[PATCH v2 00/28] x86: Improve operation under QEMU

[Tom Rini]

On Sun, Feb 16, 2025 at 01:43:45PM -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

This seems needlessly not against mainline.

-- 
Tom
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 659 bytes
Desc: not available
URL: <https://lists.denx.de/pipermail/u-boot/attachments/20250216/85aec9c5/attachment.sig>