Description of problem: iommu probe 会为系统中添加的每个设备调用，且调用顺序与设备添加的顺序一致。如果以随机顺序调用，或者根据驱动程序绑定与否来决定是否调用，就会发生各种意外的并发和竞态条件。 Version-Release number of selected component (if applicable): How reproducible: Steps to Reproduce: 1.启动uefi镜像，配置virtio-scsi和iommu，镜像使用systemd作为1号进程， /qemu-system-riscv64 -nographic -M virt,pflash0=pflash0,pflash1=pflash1,acpi=off,aia=aplic-imsic,aia-guests=5 -blockdev node-name=pflash0,driver=file,read-only=on,filename=./RISCV_VIRT_CODE.fd -blockdev node-name=pflash1,driver=file,filename=./RISCV_VIRT_VARS.fd -accel tcg -smp 32 -m 8G -drive file=./rv.qcow2,format=qcow2,id=hd0,if=none -object rng-random,filename=/dev/urandom,id=rng0 -device virtio-rng-device,rng=rng0 -device virtio-blk-device,drive=hd0,bootindex=1 -device '{"driver":"pcie-root-port","port":8,"chassis":1,"id":"pci.1","bus":"pcie.0","multifunction":true,"addr":"0x1"}' -device '{"driver":"pcie-root-port","port":9,"chassis":2,"id":"pci.2","bus":"pcie.0","addr":"0x1.0x1"}' -device '{"driver":"pcie-root-port","port":10,"chassis":3,"id":"pci.3","bus":"pcie.0","addr":"0x1.0x2"}' -device '{"driver":"pcie-root-port","port":11,"chassis":4,"id":"pci.4","bus":"pcie.0","addr":"0x1.0x3"}' -device '{"driver":"pcie-pci-bridge","id":"pci.5","bus":"pci.1","addr":"0x0"}' -device '{"driver":"pcie-root-port","port":12,"chassis":6,"id":"pci.6","bus":"pcie.0","addr":"0x1.0x4"}' -device '{"driver":"pcie-root-port","port":13,"chassis":7,"id":"pci.7","bus":"pcie.0","addr":"0x1.0x5"}' -device '{"driver":"pcie-root-port","port":14,"chassis":8,"id":"pci.8","bus":"pcie.0","addr":"0x1.0x6"}' -device '{"driver":"pcie-root-port","port":15,"chassis":9,"id":"pci.9","bus":"pcie.0","addr":"0x1.0x7"}' -device '{"driver":"pcie-root-port","port":16,"chassis":10,"id":"pci.10","bus":"pcie.0","multifunction":true,"addr":"0x2"}' -device '{"driver":"pcie-root-port","port":17,"chassis":11,"id":"pci.11","bus":"pcie.0","addr":"0x2.0x1"}' -device '{"driver":"pcie-root-port","port":18,"chassis":12,"id":"pci.12","bus":"pcie.0","addr":"0x2.0x2"}' -device '{"driver":"usb-ehci","id":"usb","bus":"pci.5","addr":"0x1"}' -device '{"driver":"virtio-serial-pci","id":"virtio-serial0","bus":"pci.6","addr":"0x0"}' -netdev user,id=hostnet0 -netdev user,id=hostnet1 -device '{"driver":"virtio-net-pci","netdev":"hostnet0","id":"net0","mac":"24:9e:4e:ba:6f:32","bus":"pci.2","addr":"0x0"}' -device '{"driver":"virtio-net-pci","netdev":"hostnet1","id":"net1","mac":"24:9e:4e:ba:6f:38","bus":"pci.3","addr":"0x0"}' -device riscv-iommu-pci,vendor-id=0x1efd,device-id=0x8,bus=pcie.0,addr=0xf \ 2.系统启动后进入救援模式，其udev-worker线程无响应 [root@test-pc ~]# ps aux | grep D USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND root 139 0.1 0.0 0 0 ? D 07:59 0:00 [kworker/u32:6+async] root 910 2.2 0.2 36136 8520 ? D 08:01 0:00 (udev-worker) root 940 1.9 0.1 36080 6708 ? D 08:01 0:00 (udev-worker) root 978 0.2 0.0 12980 2720 ? D 08:01 0:00 /sbin/modprobe -q -- fs-vfat root 1010 5.1 0.0 41940 2740 ? D 08:01 0:01 /sbin/modprobe -q -- fs-rpc_pipefs root 1082 33.3 0.0 221968 3580 ttyS0 S+ 08:01 0:00 grep --color=auto D [root@test-pc ~]# cat /proc/139/stack [<0>] blk_execute_rq+0xc2/0x130 [<0>] scsi_execute_cmd+0x9c/0x212 [<0>] scsi_probe_lun.constprop.0+0x13c/0x400 [<0>] scsi_probe_and_add_lun+0x9c/0x39e [<0>] __scsi_scan_target+0xbc/0x1cc [<0>] scsi_scan_channel+0x4a/0x78 [<0>] scsi_scan_host_selected+0xc6/0x118 [<0>] do_scsi_scan_host+0x66/0x6e [<0>] do_scan_async+0x12/0x1ac [<0>] async_run_entry_fn+0x28/0x12a [<0>] process_one_work+0x152/0x348 [<0>] worker_thread+0x1e0/0x2b8 [<0>] kthread+0xcc/0xec [<0>] ret_from_fork+0xe/0x18 [root@test-pc ~]# cat /proc/910/stack [<0>] async_synchronize_cookie_domain+0xb4/0xec [<0>] async_synchronize_full+0x10/0x18 [<0>] do_init_module+0x144/0x1d4 [<0>] load_module+0x6da/0x840 [<0>] init_module_from_file+0x76/0xb0 [<0>] idempotent_init_module+0x198/0x27a [<0>] __riscv_sys_finit_module+0x54/0xa6 [<0>] do_trap_ecall_u+0x1da/0x224 [<0>] handle_exception+0x150/0x15c 3. Actual results: Expected results: Additional info: