diff options
| author | Gavin Shan <gshan@redhat.com> | 2022-12-14 14:27:06 +0000 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2022-12-15 11:18:19 +0000 |
| commit | 6a48c64eec355ab1aff694eb4522d07a8e461368 (patch) | |
| tree | 94959e58ef82e66d206d67e27f3b2f2542281c88 /docs | |
| parent | f40408a9fe5d1db70a75a33d2b26c8af8a5d57b0 (diff) | |
hw/arm/virt: Add properties to disable high memory regions
The 3 high memory regions are usually enabled by default, but they may
be not used. For example, VIRT_HIGH_GIC_REDIST2 isn't needed by GICv2.
This leads to waste in the PA space.
Add properties ("highmem-redists", "highmem-ecam", "highmem-mmio") to
allow users selectively disable them if needed. After that, the high
memory region for GICv3 or GICv4 redistributor can be disabled by user,
the number of maximal supported CPUs needs to be calculated based on
'vms->highmem_redists'. The follow-up error message is also improved
to indicate if the high memory region for GICv3 and GICv4 has been
enabled or not.
Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Message-id: 20221029224307.138822-8-gshan@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/system/arm/virt.rst | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/docs/system/arm/virt.rst b/docs/system/arm/virt.rst index 4454706392..188a4f211f 100644 --- a/docs/system/arm/virt.rst +++ b/docs/system/arm/virt.rst @@ -98,6 +98,19 @@ compact-highmem Set ``on``/``off`` to enable/disable the compact layout for high memory regions. The default is ``on`` for machine types later than ``virt-7.2``. +highmem-redists + Set ``on``/``off`` to enable/disable the high memory region for GICv3 or + GICv4 redistributor. The default is ``on``. Setting this to ``off`` will + limit the maximum number of CPUs when GICv3 or GICv4 is used. + +highmem-ecam + Set ``on``/``off`` to enable/disable the high memory region for PCI ECAM. + The default is ``on`` for machine types later than ``virt-3.0``. + +highmem-mmio + Set ``on``/``off`` to enable/disable the high memory region for PCI MMIO. + The default is ``on``. + gic-version Specify the version of the Generic Interrupt Controller (GIC) to provide. Valid values are: |