Patrick Rudolph uploaded patch set #16 to this change.
cpu/x86/smm: Add support for long mode
Enable long mode in SMM handler.
x86_32 isn't affected by this change.
As the rsm instruction used to leave SMM doesn't restore MSR registers,
drop back to protected mode after running the smi_handler and restore
IA32_EFER MSR (which enables long mode support) to previous value.
NOTE: This commit does NOT introduce a new security model. It uses the same
page tables as the remaining firmware does.
This can be a security risk if someone is able to manipulate the
page tables stored in ROM at runtime. USE FOR TESTING ONLY!
Tested on Qemu Q35.
Change-Id: I8bba4af4688c723fc079ae905dac95f57ea956f8
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
---
M Documentation/arch/x86/index.md
A src/cpu/x86/64bit/exit32.inc
M src/cpu/x86/smm/smmhandler.S
3 files changed, 130 insertions(+), 1 deletion(-)
git pull ssh://review.coreboot.org:29418/coreboot refs/changes/81/35681/16
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