Re: [PATCH 3/4] driver: provide sysfs interfaces to access TXT log

[Matthew Garrett]

On Thu, 2013-05-09 at 08:05 +0000, Ren, Qiaowei wrote:
> On 2013-05-08, Matthew Garrett wrote:
> > How different are these logs to the TPM measurements exported via
> > securityfs?
> 
> These logs come from tboot (Trusted Boot, an open source, pre-kernel/VMM module that uses Intel Trusted Execution Technology (Intel TXT) to perform a measured and verified launch of an OS kernel/VMM.), and should be different from those TPM measurements (from BIOS?) exported via security.

Different in what way? What are they actually logging?

> > So I write a value here and then I see different chunks of log? This
> > doesn't seem like an optimal interface. What do these logs actually
> > contain? How do I know which block I should be reading?
> 
> Yes. Since total log size is bigger than one page 4K, the log have to be displayed in 4K-block indexed by block_index.
> These logs will be very helpful for txt related debugging.

If they're only intended for debugging then sysfs probably isn't the
best place for them. debugfs might make more sense.

-- 
Matthew Garrett | mjg59@xxxxxxxxxxxxx
N‹§²æìr¸›yúèšØb²X¬¶ÇvØ^–)Þ{.nÇ+‰·¥Š{±‘êçzX§¶›¡Ü}©ž²ÆzÚ&j:+v‰¨¾«‘êçzZ+€Ê+zf£¢·hšˆ§~†­†Ûiÿûàz¹®w¥¢¸?™¨è­Ú&¢)ßf”ù^jÇy§m…á@A«a¶Úÿ0¶ìh®å’i