If boot a guest with os in qemu cli, do migration from rhel8.1.0 to rhel8.0.0, migration status is failed and vm running well on src host, but qemu crash on destination host as following:

p9(rhel8.1.0):
4.18.0-85.el8.ppc64le
qemu-kvm-4.0.0-0.module+el8.1.0+3169+3c501422

p8(rhel8.0.0):
4.18.0-80.2.1.el8_0.ppc64le
qemu-kvm-2.12.0-64.module+el8.0.0+3180+d6a3561d.2.ppc64le

qemu cli:
/usr/libexec/qemu-kvm \
-M pseries-rhel7.6.0,max-cpu-compat=power8 \
-nodefaults \
-monitor stdio \
-device virtio-scsi-pci,id=virtio_scsi_pci0,bus=pci.0,addr=0x08 \
-blockdev driver=file,cache.direct=on,cache.no-flush=off,filename=/home/xianwang/rhel800-ppc64le-virtio-scsi.qcow2,node-name=drive_sys1 \
-blockdev driver=qcow2,node-name=drive_image1,file=drive_sys1 \
-device scsi-hd,id=image1,drive=drive_image1,bus=virtio_scsi_pci0.0,channel=0,scsi-id=0,lun=0,bootindex=0 \
-vnc :1 \
-vga std \
-incoming tcp:0:5801 \

after migration, on source host:
(qemu) info migrate
globals:
store-global-state: on
only-migratable: off
send-configuration: on
send-section-footer: on
decompress-error-check: on
capabilities: xbzrle: off rdma-pin-all: off auto-converge: off zero-blocks: off compress: off events: off postcopy-ram: off x-colo: off release-ram: off return-path: off pause-before-switchover: off multifd: off dirty-bitmaps: off postcopy-blocktime: off late-block-activate: off x-ignore-shared: off 
Migration status: failed
total time: 0 milliseconds
(qemu) info status 
VM status: running

on destination host:
(qemu) qemu-kvm: error while loading state for instance 0x0 of device 'spapr'
qemu-kvm: load of migration failed: No such file or directory

(In reply to xianwang from comment #1)
> If boot a guest with os in qemu cli, do migration from rhel8.1.0 to
> rhel8.0.0, migration status is failed and vm running well on src host, but
> qemu crash on destination host as following:
> 
> p9(rhel8.1.0):
> 4.18.0-85.el8.ppc64le
> qemu-kvm-4.0.0-0.module+el8.1.0+3169+3c501422
> 
> p8(rhel8.0.0):
> 4.18.0-80.2.1.el8_0.ppc64le
> qemu-kvm-2.12.0-64.module+el8.0.0+3180+d6a3561d.2.ppc64le
> 
> qemu cli:
> /usr/libexec/qemu-kvm \
> -M pseries-rhel7.6.0,max-cpu-compat=power8 \
> -nodefaults \
> -monitor stdio \
> -device virtio-scsi-pci,id=virtio_scsi_pci0,bus=pci.0,addr=0x08 \
> -blockdev
> driver=file,cache.direct=on,cache.no-flush=off,filename=/home/xianwang/
> rhel800-ppc64le-virtio-scsi.qcow2,node-name=drive_sys1 \
> -blockdev driver=qcow2,node-name=drive_image1,file=drive_sys1 \
> -device
> scsi-hd,id=image1,drive=drive_image1,bus=virtio_scsi_pci0.0,channel=0,scsi-
> id=0,lun=0,bootindex=0 \
> -vnc :1 \
> -vga std \
> -incoming tcp:0:5801 \
> 
> after migration, on source host:
> (qemu) info migrate
> globals:
> store-global-state: on
> only-migratable: off
> send-configuration: on
> send-section-footer: on
> decompress-error-check: on
> capabilities: xbzrle: off rdma-pin-all: off auto-converge: off zero-blocks:
> off compress: off events: off postcopy-ram: off x-colo: off release-ram: off
> return-path: off pause-before-switchover: off multifd: off dirty-bitmaps:
> off postcopy-blocktime: off late-block-activate: off x-ignore-shared: off 
> Migration status: failed
> total time: 0 milliseconds
> (qemu) info status 
> VM status: running
> 
> on destination host:
> (qemu) qemu-kvm: error while loading state for instance 0x0 of device 'spapr'
> qemu-kvm: load of migration failed: No such file or directory


Could you try the same migration between two P8 hosts?

