From: Jamie Lokier <jamie@shareable.org>
To: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] How to get guestOS's information
Date: Thu, 26 Oct 2006 23:08:55 +0100 [thread overview]
Message-ID: <20061026220855.GA7264@mail.shareable.org> (raw)
In-Reply-To: <1161900005.29751.60.camel@localhost.localdomain>
maestro wrote:
> You might want to consider useing the Page Directory Base Register (PDBR
> aka cr3 or in qemu-x86 env->cr[3]) to idenify differnet processes. afaik
> it is then OS-dependant how to get the corresponding PID. I did this for
> windows and i assume it's a lot easier to do the same for linux/*BSD (as
> the source is available). Since you probably will need to check for the
> current process quite often, the shorter access times for this
> information might come in handy.
Good idea.
However, on Linux cr3 is not updated for every process. Specifically,
it is not updated for kernel threads which don't have any user-space
mappings of their own. This is to avoid unnecessary TLB flushes.
-- Jamie
prev parent reply other threads:[~2006-10-26 22:09 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-10-26 7:23 [Qemu-devel] How to get guestOS's information KazuyaMatsunaga
2006-10-26 16:21 ` Rob Landley
2006-10-26 17:53 ` andrzej zaborowski
2006-10-26 18:06 ` andrzej zaborowski
2006-10-26 22:00 ` maestro
2006-10-26 22:08 ` Jamie Lokier [this message]
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