From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:43858) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RgG1j-00045d-I8 for qemu-devel@nongnu.org; Thu, 29 Dec 2011 08:28:12 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RgG1i-0000OA-Ix for qemu-devel@nongnu.org; Thu, 29 Dec 2011 08:28:11 -0500 Received: from mx1.redhat.com ([209.132.183.28]:26961) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RgG1i-0000O5-CD for qemu-devel@nongnu.org; Thu, 29 Dec 2011 08:28:10 -0500 Date: Thu, 29 Dec 2011 18:57:56 +0530 From: Amit Shah Message-ID: <20111229132756.GB4576@amit.redhat.com> References: <4EE9EBB9.9020300@de.ibm.com> <4EFC616F.4060806@de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4EFC616F.4060806@de.ibm.com> Subject: Re: [Qemu-devel] [PATCHv2] Fix virtio-console failure on unconnected pty List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Christian Borntraeger Cc: "qemu-devel@nongnu.org" , Alexander Graf On (Thu) 29 Dec 2011 [13:47:43], Christian Borntraeger wrote: > From: Christian Borntraeger > > when I tried qemu with -virtio-console pty the guest hangs and attaching on /dev/pts/ does > not return anything if the attachement is too late. > Turns out that the console is already throttled and the guest is heavily spinning but get_buf > never returns the buffer. There seems to be no way for the console to unthrottle the port. It doesn't really get throttled, since the throttling enabling/disabling isn't yet done in QEMU. What happens is that the chardev buffer gets filled up and qemu_chr_fe_write() doesn't return -- send_all() keeps spinning. I'll adjust the commit log message and submit. Thanks. Amit