From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2AC24C433DF for ; Thu, 9 Jul 2020 18:47:46 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EED2220775 for ; Thu, 9 Jul 2020 18:47:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EED2220775 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:41462 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jtbaD-0005gC-6R for qemu-devel@archiver.kernel.org; Thu, 09 Jul 2020 14:47:45 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44812) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jtbZV-00055e-3m for qemu-devel@nongnu.org; Thu, 09 Jul 2020 14:47:01 -0400 Received: from mx2.suse.de ([195.135.220.15]:39952) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jtbZS-0001l8-Uq for qemu-devel@nongnu.org; Thu, 09 Jul 2020 14:47:00 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 3EAE5AB3D; Thu, 9 Jul 2020 18:46:57 +0000 (UTC) Subject: Re: [PATCH 3/3] cpu-timers, icount: new modules From: Claudio Fontana To: Paolo Bonzini , Thomas Huth , Laurent Vivier , =?UTF-8?Q?Alex_Benn=c3=a9e?= , Peter Maydell , =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , Roman Bolshakov , Markus Armbruster References: <20200629093504.3228-1-cfontana@suse.de> <20200629093504.3228-4-cfontana@suse.de> Message-ID: Date: Thu, 9 Jul 2020 20:46:56 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=195.135.220.15; envelope-from=cfontana@suse.de; helo=mx2.suse.de X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/09 10:31:51 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x (no timestamps) [generic] X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Cornelia Huck , Eduardo Habkost , Colin Xu , Marcelo Tosatti , qemu-devel@nongnu.org, haxm-team@intel.com, Wenchao Wang , Sunil Muthuswamy , Richard Henderson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 7/9/20 8:38 PM, Claudio Fontana wrote: > On 7/8/20 5:05 PM, Paolo Bonzini wrote: >> On 08/07/20 17:00, Claudio Fontana wrote: >>>> Bisectable, 100% failure rate, etc. :( Can you split the patch in >>>> multiple parts, specifically separating any rename or introducing of >>>> includes from the final file move? >>> Hi Paolo, >>> >>> will take a look! >>> >>> Is this captured by some travis / cirrus-ci / anything I can easily see the result of? >>> >>> >> >> Nope, unfortunately we don't have an s390 CI. But if you can get your >> hands on one, just "./configure --target-list=s390x-softmmu && make && >> make check-block" will show it. > > So this is tricky, but I am making some progress after getting my hands on one. > Maybe if someone understands s390 keys better, I could be clued in. Also adding Cornelia to Cc:. Maybe the savevm_s390_storage_keys SaveVMHandlers etc assume that the icount state part of the vmstate is there? > > In short this goes away if I again set icount to enabled for qtest, > basically ensuring that --enable-tcg is there and then reenabling icount. > > qtest was forcing icount and shift=0 by creating qemu options, in order to misuse its counter feature, > instead of using a separate counter. > > Removing that ugliness we end up with different behavior of save/load, because vmstate will now suddenly not contain icount-related values anymore. > What I do not understand is why this causes a problem because save should just not store the icount state and load should just not load the icount state, > and why we die on the load of s390 keys state (it works just fine for other architectures). > > Here is a diff that makes the problem disappear, but needs --enable-tcg: > > > ---------------------------------------------------------------------------------------------------- > diff --git a/accel/qtest.c b/accel/qtest.c > index 119d0f16a4..4cb16abc2c 100644 > --- a/accel/qtest.c > +++ b/accel/qtest.c > @@ -23,6 +23,12 @@ > > static int qtest_init_accel(MachineState *ms) > { > + QemuOpts *opts = qemu_opts_create(qemu_find_opts("icount"), NULL, 0, > + &error_abort); > + qemu_opt_set(opts, "shift", "0", &error_abort); > + icount_configure(opts, &error_abort); > + qemu_opts_del(opts); > + > return 0; > } > > diff --git a/softmmu/vl.c b/softmmu/vl.c > index f39fd5270b..a5e788c86a 100644 > --- a/softmmu/vl.c > +++ b/softmmu/vl.c > @@ -2786,10 +2786,12 @@ static void configure_accelerators(const char *progname) > error_report("falling back to %s", ac->name); > } > > + /* > if (icount_enabled() && !tcg_enabled()) { > error_report("-icount is not allowed with hardware virtualization"); > exit(1); > } > + */ > } > > static void create_default_memdev(MachineState *ms, const char *path) > ---------------------------------------------------------------------------------------------------- > > Without this patch, here is the full failure, maybe someone has a good hint, otherwise I'll keep digging from here inside the s390-specific code. > > QA output created by 267 > > === No block devices at all === > > Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 > Testing: > QEMU X.Y.Z monitor - type 'help' for more information > (qemu) savevm snap0 > Error: No block device can accept snapshots > (qemu) info snapshots > No available block device supports snapshots > (qemu) loadvm snap0 > Error: No block device supports snapshots > (qemu) quit > > > === -drive if=none === > > Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 > Testing: -drive driver=file,file=TEST_DIR/t.IMGFMT,if=none > QEMU X.Y.Z monitor - type 'help' for more information > (qemu) savevm snap0 > Error: Device 'none0' is writable but does not support snapshots > (qemu) info snapshots > No available block device supports snapshots > (qemu) loadvm snap0 > Error: Device 'none0' is writable but does not support snapshots > (qemu) quit > > Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 > Testing: -drive driver=IMGFMT,file=TEST_DIR/t.IMGFMT,if=none > QEMU X.Y.Z monitor - type 'help' for more information > (qemu) savevm snap0 > (qemu) info snapshots > List of snapshots present on all disks: > ID TAG VM SIZE DATE VM CLOCK > -- snap0 SIZE yyyy-mm-dd hh:mm:ss 00:00:00.000 > (qemu) loadvm snap0 > (qemu) quit > > Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 > Testing: -drive driver=IMGFMT,file=TEST_DIR/t.IMGFMT,if=none -device virtio-blk,drive=none0 > QEMU X.Y.Z monitor - type 'help' for more information > (qemu) savevm snap0 > (qemu) info snapshots > List of snapshots present on all disks: > ID TAG VM SIZE DATE VM CLOCK > -- snap0 SIZE yyyy-mm-dd hh:mm:ss 00:00:00.000 > (qemu) loadvm snap0 > (qemu) quit > > > === -drive if=virtio === > > Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 > Testing: -drive driver=file,file=TEST_DIR/t.IMGFMT,if=virtio > QEMU X.Y.Z monitor - type 'help' for more information > (qemu) savevm snap0 > Error: Device 'virtio0' is writable but does not support snapshots > (qemu) info snapshots > No available block device supports snapshots > (qemu) loadvm snap0 > Error: Device 'virtio0' is writable but does not support snapshots > (qemu) quit > > Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 > Testing: -drive driver=IMGFMT,file=TEST_DIR/t.IMGFMT,if=virtio > QEMU X.Y.Z monitor - type 'help' for more information > (qemu) savevm snap0 > (qemu) info snapshots > List of snapshots present on all disks: > ID TAG VM SIZE DATE VM CLOCK > -- snap0 SIZE yyyy-mm-dd hh:mm:ss 00:00:00.000 > (qemu) loadvm snap0 > (qemu) quit > > > === Simple -blockdev === > > Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 > Testing: -blockdev driver=file,filename=TEST_DIR/t.IMGFMT,node-name=file > QEMU X.Y.Z monitor - type 'help' for more information > (qemu) savevm snap0 > Error: Device '' is writable but does not support snapshots > (qemu) info snapshots > No available block device supports snapshots > (qemu) loadvm snap0 > Error: Device '' is writable but does not support snapshots > (qemu) quit > > Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 > Testing: -blockdev driver=file,filename=TEST_DIR/t.IMGFMT,node-name=file -blockdev driver=IMGFMT,file=file,node-name=fmt > QEMU X.Y.Z monitor - type 'help' for more information > (qemu) savevm snap0 > (qemu) info snapshots > List of snapshots present on all disks: > ID TAG VM SIZE DATE VM CLOCK > -- snap0 SIZE yyyy-mm-dd hh:mm:ss 00:00:00.000 > (qemu) loadvm snap0 > (qemu) quit > > Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 > Testing: -blockdev driver=file,filename=TEST_DIR/t.IMGFMT,node-name=file -blockdev driver=raw,file=file,node-name=raw -blockdev driver=IMGFMT,file=raw,node-name=fmt > QEMU X.Y.Z monitor - type 'help' for more information > (qemu) savevm snap0 > (qemu) info snapshots > List of snapshots present on all disks: > ID TAG VM SIZE DATE VM CLOCK > -- snap0 SIZE yyyy-mm-dd hh:mm:ss 00:00:00.000 > (qemu) loadvm snap0 > (qemu) quit > > > === -blockdev with a filter on top === > > Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 > Testing: -blockdev driver=file,filename=TEST_DIR/t.IMGFMT,node-name=file -blockdev driver=IMGFMT,file=file,node-name=fmt -blockdev driver=copy-on-read,file=fmt,node-name=filter > QEMU X.Y.Z monitor - type 'help' for more information > (qemu) savevm snap0 > (qemu) info snapshots > List of snapshots present on all disks: > ID TAG VM SIZE DATE VM CLOCK > -- snap0 SIZE yyyy-mm-dd hh:mm:ss 00:00:00.000 > (qemu) loadvm snap0 > (qemu) quit > > > === -blockdev with a backing file === > > Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=134217728 > Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 backing_file=TEST_DIR/t.IMGFMT.base > Testing: -blockdev driver=file,filename=TEST_DIR/t.IMGFMT.base,node-name=backing-file -blockdev driver=file,filename=TEST_DIR/t.IMGFMT,node-name=file -blockdev driver=IMGFMT,file=file,backing=backing-file,node-name=fmt > QEMU X.Y.Z monitor - type 'help' for more information > (qemu) savevm snap0 > (qemu) info snapshots > List of snapshots present on all disks: > ID TAG VM SIZE DATE VM CLOCK > -- snap0 SIZE yyyy-mm-dd hh:mm:ss 00:00:00.000 > (qemu) loadvm snap0 > Unexpected storage key flag data: 0 > error while loading state for instance 0x0 of device 's390-skeys' > Error: Error -22 while loading VM state > > > > >> >>>> >>>> #if defined CONFIG_TCG || !defined NEED_CPU_H >>>> extern bool icount_enabled(void); >>>> #else >>>> #define icount_enabled() 0 >>>> #endif >>>> >>>> (This way, more TCG-only code in cpus.c gets elided). You can integrate >>>> this change in the next version. >>>> >>>> Paolo >>>> >>> >>> Weird, I tested with --disable-tcg explicitly (but may be some time ago now, as I constantly rebased). >>> >>> Will take a look at the introduction of this #defines in place of variables, >>> as this mechanisms will not work in the future for target-specific modules. >> >> This is only done for per-target files so it should not be a problem. >> >> Paolo >> >> > >