[Xen-devel] Re: [Qemu-devel] [PATCH v3] xen: implement unplug protocol in xen_platform

[Kevin Wolf <kwolf@xxxxxxxxxx>]

Am 15.07.2011 12:34, schrieb Stefano Stabellini:
> On Fri, 1 Jul 2011, Stefano Stabellini wrote:
>> On Fri, 1 Jul 2011, Kevin Wolf wrote:
>>> Am 30.06.2011 16:16, schrieb Stefano Stabellini:
>>>> On Thu, 30 Jun 2011, Kevin Wolf wrote:
>>>>>> +static int pci_piix3_xen_ide_unplug(DeviceState *dev)
>>>>>> +{
>>>>>> +    PCIDevice *pci_dev;
>>>>>> +    PCIIDEState *pci_ide;
>>>>>> +    DriveInfo *di;
>>>>>> +    int i = 0;
>>>>>> +
>>>>>> +    pci_dev = DO_UPCAST(PCIDevice, qdev, dev);
>>>>>> +    pci_ide = DO_UPCAST(PCIIDEState, dev, pci_dev);
>>>>>> +
>>>>>> +    for (; i < 3; i++) {
>>>>>> +        di = drive_get_by_index(IF_IDE, i);
>>>>>> +        if (di != NULL && di->bdrv != NULL && !di->bdrv->removable) {
>>>>>> +            DeviceState *ds = bdrv_get_attached(di->bdrv);
>>>>>> +            if (ds) {
>>>>>> +                bdrv_detach(di->bdrv, ds);
>>>>>> +            }
>>>>>> +            bdrv_close(di->bdrv);
>>>>>> +            pci_ide->bus[di->bus].ifs[di->unit].bs = NULL;
>>>>>
>>>>> Have you tested if this is enough if the guest tries to continue using
>>>>> the device? I don't know of any case where it's not sufficient, just
>>>>> trying to make sure that it's really true in practice.
>>>>
>>>> The purpose of this is to "hide" the disk from the guest. The unplug is
>>>> supposed to happen *before* the guest enumerates the IDE disks; it is
>>>> responsibility of the guest to make sure of it.
>>>> I tested it with Linux PV on HVM drivers, and Linux doesn't see the
>>>> emulated disk after the unplug, as it should be.
>>>
>>> Yeah. What I meant is that we should make sure that a misbehaving guest,
>>> which just keeps on playing with the IDE ports anyway, can't crash qemu.
>>> A quick review suggests that it is the case, but testing it anyway would
>>> be better.
>>
>> I see what you mean: I tested it, a guest cannot crash Qemu.
>>
> 
> ping?

I thought Alex had already merged it. I'm pretty sure that I stated
somewhere that the patch is okay for me now. In case I didn't:

Acked-by: Kevin Wolf <kwolf@xxxxxxxxxx>

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