We are missing an entry for the virtio-iommu-pci device. Add the
information on which machine it is currently supported and document
the new aw-bits option.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
---
 qemu-options.hx | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/qemu-options.hx b/qemu-options.hx
index 8547254dbf..6a8c970640 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -1172,6 +1172,14 @@ SRST
     Please also refer to the wiki page for general scenarios of VT-d
     emulation in QEMU: https://wiki.qemu.org/Features/VT-d.
 
+``-device virtio-iommu-pci[,option=...]``
+    This is only supported by ``-machine q35`` and ``-machine virt``.
+    It supports below options:
+
+    ``aw-bits=val`` (val between 32 and 64, default depends on machine)
+        This decides the address width of IOVA address space. With
+        q35 it defaults to 39 bits. On arm virt it defaults to 48 bits.
+
 ERST
 
 DEF("name", HAS_ARG, QEMU_OPTION_name,
-- 
2.41.0

On 2/13/24 19:28, Eric Auger wrote:
> We are missing an entry for the virtio-iommu-pci device. Add the
> information on which machine it is currently supported and document
> the new aw-bits option.
> 
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> ---
>   qemu-options.hx | 8 ++++++++
>   1 file changed, 8 insertions(+)
> 
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 8547254dbf..6a8c970640 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -1172,6 +1172,14 @@ SRST
>       Please also refer to the wiki page for general scenarios of VT-d
>       emulation in QEMU: https://wiki.qemu.org/Features/VT-d.
>   
> +``-device virtio-iommu-pci[,option=...]``
> +    This is only supported by ``-machine q35`` and ``-machine virt``.
> +    It supports below options:
> +
> +    ``aw-bits=val`` (val between 32 and 64, default depends on machine)
> +        This decides the address width of IOVA address space. With
> +        q35 it defaults to 39 bits. On arm virt it defaults to 48 bits.


Minor improvement :

  "It defaults to 39 bits on q35 machines and 48 bits on ARM virt machines."

Anyhow,

Reviewed-by: Cédric Le Goater <clg@redhat.com>

Thanks,

C.