From: Nicolin Chen <nicolinc@nvidia.com>

Add a helper to allocate an iommufd device's virtual device (in the user
space) per a viommu instance.

Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
---
 backends/iommufd.c       | 26 ++++++++++++++++++++++++++
 backends/trace-events    |  1 +
 include/system/iommufd.h |  4 ++++
 3 files changed, 31 insertions(+)

diff --git a/backends/iommufd.c b/backends/iommufd.c
index f3b95ee321..0cafa1a4b7 100644
--- a/backends/iommufd.c
+++ b/backends/iommufd.c
@@ -471,6 +471,32 @@ bool iommufd_backend_alloc_viommu(IOMMUFDBackend *be, uint32_t dev_id,
     return true;
 }
 
+bool iommufd_backend_alloc_vdev(IOMMUFDBackend *be, uint32_t dev_id,
+                                uint32_t viommu_id, uint64_t virt_id,
+                                uint32_t *out_vdev_id, Error **errp)
+{
+    int ret, fd = be->fd;
+    struct iommu_vdevice_alloc alloc_vdev = {
+        .size = sizeof(alloc_vdev),
+        .viommu_id = viommu_id,
+        .dev_id = dev_id,
+        .virt_id = virt_id,
+    };
+
+    ret = ioctl(fd, IOMMU_VDEVICE_ALLOC, &alloc_vdev);
+
+    trace_iommufd_backend_alloc_vdev(fd, dev_id, viommu_id, virt_id,
+                                     alloc_vdev.out_vdevice_id, ret);
+
+    if (ret) {
+        error_setg_errno(errp, errno, "IOMMU_VDEVICE_ALLOC failed");
+        return false;
+    }
+
+    *out_vdev_id = alloc_vdev.out_vdevice_id;
+    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 2294af2cc8..14399da111 100644
--- a/backends/trace-events
+++ b/backends/trace-events
@@ -22,3 +22,4 @@ iommufd_backend_set_dirty(int iommufd, uint32_t hwpt_id, bool start, int ret) "
 iommufd_backend_get_dirty_bitmap(int iommufd, uint32_t hwpt_id, uint64_t iova, uint64_t size, uint64_t page_size, int ret) " iommufd=%d hwpt=%u iova=0x%"PRIx64" size=0x%"PRIx64" page_size=0x%"PRIx64" (%d)"
 iommufd_backend_invalidate_cache(int iommufd, uint32_t id, uint32_t data_type, uint32_t entry_len, uint32_t entry_num, uint32_t done_num, uint64_t data_ptr, int ret) " iommufd=%d id=%u data_type=%u entry_len=%u entry_num=%u done_num=%u data_ptr=0x%"PRIx64" (%d)"
 iommufd_backend_alloc_viommu(int iommufd, uint32_t type, uint32_t dev_id, uint32_t hwpt_id, uint32_t viommu_id, int ret) " iommufd=%d type=%u dev_id=%u hwpt_id=%u viommu_id=%u (%d)"
+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)"
diff --git a/include/system/iommufd.h b/include/system/iommufd.h
index 9acdb20032..6ab3ba3cb6 100644
--- a/include/system/iommufd.h
+++ b/include/system/iommufd.h
@@ -63,6 +63,10 @@ bool iommufd_backend_alloc_viommu(IOMMUFDBackend *be, uint32_t dev_id,
                                   uint32_t viommu_type, uint32_t hwpt_id,
                                   uint32_t *out_hwpt, Error **errp);
 
+bool iommufd_backend_alloc_vdev(IOMMUFDBackend *be, uint32_t dev_id,
+                                uint32_t viommu_id, uint64_t virt_id,
+                                uint32_t *out_vdev_id, 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,
-- 
2.34.1

On Mon, 14 Jul 2025 16:59:28 +0100
Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> wrote:

> From: Nicolin Chen <nicolinc@nvidia.com>
> 
> Add a helper to allocate an iommufd device's virtual device (in the user
> space) per a viommu instance.
Same trivial suggestion as in patch 1.  Also feel free to ignore.

On Mon, Jul 14, 2025 at 04:59:28PM +0100, Shameer Kolothum wrote:
> +bool iommufd_backend_alloc_vdev(IOMMUFDBackend *be, uint32_t dev_id,
> +                                uint32_t viommu_id, uint64_t virt_id,
> +                                uint32_t *out_vdev_id, Error **errp)
> +{
> +    int ret, fd = be->fd;
> +    struct iommu_vdevice_alloc alloc_vdev = {
> +        .size = sizeof(alloc_vdev),
> +        .viommu_id = viommu_id,
> +        .dev_id = dev_id,
> +        .virt_id = virt_id,
> +    };
> +
> +    ret = ioctl(fd, IOMMU_VDEVICE_ALLOC, &alloc_vdev);
> +
> +    trace_iommufd_backend_alloc_vdev(fd, dev_id, viommu_id, virt_id,
> +                                     alloc_vdev.out_vdevice_id, ret);
> +
> +    if (ret) {
> +        error_setg_errno(errp, errno, "IOMMU_VDEVICE_ALLOC failed");
> +        return false;
> +    }
> +
> +    *out_vdev_id = alloc_vdev.out_vdevice_id;

g_assert(out_vdev_id);

Thanks
Nicolin