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 232EDC47258 for ; Wed, 17 Jan 2024 13:59:04 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rQ6RU-0002ML-Uv; Wed, 17 Jan 2024 08:58:56 -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 1rQ6RT-0002M8-LR for qemu-devel@nongnu.org; Wed, 17 Jan 2024 08:58:55 -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 1rQ6RR-00008w-VG for qemu-devel@nongnu.org; Wed, 17 Jan 2024 08:58:55 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1705499932; 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=dbbxKsoVPE9jEV8xu6idN/lsAEfYLdBvE0iBswSM+eM=; b=Ru7g6n65MSjwCbEY67iDgzWWcigmVF3Y67AVEfnYrFaN6Gavt5R1QH0509x8oN91PNEKU/ MvsUr7fDebvMP/8qXF+GXUYggpwgjIG2pICbb4j1BrjM7ewkZopWUs7wmZP9D2Mlo2Ll7F IfqSIO17RF1mzImEl0Ny1M8In5nY6SY= Received: from mail-oi1-f199.google.com (mail-oi1-f199.google.com [209.85.167.199]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-612-b4MSuMoJPL6XaayUr2gunA-1; Wed, 17 Jan 2024 08:58:49 -0500 X-MC-Unique: b4MSuMoJPL6XaayUr2gunA-1 Received: by mail-oi1-f199.google.com with SMTP id 5614622812f47-3bbc40771a9so13213072b6e.0 for ; Wed, 17 Jan 2024 05:58:49 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1705499929; x=1706104729; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=dbbxKsoVPE9jEV8xu6idN/lsAEfYLdBvE0iBswSM+eM=; b=RF0gt+U4kAsUWuFYdx/kXW3A388ZcAHwFCyMZ4DjiDMdjdwa4wvlZt29oSeKhPgDyo qDE7xDN2K3UIRx6j2/KBu3mzouj/ynR90DjJ9nAceTdfQydxJjaV2eFSowcDB6h5sjtg v5w0MeP19BD0zcGHVg7LuQQh4Z/xg8GcSNuhlDuveQ1Ct+D0TapLZgmXbpu/cQUUYR75 cvNOtvA5/gGcRB5579QJzrbMMgF7hbIkXBN0tWSrPzo5pU5m6/+Glpd13tN6ORi/Vl2X LUUwvu0vNhF6MRi7NC609iz+QRKlg4faOtF90Zgr2cZXMJ1vIIvCFg04dk905o/ETltb zSPw== X-Gm-Message-State: AOJu0YxgrNzx+dBPZQAMy1d/4Vk/wnw5Th2vpWWCJJ+UBIoLZ86WzYQf aHM9xfLmxLDeOy1bS6GtdLqvDMS9NkUpAJfYVQNBfVVAlBwOsy2aPz9gPdPqe9GXL7IcCpVq/cF sKkupx6d7lHbawni29A/i5QM= X-Received: by 2002:a05:6808:1455:b0:3bd:49a4:f854 with SMTP id x21-20020a056808145500b003bd49a4f854mr11495507oiv.68.1705499929156; Wed, 17 Jan 2024 05:58:49 -0800 (PST) X-Google-Smtp-Source: AGHT+IGC2KRahq24LyBMwZia0ELqd03xLWZBZPGpLEx9kwFiLAhCrqX9kYFCPio5y0i+b1EE6Fcxgw== X-Received: by 2002:a05:6808:1455:b0:3bd:49a4:f854 with SMTP id x21-20020a056808145500b003bd49a4f854mr11495495oiv.68.1705499928848; Wed, 17 Jan 2024 05:58:48 -0800 (PST) Received: from ?IPV6:2a01:e0a:280:24f0:9db0:474c:ff43:9f5c? ([2a01:e0a:280:24f0:9db0:474c:ff43:9f5c]) by smtp.gmail.com with ESMTPSA id 3-20020ac85643000000b004282ce42c71sm5804061qtt.86.2024.01.17.05.58.47 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 17 Jan 2024 05:58:48 -0800 (PST) Message-ID: <00e2dc08-c6a3-4e7c-aba3-187d281b71b0@redhat.com> Date: Wed, 17 Jan 2024 14:58:45 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/4] reset: Allow multiple stages of system resets Content-Language: en-US To: eric.auger@redhat.com, peterx@redhat.com, qemu-devel@nongnu.org Cc: "Michael S . Tsirkin" , Jason Wang , Alex Williamson , Igor Mammedov References: <20240117091559.144730-1-peterx@redhat.com> <20240117091559.144730-3-peterx@redhat.com> <1bc3d59d-41a6-4ca7-9d9b-ee6ba6639bd0@redhat.com> From: =?UTF-8?Q?C=C3=A9dric_Le_Goater?= In-Reply-To: <1bc3d59d-41a6-4ca7-9d9b-ee6ba6639bd0@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=clg@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -23 X-Spam_score: -2.4 X-Spam_bar: -- X-Spam_report: (-2.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.806, 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_SORBS_WEB=1.5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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 1/17/24 11:28, Eric Auger wrote: > Hi Peter, > On 1/17/24 10:15, peterx@redhat.com wrote: >> From: Peter Xu >> >> QEMU resets do not have a way to order reset hooks. Add one coarse grained >> reset stage so that some devices can be reset later than some others. > I would precise that the lowest stage has the highest priority and is > handled first. yes. May be add an enum like we have for migration : typedef enum { MIG_PRI_DEFAULT = 0, MIG_PRI_IOMMU, /* Must happen before PCI devices */ MIG_PRI_PCI_BUS, /* Must happen before IOMMU */ MIG_PRI_VIRTIO_MEM, /* Must happen before IOMMU */ MIG_PRI_GICV3_ITS, /* Must happen before PCI devices */ MIG_PRI_GICV3, /* Must happen before the ITS */ MIG_PRI_MAX, } MigrationPriority; I think it would help