From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: [PATCH v5 4/5] Initialize TPM and get durations and timeouts Date: Tue, 9 Feb 2016 11:20:13 -0700 Message-ID: <20160209182013.GA19018@obsidianresearch.com> References: <1454959628-30582-1-git-send-email-stefanb@linux.vnet.ibm.com> <1454959628-30582-5-git-send-email-stefanb@linux.vnet.ibm.com> <20160209053323.GD12657@obsidianresearch.com> <201602091626.u19GQpga021574@d01av02.pok.ibm.com> <20160209165228.GA14611@obsidianresearch.com> <201602091745.u19HjeEv001740@d03av02.boulder.ibm.com> <20160209180152.GA17475@obsidianresearch.com> <201602091812.u19ICTww018943@d03av01.boulder.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <201602091812.u19ICTww018943-Rn83F4s8Lwc+UXBhvPuGgqsjOiXwFzmk@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: tpmdd-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: Stefan Berger Cc: dhowells-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, tpmdd-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org List-Id: tpmdd-devel@lists.sourceforge.net On Tue, Feb 09, 2016 at 01:11:58PM -0500, Stefan Berger wrote: > :-( User space will just pass the fd to another process, which is the TPM > emulator, and that thing then starts failing on the broken file descriptor. .. and then it exits like any other failure and the caller has to sort it out, which it already has to handle. > Either way, I don't see how the TPM emulator can be fully operational before > tpm_chip_register() is called. You still haven't said what is wrong with doing all the work in a work queue so user space can respond normally without all this ugly hacking. > So far the code allows to start a TPM emulator on the file descript > 'late'. That breaks our invariants to user space. The /dev/tpmX, etc cannot appear until get_timeouts/etc complete. This isn't optional. Ordering startup isn't sufficient. Jason ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140