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

[Eric Auger <eric.auger.pro@gmail.com>]

Hi Peter,

On 09/03/18 18:59, Peter Maydell wrote:
> On 9 March 2018 at 17:53, Auger Eric <eric.auger@redhat.com> wrote:
>> Hi Peter,
>> On 08/03/18 20:06, Peter Maydell wrote:
>>> On 17 February 2018 at 18:46, Eric Auger <eric.auger@redhat.com> wrote:
>>>> At the moment, the SMMUv3 does not support notification on
>>>> TLB invalidation. So let's abort as soon as such notifier gets
>>>> enabled.
>>>>
>>>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>>>> ---
>>>>  hw/arm/smmuv3.c | 11 +++++++++++
>>>>  1 file changed, 11 insertions(+)
>>>>
>>>> diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
>>>> index 384393f..5efe933 100644
>>>> --- a/hw/arm/smmuv3.c
>>>> +++ b/hw/arm/smmuv3.c
>>>> @@ -1074,12 +1074,23 @@ static void smmuv3_class_init(ObjectClass *klass, void *data)
>>>>      dc->realize = smmu_realize;
>>>>  }
>>>>
>>>> +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.

Thanks

Eric
> 
> thanks
> -- PMM
>