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=-11.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 28153C433E7 for ; Wed, 22 Jul 2020 13:27:38 +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 E4FBA20674 for ; Wed, 22 Jul 2020 13:27:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ZiiDCLvs" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E4FBA20674 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]:47690 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jyEmX-0001ki-82 for qemu-devel@archiver.kernel.org; Wed, 22 Jul 2020 09:27:37 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:39574) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jyElq-0000um-Q3 for qemu-devel@nongnu.org; Wed, 22 Jul 2020 09:26:54 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:28209 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jyElp-000180-5M for qemu-devel@nongnu.org; Wed, 22 Jul 2020 09:26:54 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1595424412; 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=uJC4GIX+nGhAhxODYBvJGLRCLaTNMVYU1BJVMof6Jfk=; b=ZiiDCLvs1Dc0lxMSPTHbJ9lW1fcYn8a+WrandveAyX27AIW/8+s7nUdZoi4k7lm/8xtIgn VJxG9WY0y5AtVLMEk4WRnamrpE8Pm0ArgMa+Feek/pjR+G1sly9IBM9OWUMS4f+V+OzbGS 6Lieuq4Z1kQSwNWpZRTzUUP8E+CFM+0= 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-309-oHP21d7COZSBxZ-e74pxhg-1; Wed, 22 Jul 2020 09:26:50 -0400 X-MC-Unique: oHP21d7COZSBxZ-e74pxhg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 92B0957; Wed, 22 Jul 2020 13:26:49 +0000 (UTC) Received: from lacos-laptop-7.usersys.redhat.com (ovpn-113-129.ams2.redhat.com [10.36.113.129]) by smtp.corp.redhat.com (Postfix) with ESMTP id A16BE78540; Wed, 22 Jul 2020 13:26:48 +0000 (UTC) Subject: Re: [PATCH 1/6] x86: lpc9: let firmware negotiate 'CPU hotplug with SMI' features From: Laszlo Ersek To: Igor Mammedov , qemu-devel@nongnu.org References: <20200720141610.574308-1-imammedo@redhat.com> <20200720141610.574308-2-imammedo@redhat.com> <00b7e32c-36ad-a71a-00da-d1f0d9977e79@redhat.com> Message-ID: <2d97286a-2e8e-dd6b-822c-58959d0a74e2@redhat.com> Date: Wed, 22 Jul 2020 15:26:47 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <00b7e32c-36ad-a71a-00da-d1f0d9977e79@redhat.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=207.211.31.120; envelope-from=lersek@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/22 00:40:35 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, 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_H4=-0.01, RCVD_IN_MSPIKE_WL=-0.01, 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: boris.ostrovsky@oracle.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 07/22/20 14:03, Laszlo Ersek wrote: > On 07/20/20 16:16, Igor Mammedov wrote: >> It will allow firmware to notify QEMU that firmware requires SMI >> being triggered on CPU hot[un]plug, so that it would be able to account >> for hotplugged CPU and relocate it to new SMM base and/or safely remove >> CPU on unplug. >> >> Using negotiated features, follow up patches will insert SMI upcall >> into AML code, to make sure that firmware processes hotplug before >> guest OS would attempt to use new CPU. >> >> Signed-off-by: Igor Mammedov >> --- >> include/hw/i386/ich9.h | 2 ++ >> hw/i386/pc.c | 5 ++++- >> hw/isa/lpc_ich9.c | 12 ++++++++++++ >> 3 