From patchwork Fri Oct 20 09:07:25 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Juan Quintela X-Patchwork-Id: 13430326 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 80A02C001DF for ; Fri, 20 Oct 2023 09:10:59 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qtlUp-0004SY-4a; Fri, 20 Oct 2023 05:08:43 -0400 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 1qtlUc-0003bD-TA for qemu-devel@nongnu.org; Fri, 20 Oct 2023 05:08:31 -0400 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 1qtlUa-0005Ps-MT for qemu-devel@nongnu.org; Fri, 20 Oct 2023 05:08:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1697792908; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=FM6X7w+5oEHqp4TUVIta1dJnlWHKe/701qVSkH3Agxw=; b=S2rJStzTA/qy74sRKTzLADN1mVWXHfz2zoW716PhVFzEFf2PL0Jcvdl20HQjGBg9G6Lmrk gAG0GM14cbdyxQQMP2RaFJVBUhgefGehqAmGdEaz0gClbJ95+2OdNN0IiEaPQ4OBDF71rB CXCEngNlRXy4j3/VBs0s9ozpalb72YI= 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-550-4IOZ77zUNRmbeS5ae0fzJQ-1; Fri, 20 Oct 2023 05:08:17 -0400 X-MC-Unique: 4IOZ77zUNRmbeS5ae0fzJQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7ED4510201F3; Fri, 20 Oct 2023 09:08:15 +0000 (UTC) Received: from secure.mitica (unknown [10.39.194.127]) by smtp.corp.redhat.com (Postfix) with ESMTP id 75D852166B26; Fri, 20 Oct 2023 09:08:10 +0000 (UTC) From: Juan Quintela To: qemu-devel@nongnu.org Cc: Peter Maydell , Harsh Prateek Bora , David Hildenbrand , Samuel Thibault , Eric Farman , qemu-arm@nongnu.org, qemu-ppc@nongnu.org, Thomas Huth , Gerd Hoffmann , Fabiano Rosas , David Gibson , Corey Minyard , "Michael S. Tsirkin" , Peter Xu , Corey Minyard , Stefan Berger , Juan Quintela , Marcel Apfelbaum , =?utf-8?q?Marc-Andr=C3=A9_Lu?= =?utf-8?q?reau?= , Richard Henderson , Halil Pasic , Leonardo Bras , John Snow , Nicholas Piggin , Mark Cave-Ayland , Christian Borntraeger , Ilya Leoshkevich , Jason Wang , qemu-block@nongnu.org, qemu-s390x@nongnu.org, =?utf-8?q?C=C3=A9dric_Le_Goat?= =?utf-8?q?er?= , Daniel Henrique Barboza , Stefan Weil , Greg Kurz Subject: [PATCH v2 07/13] migration: Hack to maintain backwards compatibility for ppc Date: Fri, 20 Oct 2023 11:07:25 +0200 Message-ID: <20231020090731.28701-8-quintela@redhat.com> In-Reply-To: <20231020090731.28701-1-quintela@redhat.com> References: <20231020090731.28701-1-quintela@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.6 Received-SPF: pass client-ip=170.10.133.124; envelope-from=quintela@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, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable 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 Current code does: - register pre_2_10_vmstate_dummy_icp with "icp/server" and instance dependinfg on cpu number - for newer machines, it register vmstate_icp with "icp/server" name and instance 0 - now it unregisters "icp/server" for the 1st instance. This is wrong at many levels: - we shouldn't have two VMSTATEDescriptions with the same name - In case this is the only solution that we can came with, it needs to be: * register pre_2_10_vmstate_dummy_icp * unregister pre_2_10_vmstate_dummy_icp * register real vmstate_icp Created vmstate_replace_hack_for_ppc() with warnings left and right that it is a hack. CC: Cedric Le Goater CC: Daniel Henrique Barboza CC: David Gibson CC: Greg Kurz Signed-off-by: Juan Quintela Reviewed-by: Nicholas Piggin --- include/migration/vmstate.h | 11 +++++++++++ hw/intc/xics.c | 17 +++++++++++++++-- hw/ppc/spapr.c | 25 +++++++++++++++++++++++-- migration/savevm.c | 18 ++++++++++++++++++ 4 files changed, 67 insertions(+), 4 deletions(-) diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h index 9ca7e9cc48..65deaecc92 100644 --- a/include/migration/vmstate.h +++ b/include/migration/vmstate.h @@ -1230,6 +1230,17 @@ static inline int vmstate_register(VMStateIf *obj, int instance_id, opaque, -1, 0, NULL); } +/** + * vmstate_replace_hack_for_ppc() - ppc used to abuse vmstate_register + * + * Don't even think about using this function in new code. + * + * Returns: 0 on success, -1 on failure + */ +int vmstate_replace_hack_for_ppc(VMStateIf *obj, int instance_id, + const VMStateDescription *vmsd, + void *opaque); + /** * vmstate_register_any() - legacy function to register state * serialisation description and let the function choose the id diff --git a/hw/intc/xics.c b/hw/intc/xics.c index c7f8abd71e..a03979e72a 100644 --- a/hw/intc/xics.c +++ b/hw/intc/xics.c @@ -335,8 +335,21 @@ static void icp_realize(DeviceState *dev, Error **errp) return; } } - - vmstate_register(NULL, icp->cs->cpu_index, &vmstate_icp_server, icp); + /* + * The way that pre_2_10_icp is handling is really, really hacky. + * We used to have here this call: + * + * vmstate_register(NULL, icp->cs->cpu_index, &vmstate_icp_server, icp); + * + * But we were doing: + * pre_2_10_vmstate_register_dummy_icp() + * this vmstate_register() + * pre_2_10_vmstate_unregister_dummy_icp() + * + * So for a short amount of time we had to vmstate entries with + * the same name. This fixes it. + */ + vmstate_replace_hack_for_ppc(NULL, icp->cs->cpu_index, &vmstate_icp_server, icp); } static void icp_unrealize(DeviceState *dev) diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index cb840676d3..a75cf475ad 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -143,6 +143,11 @@ static bool pre_2_10_vmstate_dummy_icp_needed(void *opaque) } static const VMStateDescription pre_2_10_vmstate_dummy_icp = { + /* + * Hack ahead. We can't have two devices with the same name and + * instance id. So I rename this to pass make check. + * Real help from people who knows the hardware is needed. + */ .name = "icp/server", .version_id = 1, .minimum_version_id = 1, @@ -155,16 +160,32 @@ static const VMStateDescription pre_2_10_vmstate_dummy_icp = { }, }; +/* + * See comment in hw/intc/xics.c:icp_realize() + * + * You have to remove vmstate_replace_hack_for_ppc() when you remove + * the machine types that need the following function. + */ static void pre_2_10_vmstate_register_dummy_icp(int i) { vmstate_register(NULL, i, &pre_2_10_vmstate_dummy_icp, (void *)(uintptr_t) i); } +/* + * See comment in hw/intc/xics.c:icp_realize() + * + * You have to remove vmstate_replace_hack_for_ppc() when you remove + * the machine types that need the following function. + */ static void pre_2_10_vmstate_unregister_dummy_icp(int i) { - vmstate_unregister(NULL, &pre_2_10_vmstate_dummy_icp, - (void *)(uintptr_t) i); + /* + * This used to be: + * + * vmstate_unregister(NULL, &pre_2_10_vmstate_dummy_icp, + * (void *)(uintptr_t) i); + */ } int spapr_max_server_number(SpaprMachineState *spapr) diff --git a/migration/savevm.c b/migration/savevm.c index 8622f229e5..d3a30686d4 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -846,6 +846,24 @@ static void vmstate_check(const VMStateDescription *vmsd) } } +/* + * See comment in hw/intc/xics.c:icp_realize() + * + * This function can be removed when + * pre_2_10_vmstate_register_dummy_icp() is removed. + */ +int vmstate_replace_hack_for_ppc(VMStateIf *obj, int instance_id, + const VMStateDescription *vmsd, + void *opaque) +{ + SaveStateEntry *se = find_se(vmsd->name, instance_id); + + if (se) { + savevm_state_handler_remove(se); + } + return vmstate_register(obj, instance_id, vmsd, opaque); +} + int vmstate_register_with_alias_id(VMStateIf *obj, uint32_t instance_id, const VMStateDescription *vmsd, void *opaque, int alias_id,