Package: qemu-kvm
Version: 1.1.2+dfsg-6+deb7u6
Severity: normal
Dear Maintainer,
* What led up to the situation?
Tried to add a new disk to a running kvm guest
* What exactly did you do (or not do) that was effective (or
ineffective)?
Using the virsh attach-device command I tried to add a new disk
* What was the outcome of this action?
# virsh attach-device cedric.CalvaEDI.COM zz.xml
error: Failed to attach device from zz.xml
error: internal error unable to execute QEMU command 'device_add': Bus 'pci.0'
does not support hotplugging
* What outcome did you expect instead?
Happiness.
The running vm looks like:
/usr/bin/kvm -S -M pc-1.1 -enable-kvm -m 8192 -smp
1,sockets=1,cores=1,threads=1 -name cedric.CalvaEDI.COM -uuid
99cfca83-cf28-ce9b-86a4-947debc202b5 -nographic -no-user-config -nodefaults
-chardev
socket,id=charmonitor,path=/var/lib/libvirt/qemu/cedric.CalvaEDI.COM.monitor,server,nowait
-mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc -no-shutdown
-no-acpi -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -drive
file=/dev/disk/by-id/md-name-cedric:root,if=none,id=drive-virtio-disk0,format=raw,cache=none
-device
virtio-blk-pci,scsi=off,bus=pci.0,addr=0x4,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1
-drive
file=/dev/disk/by-id/md-name-belgic:archive,if=none,id=drive-virtio-disk1,format=raw
-device
virtio-blk-pci,scsi=off,bus=pci.0,addr=0x5,drive=drive-virtio-disk1,id=virtio-disk1
-drive
file=/dev/disk/by-id/md-name-belgic:backups,if=none,id=drive-virtio-disk2,format=raw
-device
virtio-blk-pci,scsi=off,bus=pci.0,addr=0x6,drive=drive-virtio-disk2,id=vir!
tio-disk2 -netdev tap,fd=20,id=hostnet0,vhost=on,vhostfd=21 -device
virtio-net-pci,netdev=hostnet0,id=net0,mac=00:16:3e:65:2d:8e,bus=pci.0,addr=0x3
-chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0
-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x7
Or, in libvirt xml format:
cedric.CalvaEDI.COM
99cfca83-cf28-ce9b-86a4-947debc202b5
8388608
4194304
1
hvm
destroy
restart
restart
/usr/bin/kvm
The device I tried to add looks like:
The error in libvirtd.log is:
2014-12-16 13:22:50.831+: 5305: error : qemuMonitorJSONCheckError:342 :
internal error unable to execute QEMU command 'device_add': Bus 'pci.0' does
not support hotplugging
2014-12-16 13:22:50.832+: 5305: warning : qemuDomainAttachPciDiskDevice:255
: qemuMonitorAddDevice failed on
file=/dev/disk/by-id/md-name-cedric:new,if=none,id=drive-virtio-disk3,format=raw,cache=none
(virtio-blk-pci,scsi=off,bus=pci.0,addr=0xb,drive=drive-virtio-disk3,id=virtio-disk3)
>From strace it seems that the commands that are being sent to kvm are:
5302 write(21,
"{\"execute\":\"drive_add\",\"arguments\":{\"pci_addr\":\"dummy\",\"opts\":\"file=/dev/disk/by-id/md-name-cedric:new,if=none,id=drive-virtio-disk3,format=raw,cache=none\"},\"id\":\"libvirt-31\"}\r\n",
177) = 177
which gets
5302 read(21, "{\"id\": \"libvirt-31\", \"error\": {\"class\":
\"CommandNotFound\", \"desc\": \"The command drive_add has not been found\",
\"data\": {\"name\": \"drive_add\"}}}\r\n", 1023) = 144
So it tries
5302 write(21,
"{\"execute\":\"human-monitor-command\",\"arguments\":{\"command-line\":\"drive_add
dummy
file=/dev/disk/by-id/md-name-cedric:new,if=none,id=drive-virtio-disk3,format=raw,cache=none\"},\"id\":\"libvirt-32\"}\r\n",
194) = 194
reply:
5302 read(21, "{\"return\": \"Duplicate ID 'drive-virtio-disk3' for
drive\\r\\n\", \"id\": \"libvirt-32\"}\r\n", 1023) = 83
Then:
5302 write(21,
"{\"execute\":\"device_add\",\"arguments\":{\"driver\":\"virtio-blk-pci\",\"scsi\":\"off\",\"bus\":\"pci.0\",\"addr\":\"0xd\",\"drive\":\"drive-virtio-disk3\",\"id\":\"virtio-disk3\"},\"id\":\"libvirt-33\"}\r\n",
173) = 173
which gets:
5302 read(21, "{\"id\": \"libvirt-33\", \"error\": {\"class\":
\"BusNoHotplug\", \"desc\": \"Bus 'pci.0' does not support hotplugging\",
\"data\": {\"bus\": \"pci.0\"}}}\r\n", 1023) = 136
Game over.
-- Package-specific info:
/proc/cpuinfo:
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Xeon(R) CPU3050 @ 2.13GHz
stepping: 2
microcode : 0x51
cpu MHz : 2133.000
cache size : 2048 KB
physical id : 0
siblings: 2
core id : 0
cpu cores : 2
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
pat pse36 clflush dts acpi
