To POST:

http://post-office.corp.redhat.com/archives/rhvirt-patches/2018-April/msg00063.html

v2:

http://post-office.corp.redhat.com/archives/rhvirt-patches/2018-April/msg00078.html

Verified on:
libvirt-3.9.0-14.virtcov.el7_5.3.x86_64
kernel-3.10.0-862.el7.x86_64
qemu-kvm-rhev-2.10.0-21.el7_5.2.x86_64


1. start vm with multipath device
# multipath -ll
mpathb (360050763008084e6e000000000000064) dm-2 IBM     ,2145            
size=20G features='1 queue_if_no_path' hwhandler='0' wp=rw
|-+- policy='service-time 0' prio=50 status=active
| `- 8:0:1:1 sde 8:64 active ready running
`-+- policy='service-time 0' prio=10 status=enabled
  `- 8:0:0:1 sdc 8:32 active ready running

# virsh dumpxml vm | grep "<disk" -A7
    <disk type='block' device='lun' sgio='filtered' snapshot='no'>
      <driver name='qemu' type='raw' cache='none' error_policy='stop' io='native'/>
      <source dev='/dev/mapper/mpathb'/>
      <target dev='sda' bus='scsi'/>
      <boot order='1'/>
      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
    </disk>

# virsh domblklist vm
Target     Source
------------------------------------------------
sda        /dev/mapper/mpathb

# virsh start vm
Domain vm started

# virsh list
 Id    Name                           State
----------------------------------------------------
 18    vm                             running

2. hot plug a multipath device
# virsh start vm
vDomain vm started

# virsh domblklist vm
Target     Source
------------------------------------------------
vda        /var/lib/avocado/data/avocado-vt/images/RHEL-7.5-x86_64-latest.qcow2


# cat mpath.xml 
    <disk type='block' device='lun' sgio='filtered' snapshot='no'>
      <driver name='qemu' type='raw' cache='none' error_policy='stop' io='native'/>
      <source dev='/dev/mapper/mpathb'/>
      <backingStore/>
      <target dev='sda' bus='scsi'/>
    </disk>

# virsh attach-device vm mpath.xml 
Device attached successfully

# virsh domblklist vm
Target     Source
------------------------------------------------
vda        /var/lib/avocado/data/avocado-vt/images/RHEL-7.5-x86_64-latest.qcow2
sda        /dev/mapper/mpathb

Hi Elad,
This bug was verified in pure libvirt env. Pls judge if you need to run some auto cases from rhev's perspective to cover some other risk area. thx

This will be tested once Bug 1568441 is ON_QA

(In reply to Elad from comment #8)
> This will be tested once Bug 1568441 is ON_QA

Why not just take the fixed image and test it? Why should we add a dependency, if it may end up not working?

Tested tier1 direct LUN automation with the qemu-kvm-rhev build from [1].

Steps:
1. Create a VM with a direct LUN attached (tested with SCSI Pass-Through as enabled and as disabled)
2. Start the VM

Results: 
Start VM succeeded.

With SCSI passthough enabled:

2018-04-18 11:55:46,601+0300 INFO  (jsonrpc/7) [api.virt] FINISH create return={'status': {'message': 'Done', 'code': 0}, 'vmList'
.
.
.
<disk snapshot="no" type="block" device="disk"><target dev="vda" bus="virtio"></target><source dev="/rhev/data-center/mnt/blockSD/3c8aaba0-ceec-44fd-8a8e-c375a1c7d692/images/a8395c4e-a15d-4c2a-b07a-fe9958328d5c/a6543775-e0f3-4b9e-9676-9408f381170b"></source><driver name="qemu" io="native" type="qcow2" error_policy="stop" cache="none"></driver><alias name="ua-a8395c4e-a15d-4c2a-b07a-fe9958328d5c"></alias><address bus="0x00" domain="0x0000" function="0x0" slot="0x07" type="pci"></address><boot order="1"></boot><serial>a8395c4e-a15d-4c2a-b07a-fe9958328d5c</serial></disk><disk snapshot="no" type="block" device="lun" sgio="unfiltered"><target dev="sda" bus="scsi"></target><source dev="/dev/mapper/3514f0c5a516008d7"></source><driver name="qemu" io="native" type="raw" error_policy="stop" cache="none"></driver><alias name="ua-66100ab8-21bc-4e65-be8b-d14acb074163"></alias><address bus="0" controller="0" unit="0" type="drive" target="0">


2018-04-18 11:55:46,605+0300 INFO  (jsonrpc/7) [jsonrpc.JsonRpcServer] RPC call VM.create succeeded in 0.06 seconds (__init__:573)



[1]
https://brewweb.engineering.redhat.com/brew/buildinfo?buildID=672831


Used:
vdsm-4.20.25-1.el7ev.x86_64
libvirt-3.9.0-14.el7_5.3.x86_64
qemu-img-rhev-2.10.0-21.el7_5.2.x86_64
qemu-kvm-common-rhev-2.10.0-21.el7_5.2.x86_64
qemu-kvm-rhev-2.10.0-21.el7_5.2.x86_64
qemu-kvm-tools-rhev-2.10.0-21.el7_5.2.x86_64
ipxe-roms-qemu-20170123-1.git4e85b27.el7_4.1.noarch
qemu-guest-agent-2.8.0-2.el7.x86_64
qemu-kvm-rhev-debuginfo-2.10.0-21.el7_5.2.x86_64
kernel - 3.10.0-862.el7.x86_64
RHEL7.5

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/RHSA-2018:1396