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 X-Spam-Level: X-Spam-Status: No, score=-11.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95D2CC43461 for ; Fri, 11 Sep 2020 06:24:17 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 18554221EB for ; Fri, 11 Sep 2020 06:24:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 18554221EB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:59598 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kGcTo-0002iY-4N for qemu-devel@archiver.kernel.org; Fri, 11 Sep 2020 02:24:16 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:33776) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kGcSb-0002CO-4j for qemu-devel@nongnu.org; Fri, 11 Sep 2020 02:23:01 -0400 Received: from mga01.intel.com ([192.55.52.88]:65029) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kGcSY-0001Xu-Jn for qemu-devel@nongnu.org; Fri, 11 Sep 2020 02:23:00 -0400 IronPort-SDR: baF9jBbz2YqEEKxGY7gvwrBiomDP9cV/F89XrhN8RXaZYCw/27CHamlsUgweJ4JLAyMWss1Rj7 oaZPu7jiusGw== X-IronPort-AV: E=McAfee;i="6000,8403,9740"; a="176764954" X-IronPort-AV: E=Sophos;i="5.76,414,1592895600"; d="scan'208";a="176764954" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Sep 2020 23:22:55 -0700 IronPort-SDR: egDDUsT7xPKkFtF7LCqY4vK+h8JKKqGkJOASSISiOJunLH2e4y+/W/YSO3kVgnWCt313E5wXUY Qa6KsK3V2sjA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.76,414,1592895600"; d="scan'208";a="481202696" Received: from sqa-gate.sh.intel.com (HELO robert-ivt.tsp.org) ([10.239.48.212]) by orsmga005.jf.intel.com with ESMTP; 10 Sep 2020 23:22:52 -0700 Message-ID: Subject: Re: [PATCH v2 1/2] Introduce (x86) CPU model deprecation API From: Robert Hoo To: Eduardo Habkost Date: Fri, 11 Sep 2020 14:22:51 +0800 In-Reply-To: <20200909181506.GM1618070@habkost.net> References: <1591843676-102054-1-git-send-email-robert.hu@linux.intel.com> <20200909181506.GM1618070@habkost.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5 (3.28.5-8.el7) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Received-SPF: none client-ip=192.55.52.88; envelope-from=robert.hu@linux.intel.com; helo=mga01.intel.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/11 02:22:56 X-ACL-Warn: Detected OS = FreeBSD 9.x or newer [fuzzy] X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: xiaoyao.li@intel.com, qemu-devel@nongnu.org, armbru@redhat.com, robert.hu@intel.com, chenyi.qiang@intel.com, pbonzini@redhat.com, rth@twiddle.net Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, 2020-09-09 at 14:15 -0400, Eduardo Habkost wrote: > Hi, > > Thanks for the patch, and sorry for taking so long to review > this. I'm finally getting to the patches that were postponed to > 5.2. > > Comments and questions below: > > On Thu, Jun 11, 2020 at 10:47:55AM +0800, Robert Hoo wrote: > > Complement versioned CPU model framework with the ability of > > marking some > > versions deprecated. When that CPU model is chosen, get some > > warning. The > > warning message is customized, e.g. telling in which future QEMU > > version will > > it be obsoleted. > > The deprecation message will also appear by x86_cpu_list_entry(), > > e.g. '-cpu > > help'. > > QMP 'query-cpu-definitions' will also return a bool value > > indicating the > > deprecation status. > > > > Changes in v2: > > Move deprecation check from parse_cpu_option() to > > machine_run_board_init(), so > > that it can cover implicit cpu_type assignment cases. > > Add qapi new member documentation. Thanks Eric for comment and > > guidance on qapi. > > > > Signed-off-by: Robert Hoo > > --- > > hw/core/machine.c | 11 +++++++++-- > > include/hw/core/cpu.h | 1 + > > qapi/machine-target.json | 7 ++++++- > > target/i386/cpu.c | 45 > > +++++++++++++++++++++++++++++++++++++++++++-- > > 4 files changed, 59 insertions(+), 5 deletions(-) > > > > diff --git a/hw/core/machine.c b/hw/core/machine.c > > index bb3a7b1..9318964 