[pve-devel] [RFC qemu-server] avoid setting lun number for drives when pvscsi controller is used

[Stefan Reiter]

On 6/14/21 8:29 AM, Fabian Ebner wrote:
> Any feedback for this?
> 

Looks good to me and works as advertised:

Reviewed-by: Stefan Reiter <s.reiter at proxmox.com>
Tested-by: Stefan Reiter <s.reiter at proxmox.com>

The `$unit = $drive->{index} % maxdev` logic doesn't seem useful here though, I
think it's a copy/paste from the IDE/SATA code below (it was already used before
this patch). How about this for a cleanup on top:


diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
index c00bde1..afd47b5 100644
--- a/PVE/QemuServer.pm
+++ b/PVE/QemuServer.pm
@@ -1424,7 +1424,6 @@ sub print_drivedevice_full {
      } elsif ($drive->{interface} eq 'scsi') {
  
  	my ($maxdev, $controller, $controller_prefix) = scsihw_infos($conf, $drive);
-	my $unit = $drive->{index} % $maxdev;
  	my $devicetype = 'hd';
  	my $path = '';
  	if (drive_is_cdrom($drive)) {
@@ -1452,7 +1451,7 @@ sub print_drivedevice_full {
  	}
  
  	if (!$conf->{scsihw} || $conf->{scsihw} =~ m/^lsi/ || $conf->{scsihw} eq 'pvscsi') {
-	   $device = "scsi-$devicetype,bus=$controller_prefix$controller.0,scsi-id=$unit";
+	   $device = "scsi-$devicetype,bus=$controller_prefix$controller.0,scsi-id=$drive->{index}";
  	} else {
  	   $device = "scsi-$devicetype,bus=$controller_prefix$controller.0,channel=0,scsi-id=0"
  	       .",lun=$drive->{index}";


> Am 13.04.21 um 10:24 schrieb Fabian Ebner:
>> Reported in the community forum[0].
>>
>> In QEMU's hw/scsi/vmw_pvscsi.c in the SCSIBusInfo struct, the max_lun property
>> is set to 0. This means that in our stack, one cannot have multiple disks and
>> use 'scsihw: pvscsi' currently, as kvm would fail with
>>       bad scsi device lun: 1
>>
>> Instead of increasing the lun number, increase the scsi-id, as we already do for
>> lsi.* (in hw/scsi/lsi53c895a.c the max_lun property is also 0).
>>
>> [0]: https://forum.proxmox.com/threads/kvm-bad-scsi-device-lun-1.84318/
>>
>> Signed-off-by: Fabian Ebner <f.ebner at proxmox.com>
>> ---
>>
>> I'm not experienced in this area, so not at all sure if this is the proper
>> solution/workaround.
>>
>>    PVE/QemuServer.pm | 2 +-
>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
>> index fdb2ac9..4ce663b 100644
>> --- a/PVE/QemuServer.pm
>> +++ b/PVE/QemuServer.pm
>> @@ -1451,7 +1451,7 @@ sub print_drivedevice_full {
>>    	    }
>>    	}
>>    
>> -	if (!$conf->{scsihw} || ($conf->{scsihw} =~ m/^lsi/)){
>> +	if (!$conf->{scsihw} || $conf->{scsihw} =~ m/^lsi/ || $conf->{scsihw} eq 'pvscsi') {
>>    	    $device = "scsi-$devicetype,bus=$controller_prefix$controller.0,scsi-id=$unit";
>>    	} else {
>>    	    $device = "scsi-$devicetype,bus=$controller_prefix$controller.0,channel=0,scsi-id=0"
>>
> 
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