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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id A4E81D6EBEE for ; Fri, 29 Nov 2024 09:49:57 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tGxcx-0002oy-Av; Fri, 29 Nov 2024 04:49:31 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tGxcv-0002oj-Gg for qemu-devel@nongnu.org; Fri, 29 Nov 2024 04:49:29 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tGxct-00089i-L7 for qemu-devel@nongnu.org; Fri, 29 Nov 2024 04:49:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1732873765; 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=PVGKQbrkPRvxEGNYnPWAoZw99mgkbWyHTtAB68sk2oI=; b=W8YMkPgouvOHsle5sBw/fU4s9si7Hg30ukM404m8PRbBoPfpHgr4o57R3z3qZzB1wUdMJH Tn4Txh8B3lnBpNjRNh5/dAt/UUIxOBy4sSUPCxz8ri9B8szUV2co5MpiaNA6yXlgm6okMn 5joGrRMAA/dejhPkHYMtnYaKdgkySPM= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-124-ka0rEgGWMtqPpueBNoiYsQ-1; Fri, 29 Nov 2024 04:49:23 -0500 X-MC-Unique: ka0rEgGWMtqPpueBNoiYsQ-1 X-Mimecast-MFC-AGG-ID: ka0rEgGWMtqPpueBNoiYsQ Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7B74F1955D9A for ; Fri, 29 Nov 2024 09:49:22 +0000 (UTC) Received: from localhost (unknown [10.42.28.6]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id C2FD5195605A; Fri, 29 Nov 2024 09:49:21 +0000 (UTC) Date: Fri, 29 Nov 2024 09:49:20 +0000 From: "Richard W.M. Jones" To: Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= Cc: qemu-devel@nongnu.org, Martin Pitt , David Hildenbrand , "Michael S. Tsirkin" Subject: Re: [PATCH for 9.2] hw/virtio: fix crash in processing balloon stats Message-ID: <20241129094920.GZ1450@redhat.com> References: <20241129094551.649339-1-berrange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20241129094551.649339-1-berrange@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 Received-SPF: pass client-ip=170.10.133.124; envelope-from=rjones@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, 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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Fri, Nov 29, 2024 at 09:45:51AM +0000, Daniel P. Berrangé wrote: > balloon_stats_get_all will iterate over guest stats upto the max > VIRTIO_BALLOON_S_NR value, calling visit_type_uint64 to populate > the QObject dict. The dict keys are obtained from the static > array balloon_stat_names which is VIRTIO_BALLOON_S_NR in size. > > Unfortunately the way that array is declared results in any > unassigned stats getting a NULL name, which will then cause > visit_type_uint64 to trigger an assert in qobject_output_add_obj. > > The balloon_stat_names array was fortunately fully populated with > names until recently: > > commit 0d2eeef77a33315187df8519491a900bde4a3d83 > Author: Bibo Mao > Date: Mon Oct 28 10:38:09 2024 +0800 > > linux-headers: Update to Linux v6.12-rc5 > > pulled a change to include/standard-headers/linux/virtio_balloon.h > which increased VIRTIO_BALLOON_S_NR by 6, and failed to add the new > names to balloon_stat_names. > > This commit fills in the missing names, and uses a static assert to > guarantee that any future changes to VIRTIO_BALLOON_S_NR will cause > a build failure until balloon_stat_names is updated. > > This problem was detected by the Cockpit Project's automated > integration tests on QEMU 9.2.0-rc1. > > Fixes: 0d2eeef77a33315187df8519491a900bde4a3d83 > Reported-by: Martin Pitt > Signed-off-by: Daniel P. Berrangé Reviewed-by: Richard W.M. Jones You probably want to have a link to the original bug report for context: Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=2329448 Rich. > --- > > NB: this is a MUST FIX for 9.2, as a trivial guest triggerable crash > regressing since 9.1 > > hw/virtio/virtio-balloon.c | 16 +++++++++++++++- > 1 file changed, 15 insertions(+), 1 deletion(-) > > diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c > index 609e39a821..afd2ad6dd6 100644 > --- a/hw/virtio/virtio-balloon.c > +++ b/hw/virtio/virtio-balloon.c > @@ -167,19 +167,33 @@ static void balloon_deflate_page(VirtIOBalloon *balloon, > } > } > > +/* > + * All stats upto VIRTIO_BALLOON_S_NR /must/ have a > + * non-NULL name declared here, since these are used > + * as keys for populating the QDict with stats > + */ > static const char *balloon_stat_names[] = { > [VIRTIO_BALLOON_S_SWAP_IN] = "stat-swap-in", > [VIRTIO_BALLOON_S_SWAP_OUT] = "stat-swap-out", > [VIRTIO_BALLOON_S_MAJFLT] = "stat-major-faults", > [VIRTIO_BALLOON_S_MINFLT] = "stat-minor-faults", > [VIRTIO_BALLOON_S_MEMFREE] = "stat-free-memory", > + > [VIRTIO_BALLOON_S_MEMTOT] = "stat-total-memory", > [VIRTIO_BALLOON_S_AVAIL] = "stat-available-memory", > [VIRTIO_BALLOON_S_CACHES] = "stat-disk-caches", > [VIRTIO_BALLOON_S_HTLB_PGALLOC] = "stat-htlb-pgalloc", > [VIRTIO_BALLOON_S_HTLB_PGFAIL] = "stat-htlb-pgfail", > - [VIRTIO_BALLOON_S_NR] = NULL > + > + [VIRTIO_BALLOON_S_OOM_KILL] = "stat-oom-kills", > + [VIRTIO_BALLOON_S_ALLOC_STALL] = "stat-alloc-stalls", > + [VIRTIO_BALLOON_S_ASYNC_SCAN] = "stat-async-scans", > + [VIRTIO_BALLOON_S_DIRECT_SCAN] = "stat-direct-scans", > + [VIRTIO_BALLOON_S_ASYNC_RECLAIM] = "stat-async-reclaims", > + > + [VIRTIO_BALLOON_S_DIRECT_RECLAIM] = "stat-direct-reclaims", > }; > +G_STATIC_ASSERT(G_N_ELEMENTS(balloon_stat_names) == VIRTIO_BALLOON_S_NR); > > /* > * reset_stats - Mark all items in the stats array as unset > -- > 2.46.0 -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://people.redhat.com/~rjones/virt-top