gve: update gve.rst
Add a note about QPL and RDA mode
BUG=b/291799463
cos-patch: bug
Change-Id: I0173819797840c19325caa9181238343dd89eca5
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/54470
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Main-Branch-Verified: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Oleksandr Tymoshenko <ovt@google.com>
diff --git a/Documentation/networking/device_drivers/ethernet/google/gve.rst b/Documentation/networking/device_drivers/ethernet/google/gve.rst
index 6d73ee7..31d621b 100644
--- a/Documentation/networking/device_drivers/ethernet/google/gve.rst
+++ b/Documentation/networking/device_drivers/ethernet/google/gve.rst
@@ -52,6 +52,15 @@
GVE supports two descriptor formats: GQI and DQO. These two formats have
entirely different descriptors, which will be described below.
+Addressing Mode
+------------------
+GVE supports two addressing modes: QPL and RDA.
+QPL ("queue-page-list") mode communicates data through a set of
+pre-registered pages.
+
+For RDA ("raw DMA addressing") mode, the set of pages is dynamic.
+Therefore, the packet buffers can be anywhere in guest memory.
+
Registers
---------
All registers are MMIO.