(In reply to Laurent Vivier from comment #2)
> (In reply to xianwang from comment #1)
> > If boot a guest with os in qemu cli, do migration from rhel8.1.0 to
> > rhel8.0.0, migration status is failed and vm running well on src host, but
> > qemu crash on destination host as following:
> > 
> > p9(rhel8.1.0):
> > 4.18.0-85.el8.ppc64le
> > qemu-kvm-4.0.0-0.module+el8.1.0+3169+3c501422
> > 
> > p8(rhel8.0.0):
> > 4.18.0-80.2.1.el8_0.ppc64le
> > qemu-kvm-2.12.0-64.module+el8.0.0+3180+d6a3561d.2.ppc64le
> > 
> > qemu cli:
> > /usr/libexec/qemu-kvm \
> > -M pseries-rhel7.6.0,max-cpu-compat=power8 \
> > -nodefaults \
> > -monitor stdio \
> > -device virtio-scsi-pci,id=virtio_scsi_pci0,bus=pci.0,addr=0x08 \
> > -blockdev
> > driver=file,cache.direct=on,cache.no-flush=off,filename=/home/xianwang/
> > rhel800-ppc64le-virtio-scsi.qcow2,node-name=drive_sys1 \
> > -blockdev driver=qcow2,node-name=drive_image1,file=drive_sys1 \
> > -device
> > scsi-hd,id=image1,drive=drive_image1,bus=virtio_scsi_pci0.0,channel=0,scsi-
> > id=0,lun=0,bootindex=0 \
> > -vnc :1 \
> > -vga std \
> > -incoming tcp:0:5801 \
> > 
> > after migration, on source host:
> > (qemu) info migrate
> > globals:
> > store-global-state: on
> > only-migratable: off
> > send-configuration: on
> > send-section-footer: on
> > decompress-error-check: on
> > capabilities: xbzrle: off rdma-pin-all: off auto-converge: off zero-blocks:
> > off compress: off events: off postcopy-ram: off x-colo: off release-ram: off
> > return-path: off pause-before-switchover: off multifd: off dirty-bitmaps:
> > off postcopy-blocktime: off late-block-activate: off x-ignore-shared: off 
> > Migration status: failed
> > total time: 0 milliseconds
> > (qemu) info status 
> > VM status: running
> > 
> > on destination host:
> > (qemu) qemu-kvm: error while loading state for instance 0x0 of device 'spapr'
> > qemu-kvm: load of migration failed: No such file or directory
> 
> 
> Could you try the same migration between two P8 hosts?

I have tried the same migration between two p8 hosts, the result is same with above
Host A:
4.18.0-80.2.1.el8_0.ppc64le
qemu-kvm-2.12.0-64.module+el8.0.0+3180+d6a3561d.2.ppc64le

Host B:
4.18.0-85.el8.ppc64le
qemu-kvm-4.0.0-0.module+el8.1.0+3169+3c501422.ppc64le

the steps and result are same with above.
rhel8.0.0-->rhel8.1.0 works well, but rhel8.1.0-->rhel8.0.0 failed.

I think this problem happens because the machine type for rhel-av-8.1.0 has not been implemented in this preview build, so the new features added for qemu-4.0.0 are not disabled for the pseries-rhel7.6.0 machine type migration on the 8.1.0 side.

Fix included in qemu-kvm-4.0.0-3.module+el8.1.0+3265+26c4ed71

Bug verification:
Host:
P8:
4.18.0-94.el8.ppc64le
qemu-kvm-4.0.0-3.module+el8.1.0+3265+26c4ed71.ppc64le
SLOF-20171214-5.gitfa98132.module+el8.1.0+2983+b2ae9c0a.noarch

P9:
4.18.0-80.1.2.el8_0.ppc64le
qemu-kvm-2.12.0-64.module+el8.0.0+3180+d6a3561d.2.ppc64le
SLOF-20171214-5.gitfa98132.module+el8+2616+396d822d.noarch

steps are same with comment 1.
result:
migration completed and vm works well after migration.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2019:3723