From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1DsI2o-00024Y-8i for qemu-devel@nongnu.org; Tue, 12 Jul 2005 06:31:18 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1DsI2V-00022W-V8 for qemu-devel@nongnu.org; Tue, 12 Jul 2005 06:31:15 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1DsI2J-0001bs-B6 for qemu-devel@nongnu.org; Tue, 12 Jul 2005 06:30:48 -0400 Received: from [195.34.32.124] (helo=Apachihuilliztli.mtu.ru) by monty-python.gnu.org with esmtp (Exim 4.34) id 1DsI8F-0000BN-Hy for qemu-devel@nongnu.org; Tue, 12 Jul 2005 06:36:55 -0400 Date: Tue, 12 Jul 2005 14:09:07 +0400 Subject: Re: [Qemu-devel] qemu tun networking bug Message-ID: <20050712100907.GA14898@home.byly.local> References: <20050711210125.GA8022@home.byly.local> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: From: byly.useless@tochka.ru (Vitaly Belostotsky) Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: 290569@bugs.debian.org Thank you very much, Henrik, based on your reply I've found the relevant linux kernel TUN/TAP problem description in http://www.kernel.org/pub/linux/kernel/v2.6/testing/ChangeLog-2.6.11-rc2 and was able to workaround the problem in my case with the small patch: --- qemu-0.7.0/vl.c.orig 2005-04-28 00:52:05.000000000 +0400 +++ qemu-0.7.0/vl.c 2005-07-12 13:14:11.583204352 +0400 @@ -1622,7 +1622,7 @@ return -1; } memset(&ifr, 0, sizeof(ifr)); - ifr.ifr_flags = IFF_TAP | IFF_NO_PI; + ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE; pstrcpy(ifr.ifr_name, IFNAMSIZ, "tun%d"); ret = ioctl(fd, TUNSETIFF, (void *) &ifr); if (ret != 0) { May be the problem deserves mentioning in some qemu docs? Regards Vitaly On Tue, Jul 12, 2005 at 03:09:43AM +0200, Henrik Nordstrom wrote: > On Tue, 12 Jul 2005, Vitaly Belostotsky wrote: > > >I've encountered some network related bug when using qemu with tun > >and I'm willing to debug it but could you please provide some help. > > you may want to try upgrading to the host kernel to 2.6.12. Had quite a > bit of issues with tun devices "hanging" in earlier Linux-2.6 versions, > but after I switched to a Fedora Core 4 host running Linux-2.6.12 things > seems much more stable. > > My diagnostics at the time indicated some flow control problem within the > host kernle tun driver, making the driver stall and not deliver packets to > the application (qemu). Your findings seems to indicate very similar > result. > > Regards > Henrik > > > _______________________________________________ > Qemu-devel mailing list > Qemu-devel@nongnu.org > http://lists.nongnu.org/mailman/listinfo/qemu-devel