* [Qemu-devel] Can not read SMI handler code with cpu_memory_rw_debug while in SMM
@ 2019-08-28 14:21 poletaev
0 siblings, 0 replies; only message in thread
From: poletaev @ 2019-08-28 14:21 UTC (permalink / raw)
To: qemu-devel
I am using OVMF2018 (https://github.com/tianocore/tianocore.github.io/wiki/OVMF) build with smm functionality. Run qemu with "-machine smm=on" option.
When SMI handler starts working, cpu_memory_rw_debug() function reads from tseg_blackhole device mem and function returns ffff... instead of actual data.
Same situation when using remote gdb debugging, guess because cpu_memory_rw_debug() is in use also.
But code of SMI handler executes normally, so cpu can access actual data and not tseg_blackhole.
Can anybody explain please, what is the difference in this context between, for example, x86_ldub_code() and cpu_memory_rw_debug()?
Is such behavior intended? (guess no)
What is tseg at all? I can't find similar terminology in intel manuals.
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2019-08-28 14:21 [Qemu-devel] Can not read SMI handler code with cpu_memory_rw_debug while in SMM poletaev
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