On Tue, May 09, 2017 at 08:39:07PM +0000, Xu, Anthony wrote:
I dig into seebios code, and found
ahci_process_op is called with A20 off,
The call trace is,
call32_smm calls call32_prep, but because the method is C16_SMM, A20 is
enabled in call32_prep.
ahci_process_op is called with A20 off.
As I understand it, entering System Managament Mode (SMM) should
automatically enable A20, so it should not be necessary for call32_smm
to enable it. Are you sure the issue is related to A20 instead of
some other issue with SMM?
I'm pretty sure the issue is related to A20, I'm not familiar with Seabios code,
I'm not sure why call32 needs to call32_smm. If my understanding is correct,
VCPU is not in SMM mode at the time.