From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35474) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bRuem-0003ZT-3W for qemu-devel@nongnu.org; Tue, 26 Jul 2016 01:11:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bRueh-00006H-UA for qemu-devel@nongnu.org; Tue, 26 Jul 2016 01:11:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42154) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bRueh-00006D-Ok for qemu-devel@nongnu.org; Tue, 26 Jul 2016 01:11:47 -0400 Date: Tue, 26 Jul 2016 10:41:38 +0530 From: Amit Shah Message-ID: <20160726051138.GB27202@grmbl.mre> References: <1469027314-31655-1-git-send-email-ehabkost@redhat.com> <1469027314-31655-27-git-send-email-ehabkost@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1469027314-31655-27-git-send-email-ehabkost@redhat.com> Subject: Re: [Qemu-devel] [PULL 26/28] apic: Use apic_id as apic's migration instance_id List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Habkost Cc: Peter Maydell , Paolo Bonzini , Igor Mammedov , qemu-devel@nongnu.org, Richard Henderson On (Wed) 20 Jul 2016 [12:08:32], Eduardo Habkost wrote: > From: Igor Mammedov > > instance_id is generated by last_used_id + 1 for a given device type > so for QEMU with 3 CPUs instance_id for APICs is a seti of [0, 1, 2] > When CPU in the middle is hot-removed and migration started > APICs with instance_ids 0 and 2 are transferred in migration stream. > However target starts with 2 CPUs and APICs' instance_ids are > generated from scratch [0, 1] hence migration fails with error > Unknown savevm section or instance 'apic' 2 > > Fix issue by manually registering APIC's vmsd with apic_id as > instance_id, in this case instance_id on target will always > match instance_id on source as apic_id is the same for a given > cpu instance. > > Reported-by: Bharata B Rao > Signed-off-by: Igor Mammedov > Reviewed-by: Dr. David Alan Gilbert > Reviewed-by: Michael S. Tsirkin > Signed-off-by: Eduardo Habkost After these patches, the static checker complains about missing sections: Section "apic-common" does not exist in dest Section "apic" does not exist in dest Section "kvm-apic" does not exist in dest This will break migration from older versions. Amit