files changed, 18 insertions(+), 1 deletion(-) >> >> diff --git a/include/hw/i386/ich9.h b/include/hw/i386/ich9.h >> index a98d10b252..d1bb3f7bf0 100644 >> --- a/include/hw/i386/ich9.h >> +++ b/include/hw/i386/ich9.h >> @@ -247,5 +247,7 @@ typedef struct ICH9LPCState { >> >> /* bit positions used in fw_cfg SMI feature negotiation */ >> #define ICH9_LPC_SMI_F_BROADCAST_BIT 0 >> +#define ICH9_LPC_SMI_F_CPU_HOTPLUG_BIT 1 >> +#define ICH9_LPC_SMI_F_CPU_HOT_UNPLUG_BIT 2 >> >> #endif /* HW_ICH9_H */ >> diff --git a/hw/i386/pc.c b/hw/i386/pc.c >> index 3d419d5991..57d50fad6b 100644 >> --- a/hw/i386/pc.c >> +++ b/hw/i386/pc.c >> @@ -97,7 +97,10 @@ >> #include "fw_cfg.h" >> #include "trace.h" >> >> -GlobalProperty pc_compat_5_0[] = {}; >> +GlobalProperty pc_compat_5_0[] = { >> + { "ICH9-LPC", "x-smi-cpu-hotplug", "off" }, >> + { "ICH9-LPC", "x-smi-cpu-hotunplug", "off" }, >> +}; >> const size_t pc_compat_5_0_len = G_N_ELEMENTS(pc_compat_5_0); >> >> GlobalProperty pc_compat_4_2[] = { >> diff --git a/hw/isa/lpc_ich9.c b/hw/isa/lpc_ich9.c >> index cd6e169d47..c9305080b5 100644 >> --- a/hw/isa/lpc_ich9.c >> +++ b/hw/isa/lpc_ich9.c >> @@ -373,6 +373,14 @@ static void smi_features_ok_callback(void *opaque) >> /* guest requests invalid features, leave @features_ok at zero */ >> return; >> } >> + if (!(guest_features & BIT_ULL(ICH9_LPC_SMI_F_BROADCAST_BIT)) && >> + guest_features & (BIT_ULL(ICH9_LPC_SMI_F_CPU_HOTPLUG_BIT) | >> + BIT_ULL(ICH9_LPC_SMI_F_CPU_HOT_UNPLUG_BIT))) { >> + /* cpu hot-[un]plug with SMI requires SMI broadcast, >> + * leave @features_ok at zero >> + */ >> + return; >> + } >> >> /* valid feature subset requested, lock it down, report success */ >> lpc->smi_negotiated_features = guest_features; >> @@ -747,6 +755,10 @@ static Property ich9_lpc_properties[] = { >> DEFINE_PROP_BOOL("noreboot", ICH9LPCState, pin_strap.spkr_hi, true), >> DEFINE_PROP_BIT64("x-smi-broadcast", ICH9LPCState, smi_host_features, >> ICH9_LPC_SMI_F_BROADCAST_BIT, true), >> + DEFINE_PROP_BIT64("x-smi-cpu-hotplug", ICH9LPCState, smi_host_features, >> + ICH9_LPC_SMI_F_CPU_HOTPLUG_BIT, true), >> + DEFINE_PROP_BIT64("x-smi-cpu-hotunplug", ICH9LPCState, smi_host_features, >> + ICH9_LPC_SMI_F_CPU_HOT_UNPLUG_BIT, true), >> DEFINE_PROP_END_OF_LIST(), >> }; >> >> > > (1) I think that, at this time, the default value for > "x-smi-cpu-hotunplug" should be false. Accordingly, the > "x-smi-cpu-hotunplug" compat property should be dropped. > > The reason is that in this series, QEMU won't actually learn to handle > CPU hot-unplug with SMI. We shouldn't advertize support for it. > > We should only recognize the feature, so that the QMP command can rely > on it for rejecting hot-unplug attempts. If (later) we have a more > advanced OVMF binary with unplug support (so that OVMF would try to > negotiate unplug), but the user runs it on QEMU-5.1 (or more precisely > with an 5.1 machine type), which will support plug, but not unplug, then > QEMU should reject the device_del QMP command. > > In brief, we need both properties because we want both device_add and > device_del to fail gracefully, but the default values (and accordingly > the compat properties) should reflect the actual feature support. So > unplug should default to false at this point. With (1) updated: Reviewed-by: Laszlo Ersek