[PATCH 3/3] docs/system/arm/virt: Fix documentation for the 'highmem' option

[Marc Zyngier <maz@kernel.org>]

The documentation for the 'highmem' option indicates that it controls
the placement of both devices and RAM. The actual behaviour of QEMU
seems to be that RAM is allowed to go beyond the 4GiB limit, and
that only devices are constraint by this option.

Align the documentation with the actual behaviour.

Cc: Andrew Jones <drjones@redhat.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 docs/system/arm/virt.rst | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/docs/system/arm/virt.rst b/docs/system/arm/virt.rst
index 59acf0eeaf..e206e7565d 100644
--- a/docs/system/arm/virt.rst
+++ b/docs/system/arm/virt.rst
@@ -86,9 +86,9 @@ mte
   Arm Memory Tagging Extensions. The default is ``off``.
 
 highmem
-  Set ``on``/``off`` to enable/disable placing devices and RAM in physical
-  address space above 32 bits. The default is ``on`` for machine types
-  later than ``virt-2.12``.
+  Set ``on``/``off`` to enable/disable placing devices in physical address
+  space above 32 bits. RAM in excess of 3GiB will always be placed above
+  32 bits. The default is ``on`` for machine types later than ``virt-2.12``.
 
 gic-version
   Specify the version of the Generic Interrupt Controller (GIC) to provide.
-- 
2.30.2