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doc: update recommended IOVA mode for async vhost

PATCH Applied Xuan Ding 2 participants 3 messages Nov 22, 2021 – Feb 8, 2022

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Xuan Ding

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#0 lore raw

PATCH 1/1 doc: update recommended IOVA mode for async vhost

DPDK 21.11 adds vfio support for DMA device in vhost. This patch updates recommended IOVA mode in async datapath.

---
 doc/guides/prog_guide/vhost_lib.rst | 9 +++++++++
 1 file changed, 9 insertions(+)
doc/guides/prog_guide/vhost_lib.rst +9 -0
index 76f5d303c9..f72ce75909 100644
@@ -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
Signature · 1 line
2.17.1
Reviewed-by on v1 1/1
#1 lore raw
Quoted 16 lines · Xuan Ding

DPDK 21.11 adds vfio support for DMA device in vhost. This patch updates recommended IOVA mode in async datapath.

---
  doc/guides/prog_guide/vhost_lib.rst | 9 +++++++++
  1 file changed, 9 insertions(+)
doc/guides/prog_guide/vhost_lib.rst +0 -0
index 76f5d303c9..f72ce75909 100644
@@ -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.

doc/guides/prog_guide/vhost_lib.rst Finally, a set of device ops is defined for device specific operations: · line 453

Quoted 10 lines
doc/guides/prog_guide/vhost_lib.rst +9 -0
+
+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

Thanks,
Maxime

#2 lore raw
In reply to Xuan Ding
Quoted 16 lines · Xuan Ding

DPDK 21.11 adds vfio support for DMA device in vhost. This patch updates recommended IOVA mode in async datapath.

---
  doc/guides/prog_guide/vhost_lib.rst | 9 +++++++++
  1 file changed, 9 insertions(+)
doc/guides/prog_guide/vhost_lib.rst +0 -0
index 76f5d303c9..f72ce75909 100644
@@ -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.

doc/guides/prog_guide/vhost_lib.rst Finally, a set of device ops is defined for device specific operations: · line 453

Quoted 10 lines
doc/guides/prog_guide/vhost_lib.rst +9 -0
+
+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