Bus 'pcie.0' does not support hotplugging

[yue]

Hi, all:
    in my case it is kata that manage qemu directly via qmp.  (QEMU emulator 
version 5.2.0 (kata-static)).

  i have tested via virsh command and make sure that qemu-system-x86_64 
supports hotplug. 
  but if qemu was started by kata,  attach-disk failed.  


1.  it is which option that play a part?   is it shpc=on?
2. in kata case, there is no boot process for vm. qemu starts with -kernel 
option and a rootfs (root=/dev/pmem0p1).  what affects hotplugging inside vm?


thank very much.



/opt/kata/bin/qemu-system-x86_64 -name sandbox-test-kata1 -machine 
q35,accel=kvm,kernel_irqchip=on,nvdimm=on -cpu host,pmu=off 
-qmp unix:/run/vc/vm/test-kata1/qmp.sock,server=on,wait=off -qmp 
unix:/run/vc/vm/test-kata1/qmp1.sock,server=on,wait=off -m 
2048M,slots=10,maxmem=258481M 
-device pci-bridge,bus=pcie.0,id=pci-bridge-0,chassis_nr=1,shpc=on,addr=2 
-device virtio-serial-pci,disable-modern=false,id=serial0 -device 
virtconsole,chardev=charconsole0,id=console0 -chardev 
socket,id=charconsole0,path=/run/vc/vm/test-kata1/console.sock,server=on,wait=off
 

-device nvdimm,id=nv0,memdev=mem0,unarmed=on -object 
memory-backend-file,id=mem0,mem-path=/opt/kata/share/kata-containers/kata-clearlinux-latest.image,size=268435456,readonly=on
 -object rng-random,id=rng0,filename=/dev/urandom -device 
virtio-rng-pci,rng=rng0 

-device pcie-root-port,id=rp0,bus=pcie.0,chassis=0,slot=0,multifunction=off 
-device pcie-root-port,id=rp1,bus=pcie.0,chassis=0,slot=1,multifunction=off 
-device 
vhost-vsock-pci,disable-modern=false,vhostfd=3,id=vsock-2924010461,guest-cid=2924010461
 
-device 
virtio-9p-pci,disable-modern=false,fsdev=extra-9p-kataShared,mount_tag=kataShared
 -fsdev 
local,id=extra-9p-kataShared,path=/run/kata-containers/shared/sandboxes/test-kata1/shared,security_model=none,multidevs=remap
 -rtc base=utc,driftfix=slew,clock=host -global 
kvm-pit.lost_tick_policy=discard -vga none -no-user-config -nodefaults 
-nographic --no-reboot -daemonize -object 
memory-backend-ram,id=dimm1,size=2048M -numa node,memdev=dimm1 

-kernel /opt/kata/share/kata-containers/vmlinux-5.10.25-85 
-append tsc=reliable no_timer_check rcupdate.rcu_expedited=1 i8042.direct=1 
i8042.dumbkbd=1 i8042.nopnp=1 i8042.noaux=1 noreplace-smp reboot=k console=hvc0 
console=hvc1 cryptomgr.notests net.ifnames=0 pci=lastbus=0 root=/dev/pmem0p1 
rootflags=dax,data=ordered,errors=remount-ro ro rootfstype=ext4 debug 
systemd.show_status=true systemd.log_level=debug panic=1 nr_cpus=48 
systemd.unit=kata-containers.target systemd.mask=systemd-networkd.service 
systemd.mask=systemd-networkd.socket agent.log=debug agent.debug_console 
agent.debug_console_vport=1026 -smp 1,cores=1,threads=1,sockets=48,maxcpus=48


{"execute" : "qmp_capabilities"} 
{"return": {}}
{ "execute": "blockdev-add", "arguments": { "driver": "raw", "node-name": 
"drive-virtio-disk2", "file": { "driver": "file", "filename": 
"/root/cirros/data-xml.raw" } } }
{"return": {}}
{"execute":"device_add","arguments":{"driver":"virtio-blk-pci","scsi":"off","bus":"pcie.0","addr":"0x7","drive":"drive-virtio-disk2","id":"virtio-disk2"},"id":"libvirt-18"}
{"id": "libvirt-18", "error": {"class": "GenericError", "desc": "Bus 'pcie.0' 
does not support hotplugging"}}