On 2/6/26 3:48 PM, Shameer Kolothum wrote:
> From: Nicolin Chen <[email protected]>
>
> Add a backend helper to mmap hardware MMIO regions exposed via iommufd for
> a vIOMMU instance. This allows user space to access HW-accelerated MMIO
> pages provided by the vIOMMU.
>
> The caller is responsible for unmapping the returned region.
>
> Signed-off-by: Nicolin Chen <[email protected]>
> Reviewed-by: Eric Auger <[email protected]>
> Signed-off-by: Shameer Kolothum <[email protected]>
> ---
> backends/iommufd.c | 22 ++++++++++++++++++++++
> backends/trace-events | 1 +
> include/system/iommufd.h | 4 ++++
> 3 files changed, 27 insertions(+)
>
> diff --git a/backends/iommufd.c b/backends/iommufd.c
> index c6b79da0d4..9e30501d38 100644
> --- a/backends/iommufd.c
> +++ b/backends/iommufd.c
> @@ -578,6 +578,28 @@ bool iommufd_backend_alloc_hw_queue(IOMMUFDBackend *be,
> uint32_t viommu_id,
> return true;
> }
>
> +/*
> + * Helper to mmap HW MMIO regions exposed via iommufd for a vIOMMU instance.
> + * The caller is responsible for unmapping the mapped region.
> + */
> +bool iommufd_backend_viommu_mmap(IOMMUFDBackend *be, uint32_t viommu_id,
> + uint64_t size, off_t offset, void **out_ptr,
> + Error **errp)
Looking at this again, there is nothing really related to iommufd. This
could simply end up as a static helper in tegra241-cmdqv.c
Eric
> +{
> + g_assert(viommu_id);
> + g_assert(out_ptr);
> +
> + *out_ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, be->fd,
> + offset);
> + trace_iommufd_backend_viommu_mmap(be->fd, viommu_id, size, offset);
> + if (*out_ptr == MAP_FAILED) {
> + error_setg_errno(errp, errno, "IOMMUFD vIOMMU mmap failed");
> + return false;
> + }
> +
> + return true;
> +}
> +
> bool host_iommu_device_iommufd_attach_hwpt(HostIOMMUDeviceIOMMUFD *idev,
> uint32_t hwpt_id, Error **errp)
> {
> diff --git a/backends/trace-events b/backends/trace-events
> index 3e70338750..f824a8d197 100644
> --- a/backends/trace-events
> +++ b/backends/trace-events
> @@ -25,6 +25,7 @@ iommufd_backend_alloc_viommu(int iommufd, uint32_t dev_id,
> uint32_t type, uint32
> iommufd_backend_alloc_vdev(int iommufd, uint32_t dev_id, uint32_t viommu_id,
> uint64_t virt_id, uint32_t vdev_id, int ret) " iommufd=%d dev_id=%u
> viommu_id=%u virt_id=0x%"PRIx64" vdev_id=%u (%d)"
> iommufd_viommu_alloc_eventq(int iommufd, uint32_t viommu_id, uint32_t type,
> uint32_t veventq_id, uint32_t veventq_fd, int ret) " iommufd=%d viommu_id=%u
> type=%u veventq_id=%u veventq_fd=%u (%d)"
> iommufd_backend_alloc_hw_queue(int iommufd, uint32_t viommu_id, uint32_t
> queue_type, uint32_t index, uint64_t addr, uint64_t size, uint32_t queue_id,
> int ret) " iommufd=%d viommu_id=%u queue_type=%u index=%u addr=0x%"PRIx64"
> size=0x%"PRIx64" queue_id=%u (%d)"
> +iommufd_backend_viommu_mmap(int iommufd, uint32_t viommu_id, uint64_t size,
> uint64_t offset) " iommufd=%d viommu_id=%u size=0x%"PRIx64" offset=0x%"PRIx64
>
> # igvm-cfg.c
> igvm_reset_enter(int type) "type=%u"
> diff --git a/include/system/iommufd.h b/include/system/iommufd.h
> index f72ad545f8..87ddc39041 100644
> --- a/include/system/iommufd.h
> +++ b/include/system/iommufd.h
> @@ -111,6 +111,10 @@ bool iommufd_backend_alloc_hw_queue(IOMMUFDBackend *be,
> uint32_t viommu_id,
> uint64_t length, uint32_t
> *out_hw_queue_id,
> Error **errp);
>
> +bool iommufd_backend_viommu_mmap(IOMMUFDBackend *be, uint32_t viommu_id,
> + uint64_t size, off_t offset, void **out_ptr,
> + Error **errp);
> +
> bool iommufd_backend_set_dirty_tracking(IOMMUFDBackend *be, uint32_t hwpt_id,
> bool start, Error **errp);
> bool iommufd_backend_get_dirty_bitmap(IOMMUFDBackend *be, uint32_t hwpt_id,
