doc: update recommended IOVA mode for async vhost

Message ID 20211122084948.39382-1-xuan.ding@intel.com (mailing list archive)
State Accepted, archived
Delegated to: Maxime Coquelin
Headers
Series doc: update recommended IOVA mode for async vhost |

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Commit Message

Ding, Xuan Nov. 22, 2021, 8:49 a.m. UTC
  DPDK 21.11 adds vfio support for DMA device in vhost. This patch
updates recommended IOVA mode in async datapath.

Signed-off-by: Xuan Ding <xuan.ding@intel.com>
---
 doc/guides/prog_guide/vhost_lib.rst | 9 +++++++++
 1 file changed, 9 insertions(+)
  

Comments

Maxime Coquelin Jan. 31, 2022, 8:41 a.m. UTC | #1
On 11/22/21 09:49, Xuan Ding wrote:
> DPDK 21.11 adds vfio support for DMA device in vhost. This patch
> updates recommended IOVA mode in async datapath.
> 
> Signed-off-by: Xuan Ding <xuan.ding@intel.com>
> ---
>   doc/guides/prog_guide/vhost_lib.rst | 9 +++++++++
>   1 file changed, 9 insertions(+)
> 
> diff --git a/doc/guides/prog_guide/vhost_lib.rst b/doc/guides/prog_guide/vhost_lib.rst
> index 76f5d303c9..f72ce75909 100644
> --- a/doc/guides/prog_guide/vhost_lib.rst
> +++ b/doc/guides/prog_guide/vhost_lib.rst
> @@ -442,3 +442,12 @@ Finally, a set of device ops is defined for device specific operations:
>   * ``get_notify_area``
>   
>     Called to get the notify area info of the queue.
> +
> +Recommended IOVA mode in async datapath
> +---------------------------------------
> +
> +When DMA devices are bound to vfio driver, VA mode is recommended.
> +For PA mode, page by page mapping may exceed IOMMU's max capability,
> +better to use 1G guest hugepage.
> +
> +For uio driver, any vfio related error message can be ignored.
> \ No newline at end of file

Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Thanks,
Maxime
  
Maxime Coquelin Feb. 8, 2022, 11:10 a.m. UTC | #2
On 11/22/21 09:49, Xuan Ding wrote:
> DPDK 21.11 adds vfio support for DMA device in vhost. This patch
> updates recommended IOVA mode in async datapath.
> 
> Signed-off-by: Xuan Ding <xuan.ding@intel.com>
> ---
>   doc/guides/prog_guide/vhost_lib.rst | 9 +++++++++
>   1 file changed, 9 insertions(+)
> 
> diff --git a/doc/guides/prog_guide/vhost_lib.rst b/doc/guides/prog_guide/vhost_lib.rst
> index 76f5d303c9..f72ce75909 100644
> --- a/doc/guides/prog_guide/vhost_lib.rst
> +++ b/doc/guides/prog_guide/vhost_lib.rst
> @@ -442,3 +442,12 @@ Finally, a set of device ops is defined for device specific operations:
>   * ``get_notify_area``
>   
>     Called to get the notify area info of the queue.
> +
> +Recommended IOVA mode in async datapath
> +---------------------------------------
> +
> +When DMA devices are bound to vfio driver, VA mode is recommended.
> +For PA mode, page by page mapping may exceed IOMMU's max capability,
> +better to use 1G guest hugepage.
> +
> +For uio driver, any vfio related error message can be ignored.
> \ No newline at end of file

Applied to dpdk-next-virtio/main.

Thanks,
Maxime
  

Patch

diff --git a/doc/guides/prog_guide/vhost_lib.rst b/doc/guides/prog_guide/vhost_lib.rst
index 76f5d303c9..f72ce75909 100644
--- a/doc/guides/prog_guide/vhost_lib.rst
+++ b/doc/guides/prog_guide/vhost_lib.rst
@@ -442,3 +442,12 @@  Finally, a set of device ops is defined for device specific operations:
 * ``get_notify_area``
 
   Called to get the notify area info of the queue.
+
+Recommended IOVA mode in async datapath
+---------------------------------------
+
+When DMA devices are bound to vfio driver, VA mode is recommended.
+For PA mode, page by page mapping may exceed IOMMU's max capability,
+better to use 1G guest hugepage.
+
+For uio driver, any vfio related error message can be ignored.
\ No newline at end of file