From nobody Thu Oct 30 15:16:57 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1526421725007194.50788298471662; Tue, 15 May 2018 15:02:05 -0700 (PDT) Received: from localhost ([::1]:34968 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fIi19-0004id-WE for importer@patchew.org; Tue, 15 May 2018 18:02:00 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35601) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fIhuq-0008Pf-Dz for qemu-devel@nongnu.org; Tue, 15 May 2018 17:55:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fIhun-00011Z-9n for qemu-devel@nongnu.org; Tue, 15 May 2018 17:55:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54378) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fIhum-00011D-V7 for qemu-devel@nongnu.org; Tue, 15 May 2018 17:55:25 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id EC8391CCC2B; Tue, 15 May 2018 21:55:23 +0000 (UTC) Received: from localhost (ovpn-116-15.gru2.redhat.com [10.97.116.15]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6A79B10512; Tue, 15 May 2018 21:55:23 +0000 (UTC) From: Eduardo Habkost To: Peter Maydell Date: Tue, 15 May 2018 18:54:31 -0300 Message-Id: <20180515215436.6457-3-ehabkost@redhat.com> In-Reply-To: <20180515215436.6457-1-ehabkost@redhat.com> References: <20180515215436.6457-1-ehabkost@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Tue, 15 May 2018 21:55:24 +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 2/7] x86/cpu: Enable CLDEMOTE(Demote Cache Line) cpu feature 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: Eduardo Habkost , "Michael S. Tsirkin" , Jingqi Liu , qemu-devel@nongnu.org, Paolo Bonzini , Richard Henderson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Jingqi Liu The CLDEMOTE instruction hints to hardware that the cache line that contains the linear address should be moved("demoted") from the cache(s) closest to the processor core to a level more distant from the processor core. This may accelerate subsequent accesses to the line by other cores in the same coherence domain, especially if the line was written by the core that demotes the line. Intel Snow Ridge has added new cpu feature, CLDEMOTE. The new cpu feature needs to be exposed to guest VM. The bit definition: CPUID.(EAX=3D7,ECX=3D0):ECX[bit 25] CLDEMOTE The release document ref below link: https://software.intel.com/sites/default/files/managed/c5/15/\ architecture-instruction-set-extensions-programming-reference.pdf Signed-off-by: Jingqi Liu Message-Id: <1525406253-54846-1-git-send-email-jingqi.liu@intel.com> Reviewed-by: Eduardo Habkost Signed-off-by: Eduardo Habkost --- target/i386/cpu.h | 1 + target/i386/cpu.c | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/target/i386/cpu.h b/target/i386/cpu.h index b58b779bff..8fbe1537c1 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -680,6 +680,7 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS]; #define CPUID_7_0_ECX_AVX512_VPOPCNTDQ (1U << 14) /* POPCNT for vectors of= DW/QW */ #define CPUID_7_0_ECX_LA57 (1U << 16) #define CPUID_7_0_ECX_RDPID (1U << 22) +#define CPUID_7_0_ECX_CLDEMOTE (1U << 25) /* CLDEMOTE Instruction */ =20 #define CPUID_7_0_EDX_AVX512_4VNNIW (1U << 2) /* AVX512 Neural Network Ins= tructions */ #define CPUID_7_0_EDX_AVX512_4FMAPS (1U << 3) /* AVX512 Multiply Accumulat= ion Single Precision */ diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 52fd35b6a1..4b39ab5dd4 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -494,7 +494,7 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS]= =3D { "avx512bitalg", NULL, "avx512-vpopcntdq", NULL, "la57", NULL, NULL, NULL, NULL, NULL, "rdpid", NULL, - NULL, NULL, NULL, NULL, + NULL, "cldemote", NULL, NULL, NULL, NULL, NULL, NULL, }, .cpuid_eax =3D 7, --=20 2.14.3