Hi Christoph, thanks for the fix. I just faced a crash[0] booting v5.3-rc1 in a KVM guest, and your patch fixed it. Feel free to add: Tested-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxxxxx> Cheers, Guilherme [0] BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI Workqueue: events_unbound async_run_entry_fn RIP: 0010:dma_direct_max_mapping_size+0x26/0x80 RSP: 0018:ffffa316c0843bc0 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffff8d98a88eb810 RCX: 0000000000000000 RDX: ffff8d98a86cab80 RSI: 000000000000007e RDI: ffff8d98a88eb810 RBP: ffffa316c0843bd0 R08: ffff8d98af9b00e0 R09: ffff8d98ad8072c0 R10: ffffa316c0843a70 R11: 00000000000311a0 R12: 0000000000000000 R13: ffff8d98a88eb810 R14: 000000000000ffff R15: ffff8d98a3dbd000 FS: 0000000000000000(0000) GS:ffff8d98af980000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000429d08000 CR4: 00000000000006e0 Call Trace: dma_max_mapping_size+0x39/0x50 __scsi_init_queue+0x7f/0x140 scsi_mq_alloc_queue+0x38/0x60 scsi_alloc_sdev+0x1da/0x2b0 scsi_probe_and_add_lun+0x471/0xe60 ? __pm_runtime_resume+0x5b/0x80 __scsi_scan_target+0xfc/0x610 ? __switch_to_asm+0x40/0x70 ? __switch_to_asm+0x34/0x70 ? __switch_to_asm+0x40/0x70 scsi_scan_channel+0x66/0xa0 scsi_scan_host_selected+0xf3/0x160 do_scsi_scan_host+0x93/0xa0 do_scan_async+0x1c/0x190 [...]
