[v3] hw/arm/virt: Add support for user-creatable accelerated SMMUv3

[RFC PATCH v3 01/15] backends/iommufd: Introduce iommufd_backend_alloc_viommu

Posted by Shameer Kolothum via 4 months ago

From: Nicolin Chen <nicolinc@nvidia.com>

Add a helper to allocate a viommu object.

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       | 25 +++++++++++++++++++++++++
 backends/trace-events    |  1 +
 include/system/iommufd.h |  4 ++++
 3 files changed, 30 insertions(+)

diff --git a/backends/iommufd.c b/backends/iommufd.c
index 2a33c7ab0b..f3b95ee321 100644
--- a/backends/iommufd.c
+++ b/backends/iommufd.c
@@ -446,6 +446,31 @@ bool iommufd_backend_invalidate_cache(IOMMUFDBackend *be, uint32_t id,
     return !ret;
 }
 
+bool iommufd_backend_alloc_viommu(IOMMUFDBackend *be, uint32_t dev_id,
+                                  uint32_t viommu_type, uint32_t hwpt_id,
+                                  uint32_t *out_viommu_id, Error **errp)
+{
+    int ret, fd = be->fd;
+    struct iommu_viommu_alloc alloc_viommu = {
+        .size = sizeof(alloc_viommu),
+        .type = viommu_type,
+        .dev_id = dev_id,
+        .hwpt_id = hwpt_id,
+    };
+
+    ret = ioctl(fd, IOMMU_VIOMMU_ALLOC, &alloc_viommu);
+
+    trace_iommufd_backend_alloc_viommu(fd, viommu_type, dev_id, hwpt_id,
+                                       alloc_viommu.out_viommu_id, ret);
+    if (ret) {
+        error_setg_errno(errp, errno, "IOMMU_VIOMMU_ALLOC failed");
+        return false;
+    }
+
+    *out_viommu_id = alloc_viommu.out_viommu_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 56132d3fd2..2294af2cc8 100644
--- a/backends/trace-events
+++ b/backends/trace-events
@@ -21,3 +21,4 @@ iommufd_backend_free_id(int iommufd, uint32_t id, int ret) " iommufd=%d id=%d (%
 iommufd_backend_set_dirty(int iommufd, uint32_t hwpt_id, bool start, int ret) " iommufd=%d hwpt=%u enable=%d (%d)"
 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)"
diff --git a/include/system/iommufd.h b/include/system/iommufd.h
index c9c72ffc45..9acdb20032 100644
--- a/include/system/iommufd.h
+++ b/include/system/iommufd.h
@@ -59,6 +59,10 @@ bool iommufd_backend_alloc_hwpt(IOMMUFDBackend *be, uint32_t dev_id,
                                 uint32_t data_type, uint32_t data_len,
                                 void *data_ptr, uint32_t *out_hwpt,
                                 Error **errp);
+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_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

Re: [RFC PATCH v3 01/15] backends/iommufd: Introduce iommufd_backend_alloc_viommu

Posted by Jonathan Cameron via 4 months ago

On Mon, 14 Jul 2025 16:59:27 +0100
Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> wrote:

> From: Nicolin Chen <nicolinc@nvidia.com>
> 
> Add a helper to allocate a viommu object.
> 
> 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>

One trivial comment inline. Feel free to ignore.

> ---
>  backends/iommufd.c       | 25 +++++++++++++++++++++++++
>  backends/trace-events    |  1 +
>  include/system/iommufd.h |  4 ++++
>  3 files changed, 30 insertions(+)
> 
> diff --git a/backends/iommufd.c b/backends/iommufd.c
> index 2a33c7ab0b..f3b95ee321 100644
> --- a/backends/iommufd.c
> +++ b/backends/iommufd.c
> @@ -446,6 +446,31 @@ bool iommufd_backend_invalidate_cache(IOMMUFDBackend *be, uint32_t id,
>      return !ret;
>  }
>  
> +bool iommufd_backend_alloc_viommu(IOMMUFDBackend *be, uint32_t dev_id,
> +                                  uint32_t viommu_type, uint32_t hwpt_id,
> +                                  uint32_t *out_viommu_id, Error **errp)
> +{
> +    int ret, fd = be->fd;

Not sure the fd local variable is worth bothering with given be->fd is
very short and you only have a couple of users.

> +    struct iommu_viommu_alloc alloc_viommu = {
> +        .size = sizeof(alloc_viommu),
> +        .type = viommu_type,
> +        .dev_id = dev_id,
> +        .hwpt_id = hwpt_id,
> +    };
> +
> +    ret = ioctl(fd, IOMMU_VIOMMU_ALLOC, &alloc_viommu);
> +
> +    trace_iommufd_backend_alloc_viommu(fd, viommu_type, dev_id, hwpt_id,
> +                                       alloc_viommu.out_viommu_id, ret);
> +    if (ret) {
> +        error_setg_errno(errp, errno, "IOMMU_VIOMMU_ALLOC failed");
> +        return false;
> +    }
> +
> +    *out_viommu_id = alloc_viommu.out_viommu_id;
> +    return true;
> +}

Re: [RFC PATCH v3 01/15] backends/iommufd: Introduce iommufd_backend_alloc_viommu

Posted by Nicolin Chen 4 months ago

On Mon, Jul 14, 2025 at 04:59:27PM +0100, Shameer Kolothum wrote:
> +bool iommufd_backend_alloc_viommu(IOMMUFDBackend *be, uint32_t dev_id,
> +                                  uint32_t viommu_type, uint32_t hwpt_id,
> +                                  uint32_t *out_viommu_id, Error **errp)
> +{
> +    int ret, fd = be->fd;
> +    struct iommu_viommu_alloc alloc_viommu = {
> +        .size = sizeof(alloc_viommu),
> +        .type = viommu_type,
> +        .dev_id = dev_id,
> +        .hwpt_id = hwpt_id,
> +    };
> +
> +    ret = ioctl(fd, IOMMU_VIOMMU_ALLOC, &alloc_viommu);
> +
> +    trace_iommufd_backend_alloc_viommu(fd, viommu_type, dev_id, hwpt_id,
> +                                       alloc_viommu.out_viommu_id, ret);

Let's do "dev_id, viommu_type, hwpt_id, ..." following the sequence
of the inputs from the function.

> +    if (ret) {
> +        error_setg_errno(errp, errno, "IOMMU_VIOMMU_ALLOC failed");
> +        return false;
> +    }
> +
> +    *out_viommu_id = alloc_viommu.out_viommu_id;

Let's add a g_assert(out_viommu_id) in front of this line.

Thanks
Nicolin