From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3xCYW34vmvzDr3M for ; Thu, 20 Jul 2017 09:43:11 +1000 (AEST) Message-ID: <1500507770.3350.41.camel@kernel.crashing.org> Subject: Re: KVM guests freeze under upstream kernel From: Benjamin Herrenschmidt To: joserz@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org Cc: paulus@samba.org, mpe@ellerman.id.au, oohall@gmail.com Date: Thu, 20 Jul 2017 09:42:50 +1000 In-Reply-To: <20170719194634.GA1222@pacoca> References: <20170719194634.GA1222@pacoca> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 2017-07-19 at 16:46 -0300, joserz@linux.vnet.ibm.com wrote: > Hello! > > We're not able to boot any KVM guest using upstream kernel (cb8c65ccff7f77d0285f1b126c72d37b2572c865 - 4.13.0-rc1+). > After reaching the SLOF initial counting, the guest simply freezes: Can you send our .config ? > SLOF > ********************************************************************** > QEMU Starting > Build Date = Mar 3 2017 13:29:19 > FW Version = git-66d250ef0fd06bb8 > Press "s" to enter Open Firmware. > > C0360 > > After bisecting I found the commit: > > https://github.com/torvalds/linux/commit/ebd3119 > > powerpc/mm: Add devmap support for ppc64 > > Add support for the devmap bit on PTEs and PMDs for PPC64 Book3S. This > is used to differentiate device backed memory from transparent huge > pages since they are handled in more or less the same manner by the core > mm code. > > Reverting the commit and rebuilding 4.13.0-rc1+ was enough to make a workaround. > But I'll need some help from you guys in order to solve it. > > Thanks! > > Jose Ziviani