100644 > > --- a/hw/core/machine.c > > +++ b/hw/core/machine.c > > @@ -1083,6 +1083,8 @@ MemoryRegion > > *machine_consume_memdev(MachineState *machine, > > void machine_run_board_init(MachineState *machine) > > { > > MachineClass *machine_class = MACHINE_GET_CLASS(machine); > > + ObjectClass *oc = object_class_by_name(machine->cpu_type); > > + CPUClass *cc; > > > > if (machine->ram_memdev_id) { > > Object *o; > > @@ -1102,11 +1104,10 @@ void machine_run_board_init(MachineState > > *machine) > > * specified a CPU with -cpu check here that the user CPU is > > supported. > > */ > > if (machine_class->valid_cpu_types && machine->cpu_type) { > > - ObjectClass *class = object_class_by_name(machine- > > >cpu_type); > > int i; > > > > for (i = 0; machine_class->valid_cpu_types[i]; i++) { > > - if (object_class_dynamic_cast(class, > > + if (object_class_dynamic_cast(oc, > > machine_class- > > >valid_cpu_types[i])) { > > /* The user specificed CPU is in the valid field, > > we are > > * good to go. > > @@ -1129,6 +1130,12 @@ void machine_run_board_init(MachineState > > *machine) > > } > > } > > > > + /* Check if CPU type is deprecated and warn if so */ > > + cc = CPU_CLASS(oc); > > + if (cc->deprecation_check) { > > + cc->deprecation_check(oc); > > + } > > Why do we need target-specific code here? A CPUClass::deprecated > field would be much simpler. > Because the Warning message composing is target-specific, using X86CPUVersionDefinition.note. Other targets can have their own warning message composing approaches. > > + > > machine_class->init(machine); > > } > > > > diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h > > index 497600c..1ca47dc 100644 > > --- a/include/hw/core/cpu.h > > +++ b/include/hw/core/cpu.h > > @@ -218,6 +218,7 @@ typedef struct CPUClass { > > void (*disas_set_info)(CPUState *cpu, disassemble_info *info); > > vaddr (*adjust_watchpoint_address)(CPUState *cpu, vaddr addr, > > int len); > > void (*tcg_initialize)(void); > > + void (*deprecation_check)(ObjectClass *oc); > > > > /* Keep non-pointer data at the end to minimize holes. */ > > int gdb_num_core_regs; > > diff --git a/qapi/machine-target.json b/qapi/machine-target.json > > index f2c8294..c24f506 100644 > > --- a/qapi/machine-target.json > > +++ b/qapi/machine-target.json > > @@ -285,6 +285,10 @@ > > # in the VM configuration, because aliases may stop > > being > > # migration-safe in the future (since 4.1) > > # > > +# @deprecated: If true, this CPU model is deprecated and may be > > removed in > > +# in some future version of QEMU according to the > > QEMU deprecation > > +# policy. (since 5.1) > > Next version needs to say "since 5.2". Sure. > > > +# > > # @unavailable-features is a list of QOM property names that > > # represent CPU model attributes that prevent the CPU from > > running. > > # If the QOM property is read-only, that means there's no known > > @@ -309,7 +313,8 @@ > > 'static': 'bool', > > '*unavailable-features': [ 'str' ], > > 'typename': 'str', > > - '*alias-of' : 'str' }, > > + '*alias-of' : 'str', > > + 'deprecated' : 'bool' }, > > 'if': 'defined(TARGET_PPC) || defined(TARGET_ARM) || > > defined(TARGET_I386) || defined(TARGET_S390X) || > > defined(TARGET_MIPS)' } > > > > ## > > diff --git a/target/i386/cpu.c b/target/i386/cpu.c > > index ba05da3..0d8638a 100644 > > --- a/target/i386/cpu.c > > +++ b/target/i386/cpu.c > > @@ -1599,6 +1599,7 @@ typedef struct X86CPUVersionDefinition { > > const char *alias; > > const char *note; > > PropValue *props; > > + bool deprecated; > > } X86CPUVersionDefinition; > > > > /* Base definition for a CPU model */ > > @@ -1638,6 +1639,11 @@ struct X86CPUModel { > > * This matters only for "-cpu help" and query-cpu-definitions > > */ > > bool is_alias; > > + /* > > + * If true, this model is deprecated, and may be removed in > > the future. > > + * Trying to use it now will cause a warning. > > + */ > > + bool deprecated; > > }; > > > > /* Get full model name for CPU version */ > > @@ -4128,8 +4134,7 @@ static X86CPUVersion > > x86_cpu_model_resolve_version(const X86CPUModel *model) > > X86CPUVersion v = model->version; > > if (v == CPU_VERSION_AUTO) { > > v = default_cpu_version; > > - } > > - if (v == CPU_VERSION_LATEST) { > > + } else if (v == CPU_VERSION_LATEST) { > > Why is this change necessary? Just kind of compulsion of avoiding unnecessary if() :-). 