RE: [PATCH v4 1/5] hyperv: Introduce new hypercall interfaces used by Hyper-V guest IOMMU

[Michael Kelley]

From: Yu Zhang <zhangyu1@xxxxxxxxxxxxxxxxxxx> Sent: Friday, August 21, 2026 6:27 AM
> 
> Hyper-V guest IOMMU is a para-virtualized IOMMU based on hypercalls.
> Introduce the hypercalls used by the child partition to interact with
> this facility.
> 
> These hypercalls fall into below categories:
> - Detection and capability: HVCALL_GET_IOMMU_CAPABILITIES is used to
>   detect the existence and capabilities of the guest IOMMU.
> 
> - Device management: HVCALL_GET_LOGICAL_DEVICE_PROPERTY is used to
>   check whether an endpoint device is managed by the guest IOMMU.
> 
> - Domain management: A set of hypercalls is provided to handle the
>   creation, configuration, and deletion of guest domains, as well as
>   the attachment/detachment of endpoint devices to/from those domains.
> 
> - IOTLB flushing: HVCALL_FLUSH_DEVICE_DOMAIN is used to ask Hyper-V
>   for a domain-selective IOTLB flush (which in its handler may flush
>   the device TLB as well).
> 
> Signed-off-by: Wei Liu <wei.liu@xxxxxxxxxx>
> Co-developed-by: Easwar Hariharan <easwar.hariharan@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Easwar Hariharan <easwar.hariharan@xxxxxxxxxxxxxxxxxxx>
> Co-developed-by: Yu Zhang <zhangyu1@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Yu Zhang <zhangyu1@xxxxxxxxxxxxxxxxxxx>
> Reviewed-by: Jacob Pan <jacob.pan@xxxxxxxxxxxxxxxxxxx>

Reviewed-by: Michael Kelley <mhklinux@xxxxxxxxxxx>

> ---
>  drivers/hv/hv_common.c      |   1 +
>  include/hyperv/hvgdk_mini.h |   9 +++
>  include/hyperv/hvhdk_mini.h | 137 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 147 insertions(+)