Re: [Qemu-devel] [PATCH v3] Add remove_boot_device_path() function for hot-unplug device

[Jun Li <junmuzi@gmail.com>]

On 05/21/2014 04:13 PM, Andreas Färber wrote:
> Am 19.05.2014 17:57, schrieb Michael S. Tsirkin:
>> On Mon, May 19, 2014 at 05:31:43PM +0200, Andreas Färber wrote:
>>> Hi,
>>>
>>> Am 19.05.2014 17:03, schrieb Jun Li:
>>>> Add remove_boot_device_path() function to remove bootindex when hot-unplug
>>>> a device. This patch fixed virtio-blk/virtio-net/scsi-disk/scsi-generic device.
>>>>
>>>> Signed-off-by: Jun Li <junmuzi@gmail.com>
>>>> ---
>>>> This patch also fixed bug1086603, ref:
>>>> https://bugzilla.redhat.com/show_bug.cgi?id=1086603
>>>>
>>>> This version of patch delete dev and suffix parameter from function remove_boot_device_path().
>>>> ---
>>>>   hw/block/virtio-blk.c   |  1 +
>>>>   hw/net/virtio-net.c     |  1 +
>>>>   hw/scsi/scsi-disk.c     |  1 +
>>>>   hw/scsi/scsi-generic.c  |  1 +
>>> On v1 I believe I reminded you of spapr_llan. Your patch is adding a new
>>> remove_*() function, but is using it only for roughly half of the
>>> devices that currently call add_boot_device_path(). Why? I can
>>> understand that ISA devices will not be hot-unpluggable, but all PCI and
>>> USB devices are.
>> Can we remove the device from boot path automatically
>> when it's going away?
> I'm not familiar with that code myself; assuming that only one path gets
> registered per device, I guess we could add a field to DeviceState and
> if non-NULL call the unregistration from device_set_unrealize().
>
> Jun, if that works it would save you some work.


Hi Andreas,

      Add a field to DeviceState is another method to fix this issue. 
But when using this method, should delete add_boot_device_path() and add 
boot path in register per device. I can not estimate the potential 
issues. Could any guy give your opinion? I will do some researches this 
weekend. Thx.

      Add remove_boot_device_path(), we can call this function where it 
needs. It's easy to realize. :-)


Best Regards,
Jun Li