qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [PATCH V27 1/7] Support for TPM command line options


From: Stefan Berger
Subject: Re: [Qemu-devel] [PATCH V27 1/7] Support for TPM command line options
Date: Tue, 19 Mar 2013 10:49:07 -0400
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120911 Thunderbird/15.0.1

On 03/19/2013 10:28 AM, Markus Armbruster wrote:
Stefan Berger <address@hidden> writes:


I can write an OS that sends a command to the TPM and then shuts down
without waiting for the program to terminate or the even the response
from the TPM to come back . In this case we would need to cancel the
command on exit()l.
Aha, now we're getting somewhere.

Are you talking about the following scenario?

* Guest sends TPM command, QEMU passes it through, QEMU thread blocks in
   write() to TPM.

* Guest powers down, QEMU is configured to terminate on powerdown, calls
   exit().

* Unless you explicitly cancel the TPM command, $BAD_THINGS can happen.

If yes, please describe at least one instance of $BAD_THINGS for me
again.

BAD_THINGS = If a TPM command is executing as in the scenario you are describing, the thread will still be caught in the write(), thus the QEMU process cannot terminate and will be stuck in the thread-join as it is implemented now. If there was no thread-join QEMU would probably linger around as a zombie for a while.

   Stefan




reply via email to

[Prev in Thread] Current Thread [Next in Thread]