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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1B359C433F5 for ; Thu, 28 Apr 2022 17:27:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350402AbiD1RaT (ORCPT ); Thu, 28 Apr 2022 13:30:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34446 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244981AbiD1RaO (ORCPT ); Thu, 28 Apr 2022 13:30:14 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id B8F8635262 for ; Thu, 28 Apr 2022 10:26:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1651166817; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ZRY0CP0uuG/LK26ciYdoHEggTFpAtfPg+TlemPGY9CE=; b=Q5OUqnRwUsKOsMcshF3Dg1PqFKJ1LLl7aSPvH9LPD3xmElHXR94nREqjsB0TfbpIzoTEKO xbmMm4h4/nEfAmhs1qe4rMRxlX6Jze7CEg6g+icB87PeugxOlXWsswPAqmSUAa0oMEyY3b NKZP92e5S5DC7Uodrd5clM80hTeBMfs= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-602-lHxxeDkwM6WjHK5gSxSWgA-1; Thu, 28 Apr 2022 13:26:54 -0400 X-MC-Unique: lHxxeDkwM6WjHK5gSxSWgA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D40511014A62; Thu, 28 Apr 2022 17:26:53 +0000 (UTC) Received: from starship (unknown [10.40.192.41]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5A52D1121319; Thu, 28 Apr 2022 17:26:50 +0000 (UTC) Message-ID: <47eb853424ef6c7dd6439ac33dfeb64a29f49c44.camel@redhat.com> Subject: Re: [syzbot] WARNING in kvm_mmu_uninit_tdp_mmu (2) From: Maxim Levitsky To: Paolo Bonzini , Sean Christopherson Cc: syzbot , bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, jmattson@google.com, joro@8bytes.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@redhat.com, syzkaller-bugs@googlegroups.com, tglx@linutronix.de, vkuznets@redhat.com, wanpengli@tencent.com, x86@kernel.org Date: Thu, 28 Apr 2022 20:26:49 +0300 In-Reply-To: References: <00000000000082452505dd503126@google.com> <13b3235ef66f22475fd4059df95ad0144548ccd1.camel@redhat.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.5 (3.36.5-2.fc32) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2022-04-28 at 19:22 +0200, Paolo Bonzini wrote: > On 4/28/22 17:32, Sean Christopherson wrote: > > On Tue, Apr 26, 2022, Maxim Levitsky wrote: > > > I can reproduce this in a VM, by running and CTRL+C'in my ipi_stress test, > > > > Can you post your ipi_stress test? I'm curious to see if I can repro, and also > > very curious as to what might be unique about your test. I haven't been able to > > repro the syzbot test, nor have I been able to repro by killing VMs/tests. > > Did you test with CONFIG_PREEMPT=y? yes, I test with CONFIG_PREEMPT but I only enabled it a day ago, I think I had seen this warning before, but could bit, I'll check if that fails without CONFIG_PREEMPT as well. What I recently changed, is that I enabled lockdep and related settings on all my machines and VMs, I enabled CONFIG_PREEMPT, and I also switched to tdp_mmu on all systems. Bugs are biting but it is better this way, especially to weed out the last bugs of my nested avic code :) Best regards, Maxim Levitsky > > (BTW, the fact that it reproduces under 5.17 is a mixed blessing, > because it means that we can analyze/stare at a simpler codebase). > > Paolo >