From patchwork Mon Apr 16 16:39:53 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eduardo Habkost X-Patchwork-Id: 10343473 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 8A104601D7 for ; Mon, 16 Apr 2018 16:44:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7AA6B2881C for ; Mon, 16 Apr 2018 16:44:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6F51628820; Mon, 16 Apr 2018 16:44:05 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id E95292881C for ; Mon, 16 Apr 2018 16:44:04 +0000 (UTC) Received: from localhost ([::1]:57305 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f87Ea-00048g-4p for patchwork-qemu-devel@patchwork.kernel.org; Mon, 16 Apr 2018 12:44:04 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47648) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f87Ag-0001fW-4c for qemu-devel@nongnu.org; Mon, 16 Apr 2018 12:40:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f87Af-0006qf-4W for qemu-devel@nongnu.org; Mon, 16 Apr 2018 12:40:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41748) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1f87Ae-0006qG-Up for qemu-devel@nongnu.org; Mon, 16 Apr 2018 12:40:01 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 339BD80F93; Mon, 16 Apr 2018 16:40:00 +0000 (UTC) Received: from localhost (ovpn-116-12.gru2.redhat.com [10.97.116.12]) by smtp.corp.redhat.com (Postfix) with ESMTP id 34FF57E4F5; Mon, 16 Apr 2018 16:39:57 +0000 (UTC) From: Eduardo Habkost To: Peter Maydell Date: Mon, 16 Apr 2018 13:39:53 -0300 Message-Id: <20180416163953.31188-2-ehabkost@redhat.com> In-Reply-To: <20180416163953.31188-1-ehabkost@redhat.com> References: <20180416163953.31188-1-ehabkost@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Mon, 16 Apr 2018 16:40:00 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 1/1] i386: Don't automatically enable FEAT_KVM_HINTS bits X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , qemu-devel@nongnu.org, Eduardo Habkost , Richard Henderson Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP The assumption in the cpu->max_features code is that anything enabled on GET_SUPPORTED_CPUID should be enabled on "-cpu host". This shouldn't be the case for FEAT_KVM_HINTS. This adds a new FeatureWordInfo::no_autoenable_flags field, that can be used to prevent FEAT_KVM_HINTS bits to be enabled automatically. Reviewed-by: Paolo Bonzini Signed-off-by: Eduardo Habkost Message-Id: <20180410211534.26079-1-ehabkost@redhat.com> Tested-by: Wanpeng Li Signed-off-by: Eduardo Habkost --- target/i386/cpu.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 1a6b082b6f..a20fe26573 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -295,6 +295,8 @@ typedef struct FeatureWordInfo { uint32_t tcg_features; /* Feature flags supported by TCG */ uint32_t unmigratable_flags; /* Feature flags known to be unmigratable */ uint32_t migratable_flags; /* Feature flags known to be migratable */ + /* Features that shouldn't be auto-enabled by "-cpu host" */ + uint32_t no_autoenable_flags; } FeatureWordInfo; static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { @@ -400,6 +402,11 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { }, .cpuid_eax = KVM_CPUID_FEATURES, .cpuid_reg = R_EDX, .tcg_features = TCG_KVM_FEATURES, + /* + * KVM hints aren't auto-enabled by -cpu host, they need to be + * explicitly enabled in the command-line. + */ + .no_autoenable_flags = ~0U, }, [FEAT_HYPERV_EAX] = { .feat_names = { @@ -4062,7 +4069,8 @@ static void x86_cpu_expand_features(X86CPU *cpu, Error **errp) */ env->features[w] |= x86_cpu_get_supported_feature_word(w, cpu->migratable) & - ~env->user_features[w]; + ~env->user_features[w] & \ + ~feature_word_info[w].no_autoenable_flags; } }