From patchwork Fri Sep 25 21:10:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eduardo Habkost X-Patchwork-Id: 1371597 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=QGfG9Ubc; dkim-atps=neutral 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 ozlabs.org (Postfix) with ESMTPS id 4Byl2S3Bmbz9sTC for ; Sat, 26 Sep 2020 07:11:09 +1000 (AEST) Received: from localhost ([::1]:36336 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kLuzg-0006rR-0W for incoming@patchwork.ozlabs.org; Fri, 25 Sep 2020 17:11:04 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55094) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kLuz8-0006r2-6l for qemu-devel@nongnu.org; Fri, 25 Sep 2020 17:10:31 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:40274) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kLuz5-0000nE-Js for qemu-devel@nongnu.org; Fri, 25 Sep 2020 17:10:29 -0400 Dkim-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1601068226; 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; bh=WH4T3xdvo86Aiq7Mn9tcfivSkOwhMWSmDTmn/2UbH+A=; b=QGfG9UbcGegSeikSSdpSVH10dLbBRLfHH1lipD/A7o0jV42L12jN4fRzs1EdSHfHnEFrMk WN2wNzQjYsYknxas9EONBC3ybGFFjymx2VN9ZhQ22m3JTvqQuqpqbsSAHeDD66fahQi7MI eXvMyukgSpKAZgIHLfxTf03vW7UYcbA= 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-570-mT52xFQ-OsmMcfnLH2gx-g-1; Fri, 25 Sep 2020 17:10:23 -0400 X-MC-Unique: mT52xFQ-OsmMcfnLH2gx-g-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DC9D2427C2; Fri, 25 Sep 2020 21:10:22 +0000 (UTC) Received: from localhost (unknown [10.10.67.5]) by smtp.corp.redhat.com (Postfix) with ESMTP id 83ECF1002C07; Fri, 25 Sep 2020 21:10:22 +0000 (UTC) From: Eduardo Habkost To: qemu-devel@nongnu.org Subject: [PATCH] i386: Document when features can be added to kvm_default_props Date: Fri, 25 Sep 2020 17:10:21 -0400 Message-Id: <20200925211021.4158567-1-ehabkost@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=ehabkost@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=63.128.21.124; envelope-from=ehabkost@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/25 01:07:33 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -32 X-Spam_score: -3.3 X-Spam_bar: --- X-Spam_report: (-3.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.199, 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_H5=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 , Vitaly Kuznetsov , Eduardo Habkost , Richard Henderson Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" It's very easy to mistakenly extend kvm_default_props to include features that require a kernel version that's too recent. Add a comment warning about that, pointing to the documentation file where the minimum kernel version for KVM is documented. Signed-off-by: Eduardo Habkost Acked-by: Paolo Bonzini --- target/i386/cpu.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 3ffd877dd51..c8558bb49ac 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -4098,8 +4098,14 @@ static X86CPUDefinition builtin_x86_defs[] = { }, }; -/* KVM-specific features that are automatically added/removed +/* + * KVM-specific features that are automatically added/removed * from all CPU models when KVM is enabled. + * + * NOTE: features can be enabled by default only if they were + * already available in the oldest kernel version supported + * by the KVM accelerator (see "OS requirements" section at + * docs/system/target-i386.rst) */ static PropValue kvm_default_props[] = { { "kvmclock", "on" },