Re: [PATCH for-5.1 4/4] docs/system: Document the arm virt board

["Alex Bennée" <alex.bennee@linaro.org>]

Peter Maydell <peter.maydell@linaro.org> writes:

> Document the arm 'virt' board, which has been undocumented
> for far too long given that it is the main recommended board
> type for arm guests.
>
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  docs/system/arm/virt.rst   | 157 +++++++++++++++++++++++++++++++++++++
>  docs/system/target-arm.rst |   1 +
>  MAINTAINERS                |   1 +
>  3 files changed, 159 insertions(+)
>  create mode 100644 docs/system/arm/virt.rst
>
> diff --git a/docs/system/arm/virt.rst b/docs/system/arm/virt.rst
> new file mode 100644
> index 00000000000..6a7823d8bca
> --- /dev/null
> +++ b/docs/system/arm/virt.rst
> @@ -0,0 +1,157 @@
> +'virt' generic virtual platform (``virt``)
> +==========================================
> +
> +The `virt` board is a platform which does not correspond to any
> +real hardware; it is designed for use in virtual machines.
> +It is the recommended board type if you simply want to run
> +a guest such as Linux and do not care about reproducing the
> +idiosyncrasies and limitations of a particular bit of real-world
> +hardware.
> +
> +This is a "versioned" board model, so as well as the ``virt`` machine
> +type itself (which may have improvements, bugfixes and other minor
> +changes between QEMU versions) a version is provided that guarantees
> +to have the same behaviour as that of previous QEMU releases, so
> +that VM migration will work between QEMU versions. For instance the
> +``virt-5.0`` machine type will behave like the ``virt`` machine from
> +the QEMU 5.0 release, and migration should work between ``virt-5.0``
> +of the 5.0 release and ``virt-5.0`` of the 5.1 release. Migration
> +is not guaranteed to work between different QEMU releases for
> +the non-versioned ``virt`` machine type.
> +
> +Supported devices
> +"""""""""""""""""
> +
> +The virt board supports:
> +
> +- Flash memory
> +- One PL011 UART
> +- An RTC
> +- The fw_cfg device that allows a guest to obtain data from QEMU
> +- A PL061 GPIO controller
> +- An optional SMMUv3 IOMMU
> +- hotpluggable DIMMs
> +- hotpluggable NVDIMs
> +- 32 virtio-mmio transport devices

We seem to miss out we also support the virtio-pci transports here.

Otherwise:

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>


-- 
Alex Bennée