Hi Eric,
>-----Original Message-----
>From: Eric Auger <eric.au...@redhat.com>
>Subject: Re: [PATCH v6 07/19] vfio/container: Implement
>HostIOMMUDeviceClass::realize() handler
>
>Hi Zhenzhong,
>
>On 6/3/24 08:10, Zhenzhong Duan wrote:
>> Utilize range_get_last_bit() to get host IOMMU address width and
>> package it in HostIOMMUDeviceCaps for query with .get_cap().
>>
>> Signed-off-by: Zhenzhong Duan <zhenzhong.d...@intel.com>
>> ---
>> hw/vfio/container.c | 26 ++++++++++++++++++++++++++
>> 1 file changed, 26 insertions(+)
>>
>> diff --git a/hw/vfio/container.c b/hw/vfio/container.c
>> index c4fca2dfca..48800fe92f 100644
>> --- a/hw/vfio/container.c
>> +++ b/hw/vfio/container.c
>> @@ -1136,6 +1136,31 @@ static void
>vfio_iommu_legacy_class_init(ObjectClass *klass, void *data)
>> vioc->pci_hot_reset = vfio_legacy_pci_hot_reset;
>> };
>>
>> +static bool hiod_legacy_vfio_realize(HostIOMMUDevice *hiod, void
>*opaque,
>> + Error **errp)
>> +{
>> + VFIODevice *vdev = opaque;
>> + /* iova_ranges is a sorted list */
>> + GList *l = g_list_last(vdev->bcontainer->iova_ranges);
>> +
>> + /* Only support query HOST_IOMMU_DEVICE_CAP_AW_BITS with
>legacy backend */
>I don't get the comment as HOST_IOMMU_DEVICE_CAP_AW_BITS support
>seems
>to be introduced in [PATCH v6 11/19] backends/iommufd: Implement
>HostIOMMUDeviceClass::get_cap() handler
Sorry about my poor English, I mean legacy backend only support
HOST_IOMMU_DEVICE_CAP_AW_BITS, no other caps.
May be only:
/* Only support query HOST_IOMMU_DEVICE_CAP_AW_BITS */
>> + if (l) {
>> + Range *range = l->data;
>> + hiod->caps.aw_bits = range_get_last_bit(range) + 1;
>> + } else {
>> + hiod->caps.aw_bits = 0xff;
>why this value?
0xff means no limitation on aw_bits from host side. Aw_bits check
should always pass. This could be a case that an old kernel doesn't
support query iova ranges.
Will add a define like:
#define HOST_IOMMU_DEVICE_CAP_AW_BITS_MAX 0xff
Thanks
Zhenzhong
>> + }
>> +
>> + return true;
>> +}
>> +
>> +static void hiod_legacy_vfio_class_init(ObjectClass *oc, void *data)
>> +{
>> + HostIOMMUDeviceClass *hioc = HOST_IOMMU_DEVICE_CLASS(oc);
>> +
>> + hioc->realize = hiod_legacy_vfio_realize;
>> +};
>> +
>> static const TypeInfo types[] = {
>> {
>> .name = TYPE_VFIO_IOMMU_LEGACY,
>> @@ -1144,6 +1169,7 @@ static const TypeInfo types[] = {
>> }, {
>> .name = TYPE_HOST_IOMMU_DEVICE_LEGACY_VFIO,
>> .parent = TYPE_HOST_IOMMU_DEVICE,
>> + .class_init = hiod_legacy_vfio_class_init,
>> }
>> };
>>
>
>Thanks
>
>Eric
