Bug 1660809

Summary:	Migration failed with "qemu-kvm: Unknown ramblock "vga.vram"" when migrate a vm from RHEL7.6 to RHEL8.0
Product:	Red Hat Enterprise Linux Advanced Virtualization	Reporter:	xianwang <xianwang>
Component:	qemu-kvm	Assignee:	Virtualization Maintenance <virt-maint>
qemu-kvm sub component:	General	QA Contact:	Virtualization Bugs <virt-bugs>
Status:	CLOSED CURRENTRELEASE	Docs Contact:
Severity:	high
Priority:	high	CC:	chayang, dgibson, dzheng, jinzhao, juzhang, knoel, lvivier, michen, qzhang, rbalakri, virt-maint, xianwang, ymankad
Version:	8.0	Keywords:	Regression
Target Milestone:	rc
Target Release:	8.0
Hardware:	ppc64le
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-01-07 07:21:12 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1656508
Bug Blocks:	1600914

Description xianwang 2018-12-19 09:49:51 UTC

Description of problem:
Mirate a vm from rhel7 to rhel8, guest with device "-vga std", migration failed with error message "(qemu) qemu-kvm: Unknown ramblock "vga.vram", cannot accept migration", and this issue is only on fast train(qemu-3.1), it does not exist on slow train(qemu-2.12). 

Version-Release number of selected component (if applicable):
Host A(rhel7.6):
3.10.0-886.el7.x86_64
qemu-kvm-rhev-2.12.0-18.el7_6.3.x86_64

Host B(rhel8.0):
4.18.0-51.el8.x86_64
qemu-kvm-3.1.0-0.module+el8+2266+616cf026.next.candidate.x86_64

How reproducible:
100%

Steps to Reproduce:
1.Boot a guest with vga device on source host(rhel7.6)
/usr/libexec/qemu-kvm -M pc-i440fx-rhel7.6.0 -nodefaults -monitor stdio -vga std

2.Boot a guest on destination host(rhel8.0)
/usr/libexec/qemu-kvm -M pc-i440fx-rhel7.6.0 -nodefaults -monitor stdio -vga std -incoming tcp:0:5801

3.On source host, do migration 
(qemu) migrate -d tcp:10.73.72.82:5801

Actual results:
Migration failed, vm is running on source host.

Source:
(qemu) info migrate
Migration status: failed
(qemu) info status 
VM status: running

Destination:
(qemu) qemu-kvm: Unknown ramblock "vga.vram", cannot accept migration
qemu-kvm: error while loading state for instance 0x0 of device 'ram'
qemu-kvm: load of migration failed: Invalid argument


Expected results:
migration complete and vm works well.

Additional info:

Comment 1 xianwang 2018-12-19 09:55:44 UTC

This issue exists both on x86_64 and ppc.
It is only on fast train(qemu-3.1), slow train(qemu-2.12) does not exist this issue.

Comment 2 Laurent Vivier 2018-12-19 12:39:42 UTC

(In reply to xianwang from comment #1)
> This issue exists both on x86_64 and ppc.
> It is only on fast train(qemu-3.1), slow train(qemu-2.12) does not exist
> this issue.

I think this is because rhel-8.0 machine type is missing.

For x86_64, we already have BZ1655820 for that.

I take this one for ppc64le.

Comment 5 Laurent Vivier 2018-12-21 13:25:35 UTC

This fails because the machine type is missing. Machine type is addressed by BZ 1656508.

Patch has been sent downstream, wainting ACks.

I don't close this BZ as a duplicate to allow to check the new machine type fixes the problem.

Comment 7 Laurent Vivier 2019-01-04 08:45:19 UTC

Could you re-test with qemu-kvm-3.1.0-3.el8 on destination host(rhel8.0 fasttrain)?

Comment 8 xianwang 2019-01-07 06:54:29 UTC

(In reply to Laurent Vivier from comment #7)
> Could you re-test with qemu-kvm-3.1.0-3.el8 on destination host(rhel8.0
> fasttrain)?

I have tried with qemu-kvm-3.1.0-3.el8 on destination host, the result is PASS.
host A(rhel7.6)
4.14.0-115.5.1.el7a.ppc64le
qemu-kvm-rhev-2.12.0-18.el7_6.3.ppc64le
SLOF-20171214-2.gitfa98132.el7.noarch

host B(rhel8.0)
4.18.0-57.el8.ppc64le
qemu-kvm-3.1.0-3.module+el8+2614+d714d2bb.ppc64le
SLOF-20171214-5.gitfa98132.module+el8+2618+c5e2b86b.noarch

with general qemu cli:
/usr/libexec/qemu-kvm \
    -name 'avocado-vt-vm1'  \
    -sandbox off  \
    -nodefaults  \
    -machine pseries-rhel7.6.0,max-cpu-compat=power8 \
    -uuid 8aeab7e2-f341-4f8c-80e8-59e2968d85c2 \
    -device virtio-serial-pci,id=virtio_serial_pci0,bus=pci.0,addr=0x3 \
    -object iothread,id=iothread0 \
    -device spapr-vscsi,id=scsi2 \
    -device nec-usb-xhci,id=usb1,bus=pci.0,addr=0x5 \
    -device pci-bridge,chassis_nr=1,id=bridge1,bus=pci.0,addr=0x6 \
    -device virtio-scsi-pci,id=scsi1,bus=bridge1,addr=0x7 \
    -blockdev driver=file,cache.direct=on,cache.no-flush=off,filename=/home/xianwang/rhel76-ppc64le-virtio-scsi.qcow2,node-name=drive_scsi1 \
    -blockdev driver=qcow2,node-name=drive_scsi11,file=drive_scsi1 \
    -device scsi-hd,drive=drive_scsi11,id=scse-disk1,bus=scsi1.0,channel=0,scsi-id=0,lun=0,bootindex=0 \
    -device virtio-scsi-pci,id=scsi_add,bus=pci.0,addr=0x9 \
    -device virtio-net-pci,mac=9a:7b:7c:7d:7e:72,id=id9HRc5V,vectors=4,netdev=idjlQN53,bus=pci.0,addr=0xa \
    -netdev tap,id=idjlQN53,vhost=on,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown \
    -m 2048,slots=4,maxmem=32G \
    -smp 4 \
    -vga std \
    -vnc :1 \
    -chardev socket,id=console0,path=/tmp/console0,server,nowait \
    -device spapr-vty,chardev=console0 \
    -cpu host \
    -device usb-kbd \
    -incoming tcp:0:5801 \
    -device usb-mouse \
    -qmp tcp:0:8881,server,nowait \
    -msg timestamp=on \
    -rtc base=localtime,clock=vm,driftfix=slew  \
    -monitor stdio \
    -boot order=cdn,once=n,menu=on,strict=off \
    -enable-kvm \
    -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0xc \
    -watchdog i6300esb \
    -watchdog-action debug \
    -name debug-threads=on \

migration both succeed for rhel7<->rhel8

So, I think this bug is fixed.

Comment 9 xianwang 2019-01-07 07:21:12 UTC

referring to comment 4, I will close this bug as CURRENTRELEASE, if there is something mistakes, you could update it.