[PATCH 3/7] qemu: Introduce qemuCheckBootIndex and qemuChangeDiskBootIndex API

[Jiang Jiacheng]

On 2022/11/22 23:06, Peter Krempa wrote:
> On Thu, Nov 17, 2022 at 10:05:29 +0800, Jiang Jiacheng wrote:
>> Introduce qemuCheckBootIndex to check the new bootindex and is it nessary
>> to update the bootindex. Introduce qemuChangeDiskBootIndex to support update
>> disk's bootindex according to different disks' type.
>>
>> Signed-off-by: Jiang Jiacheng <jiangjiacheng at huawei.com>
>> ---
>>  src/qemu/qemu_conf.c | 67 ++++++++++++++++++++++++++++++++++++++++++++
>>  src/qemu/qemu_conf.h |  7 +++++
> 
> qemu_conf.* seems to be inappropriate file for these helpers. qemu_conf
> is a module which deals mostly with the configuration of the qemu driver
> itself and host-side specifics.
> 
> qemu_domain is usually a better fit.
> 
Thank for your suggestion, I will move it to qemu_domain in my next patch.

>>  2 files changed, 74 insertions(+)
>>
>> diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c
>> index 0071a95cb6..9a7992db01 100644
>> --- a/src/qemu/qemu_conf.c
>> +++ b/src/qemu/qemu_conf.c
>> @@ -1681,3 +1681,70 @@ qemuDomainChangeBootIndex(virDomainObj *vm,
>>  
>>      return ret;
>>  }
>> +
>> +/**
>> + * qemuCheckBootIndex:
>> + * @devInfo: origin device info
>> + * @new_bootindex: new bootIndex
>> + *
>> + * check whether the device's bootIndex could be changed or neet to
>> + * be changed
>> + *
>> + * Returns: 1 on need to change
>> + *          0 on don't need to change
>> + *          -1 on could not change with an error
>> + */
>> +int
>> +qemuCheckBootIndex(virDomainDeviceInfo *devInfo,
>> +                   const int new_bootindex)
>> +{
>> +    if (!devInfo->bootIndexSpecified) {
>> +        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
>> +                       _("this device does not set boot index, cannot change it."));
>> +        return -1;
> 
> This check doesn't seem to make much sense. What if you want to add boot
> index?>
The bootindex changable devices is fixed when start the domain, so it is
not supported to add a boot index, this check is used to prevent them.
However, it do have problems as you mentioned in next patch, the logical
here should be optimized.

>> +    }
>> +
>> +    /* if the new bootindex is different from the old bootindex,
>> +     * we will update the bootindex. */
>> +    if (devInfo->bootIndex != new_bootindex) {
>> +        return 1;
>> +    }
>> +
>> +    return 0;
>> +}
>