RE: [PATCH v3 29/37] vfio/iommufd: Bypass EEH if iommufd backend

[Duan, Zhenzhong]

>-----Original Message-----
>From: Cédric Le Goater <clg@redhat.com>
>Sent: Tuesday, October 31, 2023 5:01 PM
>Subject: Re: [PATCH v3 29/37] vfio/iommufd: Bypass EEH if iommufd backend
>
>On 10/31/23 03:26, Duan, Zhenzhong wrote:
>>
>>
>>> -----Original Message-----
>>> From: Cédric Le Goater <clg@redhat.com>
>>> Sent: Monday, October 30, 2023 9:57 PM
>>> Subject: Re: [PATCH v3 29/37] vfio/iommufd: Bypass EEH if iommufd backend
>>>
>>> On 10/26/23 12:30, Zhenzhong Duan wrote:
>>>> IBM EEH is only supported by legacy backend currently, bypass it
>>>> for IOMMUFD backend.
>>>>
>>>> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
>>>> ---
>>>>    hw/ppc/spapr_pci_vfio.c | 4 ++--
>>>>    1 file changed, 2 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/hw/ppc/spapr_pci_vfio.c b/hw/ppc/spapr_pci_vfio.c
>>>> index d1d07bec46..a2518838a1 100644
>>>> --- a/hw/ppc/spapr_pci_vfio.c
>>>> +++ b/hw/ppc/spapr_pci_vfio.c
>>>> @@ -93,10 +93,10 @@ static VFIOContainer
>>> *vfio_eeh_as_container(AddressSpace *as)
>>>>
>>>>        bcontainer = QLIST_FIRST(&space->containers);
>>>>
>>>> -    if (QLIST_NEXT(bcontainer, next)) {
>>>> +    if (QLIST_NEXT(bcontainer, next) || bcontainer->ops != 
>>>> &vfio_legacy_ops)
>{
>>>
>>> It's curious that a test on the VFIOIOMMUOps is needed so deep in
>>> the software stack, and spapr should have its own VFIOIOMMUOps, which
>>> de facto doesn't support iommufd.
>>
>> Yes, in this series, spapr shares same ops vfio_legacy_ops, in next series I
>should
>> check with vfio_iommu_spapr_ops.
>
>Well, since PPC doesn't support IOMMUFD it should be tested before or compile
>out as suggested on patch 23 "Add iommufd configure option"

Got it, I'll disabled it for PPC as you suggested.

Thanks
Zhenzhong

>
>Thanks,
>
>C.
>
>
>> The general vfio-pci device supports iommu property, if we pass a vfio device
>> with iommufd backend, I guess we will crash Qemu if there is no check here.
>>
>> Thanks
>> Zhenzhong
>>