libvirt users - Jun 2013 - Re: Question about vport operation for FC HBA

Hi,

When I want to use NPIV for a FC HBA in my Linux machine, I got the 
below error msg in virsh:

virsh # nodedev-create /home/kvm/vHBA.xml
error: Failed to create node device from /home/kvm/vHBA.xml
error: internal error Parent device scsi_host20 is not capable of vport 
operations

I checked the /sys/class folder for my HBA device that I want to use its 
NPIV feature, it's there:
/sys/class/fc_host/host20/vport_create

I can create a vHBA by using "echo 'xxxx:xxxx' >
./vport_create", a new
fc host will be created after that.

But I can't find any FC host with:
#virsh nodedev-list --cap fc_host

SCSI hosts can be found for above "nodedev-list  --cap scsi_host".

The libvirt I am working on is based ver 1.0.5, I checked the code and 
found below function is seems related with this issue:
src/util/virutil.c:
int
virIsCapableVport(const char *sysfs_prefix,
                   int host)

This function looks up if there is "vport_create" file under 
/sys/class/fc_host/host20, as the way to decide if a HBA device is 
capable of vport operation.

But seems this file is not compiled and virsh doesn't call it in my 
source code environment... is there any tips  ?

BRs,
Dennis

On 06/20/2013 11:07 AM, Dennis Chen wrote:
> Hi,
> 
> When I want to use NPIV for a FC HBA in my Linux machine, I got the below
> error msg in virsh:
> 
> virsh # nodedev-create /home/kvm/vHBA.xml
> error: Failed to create node device from /home/kvm/vHBA.xml
> error: internal error Parent device scsi_host20 is not capable of vport
> operations
> 
> I checked the /sys/class folder for my HBA device that I want to use its
NPIV
> feature, it's there:
> /sys/class/fc_host/host20/vport_create
> 
> I can create a vHBA by using "echo 'xxxx:xxxx' >
./vport_create", a new fc
> host will be created after that.
> 
> But I can't find any FC host with:
> #virsh nodedev-list --cap fc_host
> 
> SCSI hosts can be found for above "nodedev-list  --cap
scsi_host".
> 
> The libvirt I am working on is based ver 1.0.5, I checked the code and
found
> below function is seems related with this issue:
> src/util/virutil.c:
> int
> virIsCapableVport(const char *sysfs_prefix,
>                   int host)
> 
> This function looks up if there is "vport_create" file under
> /sys/class/fc_host/host20, as the way to decide if a HBA device is capable
of
> vport operation.
> 
> But seems this file is not compiled and virsh doesn't call it in my
source
> code environment... is there any tips  ?
Hi, there was a bug in the nodedev driver, it used ../fc_host/host0/.. even
when the host number was different.

It should be fixed by this commit (pushed in the git, but not yet a part of a
release):
http://libvirt.org/git/?p=libvirt.git;a=commitdiff;h=371c155

Hopefully that fixes it for you.

Relevant bugs:
https://bugzilla.redhat.com/show_bug.cgi?id=952105
https://bugzilla.redhat.com/show_bug.cgi?id=973543

Jan

On 06/20/2013 06:05 PM, Ján Tomko wrote:
> On 06/20/2013 11:07 AM, Dennis Chen wrote:
>> Hi,
>>
>> When I want to use NPIV for a FC HBA in my Linux machine, I got the
below
>> error msg in virsh:
>>
>> virsh # nodedev-create /home/kvm/vHBA.xml
>> error: Failed to create node device from /home/kvm/vHBA.xml
>> error: internal error Parent device scsi_host20 is not capable of vport
>> operations
>> ...
>> But seems this file is not compiled and virsh doesn't call it in my
source
>> code environment... is there any tips  ?
> Hi, there was a bug in the nodedev driver, it used ../fc_host/host0/.. even
> when the host number was different.
>
> It should be fixed by this commit (pushed in the git, but not yet a part of
a
> release):
> http://libvirt.org/git/?p=libvirt.git;a=commitdiff;h=371c155
>
> Hopefully that fixes it for you.
>
> Relevant bugs:
> https://bugzilla.redhat.com/show_bug.cgi?id=952105
> https://bugzilla.redhat.com/show_bug.cgi?id=973543
>
> Jan
>
After use the latest libvirt 1.0.6 + your patch,   it resolved below 
issues in my environment:
1. The internal error Parent device scsi_host20 is not capable of vport
2. nodedev-dumpxml can get correct info of the HBA device.

But seems there's another problem---

My vHBA.xml:
<device>
   <parent>scsi_host20</parent>
   <capability type='scsi_host'>
     <capability type='fc_host'>
       <wwpn>20008c7cff30be58</wwpn>
       <wwnn>10008d7cff30beb8</wwnn>
     </capability>
   </capability>
</device>

The output of the nodedev-create command:
virsh # nodedev-create /home/kvm/vHBA.xml
(after about 30s silence...)
error: Failed to create node device from /home/kvm/vHBA.xml
error: Node device not found

Actually I found that the new vHBA device is generated sucessfully 
(scsi_host31), and the "nodedev-dumpxml" for this device is:
virsh # nodedev-dumpxml scsi_host31
<device>
   <name>scsi_host31</name>
   <parent>scsi_host20</parent>
   <capability type='scsi_host'>
     <host>31</host>
     <capability type='fc_host'>
       <wwnn>20008c7cff30be58</wwnn>      ----- the wwpn value in
vHBA.xml
       <wwpn>10008d7cff30beb8</wwpn>      ----- the wwnn value in
vHBA.xml
       <fabric_wwn>0</fabric_wwn>
     </capability>
   </capability>
</device>

any suggestion?

BRs,
Dennis