From: poletaev@ispras.ru
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] Can not read SMI handler code with cpu_memory_rw_debug while in SMM
Date: Wed, 28 Aug 2019 14:21:58 +0000 [thread overview]
Message-ID: <51deeefdf33168ff11234ffd96ee646d@rainloop.ispras.ru> (raw)
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.
reply other threads:[~2019-08-28 14:47 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=51deeefdf33168ff11234ffd96ee646d@rainloop.ispras.ru \
--to=poletaev@ispras.ru \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.