Hi Zhenzhong,
On 6/23/25 4:20 AM, Duan, Zhenzhong wrote:
> Hi Eric,
>
>> -----Original Message-----
>> From: Eric Auger <eric.au...@redhat.com>
>> Subject: Re: [PATCH v2 02/19] hw/pci: Introduce pci_device_get_viommu_cap()
>>
>> Hi Zhenzhong,
>>
>> On 6/20/25 9:17 AM, Zhenzhong Duan wrote:
>>> pci_device_get_viommu_cap() call pci_device_get_iommu_bus_devfn()
>>> to get iommu_bus->iommu_ops and call get_viommu_cap() callback to
>>> get a bitmap with each bit represents a vIOMMU exposed capability.
>>>
>>> Suggested-by: Yi Liu <yi.l....@intel.com>
>>> Signed-off-by: Zhenzhong Duan <zhenzhong.d...@intel.com>
>>> ---
>>> include/hw/pci/pci.h | 22 ++++++++++++++++++++++
>>> hw/pci/pci.c | 11 +++++++++++
>>> 2 files changed, 33 insertions(+)
>>>
>>> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
>>> index df3cc7b875..829757b2c2 100644
>>> --- a/include/hw/pci/pci.h
>>> +++ b/include/hw/pci/pci.h
>>> @@ -453,6 +453,18 @@ typedef struct PCIIOMMUOps {
>>> * @devfn: device and function number of the PCI device.
>>> */
>>> void (*unset_iommu_device)(PCIBus *bus, void *opaque, int devfn);
>>> + /**
>>> + * @get_viommu_cap: get vIOMMU capabilities
>>> + *
>>> + * Optional callback, if not implemented, then vIOMMU doesn't
>>> + * support exposing capabilities to other subsystem, e.g., VFIO.
>>> + * vIOMMU can choose which capabilities to expose.
>>> + *
>>> + * @opaque: the data passed to pci_setup_iommu().
>>> + *
>>> + * Returns: 64bit bitmap with each bit represents a capability.
>> I think we need to clarify what this bitmap contains as capability bits
>> (enum type)
> Sure, will be like:
>
> * Returns: 64bit bitmap with each bit represents a capability emulated
> * by VIOMMU_CAP_* in include/hw/iommu.h
>
> enum {
> VIOMMU_CAP_STAGE1 = BIT_ULL(0), /* stage1 page table supported */
> };
looks good to me
Eric
>
> Thanks
> Zhenzhong
>
