tree aaf35e40a351cc1d945129af8d19a27750f8df2c
parent cbfe4ba76ad9d9f43bef2c366b180c5d594a0703
author Patrick Rudolph <patrick.rudolph@9elements.com> 1610025158 +0100
committer Patrick Georgi <pgeorgi@google.com> 1610350459 +0000

mb/emulation/qemu: Copy page tables to DRAM in assembly

To work around various bugs running KVM enabled, copy page tables to
DRAM in assembly before jumping to x86_64 mode.

Tested on QEMU using KVM, no more stange bugs happen:
Tested on host
 - CPU Intel(R) Core(TM) i7-7700HQ
 - Linux 5.9
 - qemu 4.2.1
 Used to crash on emulating MMX instructions and failed to translate
 some addresses using the virtual MMU when running in long mode.

Tested on host
 - CPU AMD EPYC 7401P 24-Core Processor
 - Linux 5.4
 - qemu 4.2.1
 Used to crash on jumping to long mode.

Change-Id: Ic0bdd2bef7197edd2e7488a8efdeba7eb4ab0dd4
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49228
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>