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=-16.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 C6020C433E0 for ; Fri, 12 Feb 2021 13:59:31 +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 333C564E57 for ; Fri, 12 Feb 2021 13:59:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 333C564E57 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:39406 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lAYyo-0003Gd-7Q for qemu-devel@archiver.kernel.org; Fri, 12 Feb 2021 08:59:30 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:50670) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lAYsa-0003w4-4p for qemu-devel@nongnu.org; Fri, 12 Feb 2021 08:53:04 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:50240) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lAYsY-0006UP-6i for qemu-devel@nongnu.org; Fri, 12 Feb 2021 08:53:03 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1613137981; 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=aw8fTwhtM66724aX4iRbc5McdoOYcIthTOGwSmU3hJY=; b=GxvIM4v5fb66WRYL59VnKBjQmsNSAVonNdIglmPEJ55RmGCLtGIgcw8Ic5fLoibHO+g8f6 0xgimVHkrKYXAL2C23PlYEgQuriInYRln4OKB/6xWWeyqI99Nx7EH4k5kuEmyKppSqyE+6 MOJCHgdXhGe4i9zVyj37aRX0//GCWms= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-23-Ypx-loQ4ObOMZXgsEzicuw-1; Fri, 12 Feb 2021 08:52:58 -0500 X-MC-Unique: Ypx-loQ4ObOMZXgsEzicuw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 63185801965 for ; Fri, 12 Feb 2021 13:52:57 +0000 (UTC) Received: from localhost (unknown [10.40.208.60]) by smtp.corp.redhat.com (Postfix) with ESMTP id C122060CFB; Fri, 12 Feb 2021 13:52:55 +0000 (UTC) Date: Fri, 12 Feb 2021 14:52:53 +0100 From: Igor Mammedov To: Vitaly Kuznetsov Subject: Re: [PATCH v4 17/21] i386: support 'hv-passthrough, hv-feature=off' on the command line Message-ID: <20210212145253.0ae15cfb@redhat.com> In-Reply-To: <87r1llllg5.fsf@vitty.brq.redhat.com> References: <20210210164033.607612-1-vkuznets@redhat.com> <20210210164033.607612-18-vkuznets@redhat.com> <20210211181459.08f14c22@redhat.com> <87r1llllg5.fsf@vitty.brq.redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=imammedo@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=imammedo@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -33 X-Spam_score: -3.4 X-Spam_bar: --- X-Spam_report: (-3.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.569, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , Marcelo Tosatti , qemu-devel@nongnu.org, Eduardo Habkost Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, 12 Feb 2021 09:49:46 +0100 Vitaly Kuznetsov wrote: > Igor Mammedov writes: > > > On Wed, 10 Feb 2021 17:40:29 +0100 > > Vitaly Kuznetsov wrote: > > > >> Currently, we support 'hv-passthrough,hv-feature=on' enablement, this > >> is supposed to mean "hv-feature is mandatory, don't start without it". Add > >> support for 'hv-passthrough,hv-feature=off' meaning "enable everything > >> supported by the host except for hv-feature". > >> > >> While on it, make 'hv-passthrough' parse semantics in-line with other > >> options in qemu: when specified, it overrides what was previously set with > >> what's supported by the host. This can later be modified with 'hv-feature=on'/ > >> 'hv-feature=off'. > >> > >> Signed-off-by: Vitaly Kuznetsov > >> --- > >> target/i386/cpu.c | 28 +++++++++++++++++++++++++++- > >> target/i386/kvm/kvm.c | 4 ++++ > >> 2 files changed, 31 insertions(+), 1 deletion(-) > >> > >> diff --git a/target/i386/cpu.c b/target/i386/cpu.c > >> index e8a004c39d04..f8df2caed779 100644 > >> --- a/target/i386/cpu.c > >> +++ b/target/i386/cpu.c > >> @@ -4725,6 +4725,29 @@ static void x86_hv_stimer_direct_set(Object *obj, bool value, Error **errp) > >> x86_hv_feature_set(obj, value, HYPERV_FEAT_STIMER_DIRECT); > >> } > >> > >> +static bool x86_hv_passthrough_get(Object *obj, Error **errp) > >> +{ > >> + X86CPU *cpu = X86_CPU(obj); > >> + > >> + return cpu->hyperv_passthrough; > >> +} > >> + > >> +static void x86_hv_passthrough_set(Object *obj, bool value, Error **errp) > >> +{ > >> + X86CPU *cpu = X86_CPU(obj); > >> + > >> + cpu->hyperv_passthrough = value; > >> + > >> + /* hv-passthrough overrides everything with what's supported by the host */ > >> + if (value) { > >> + cpu->hyperv_features = 0; > >> + cpu->hyperv_features_on = 0; > >> + cpu->hyperv_features_off = 0; > > > > why do we have _on|_off fields? > > > > You mean 'why do we have them at all' or 'why do we reset them here'? > For the former, we need to distinguish between > 'hv-passthroug,hv-feature=off' and just 'hv-passthrough'; > 'hv-passthrough,hv-evmcs=on' and just 'hv-passthrough'. For the later, that's what I was asking for, eventually I found it being buried in kvm code > I'd like to make the samentics you've asked for: > 'hv-feature,hv-passthrough' == 'hv-passthrough' you essentially you wrote your own hv-foo parser in kvm_hyperv_expand_features(), which is a bit complicated for my taste. With scratch CPU you can simplify and make it easier to read. > (though I still see it as a gotcha for an unprepared user) this way it at least works the same way like any other property. > >> + } > >> + > >> + return; > >> +} > >> + > >> /* Generic getter for "feature-words" and "filtered-features" properties */ > >> static void x86_cpu_get_feature_words(Object *obj, Visitor *v, > >> const char *name, void *opaque, > >> @@ -7281,7 +7304,6 @@ static Property x86_cpu_properties[] = { > >> HYPERV_SPINLOCK_NEVER_NOTIFY), > >> DEFINE_PROP_ON_OFF_AUTO("hv-no-nonarch-coresharing", X86CPU, > >> hyperv_no_nonarch_cs, ON_OFF_AUTO_OFF), > >> - DEFINE_PROP_BOOL("hv-passthrough", X86CPU, hyperv_passthrough, false), > >> > >> DEFINE_PROP_BOOL("check", X86CPU, check_cpuid, true), > >> DEFINE_PROP_BOOL("enforce", X86CPU, enforce_cpuid, false), > >> @@ -7460,6 +7482,10 @@ static void x86_cpu_common_class_init(ObjectClass *oc, void *data) > >> x86_hv_stimer_direct_get, > >> x86_hv_stimer_direct_set); > >> > >> + object_class_property_add_bool(oc, "hv-passthrough", > >> + x86_hv_passthrough_get, > >> + x86_hv_passthrough_set); > >> + > >> for (w = 0; w < FEATURE_WORDS; w++) { > >> int bitnr; > >> for (bitnr = 0; bitnr < 64; bitnr++) { > >> diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c > >> index 30013f0d7cee..fca088d4d3b5 100644 > >> --- a/target/i386/kvm/kvm.c > >> +++ b/target/i386/kvm/kvm.c > >> @@ -1153,6 +1153,10 @@ static int hv_cpuid_check_and_set(CPUState *cs, int feature, Error **errp) > >> return 0; > >> } > >> > >> + if (cpu->hyperv_passthrough && (cpu->hyperv_features_off & BIT(feature))) { > >> + return 0; > >> + } > >> + > >> deps = kvm_hyperv_properties[feature].dependencies; > >> while (deps) { > >> dep_feat = ctz64(deps); > > >