[PATCH v4 00/47] x86: Improve operation under QEMU

[Simon Glass]

Hi Tom,

On Fri, 7 Mar 2025 at 14:23, Tom Rini <trini at konsulko.com> wrote:
>
> On Thu, Mar 06, 2025 at 09:03:27AM -0700, Simon Glass wrote:
>
> > U-Boot can start and boot an OS in both qemu-x86 and qemu-x86_64 but it
> > is not perfect.
> >
> > With both builds, executing the VESA ROM causes an intermittent hang, at
> > least on some AMD CPUs.
> >
> > With qemu-x86_64 kvm cannot be used since the move to long mode (64-bit)
> > is done in a way that works on real hardware but not with QEMU. This
> > means that performance is 4-5x slower than it could be, at least on my
> > CPU.
> >
> > We can work around the first problem by using Bochs, which is anyway a
> > better choice than VESA for QEMU. The second can be addressed by using
> > the same descriptor across the jump to long mode.
> >
> > With an MTRR fix this allows booting into Ubuntu on qemu-x86_64
> >
> > In v3 some e820 patches are included to make booting reliable and avoid
> > ACPI tables being dropped. Also, several MTTR problems are addressed, to
> > support memory sizes above 4GB reliably.
>
> Do you plan to rebase the prerequisite series' this requires so that it
> can be merged?

Here's my understanding of where things are:

1. You rejected the membuf series and my replies to try to resolve
that haven't gone anywhere yet. So your tree doesn't have any tests
for that code and still has the old naming.

2. I sent the first part of the PXE series so you could apply that.

3. You rejected the second part of this series because it didn't
include support for lwip without cmdline. I offered to handle that
case later but I'm pretty sure you rejected that too.

4. This series is now marked 'changes requested' but the only feedback
I see is in the RFC patch.

Regards,
Simon