[libvirt] [PATCH] domain_conf: skip boot order check of CD-ROM or floppy device

[Chen Hanxiao]

At 2018-01-05 23:01:50, "John Ferlan" <jferlan at redhat.com> wrote:
>
>
>On 12/25/2017 06:21 AM, Chen Hanxiao wrote:
>> From: Chen Hanxiao <chenhanxiao at gmail.com>
>> 
>> If we insert or eject a CD-ROM/floppy device with a boot order,
>> we may get:
>>   unsupported configuration: boot order 2 is already used by another device
>> 
>> This check should be skipped in this case.
>> 
>> Signed-off-by: Chen Hanxiao <chenhanxiao at gmail.com>
>> ---
>>  src/conf/domain_conf.c | 16 ++++++++++++----
>>  1 file changed, 12 insertions(+), 4 deletions(-)
>> 
>
>Is there a specific reason for your assertion?  Given what scenario?
1) create a VM by virt-manger with a virtio disk and a cd-rom
2) set boot order of them
3) Try to eject a CD-rom device, such as installing an OS with multiple DVDs
    i. e: virsh change-media ...
4) got:
  unsupported configuration: boot order 2 is already used by another device.

>
>virDomainDefCompatibleDevice is called from Attach and Update qemu/lxc
>code currently.
>
>I dunno, but if someone is trying to attach or update a floppy/cdrom and
>wanted to use a boot index in use by something else, then I would think
>inhibiting that is a good idea...

We updated the source file of floppy/cdrom, which is not a hotplug operation,
so the boot order check should be skipped.

Regards,
- Chen

>
>> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
>> index 9a62bc472..885ab88d2 100644
>> --- a/src/conf/domain_conf.c
>> +++ b/src/conf/domain_conf.c
>> @@ -26880,11 +26880,19 @@ virDomainDeviceInfoCheckBootIndex(virDomainDefPtr def ATTRIBUTE_UNUSED,
>>  {
>>      virDomainDeviceInfoPtr newinfo = opaque;
>>  
>> +    int disk_device = device->data.disk->device;
>
>Typically the deref would be something like virDomainDiskDefPtr disk =
>device->data.disk; and then "disk->device"
>
>BTW: @device would then no longer be ATTRIBUTE_UNUSED.
>
>
>John
>
>>      if (info->bootIndex == newinfo->bootIndex) {
>> -        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
>> -                       _("boot order %u is already used by another device"),
>> -                       newinfo->bootIndex);
>> -        return -1;
>> +        /* Skip check for insert or eject CD-ROM device */
>> +        if (disk_device == VIR_DOMAIN_DISK_DEVICE_FLOPPY ||
>> +            disk_device == VIR_DOMAIN_DISK_DEVICE_CDROM) {
>> +            VIR_DEBUG("Skip boot index check for floppy or CDROM");
>> +            return 0;
>> +        } else {
>> +            virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
>> +                           _("boot order %u is already used by another device"),
>> +                           newinfo->bootIndex);
>> +            return -1;
>> +        }
>>      }
>>      return 0;
>>  }
>>