Hi Thomas, I am running linux-next on my Dell R630 and the system crashed at boot time. I bisected linux-next and got to your commit: commit 3b9c1d377d67072d1d8a2373b4969103cca00dab Author: Thomas Gleixner Date: Wed Aug 26 13:16:46 2020 +0200 x86/msi: Consolidate MSI allocation Convert the interrupt remap drivers to retrieve the pci device from the msi descriptor and use info::hwirq. This is the first step to prepare x86 for using the generic MSI domain ops. Signed-off-by: Thomas Gleixner Acked-by: Wei Liu Acked-by: Joerg Roedel Link: https://lore.kernel.org/r/20200826112332.466405395@linutronix.de The crash log is below and my .config is attached. [ 11.742181] RAPL PMU: hw unit of domain dram 2^-16 Joules [ 11.768742] check: Scanning for low memory corruption every 60 seconds [ 11.781653] Initialise system trusted keyrings [ 11.786858] workingset: timestamp_bits=40 max_order=26 bucket_order=0 [ 11.800237] zbud: loaded [ 11.807003] fuse: init (API version 7.31) [ 11.812713] Key type asymmetric registered [ 11.817286] Asymmetric key parser 'x509' registered [ 11.822750] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 247) [ 11.831235] io scheduler mq-deadline registered [ 11.837559] BUG: kernel NULL pointer dereference, address: 0000000000000018 [ 11.840905] #PF: supervisor read access in kernel mode [ 11.840905] #PF: error_code(0x0000) - not-present page [ 11.840905] PGD 0 P4D 0 [ 11.840905] Oops: 0000 [#1] SMP PTI [ 11.840905] CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.9.0-rc5-1gb-thp+ #57 [ 11.840905] Hardware name: Dell Inc. PowerEdge R630/02C2CP, BIOS 2.11.0 11/02/2019 [ 11.840905] Workqueue: events work_for_cpu_fn [ 11.840905] RIP: 0010:msi_desc_to_pci_dev+0x5/0x10 [ 11.840905] Code: c7 98 79 35 a3 e8 89 89 b5 ff e9 bb eb ff ff cc cc cc cc cc cc 0f 1f 44 00 00 8b 05 65 c3 14 01 c3 0f 1f 40 00 0f 1f 44 00 00 <48> 8b 47 18 48 2d b0 00 00 00 c3 0f 1f 44 00 00 48 8b 47 18 48 8b [ 11.840905] RSP: 0000:ffffbd1bc00cfc88 EFLAGS: 00010297 [ 11.840905] RAX: 0000000000000000 RBX: ffff972073e10000 RCX: 0000000000000000 [ 11.840905] RDX: ffffbd1bc00cfc98 RSI: 0000000000000000 RDI: 0000000000000000 [ 11.840905] RBP: ffff9720778d7080 R08: ffff972073e10338 R09: ffff972073e10338 [ 11.840905] R10: 000000000000000d R11: 0000000000000000 R12: 0000000000000002 [ 11.840905] R13: 0000000000000000 R14: ffff972073e100b0 R15: ffff972073e10000 [ 11.840905] FS: 0000000000000000(0000) GS:ffff97207f800000(0000) knlGS:0000000000000000 [ 11.840905] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 11.840905] CR2: 0000000000000018 CR3: 0000001989612001 CR4: 00000000003706f0 [ 11.840905] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 11.840905] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 11.840905] Call Trace: [ 11.840905] intel_get_irq_domain+0x24/0xb0 [ 11.840905] native_setup_msi_irqs+0x3b/0x90 [ 11.840905] __pci_enable_msi_range+0x314/0x500 [ 11.840905] pci_alloc_irq_vectors_affinity+0xd2/0x130 [ 11.840905] pcie_port_device_register+0x135/0x550 [ 11.840905] ? dequeue_entity+0xa4/0x430 [ 11.840905] ? newidle_balance+0x265/0x3e0 [ 11.840905] pcie_portdrv_probe+0x2d/0xb0 [ 11.840905] local_pci_probe+0x42/0x80 [ 11.840905] ? __schedule+0x29d/0x8b0 [ 11.840905] work_for_cpu_fn+0x16/0x20 [ 11.840905] process_one_work+0x1ab/0x3a0 [ 11.840905] worker_thread+0x1df/0x3c0 [ 11.840905] ? rescuer_thread+0x3b0/0x3b0 [ 11.840905] kthread+0x134/0x150 [ 11.840905] ? __kthread_bind_mask+0x60/0x60 [ 11.840905] ret_from_fork+0x22/0x30 [ 11.840905] Modules linked in: [ 11.840905] CR2: 0000000000000018 [ 11.840905] ---[ end trace d9574f52cc5ec884 ]--- [ 11.840905] RIP: 0010:msi_desc_to_pci_dev+0x5/0x10 [ 11.840905] Code: c7 98 79 35 a3 e8 89 89 b5 ff e9 bb eb ff ff cc cc cc cc cc cc 0f 1f 44 00 00 8b 05 65 c3 14 01 c3 0f 1f 40 00 0f 1f 44 00 00 <48> 8b 47 18 48 2d b0 00 00 00 c3 0f 1f 44 00 00 48 8b 47 18 48 8b [ 11.840905] RSP: 0000:ffffbd1bc00cfc88 EFLAGS: 00010297 [ 11.840905] RAX: 0000000000000000 RBX: ffff972073e10000 RCX: 0000000000000000 [ 11.840905] RDX: ffffbd1bc00cfc98 RSI: 0000000000000000 RDI: 0000000000000000 [ 11.840905] RBP: ffff9720778d7080 R08: ffff972073e10338 R09: ffff972073e10338 [ 11.840905] R10: 000000000000000d R11: 0000000000000000 R12: 0000000000000002 [ 11.840905] R13: 0000000000000000 R14: ffff972073e100b0 R15: ffff972073e10000 [ 11.840905] FS: 0000000000000000(0000) GS:ffff97207f800000(0000) knlGS:0000000000000000 [ 11.840905] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 11.840905] CR2: 0000000000000018 CR3: 0000001989612001 CR4: 00000000003706f0 [ 11.840905] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 11.840905] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 11.840905] Kernel panic - not syncing: Fatal exception [ 11.840905] Kernel Offset: 0x21000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 11.840905] ---[ end Kernel panic - not syncing: Fatal exception ]--- — Best Regards, Yan Zi