|
From: | Stefan Berger |
Subject: | Re: [Qemu-devel] [PATCH V14 2/7] Add TPM (frontend) hardware interface (TPM TIS) to Qemu |
Date: | Wed, 22 Feb 2012 10:03:03 -0500 |
User-agent: | Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.23) Gecko/20110928 Fedora/3.1.15-1.fc14 Lightning/1.0b3pre Thunderbird/3.1.15 |
On 02/21/2012 11:34 PM, Michael S. Tsirkin wrote:
Maybe it's just me, but I prefer to have locks around the code that has the criticial section, rather than entering a function with locks held, especially since it would be in a different file (backend) where the lock then is grabbed.On Tue, Feb 21, 2012 at 07:21:28PM -0500, Stefan Berger wrote:On 02/21/2012 06:08 PM, Michael S. Tsirkin wrote:The locking times are short since no major computations are done while the lock is held. Considering that the TPM TIS interface is a non-DMA, byte-by-byte send/receive interface, the performance problems, if at all a problem, are to be found somewhere else : VMExits for example; if interface is used in polling mode, then the interval between polls. StefanIn that case, you can take the qemu lock in your backend and avoid locking in the frontend completely.
Also I do need a lock in the frontend for the condition that is used there. Stefan
[Prev in Thread] | Current Thread | [Next in Thread] |