understand the reset ordering and maintenance when grepping qemu_register_reset_one(). Thanks, C. >> >> Signed-off-by: Peter Xu >> --- >> include/sysemu/reset.h | 5 ++++ >> hw/core/reset.c | 60 +++++++++++++++++++++++++++++++----------- >> 2 files changed, 49 insertions(+), 16 deletions(-) >> >> diff --git a/include/sysemu/reset.h b/include/sysemu/reset.h >> index 609e4d50c2..0de697ce9f 100644 >> --- a/include/sysemu/reset.h >> +++ b/include/sysemu/reset.h >> @@ -5,9 +5,14 @@ >> >> typedef void QEMUResetHandler(void *opaque); >> >> +#define QEMU_RESET_STAGES_N 2 >> + >> void qemu_register_reset(QEMUResetHandler *func, void *opaque); >> +void qemu_register_reset_one(QEMUResetHandler *func, void *opaque, >> + bool skip_snap, int stage); >> void qemu_register_reset_nosnapshotload(QEMUResetHandler *func, void *opaque); >> void qemu_unregister_reset(QEMUResetHandler *func, void *opaque); >> +void qemu_unregister_reset_one(QEMUResetHandler *func, void *opaque, int stage); >> void qemu_devices_reset(ShutdownCause reason); >> >> #endif >> diff --git a/hw/core/reset.c b/hw/core/reset.c >> index 8cf60b2b09..a84c9bee84 100644 >> --- a/hw/core/reset.c >> +++ b/hw/core/reset.c >> @@ -36,55 +36,83 @@ typedef struct QEMUResetEntry { >> bool skip_on_snapshot_load; >> } QEMUResetEntry; >> >> -static QTAILQ_HEAD(, QEMUResetEntry) reset_handlers = >> - QTAILQ_HEAD_INITIALIZER(reset_handlers); >> +typedef QTAILQ_HEAD(QEMUResetList, QEMUResetEntry) QEMUResetList; >> +static QEMUResetList reset_handlers[QEMU_RESET_STAGES_N]; >> >> -static void qemu_register_reset_one(QEMUResetHandler *func, void *opaque, >> - bool skip_snap) >> +static void __attribute__((__constructor__)) qemu_reset_handlers_init(void) >> +{ >> + QEMUResetList *head; >> + int i = 0; > nit: you may put the declarations within the block >> + >> + for (i = 0; i < QEMU_RESET_STAGES_N; i++) { >> + head = &reset_handlers[i]; >> + QTAILQ_INIT(head); >> + } >> +} >> + >> +void qemu_register_reset_one(QEMUResetHandler *func, void *opaque, >> + bool skip_snap, int stage) >> { >> QEMUResetEntry *re = g_new0(QEMUResetEntry, 1); >> + QEMUResetList *head; >> + >> + assert(stage >= 0 && stage < QEMU_RESET_STAGES_N); >> + head = &reset_handlers[stage]; >> >> re->func = func; >> re->opaque = opaque; >> re->skip_on_snapshot_load = skip_snap; >> - QTAILQ_INSERT_TAIL(&reset_handlers, re, entry); >> + QTAILQ_INSERT_TAIL(head, re, entry); >> } >> >> void qemu_register_reset(QEMUResetHandler *func, void *opaque) >> { >> - /* By default, do not skip during load of a snapshot */ > Shouldn't the above comment stay since the statement is not affected by > this patch? Or remove it in previous patch? >> - qemu_register_reset_one(func, opaque, false); >> + qemu_register_reset_one(func, opaque, false, 0); >> } >> >> void qemu_register_reset_nosnapshotload(QEMUResetHandler *func, void *opaque) >> { >> - qemu_register_reset_one(func, opaque, true); >> + qemu_register_reset_one(func, opaque, true, 0); >> } >> >> -void qemu_unregister_reset(QEMUResetHandler *func, void *opaque) >> +void qemu_unregister_reset_one(QEMUResetHandler *func, void *opaque, int stage) >> { >> + QEMUResetList *head; >> QEMUResetEntry *re; >> >> - QTAILQ_FOREACH(re, &reset_handlers, entry) { >> + assert(stage >= 0 && stage < QEMU_RESET_STAGES_N); >> + head = &reset_handlers[stage]; >> + >> + QTAILQ_FOREACH(re, head, entry) { >> if (re->func == func && re->opaque == opaque) { >> - QTAILQ_REMOVE(&reset_handlers, re, entry); >> + QTAILQ_REMOVE(head, re, entry); >> g_free(re); >> return; >> } >> } >> } >> >> +void qemu_unregister_reset(QEMUResetHandler *func, void *opaque) >> +{ >> + qemu_unregister_reset_one(func, opaque, 0); >> +} >> + >> void qemu_devices_reset(ShutdownCause reason) >> { >> QEMUResetEntry *re, *nre; >> + QEMUResetList *head; >> + int stage; >> >> /* reset all devices */ >> - QTAILQ_FOREACH_SAFE(re, &reset_handlers, entry, nre) { >> - if (reason == SHUTDOWN_CAUSE_SNAPSHOT_LOAD && >> - re->skip_on_snapshot_load) { >> - continue; >> + for (stage = 0; stage < QEMU_RESET_STAGES_N; stage++) { >> + head = &reset_handlers[stage]; >> + QTAILQ_FOREACH_SAFE(re, head, entry, nre) { >> + if (reason == SHUTDOWN_CAUSE_SNAPSHOT_LOAD && >> + re->skip_on_snapshot_load) { >> + continue; >> + } >> + re->func(re->opaque); >> } >> - re->func(re->opaque); >> } >> } >> > Thanks > > Eric > >