From nobody Fri Nov 7 09:11:04 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; 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 209.51.188.17 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 [209.51.188.17]) by mx.zohomail.com with SMTPS id 1547477434093926.8547226526307; Mon, 14 Jan 2019 06:50:34 -0800 (PST) Received: from localhost ([127.0.0.1]:44507 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gj3ZO-0005xN-Od for importer@patchew.org; Mon, 14 Jan 2019 09:50:30 -0500 Received: from eggs.gnu.org ([209.51.188.92]:58910) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gj3Qv-0006Ly-5I for qemu-devel@nongnu.org; Mon, 14 Jan 2019 09:41:46 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gj3Qt-00026f-Se for qemu-devel@nongnu.org; Mon, 14 Jan 2019 09:41:45 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60022) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gj3Qt-00025m-JF for qemu-devel@nongnu.org; Mon, 14 Jan 2019 09:41:43 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A2DA281E05; Mon, 14 Jan 2019 14:34:46 +0000 (UTC) Received: from localhost (ovpn-116-76.gru2.redhat.com [10.97.116.76]) by smtp.corp.redhat.com (Postfix) with ESMTP id 33FA41853A; Mon, 14 Jan 2019 14:34:43 +0000 (UTC) From: Eduardo Habkost To: Peter Maydell , qemu-devel@nongnu.org Date: Mon, 14 Jan 2019 12:34:29 -0200 Message-Id: <20190114143432.4771-3-ehabkost@redhat.com> In-Reply-To: <20190114143432.4771-1-ehabkost@redhat.com> References: <20190114143432.4771-1-ehabkost@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Mon, 14 Jan 2019 14:34:46 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 2/5] target-i386: Reenable RDTSCP support on Opteron_G[345] CPU models CPU models 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 , kvm@vger.kernel.org, "Michael S. Tsirkin" , Marcelo Tosatti , Paolo Bonzini , Borislav Petkov , Richard Henderson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Borislav Petkov The missing functionality was added ~3 years ago with the Linux commit 46896c73c1a4 ("KVM: svm: add support for RDTSCP") so reenable RDTSCP support on those CPU models. Opteron_G2 - being family 15, model 6, doesn't have RDTSCP support (the real hardware doesn't have it. K8 got RDTSCP support with the NPT models, i.e., models >=3D 0x40). Document the host's minimum required kernel version, while at it. Signed-off-by: Borislav Petkov Message-ID: <20181212200803.GG6653@zn.tnic> [ehabkost: moved compat properties code to pc.c] Signed-off-by: Eduardo Habkost --- hw/i386/pc.c | 3 +++ target/i386/cpu.c | 11 ++++------- qemu-doc.texi | 13 +++++++++++++ 3 files changed, 20 insertions(+), 7 deletions(-) diff --git a/hw/i386/pc.c b/hw/i386/pc.c index fc65049e1d..5cac33fcb9 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -112,6 +112,9 @@ struct hpet_fw_config hpet_cfg =3D {.count =3D UINT8_MA= X}; =20 GlobalProperty pc_compat_3_1[] =3D { { "intel-iommu", "dma-drain", "off" }, + { "Opteron_G3" "-" TYPE_X86_CPU, "rdtscp", "off" }, + { "Opteron_G4" "-" TYPE_X86_CPU, "rdtscp", "off" }, + { "Opteron_G5" "-" TYPE_X86_CPU, "rdtscp", "off" }, }; const