On 12/10/25 2:37 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]> > Signed-off-by: Shameer Kolothum <[email protected]> Reviewed-by: Eric Auger <[email protected]> Eric > --- > backends/iommufd.c | 24 ++++++++++++++++++++++++ > backends/trace-events | 1 + > include/system/iommufd.h | 4 ++++ > 3 files changed, 29 insertions(+) > > diff --git a/backends/iommufd.c b/backends/iommufd.c > index a644763239..015e5249d6 100644 > --- a/backends/iommufd.c > +++ b/backends/iommufd.c > @@ -575,6 +575,30 @@ 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) > +{ > + g_assert(viommu_id); > + g_assert(out_ptr); > + > + *out_ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, be->fd, > + offset); > + if (*out_ptr == MAP_FAILED) { > + error_setg_errno(errp, errno, "failed to mmap (size=0x%" PRIx64 > + " offset=0x%" PRIx64 ") for viommu (id=%d)", > + size, offset, viommu_id); > + return false; > + } > + > + trace_iommufd_backend_viommu_mmap(be->fd, viommu_id, size, offset); > + 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 a22ad30e55..046f453caa 100644 > --- a/backends/trace-events > +++ b/backends/trace-events > @@ -25,3 +25,4 @@ 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 > vqueue_type, uint32_t index, uint64_t addr, uint64_t size, uint32_t > vqueue_id, int ret) " iommufd=%d viommu_id=%u vqueue_type=%u index=%u > addr=0x%"PRIx64" size=0x%"PRIx64" vqueue_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 > diff --git a/include/system/iommufd.h b/include/system/iommufd.h > index 9b8602a558..e3905c9a40 100644 > --- a/include/system/iommufd.h > +++ b/include/system/iommufd.h > @@ -110,6 +110,10 @@ bool iommufd_backend_alloc_hw_queue(IOMMUFDBackend *be, > uint32_t viommu_id, > uint64_t addr, 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,
