Re: [Qemu-devel] [edk2] syslinux vs. OVMF

[Laszlo Ersek <lersek@redhat.com>]

On 04/10/15 10:14, Gerd Hoffmann wrote:
>   Hi,
> 
>> In summary, please ask Gerd to rebuild the ipxe binaries that are
>> bundled with upstream qemu such that they include those two iPXE patches
>> of ours (see the last reference).
> 
> https://www.kraxel.org/cgit/qemu/log/?h=rebase/roms-next
> 
> Can you give this a try?

Thank you for this update, I tested it.

(1) I reproduced the issue, so that I could be sure that the fix wasn't
meaningless. Indeed the bug reproduces with the iPXE binaries bundled
with upstream qemu.

I then checked out, built and installed your branch, and tried again,
with virtio-net and then e1000.

(2) Virito-net results:
- OVMF        loads shim.efi    via network
- shim.efi    loads grubx64.efi via network
- grubx64.efi loads grub.cfg    via network
- grubx64.efi loads vmlinuz     via network

However, while grubx64.efi loads initrd.img via the network, qemu
crashes the guest, with the following message:

qemu-system-x86_64: Guest moved used index from 46499 to 65534

This is a virtio protocol bug in the guest (efi-virtio.rom), *or* in
QEMU. I don't know.

* e1000 results:
- OVMF        loads shim.efi    via network
- shim.efi    loads grubx64.efi via network
- grubx64.efi loads grub.cfg    via network
- grubx64.efi loads vmlinuz     via network
- grubx64.efi loads initrd.img  via network
- guest kernel boots

So, I think the update is fine in general; but maybe there's a new
virtio-related bug in either "efi-virtio.rom" or in QEMU.

(When I originally wrote the (earlier versions of the) patches, I tested
them with virtio-net using RHEL-7 qemu, so I guess this could be an
upstream QEMU regression. The machine type I used for testing was
pc-i440fx-2.3.)

(3) ... Confirmed, this is a qemu regression. Namely, I checked your new
efi-virtio.rom with RHEL-7 qemu, and it works fine. CC'ing qemu-devel.

(4) Independently -- can you please update the commit message on
"roms/ipxe-patches/0002-efi-make-load-file-protocol-optional.patch"?

The code is indeed all yours in that patch, but I did the initial
analysis and the first fix. Can you please add a Suggested-by, and
reference (or even: include) the analysis in
<http://lists.ipxe.org/pipermail/ipxe-devel/2015-February/003979.html>?

Thanks!
Laszlo