not cause a crash. We might erroneously prevent > > > access to VF devices, but it shouldn't crash. So maybe there's > > > another bug elsewhere that we should fix first. > > > > I built with CONFIG_PCI_IOV=y and notice a crash when I use it: > > > > centqds-60 cd /sys/class/net/ > > centqds-61 ls > > enP1p1s0@ enP2p1s0f0@ enP2p1s0f1@ lo@ sit0@ > > centqds-62 cd enP2p1s0f1/device > > centqds-63 ls > > broken_parity_status driver_override msi_irqs/ sriov_numvfs class > > enable net/ sriov_totalvfs config iommu_group@ power/ subsystem@ > > consistent_dma_mask_bits irq remove subsystem_device device > > local_cpulist rescan subsystem_vendor devspec local_cpus reset uevent > > dma_mask_bits modalias resource vendor driver@ msi_bus rom > > centqds-64 zcat /proc/config.gz | grep _IOV CONFIG_PCI_IOV=y > > centqds-65 sudo su > > [root@centqds 0002:01:00.1]# echo 2 > sriov_numvfs [ 317.604543] ixgbe > > 0002:01:00.1 enP2p1s0f1: SR-IOV enabled with 2 VFs [ 317.714431] > > (null): of_irq_parse_pci() failed with rc=134 > > > > [ 317.719906] -----------[ cut here ]----------- [ 317.724525] > > WARNING: CPU: 6 PID: 3179 at drivers/pci/probe.c:1555 > > pci_device_add+0x144/0x148() [ 317.733123] Modules linked in: > > [ 317.736175] CPU: 6 PID: 3179 Comm: bash Not tainted > > 4.1.8-00024-g0a32d65-dirty #32 [ 317.743731] Hardware name: Freescale > > Layerscape 2088a QDS Board (DT) [ 317.750077] Call trace: > > [ 317.752516] [<fffffe0000096cf8>] dump_backtrace+0x0/0x12c Message > > from[ 317.757916] [<fffffe0000096e34>] show_stack+0x10/0x1c > > syslogd@centqds[ 317.764341] [<fffffe00008937fc>] dump_stack+0x84/0xd4 > > at Jul 26 15:51[ 317.770770] [<fffffe00000be590>] > > warn_slowpath_common+0x94/0xcc > > :10 ... > > kerne[ 317.778067] [<fffffe00000be68c>] warn_slowpath_null+0x14/0x20 > > l:Call trace: > > [ 317.785192] [<fffffe00003c5fa4>] pci_device_add+0x140/0x148 [ > > 317.792133] [<fffffe00003de784>] pci_enable_sriov+0x470/0x7a0 [ > > 317.797873] [<fffffe00005fa9dc>] ixgbe_pci_sriov_configure+0x8c/0x148 > > [ 317.804302] [<fffffe00003cf354>] sriov_numvfs_store+0x78/0x11c [ > > 317.810129] [<fffffe0000443d80>] dev_attr_store+0x14/0x28 [ > > 317.815521] [<fffffe0000200164>] sysfs_kf_write+0x40/0x4c [ > > 317.820908] [<fffffe00001ff5ec>] kernfs_fop_write+0xb8/0x180 [ > > 317.826561] [<fffffe000019a568>] __vfs_write+0x28/0x10c [ 317.831775] > > [<fffffe000019ad00>] vfs_write+0x90/0x1a0 [ 317.836819] > > [<fffffe000019b584>] SyS_write+0x40/0xa0 [ 317.841772] --[ end trace > > 83725a9784fd702a ]-- [ 317.846393] BUG: failure at > > fs/sysfs/file.c:481/sysfs_create_bin_file()! > > [ 317.853081] Kernel panic - not syncing: BUG! > > [ 317.857339] CPU: 6 PID: 3179 Comm: bash Tainted: G W > > 4.1.8-00024-g0a32d65-dirty #32 [ 317.866110] Hardware name: Freescale > > Layerscape 2088a QDS Board (DT) [ 317.872451] Call trace: > > [ 317.874887] [<fffffe0000096cf8>] dump_backtrace+0x0/0x12c [ > > 317.880274] [<fffffe0000096e34>] show_stack+0x10/0x1c [ 317.885315] > > [<fffffe00008937fc>] dump_stack+0x84/0xd4 [ 317.890354] > > [<fffffe00008909e8>] panic+0xe4/0x21c [ 317.895047] > > [<fffffe0000200988>] sysfs_create_bin_file+0x60/0x64 [ 317.901041] > > [<fffffe00003cf52c>] pci_create_sysfs_dev_files+0x48/0x2a8 > > [ 317.907556] [<fffffe00003c4238>] pci_bus_add_device+0x20/0x6c > > > > The code process is that: "echo 2 > sriov_numvf" makes driver > load .sriov_configure. At last to load pci_enable_sriov(). > > The first time vf device operate the config space in the > pci_setup_device() (this function was load in the virtfn_add()) is > pci_read_config_byte(dev, PCI_HEADER_TYPE, &hdr_type) return failure. So > the virtfn didn't initialized proper. > > > > This found to be "bus->primary == pp->root_bus_nr && dev > 0" then > return failure in host controller. The dev came from devfn must not > zero(is about 0x10). > > > > then read config space failure. This makes the dev->bus is NULL. Lead > to upper crash. > > I think the crash (BUG: failure at > fs/sysfs/file.c:481/sysfs_create_bin_file()) > happens in this path: > > sriov_numvfs_store > ixgbe_pci_sriov_configure > ixgbe_pci_sriov_enable > pci_enable_sriov > sriov_enable > pci_iov_add_virtfn > virtfn = pci_alloc_dev() > pci_setup_device(virtfn) > if (pci_read_config_byte(dev, PCI_HEADER_TYPE, > &hdr_type)) > return -EIO > pci_bus_add_device(virtfn) > pci_create_sysfs_dev_files > sysfs_create_bin_file > BUG_ON(!kobj) > > If the config read of PCI_HEADER_TYPE fails, pci_setup_device() returns > -EIO, but pci_iov_add_virtfn() doesn't check it. Can you update > pci_iov_add_virtfn() so it checks that return value? That should fix > the crash, even without your designware patch. > > Obviously, it won't make SR-IOV work, so we still need both patches. Thanks, I'll provide patch in V2. > > Bjorn ��.n��������+%������w��{.n�����{���"�)�� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
