Hi Bjorn, On 2020/2/23 0:55, Bjorn Helgaas wrote: > [+cc Matthew, Thomas] > > On Wed, Oct 16, 2019 at 09:36:23PM +0800, Xiang Zheng wrote: >> Hi all, >> >> Recently I encountered a kernel panic while doing vfio-pci hot-plug/unplug test repeatly on my Arm-KVM virtual machines. > > Did we ever do anything about this panic? I don't see any resolution > in the email thread. > I had sent a v3 patch two months ago and wait for more substantive comments to address this problem. Maybe you missed this email.:) v3: https://lkml.org/lkml/2019/12/10/36 v2: https://lkml.org/lkml/2019/11/18/977 >> See the call stack below: >> >> [66628.697280] vfio-pci 0000:06:03.5: enabling device (0000 -> 0002) >> [66628.809290] vfio-pci 0000:06:03.1: enabling device (0000 -> 0002) >> [66628.921283] vfio-pci 0000:06:02.7: enabling device (0000 -> 0002) >> [66629.029280] vfio-pci 0000:06:03.6: enabling device (0000 -> 0002) >> [66629.137338] vfio-pci 0000:06:03.2: enabling device (0000 -> 0002) >> [66629.249285] vfio-pci 0000:06:03.7: enabling device (0000 -> 0002) >> [66630.237261] Unable to handle kernel read from unreadable memory at virtual address ffff802dac469000 >> [66630.246266] Mem abort info: >> [66630.249047] ESR = 0x8600000d >> [66630.252088] Exception class = IABT (current EL), IL = 32 bits >> [66630.257981] SET = 0, FnV = 0 >> [66630.261022] EA = 0, S1PTW = 0 >> [66630.264150] swapper pgtable: 4k pages, 48-bit VAs, pgdp = 00000000fb16886e >> [66630.270992] [ffff802dac469000] pgd=0000203fffff6803, pud=00e8002d80000f11 >> [66630.277751] Internal error: Oops: 8600000d [#1] SMP >> [66630.282606] Process qemu-kvm (pid: 37201, stack limit = 0x00000000d8f19858) >> [66630.289537] CPU: 41 PID: 37201 Comm: qemu-kvm Kdump: loaded Tainted: G OE 4.19.36-vhulk1907.1.0.h453.eulerosv2r8.aarch64 #1 >> [66630.301822] Hardware name: Huawei TaiShan 2280 V2/BC82AMDDA, BIOS 0.88 07/24/2019 >> [66630.309270] pstate: 80400089 (Nzcv daIf +PAN -UAO) >> [66630.314042] pc : 0xffff802dac469000 >> [66630.317519] lr : __wake_up_common+0x90/0x1a8 >> [66630.321768] sp : ffff00027746bb00 >> [66630.325067] x29: ffff00027746bb00 x28: 0000000000000000 >> [66630.330355] x27: 0000000000000000 x26: ffff0000092755b8 >> [66630.335643] x25: 0000000000000000 x24: 0000000000000000 >> [66630.340930] x23: 0000000000000003 x22: ffff00027746bbc0 >> [66630.346219] x21: 000000000954c000 x20: ffff0001f542bc6c >> [66630.351506] x19: ffff0001f542bb90 x18: 0000000000000000 >> [66630.356793] x17: 0000000000000000 x16: 0000000000000000 >> [66630.362081] x15: 0000000000000000 x14: 0000000000000000 >> [66630.367368] x13: 0000000000000000 x12: 0000000000000000 >> [66630.372655] x11: 0000000000000000 x10: 0000000000000bb0 >> [66630.377942] x9 : ffff00027746ba50 x8 : ffff80367ff6ca10 >> [66630.383229] x7 : ffff802e20d59200 x6 : 000000000000003f >> [66630.388517] x5 : ffff00027746bbc0 x4 : ffff802dac469000 >> [66630.393806] x3 : 0000000000000000 x2 : 0000000000000000 >> [66630.399093] x1 : 0000000000000003 x0 : ffff0001f542bb90 >> [66630.404381] Call trace: >> [66630.406818] 0xffff802dac469000 >> [66630.409945] __wake_up_common_lock+0xa8/0x1a0 >> [66630.414283] __wake_up+0x40/0x50 >> [66630.417499] pci_cfg_access_unlock+0x9c/0xd0 >> [66630.421752] pci_try_reset_function+0x58/0x78 >> [66630.426095] vfio_pci_ioctl+0x478/0xdb8 [vfio_pci] >> [66630.430870] vfio_device_fops_unl_ioctl+0x44/0x70 [vfio] >> [66630.436158] do_vfs_ioctl+0xc4/0x8c0 >> [66630.439718] ksys_ioctl+0x8c/0xa0 >> [66630.443018] __arm64_sys_ioctl+0x28/0x38 >> [66630.446925] el0_svc_common+0x78/0x130 >> [66630.450657] el0_svc_handler+0x38/0x78 >> [66630.454389] el0_svc+0x8/0xc >> [66630.457260] Code: 00000000 00000000 00000000 00000000 (ac46d000) >> [66630.463325] kernel fault(0x1) notification starting on CPU 41 >> [66630.469044] kernel fault(0x1) notification finished on CPU 41 >> >> The chance to reproduce this problem is very small. We had an initial analysis of this problem, >> and found it was caused by the illegal value of the 'curr->func' in the __wake_up_common() function. >> >> I cannot image how 'curr->func' can be wrote to 0xffff802dac469000. Is there any problem about >> concurrent competition between the pci_wait_cfg() function and the wake_up_all() function? >> >> >> -- >> >> Thanks, >> Xiang >> > > . > -- Thanks, Xiang
