[PATCH 5/7] qemu: Support update net's bootindex

[Peter Krempa]

On Thu, Nov 17, 2022 at 10:05:31 +0800, Jiang Jiacheng wrote:
> Support to update the net's bootindex using 'virsh update-device'.
> Using flag --config or --persistent to change the boot index and the
> change will be affected after reboot. With --persistent, we can get
> the result of change immediently, but it still takes effect after reboot.
> 
> Signed-off-by: Jiang Jiacheng <jiangjiacheng at huawei.com>
> ---
>  src/qemu/qemu_driver.c  |  4 ++++
>  src/qemu/qemu_hotplug.c | 17 ++++++++++++-----
>  2 files changed, 16 insertions(+), 5 deletions(-)
> 
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index 65abc04998..863b779514 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -7568,6 +7568,10 @@ qemuDomainUpdateDeviceConfig(virDomainDef *vmdef,
>                                           false) < 0)
>              return -1;
>  
> +        if (qemuCheckBootIndex(&vmdef->nets[pos]->info,
> +                               net->info.bootIndex) < 0)
> +            return -1;

Same as with disks. This check makes no sense for the *Config variant.

> +
>          if (virDomainNetUpdate(vmdef, pos, net))
>              return -1;
>  
> diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
> index da92ced2f4..5d1913d0c7 100644
> --- a/src/qemu/qemu_hotplug.c
> +++ b/src/qemu/qemu_hotplug.c
> @@ -3468,6 +3468,7 @@ qemuDomainChangeNet(virQEMUDriver *driver,
>      bool needCoalesceChange = false;
>      bool needVlanUpdate = false;
>      bool needIsolatedPortChange = false;
> +    int needChangeIndex = 0;
>      int ret = -1;
>      int changeidx = -1;
>      g_autoptr(virConnect) conn = NULL;
> @@ -3633,11 +3634,8 @@ qemuDomainChangeNet(virQEMUDriver *driver,
>          goto cleanup;
>      }
>  
> -    if (newdev->info.bootIndex == 0)
> -        newdev->info.bootIndex = olddev->info.bootIndex;

You are deleting too much of the logic here, this code specifically
ensures that if the new device's boot index is not specified it adopts
the old one, thus this needs to be changed suich that it's still adopted
in cases when an explicit new boot index was not specified.

> -    if (olddev->info.bootIndex != newdev->info.bootIndex) {
> -        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
> -                       _("cannot modify network device boot index setting"));
> +    if ((needChangeIndex = qemuCheckBootIndex(&olddev->info,
> +                                              newdev->info.bootIndex)) < 0) {

This once again (due to the weird check) breaks update of network
devices which don't have bootindex enabled.

>          goto cleanup;
>      }
>