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authorPatrick Rudolph <patrick.rudolph@9elements.com>2021-01-07 14:12:38 +0100
committerPatrick Georgi <pgeorgi@google.com>2021-01-11 07:34:19 +0000
commit82e111cc2a8795cefca36e57031d3d2da0f919aa (patch)
treeaaf35e40a351cc1d945129af8d19a27750f8df2c /src/mainboard/emulation/qemu-q35/mainboard.c
parentcbfe4ba76ad9d9f43bef2c366b180c5d594a0703 (diff)
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>
Diffstat (limited to 'src/mainboard/emulation/qemu-q35/mainboard.c')
-rw-r--r--src/mainboard/emulation/qemu-q35/mainboard.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/src/mainboard/emulation/qemu-q35/mainboard.c b/src/mainboard/emulation/qemu-q35/mainboard.c
index d329e5affb..c88874f4f2 100644
--- a/src/mainboard/emulation/qemu-q35/mainboard.c
+++ b/src/mainboard/emulation/qemu-q35/mainboard.c
@@ -44,6 +44,12 @@ static void qemu_nb_read_resources(struct device *dev)
/* reserve mmconfig */
fixed_mem_resource(dev, 2, CONFIG_MMCONF_BASE_ADDRESS >> 10, 0x10000000 >> 10,
IORESOURCE_RESERVE);
+
+ if (CONFIG(ARCH_RAMSTAGE_X86_64)) {
+ /* Reserve page tables in DRAM. FIXME: Remove once x86_64 page tables reside in CBMEM */
+ reserved_ram_resource(dev, 0, CONFIG_ARCH_X86_64_PGTBL_LOC / KiB,
+ (6 * 0x1000) / KiB);
+ }
}