Description of problem: 虚拟机 cpu hotplug后，新增的cpu处于off line状态，手动使能才能online Version-Release number of selected component (if applicable): kernel版本 5.10.134-16.2_rc1.an23.loongarch64 qemu版本 6.2.0-4.an23 Steps to Reproduce: 1. 虚拟机启动，命令如下： MALLOC_PERTURB_=1 /usr/bin/qemu-system-loongarch64 \ -name 'avocado-vt-vm1' \ -sandbox on \ -machine loongson7a,memory-backend=mem-machine_mem \ -device pcie-root-port,id=pcie-root-port-0,multifunction=on,bus=pcie.0,addr=0x1,chassis=1 \ -device pcie-pci-bridge,id=pcie-pci-bridge-0,addr=0x0,bus=pcie-root-port-0 \ -nodefaults \ -device VGA,bus=pcie.0,addr=0x2 \ -m 2048 \ -object memory-backend-ram,size=2048M,id=mem-machine_mem \ -smp 1,maxcpus=2,cores=2,threads=1,sockets=1 \ -cpu 'Loongson-3A5000' \ -device pcie-root-port,id=pcie-root-port-1,port=0x1,addr=0x1.0x1,bus=pcie.0,chassis=2 \ -device qemu-xhci,id=usb1,bus=pcie-root-port-1,addr=0x0 \ -device usb-tablet,id=usb-tablet1,bus=usb1.0,port=1 \ -device pcie-root-port,id=pcie-root-port-2,port=0x2,addr=0x1.0x2,bus=pcie.0,chassis=3 \ -device virtio-scsi-pci,id=virtio_scsi_pci0,bus=pcie-root-port-2,addr=0x0 \ -blockdev node-name=file_image1,driver=file,filename=/root/avocado/data/avocado-vt/images/AnolisOS-23.1-loongarch64.qcow2 \ -blockdev node-name=drive_image1,driver=qcow2,file=file_image1 \ -device scsi-hd,id=image1,drive=drive_image1 \ -device pcie-root-port,id=pcie-root-port-3,port=0x3,addr=0x1.0x3,bus=pcie.0,chassis=4 \ -device virtio-net-pci,mac=9a:71:8a:31:b2:50,id=idGpZRT0,netdev=idFQ18KT,bus=pcie-root-port-3,addr=0x0 \ -netdev tap,id=idFQ18KT \ -vnc :0 \ -rtc base=utc,clock=host \ -boot menu=off,order=cdn,once=c,strict=off \ -bios loongarch_bios.bin \ -enable-kvm \ -device pcie-root-port,id=pcie_extra_root_port_0,multifunction=on,bus=pcie.0,addr=0x3,chassis=5 \ -serial stdio \ -monitor telnet:localhost:4444,server,nowait 2. 虚拟机启动后，qemu monitor 进行 cpu hotplug，命令如下： # telnet localhost 4444 Trying ::1... Connected to localhost. Escape character is '^]'. QEMU 6.2.0 monitor - type 'help' for more information (qemu) (qemu) device_add Loongson-3A5000-loongarch-cpu,id=vcpu1,core-id=1 Actual results: 虚拟机 cpu hotplug后，新增的cpu处于off line状态 # lscpu Architecture: loongarch64 Byte Order: Little Endian CPU(s): 2 On-line CPU(s) list: 0 Off-line CPU(s) list: 1 BIOS Vendor ID: Loongson Model name: - BIOS Model name: Loongson-3A5000-HV CPU @ 2.0GHz BIOS CPU family: 1 Thread(s) per core: 1 Core(s) per socket: 1 Socket(s): 1 BogoMIPS: 4000.00 Flags: cpucfg lam ual fpu complex crypto Caches (sum of all): L1d: 64 KiB (1 instance) L1i: 64 KiB (1 instance) L2: 256 KiB (1 instance) L3: 16 MiB (1 instance) NUMA: NUMA node(s): 1 NUMA node0 CPU(s): 0 # cat /sys/devices/system/cpu/cpu1/online 0 # echo 1 > /sys/devices/system/cpu/cpu1/online [ 734.434973][ T878] Booting CPU#1... [ 734.437981][ T0] 64-bit Loongson Processor probed (LA464 Core) [ 734.439597][ T0] CPU1 revision is: 0014c010 (Loongson-64bit) [ 734.441063][ T0] FPU1 revision is: 00000000 [ 734.442279][ T0] CPU#1 finished [ 734.445248][ T1048] pv stealtime: cpu 1, st:0x900000000a0005c0 phys:0xa0005c0 [ 734.448890][ T1048] Will online and init hotplugged CPU: 1 Expected results: cpu hoyplug 后，成功被添加，自动成功上线
将anolis23的kernel安装在其他操作上面启动虚拟机，进行cpu hotplug测试，cpu可以上线，由此可以证明此问题与qemu虚拟机和虚拟机内核无关，应与操作系统有关系，且可能与/usr/lib/systemd/systemd-udevd策略有关
x86 AnolisOS-23 也有此问题
请使用最新 qemu 8.2 进行再次测试
