Re: [PATCH V0] iommu/hyperv: Create hyperv subdirectory under iommu

[Yu Zhang]

On Mon, May 25, 2026 at 06:20:37PM -0700, Mukesh R wrote:
> Create hyperv subdirectory under drivers/iommu in anticipation of more
> hyperv related files for upcoming PCI passthru and pv IOMMU patches.
> Also, the current file hyperv-iommu.c actually implements irq remapping,
> so rename to more appropriate hv-irq-remap.c and move it under the new
> hyperv subdirectory. Lastly, this file should not be tied to
> CONFIG_HYPERV_IOMMU, but to CONFIG_HYPERV and CONFIG_IRQ_REMAP.
> 

Thanks for this pathch, Mukesh!

Jason raised a question about whether Hyper-V's IRQ remapping file belongs
under drivers/iommu/hyperv/ at all, since unlike Intel/AMD, Hyper-V's IRQ
remapping is not co-mingled with the IOMMU hardware:

	https://lore.kernel.org/all/20260520133807.GS7702@xxxxxxxx/

Though we don't end up moving it elsewhere (the IRQ remapping framework
and its internal header, irq_remapping.h, live under drivers/iommu/, and
all existing backends sit alongside them), it would be good to acknowledge
this in the commit message and explain the rationale,


> Signed-off-by: Mukesh R <mrathor@xxxxxxxxxxxxxxxxxxx>
> ---
>  MAINTAINERS                                             | 2 +-
>  drivers/iommu/Makefile                                  | 2 +-
>  drivers/iommu/hyperv/Makefile                           | 2 ++
>  drivers/iommu/{hyperv-iommu.c => hyperv/hv-irq-remap.c} | 8 +-------
>  drivers/iommu/irq_remapping.c                           | 2 +-
>  5 files changed, 6 insertions(+), 10 deletions(-)
>  create mode 100644 drivers/iommu/hyperv/Makefile
>  rename drivers/iommu/{hyperv-iommu.c => hyperv/hv-irq-remap.c} (99%)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index d1cc0e12fe1f..b651ee0c6e6b 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -11914,7 +11914,7 @@ F:	drivers/clocksource/hyperv_timer.c
>  F:	drivers/hid/hid-hyperv.c
>  F:	drivers/hv/
>  F:	drivers/input/serio/hyperv-keyboard.c
> -F:	drivers/iommu/hyperv-iommu.c
> +F:	drivers/iommu/hyperv/hv-irq-remap.c
>  F:	drivers/net/ethernet/microsoft/
>  F:	drivers/net/hyperv/
>  F:	drivers/pci/controller/pci-hyperv-intf.c
> diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
> index 0275821f4ef9..d9683422aecb 100644
> --- a/drivers/iommu/Makefile
> +++ b/drivers/iommu/Makefile
> @@ -4,6 +4,7 @@ obj-$(CONFIG_AMD_IOMMU) += amd/
>  obj-$(CONFIG_INTEL_IOMMU) += intel/
>  obj-$(CONFIG_RISCV_IOMMU) += riscv/
>  obj-$(CONFIG_GENERIC_PT) += generic_pt/fmt/
> +obj-$(CONFIG_HYPERV) += hyperv/
>  obj-$(CONFIG_IOMMU_API) += iommu.o
>  obj-$(CONFIG_IOMMU_SUPPORT) += iommu-pages.o
>  obj-$(CONFIG_IOMMU_API) += iommu-traces.o
> @@ -30,7 +31,6 @@ obj-$(CONFIG_TEGRA_IOMMU_SMMU) += tegra-smmu.o
>  obj-$(CONFIG_EXYNOS_IOMMU) += exynos-iommu.o
>  obj-$(CONFIG_FSL_PAMU) += fsl_pamu.o fsl_pamu_domain.o
>  obj-$(CONFIG_S390_IOMMU) += s390-iommu.o
> -obj-$(CONFIG_HYPERV_IOMMU) += hyperv-iommu.o

Any reason why we are removing the CONFIG_HYPERV_IOMMU? You are leaving
CONFIG_HYPERV_IOMMU an orphan configuration now (and also the  backward
compatibility issue?).

>  obj-$(CONFIG_VIRTIO_IOMMU) += virtio-iommu.o
>  obj-$(CONFIG_IOMMU_SVA) += iommu-sva.o
>  obj-$(CONFIG_IOMMU_IOPF) += io-pgfault.o

B.R.
Yu