[PATCH v1] arm64:pci: fix the IOV device enabled crash issue in designware
From: Po Liu <hidden>
Date: 2016-08-25 04:53:19
Also in:
linux-pci
Hi Bjorn, Best regards, Liu Po
-----Original Message----- From: Bjorn Helgaas [mailto:helgaas at kernel.org] Sent: Thursday, August 25, 2016 4:51 AM To: Po Liu Cc: linux-pci at vger.kernel.org; Roy Zang; Arnd Bergmann; Stuart Yoder; Yang-Leo Li; linux-arm-kernel at lists.infradead.org; Bjorn Helgaas; Mingkai Hu; Ley Foon Tan; Michal Simek; S?ren Brinkmann; Jingoo Han; Pratyush Anand Subject: Re: [PATCH v1] arm64:pci: fix the IOV device enabled crash issue in designware [+cc Jingoo, Pratyush, Michal, S?ren, 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 at 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 at 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.
> The read/write config space from host would judge the pcie device > plugin or not by: > > if (bus->primary == pp->root_bus_nr && dev > 0) > return 0; I'm guessing other drivers have the same issue, e.g., altera_pcie_valid_config(), xilinx_pcie_valid_device(). Can you look through them and fix them all at once?
Ok, if the problem is same.
> Although all pcie devices for dev(coming from the device and function > number) is zero. But the dev is not zero for VF. So remove the > condition. > > Signed-off-by: Po Liu [off-list ref] > --- > drivers/pci/host/pcie-designware.c | 7 ------- > 1 file changed, 7 deletions(-) > > diff --git a/drivers/pci/host/pcie-designware.c > b/drivers/pci/host/pcie-designware.c > index 12afce1..dd20eb2 100644 > --- a/drivers/pci/host/pcie-designware.c > +++ b/drivers/pci/host/pcie-designware.c > @@ -670,13 +670,6 @@ static int dw_pcie_valid_config(struct pcie_port *pp, > if (bus->number == pp->root_bus_nr && dev > 0) > return 0; > > - /* > - * do not read more than one device on the bus directly attached > - * to RC's (Virtual Bridge's) DS side. > - */ > - if (bus->primary == pp->root_bus_nr && dev > 0) > - return 0; > - > return 1; > } > > -- > 2.1.0.27.g96db324 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel