Re: [PATCH v3] hw/riscv: virt: Assume M-mode FW in pflash0 only when "-bios none"

[Andrea Bolognani]

On Wed, May 24, 2023 at 11:03:52PM +0530, Sunil V L wrote:
> On Wed, May 24, 2023 at 03:50:34PM +0000, Andrea Bolognani wrote:
> > First off, the only RISC-V edk2 build readily accessible to me (from
> > the edk2-riscv64 Fedora package) is configured to work off a R/W
> > pflash1. You said that you have edk2 patches making R/O CODE pflash0
> > and R/W VARS pflash1 ready. Any chance you could make either the
> > build output, or the patches and some hints on how to build edk2
> > after applying them, somewhere?
>
> Please build EDK2 using the branch
> https://github.com/vlsunil/edk2/tree/separate_code_vars.
>
> The instructions to build is in
> https://github.com/vlsunil/riscv-uefi-edk2-docs/wiki/RISC-V-Qemu-Virt-support#build-edk2
>
> However, now it will create two images for code and vars.

Following your pointers, I was able to build suitable edk2 images and
verify that they work with a patched QEMU, so

  Tested-by: Andrea Bolognani <abologna@redhat.com>

Note, however, that said testing was limited to verifying that edk2
would come up.

I have also tried booting an openSUSE Tumbleweed "JeOS" image, since
that's the only distro I'm aware of that uses UEFI boot on RISC-V at
this point - though they use U-Boot's UEFI support rather than edk2.

During that attempt, I ended up in the edk2 shell. Running

  fs0:\efi\boot\bootriscv64.efi

brings up GRUB just fine, but selecting the default boot entry
results in

  Loading Linux 6.3.2-1-default ...
  Loading initial ramdisk ...
  EFI stub: Booting Linux Kernel...
  EFI stub: Loaded initrd from LINUX_EFI_INITRD_MEDIA_GUID device path
  EFI stub: Generating empty DTB
  EFI stub: Exiting boot services...

being printed, after which it's back to OpenSBI and from there to
edk2 again.

I feel that this has probably more to do with the way the openSUSE
image has been built than edk2, but I thought I'd report my
experience nonetheless in case there's any useful information that
can be gathered from it :)

> > Going further and testing libvirt integration. After hacking around
> > other issues, I finally stumbled upon this error:
> >
> >   qemu-system-riscv64: Property 'virt-machine.pflash0' not found
>
> Thanks!. This needs some investigation. Let me look into supporting
> this.

Yes please! It's critical to libvirt integration. Feel free to CC me
when you post patches and I'll gladly test them.

-- 
Andrea Bolognani / Red Hat / Virtualization