Re: [edk2-devel] [PATCH v2 18/19] OvmfPkg/Microvm: add README

["Yao, Jiewen" <jiewen.yao@intel.com>]

Acked-by: Jiewen Yao <Jiewen.yao@intel.com>

> -----Original Message-----
> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Gerd
> Hoffmann
> Sent: Friday, September 3, 2021 8:56 PM
> To: devel@edk2.groups.io
> Cc: Gerd Hoffmann <kraxel@redhat.com>
> Subject: [edk2-devel] [PATCH v2 18/19] OvmfPkg/Microvm: add README
> 
> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3599
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  OvmfPkg/Microvm/README | 54
> ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 54 insertions(+)
>  create mode 100644 OvmfPkg/Microvm/README
> 
> diff --git a/OvmfPkg/Microvm/README b/OvmfPkg/Microvm/README
> new file mode 100644
> index 000000000000..78c2b53318de
> --- /dev/null
> +++ b/OvmfPkg/Microvm/README
> @@ -0,0 +1,54 @@
> +
> +This is an *experimental* port of OVMF for the qemu microvm
> +machine type.
> +
> +microvm background info
> +-----------------------
> +
> +microvm is designed for modern, virtio-based workloads.  Most legacy
> +lpc/isa devices like pit and pic can be turned off.  virtio-mmio
> +(i.e. '-device virtio-{blk,net,scsi,...}-device') is used for
> +storage/network/etc.
> +
> +Optional pcie support is available and any pcie device supported by
> +qemu can be plugged in (including virtio-pci if you prefer that over
> +virtio-mmio).
> +
> +https://qemu.readthedocs.io/en/latest/system/i386/microvm.html
> +https://www.kraxel.org/blog/2020/10/qemu-microvm-acpi/
> +
> +design issues
> +-------------
> +
> +Not fully clear yet how to do hardware detection best.  Right now
> +using device tree to find virtio-mmio devices and pcie host bridge,
> +can reuse existing ArmVirtPkg code that way.  Needs patched qemu.
> +
> +features
> +--------
> + [working] serial console
> + [working] direct kernel boot
> + [in progress] virtio-mmio support
> + [in progress] pcie support
> +
> +known limitations
> +-----------------
> + * rtc=on is required for now.
> + * can't use separate code/vars (actually an microvm limitation,
> +   there is no pflash support).
> + * transitional virtio-pci devices do not work.  microvm doesn't
> +   support ioports on pcie, and ovmf doesn't initialize pcie devices
> +   with ioports if there is no address space for them (even though
> +   pcie devices are required to be functional without ioports).
> +
> +known bugs
> +----------
> + * timer has wrong frequency (running fast on my hardware).
> +
> +usage
> +-----
> +qemu-system-x86_64 \
> +    -nographic \
> +    -machine microvm,acpi=on,pit=off,pic=off,rtc=on \
> +    -bios /path/to/MICROVM.fd \
> +    [ ... more args here ... ]
> --
> 2.31.1
> 
> 
> 
> 
>