Description of problem: After migrate the RHEL guest to destination host, I tried to hot remove the pci device (NIC card). But it failed with some message in dmesg of guest(please look at the additional info). And this issue does not exist in windows guest. CLI: /usr/libexec/qemu-kvm -no-hpet -usbdevice tablet -rtc-td-hack -smp 2 -m 2048 -drive file=/mnt/RHEL-Server-5.4-32.raw,media=disk,if=ide,index=0 -net nic,macaddr=00:1a:4a:10:20:5f,vlan=0,model=rtl8139 -net tap,vlan=0,script=/etc/qemu-ifup -uuid 75e6b75d-a8fd-4024-bae4-a0daa5dace9c -cpu qemu64,+sse2 -boot c -monitor stdio -vnc :10 Version-Release number of selected component (if applicable): host kernel:2.6.18-164.6.1.el5 kvm-83-135.el5 and also kvm-83-105.el5_4.10 How reproducible: 100% Steps to Reproduce: 1.Launch a guest on source host with above command line. 2.Migrate it to destination host. 3.In guest's terminal: #modprobe acpiphp 4.On qemu monitor: (qemu)info pci (qemu)pci_del pci_addr=3 (qemu)info pci Actual results: The NIC card can not be removed from guest after migration. Expected results: The NIC card can be removed successfully. Additional info: #dmesg (in guest) acpiphp: ACPI Hot Plug PCI Controller Driver version: 0.5 acpiphp_glue: can't get bus number, assuming 0 decode_hpp: Could not get hotplug parameters. Use defaults acpiphp: Slot [1] registered acpiphp: Slot [2] registered acpiphp: Slot [3] registered acpiphp: Slot [4] registered acpiphp: Slot [5] registered acpiphp: Slot [6] registered acpiphp: Slot [7] registered acpiphp: Slot [8] registered acpiphp: Slot [9] registered acpiphp: Slot [10] registered acpiphp: Slot [11] registered acpiphp: Slot [12] registered acpiphp: Slot [13] registered acpiphp: Slot [14] registered acpiphp: Slot [15] registered acpiphp: Slot [16] registered acpiphp: Slot [17] registered acpiphp: Slot [18] registered acpiphp: Slot [19] registered acpiphp: Slot [20] registered acpiphp: Slot [21] registered acpiphp: Slot [22] registered acpiphp: Slot [23] registered acpiphp: Slot [24] registered acpiphp: Slot [25] registered acpiphp: Slot [26] registered acpiphp: Slot [27] registered acpiphp: Slot [28] registered acpiphp: Slot [29] registered acpiphp: Slot [30] registered acpiphp: Slot [31] registered Host info(4 cpus, here only list one): processor : 3 vendor_id : GenuineIntel cpu family : 6 model : 23 model name : Intel(R) Core(TM)2 Quad CPU Q9550 @ 2.83GHz stepping : 10 cpu MHz : 2826.231 cache size : 6144 KB physical id : 0 siblings : 4 core id : 3 cpu cores : 4 apicid : 3 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx lm constant_tsc pni monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr sse4_1 lahf_lm bogomips : 5652.33 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: