Re: [Qemu-devel] [PATCH v9 10/14] hw/arm/smmuv3: Abort on vfio or vhost case

[Peter Maydell]

On 12 March 2018 at 10:53, Eric Auger <address@hidden> wrote:
> Hi Peter,
>
> On 09/03/18 18:59, Peter Maydell wrote:
>> On 9 March 2018 at 17:53, Auger Eric <address@hidden> wrote:
>>> Hi Peter,
>>> On 08/03/18 20:06, Peter Maydell wrote:
>>>> On 17 February 2018 at 18:46, Eric Auger <address@hidden> wrote:
>>>>> +static void smmuv3_notify_flag_changed(IOMMUMemoryRegion *iommu,
>>>>> +                                       IOMMUNotifierFlag old,
>>>>> +                                       IOMMUNotifierFlag new)
>>>>> +{
>>>>> +    if (old == IOMMU_NOTIFIER_NONE) {
>>>>> +        error_setg(&error_fatal,
>>>>> +                   "SMMUV3: vhost and vfio notifiers not yet supported");
>>>>> +    }
>>>>> +}
>>>>
>>>> Is this triggerable by the guest, or by the user on the command
>>>> line, or only by a bug in the board or other QEMU code?
>>> by the user on the command line.
>>
>> OK. Do they get this error immediately on startup, or only later
>> in execution? (If the latter, is it possible to make the error
>> happen earlier?)

> later in execution. We also have to handle the case where such device is
> hot-plugged. At best if could be done on smmu_find_add_as() by checking
> the type of attached device but this wouldn't happen much earlier. By
> the way we will soon support vhost and we will just rule out vfio
> integration by detecting map notifiers.

Hmm. error_fatal is a bit unfortunate for a hotplug event -- ideally
you would want to cause the hotplug to cleanly fail without aborting
the running QEMU session.

thanks
-- PMM