在x86平台对比测试如下： x86平台测试分析过程 测试iso: anolisos-23.2 内核版本： linux-6.6 qemu版本： 8.2.2 iso下载地址: https://mirrors.openanolis.cn/anolis/23/isos/GA/x86_64/AnolisOS-23.2-x86_64-boot.iso 1. 在x86机器上面创建虚拟机(anolis-23.2)并启动，然后进入该虚拟机内，再次用上述的anolis-23.2 iso创建虚拟机(anolis-23.2-x86-64-test)，并制作qcow2文件：anolis-23.2-x86-64-test.qcow2 2. 然后在anolis-23.2虚拟机终端执行如下命令启动anolis-23.2-x86-64-test虚拟机 执行命令： /usr/bin/qemu-system-x86_64 -M pc-i440fx-8.2 -accel kvm -cpu host -m 2048 -smp 2,maxcpus=4,sockets=1,cores=4,threads=1 -no-user-config -nodefaults -no-shutdown -boot strict=on -drive file=/var/lib/libvirt/images/anolis-23.2-x86-64-test.qcow2,if=virtio -nographic -serial stdio -monitor telnet:localhost:4444,server,nowait -msg timestamp=on 串口进入该虚拟机后执行lscpu查看： [root@anolis ~]# lscpu Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Address sizes: 46 bits physical, 48 bits virtual Byte Order: Little Endian CPU(s): 2 On-line CPU(s) list: 0,1 Vendor ID: GenuineIntel BIOS Vendor ID: QEMU Model name: 12th Gen Intel(R) Core(TM) i7-12700 BIOS Model name: pc-i440fx-8.2 CPU @ 2.0GHz BIOS CPU family: 1 CPU family: 6 Model: 151 Thread(s) per core: 1 Core(s) per socket: 2 Socket(s): 1 Stepping: 2 BogoMIPS: 4224.00 在虚拟机anolis-23.2另一终端执行如下操作，并添加一个cpu # telnet localhost 4444 Trying ::1... Connected to localhost. Escape character is '^]'. QEMU 8.2.2 monitor - type 'help' for more information (qemu) (qemu) device_add host-x86_64-cpu,core-id=2,id=vcpu2,socket-id=0,thread-id=0 (qemu) 再次在虚拟机anolis-23.2-x86-64-test中执行lscpu查看 [root@anolis ~]# lscpu Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Address sizes: 46 bits physical, 48 bits virtual Byte Order: Little Endian CPU(s): 3 On-line CPU(s) list: 0,1 Off-line CPU(s) list: 2 Vendor ID: GenuineIntel BIOS Vendor ID: QEMU Model name: 12th Gen Intel(R) Core(TM) i7-12700 BIOS Model name: pc-i440fx-8.2 CPU @ 2.0GHz BIOS CPU family: 1 CPU family: 6 Model: 151 Thread(s) per core: 1 Core(s) per socket: 2 Socket(s): 1 Stepping: 2 BogoMIPS: 4224.00 到此可知，在x86平台，qemu-8.2.2环境下，通过device_add添加的cpu默认状态也是offline 通过手动方式执行下面操作可以使新添加的cpu online [root@anolis ~]# cat /sys/devices/system/cpu/cpu2/online 0 [root@anolis ~]# echo 1 > /sys/devices/system/cpu/cpu2/online [ 1409.868102] smpboot: Booting Node 0 Processor 2 APIC 0x2 [ 1409.891705] Will online and init hotplugged CPU: 2 [root@anolis ~]# lscpu Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Address sizes: 46 bits physical, 48 bits virtual Byte Order: Little Endian CPU(s): 3 On-line CPU(s) list: 0-2 Vendor ID: GenuineIntel BIOS Vendor ID: QEMU Model name: 12th Gen Intel(R) Core(TM) i7-12700 BIOS Model name: pc-i440fx-8.2 CPU @ 2.0GHz BIOS CPU family: 1 CPU family: 6 Model: 151 Thread(s) per core: 1 Core(s) per socket: 3 Socket(s): 1 Stepping: 2 BogoMIPS: 4224.00 在虚拟机anolis-23.2终端执行如下操作，删掉添加的cpu # telnet localhost 4444 Trying ::1... Connected to localhost. Escape character is '^]'. QEMU 8.2.2 monitor - type 'help' for more information (qemu) device_del vcpu2 (qemu) 然后在虚拟机anolis-23.2-x86-64-test执行lscpu查看 [root@anolis ~]# lscpu Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Address sizes: 46 bits physical, 48 bits virtual Byte Order: Little Endian CPU(s): 2 On-line CPU(s) list: 0,1 Vendor ID: GenuineIntel BIOS Vendor ID: QEMU Model name: 12th Gen Intel(R) Core(TM) i7-12700 BIOS Model name: pc-i440fx-8.2 CPU @ 2.0GHz BIOS CPU family: 1 CPU family: 6 Model: 151 Thread(s) per core: 1 Core(s) per socket: 2 Socket(s): 1 Stepping: 2 BogoMIPS: 4224.00 *** 因此可知，通过device_add添加的cpu默认状态在x86和loongarch平台下面都是offline