'v' can only be one of CPU_VERSION_AUTO and CPU_VERSION_LATEST, unnecessary to judge twice. > > > return x86_cpu_model_last_version(model); > > } > > return v; > > @@ -4975,6 +4980,7 @@ static void x86_cpu_definition_entry(gpointer > > data, gpointer user_data) > > info->migration_safe = cc->migration_safe; > > info->has_migration_safe = true; > > info->q_static = cc->static_model; > > + info->deprecated = cc->model ? cc->model->deprecated : false; > > /* > > * Old machine types won't report aliases, so that alias > > translation > > * doesn't break compatibility with previous QEMU versions. > > @@ -5411,6 +5417,7 @@ static void > > x86_register_cpudef_types(X86CPUDefinition *def) > > m->cpudef = def; > > m->version = vdef->version; > > m->note = vdef->note; > > + m->deprecated = vdef->deprecated; > > x86_register_cpu_model_type(name, m); > > > > if (vdef->alias) { > > @@ -5418,6 +5425,8 @@ static void > > x86_register_cpudef_types(X86CPUDefinition *def) > > am->cpudef = def; > > am->version = vdef->version; > > am->is_alias = true; > > + am->note = vdef->note; > > Is this extra line related to the deprecation feature? > > It doesn't seem related, and it doesn't seem necessary as the > `note` field is already ignored for alias CPU models. Because it is unused by other features, I use it to store model specific deprecation message. > > > + am->deprecated = vdef->deprecated; > > x86_register_cpu_model_type(vdef->alias, am); > > } > > } > > @@ -7233,6 +7242,37 @@ static Property x86_cpu_properties[] = { > > DEFINE_PROP_END_OF_LIST() > > }; > > > > +static void x86_cpu_deprecation_check(ObjectClass *oc) > > +{ > > + X86CPUClass *xcc = X86_CPU_CLASS(oc); > > + X86CPUVersion effective_version; > > + const X86CPUVersionDefinition *vdef; > > + > > + if (xcc->model == NULL) { > > + return; > > + } > > + > > + if (xcc->model->version == CPU_VERSION_LEGACY) { > > + /* Treat legacy version as v1 */ > > + effective_version = 1; > > + } else { > > + effective_version = x86_cpu_model_resolve_version(xcc- > > >model); > > + } > > + > > + vdef = xcc->model->cpudef->versions; > > + > > + if (vdef == NULL) { > > + return; > > + } else { > > + if (vdef[effective_version - 1].deprecated) { > > + warn_report("Effective CPU model '%s' -- %s", > > + x86_cpu_versioned_model_name(xcc->model- > > >cpudef,\ > > + effective_version) > > , > > + vdef[effective_version - 1].note); > > + } > > + } > > Why do we need this extra logic? Isn't it simpler to just add a > bool CPUClass::deprecated field, and set: > > cpu->deprecated = model->deprecated; > > inside x86_cpu_cpudef_class_init()? > All these are to fulfill the target you expected earlier: "We need a proper CPU model deprecation API. Deprecation info should appear on query-cpu-definitions and should trigger a warning when using the CPU model." So I think each deprecated model shall have its own deprecation message, e.g. by which version it's going to be deprecation, etc. > > +} > > + > > static void x86_cpu_common_class_init(ObjectClass *oc, void *data) > > { > > X86CPUClass *xcc = X86_CPU_CLASS(oc); > > @@ -7291,6 +7331,7 @@ static void > > x86_cpu_common_class_init(ObjectClass *oc, void *data) > > cc->tlb_fill = x86_cpu_tlb_fill; > > #endif > > cc->disas_set_info = x86_disas_set_info; > > + cc->deprecation_check = x86_cpu_deprecation_check; > > > > dc->user_creatable = true; > > } > > -- > > 1.8.3.1 > > > >