size_t pc_compat_3_1_len =3D G_N_ELEMENTS(pc_compat_3_1); =20 diff --git a/target/i386/cpu.c b/target/i386/cpu.c index bd005f5374..4cfc0daf97 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -2736,7 +2736,6 @@ static X86CPUDefinition builtin_x86_defs[] =3D { CPUID_DE | CPUID_FP87, .features[FEAT_1_ECX] =3D CPUID_EXT_CX16 | CPUID_EXT_SSE3, - /* Missing: CPUID_EXT2_RDTSCP */ .features[FEAT_8000_0001_EDX] =3D CPUID_EXT2_LM | CPUID_EXT2_NX | CPUID_EXT2_SYSCALL, .features[FEAT_8000_0001_ECX] =3D @@ -2760,9 +2759,9 @@ static X86CPUDefinition builtin_x86_defs[] =3D { .features[FEAT_1_ECX] =3D CPUID_EXT_POPCNT | CPUID_EXT_CX16 | CPUID_EXT_MONITOR | CPUID_EXT_SSE3, - /* Missing: CPUID_EXT2_RDTSCP */ .features[FEAT_8000_0001_EDX] =3D - CPUID_EXT2_LM | CPUID_EXT2_NX | CPUID_EXT2_SYSCALL, + CPUID_EXT2_LM | CPUID_EXT2_NX | CPUID_EXT2_SYSCALL | + CPUID_EXT2_RDTSCP, .features[FEAT_8000_0001_ECX] =3D CPUID_EXT3_MISALIGNSSE | CPUID_EXT3_SSE4A | CPUID_EXT3_ABM | CPUID_EXT3_SVM | CPUID_EXT3_LAHF_LM, @@ -2787,10 +2786,9 @@ static X86CPUDefinition builtin_x86_defs[] =3D { CPUID_EXT_POPCNT | CPUID_EXT_SSE42 | CPUID_EXT_SSE41 | CPUID_EXT_CX16 | CPUID_EXT_SSSE3 | CPUID_EXT_PCLMULQDQ | CPUID_EXT_SSE3, - /* Missing: CPUID_EXT2_RDTSCP */ .features[FEAT_8000_0001_EDX] =3D CPUID_EXT2_LM | CPUID_EXT2_PDPE1GB | CPUID_EXT2_NX | - CPUID_EXT2_SYSCALL, + CPUID_EXT2_SYSCALL | CPUID_EXT2_RDTSCP, .features[FEAT_8000_0001_ECX] =3D CPUID_EXT3_FMA4 | CPUID_EXT3_XOP | CPUID_EXT3_3DNOWPREFETCH | CPUID_EXT3_MISALIGNSSE | @@ -2818,10 +2816,9 @@ static X86CPUDefinition builtin_x86_defs[] =3D { CPUID_EXT_AES | CPUID_EXT_POPCNT | CPUID_EXT_SSE42 | CPUID_EXT_SSE41 | CPUID_EXT_CX16 | CPUID_EXT_FMA | CPUID_EXT_SSSE3 | CPUID_EXT_PCLMULQDQ | CPUID_EXT_SSE3, - /* Missing: CPUID_EXT2_RDTSCP */ .features[FEAT_8000_0001_EDX] =3D CPUID_EXT2_LM | CPUID_EXT2_PDPE1GB | CPUID_EXT2_NX | - CPUID_EXT2_SYSCALL, + CPUID_EXT2_SYSCALL | CPUID_EXT2_RDTSCP, .features[FEAT_8000_0001_ECX] =3D CPUID_EXT3_TBM | CPUID_EXT3_FMA4 | CPUID_EXT3_XOP | CPUID_EXT3_3DNOWPREFETCH | CPUID_EXT3_MISALIGNSSE | diff --git a/qemu-doc.texi b/qemu-doc.texi index f7ad1dfe4b..16b955cbf9 100644 --- a/qemu-doc.texi +++ b/qemu-doc.texi @@ -37,6 +37,7 @@ * QEMU System emulator for non PC targets:: * QEMU Guest Agent:: * QEMU User space emulator:: +* System requirements:: * Implementation notes:: * Deprecated features:: * Supported build platforms:: @@ -2813,6 +2814,18 @@ Act as if the host page size was 'pagesize' bytes Run the emulation in single step mode. @end table =20 +@node System requirements +@chapter System requirements + +@section KVM kernel module + +On x86_64 hosts, the default set of CPU features enabled by the KVM accele= rator +require the host to be running Linux v4.5 or newer. + +The OpteronG[345] CPU models require KVM support for RDTSCP, which was +added with Linux 4.5 which is supported by the major distros. And even +if RHEL7 has kernel 3.10, KVM there has the required functionality there +to make it close to a 4.5 or newer kernel. =20 @include qemu-tech.texi =20 --=20 2.18.0.rc1.1.g3f1ff2140