From nobody Thu Nov 6 22:55:43 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; dkim=fail; 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 Return-Path: Received: from lists.gnu.org (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 1544645419743108.14393636611942; Wed, 12 Dec 2018 12:10:19 -0800 (PST) Received: from localhost ([::1]:47870 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gXAph-00064F-Ew for importer@patchew.org; Wed, 12 Dec 2018 15:10:13 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56403) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gXAo7-0005D4-5U for qemu-devel@nongnu.org; Wed, 12 Dec 2018 15:08:36 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gXAo2-0004FV-NX for qemu-devel@nongnu.org; Wed, 12 Dec 2018 15:08:35 -0500 Received: from mail.skyhub.de ([5.9.137.197]:47510) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gXAo2-0003tn-8t for qemu-devel@nongnu.org; Wed, 12 Dec 2018 15:08:30 -0500 Received: from zn.tnic (p200300EC2BCDD8007CFD4A6887308591.dip0.t-ipconnect.de [IPv6:2003:ec:2bcd:d800:7cfd:4a68:8730:8591]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 9F1AD1EC096B; Wed, 12 Dec 2018 21:08:06 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1544645286; 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:in-reply-to:in-reply-to: references:references; bh=q44/+zDd3B/JoofMZtzRarkzYkmli8JtdY5LcCzimpY=; b=aRzh8EMXWnv/YPHFhj6GiW5NeHuw0AFSTsS9rw2SbV96y8ZoC6SrITCLakhYSOHzCjKXDd IAsi/SUudXfEVmvU5q2H2xkSokzKSbJ92qL+Wey7XsSu1zUOOtD2P4/knOEE9ohriscTw7 ncmg3SLRDu+4Wfsqp0rXMfnl+Suxzlw= Date: Wed, 12 Dec 2018 21:08:03 +0100 To: Eduardo Habkost Message-ID: <20181212200803.GG6653@zn.tnic> References: <20181210184153.GB5482@zn.tnic> <20181210190600.GK4669@habkost.net> <20181210194258.GD5482@zn.tnic> <20181210200843.GN4669@habkost.net> <20181211103839.GC921@redhat.com> <20181211115546.GQ4669@habkost.net> <20181211153017.GN921@redhat.com> <20181211161440.GG27375@zn.tnic> <20181212195235.GX7141@habkost.net> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20181212195235.GX7141@habkost.net> User-Agent: Mutt/1.10.1 (2018-07-13) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 5.9.137.197 Subject: [Qemu-devel] [PATCH -v2] 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: , From: Borislav Petkov via Qemu-devel Reply-To: Borislav Petkov Cc: Tom Lendacky , kvm ML , Andre Przywara , =?utf-8?B?SsO2cmcgUsO2ZGVs?= , lkml , qemu-devel@nongnu.org, Paolo Bonzini Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" On Wed, Dec 12, 2018 at 05:52:35PM -0200, Eduardo Habkost wrote: > Why did you remove this entry from PC_COMPAT_2_4? >=20 > We must keep compatibility with old behavior of Opteron_G2 on > pc-2.4, even if the old behavior was incorrect. Ok, hunk reverted. v2 below. Thx. --- 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 --- v2: Keep Opteron_G2 in PC_COMPAT_2_4 unchanged. include/hw/i386/pc.h | 13 +++++++++++++ qemu-doc.texi | 13 +++++++++++++ target/i386/cpu.c | 11 ++++------- 3 files changed, 30 insertions(+), 7 deletions(-) diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h index 9d29c4b1df2a..236d962d2547 100644 --- a/include/hw/i386/pc.h +++ b/include/hw/i386/pc.h @@ -296,6 +296,19 @@ bool e820_get_entry(int, uint32_t, uint64_t *, uint64_= t *); =20 #define PC_COMPAT_3_1 \ HW_COMPAT_3_1 \ + {\ + .driver =3D "Opteron_G3" "-" TYPE_X86_CPU,\ + .property =3D "rdtscp",\ + .value =3D "off",\ + },{\ + .driver =3D "Opteron_G4" "-" TYPE_X86_CPU,\ + .property =3D "rdtscp",\ + .value =3D "off",\ + },{\ + .driver =3D "Opteron_G5" "-" TYPE_X86_CPU,\ + .property =3D "rdtscp",\ + .value =3D "off",\ + }, =20 #define PC_COMPAT_3_0 \ HW_COMPAT_3_0 \ diff --git a/qemu-doc.texi b/qemu-doc.texi index f7ad1dfe4b69..16b955cbf985 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 diff --git a/target/i386/cpu.c b/target/i386/cpu.c index f81d35e1f914..a7def11b27cd 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -2706,7 +2706,6 @@ 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 @@ -2730,9 +2729,9 @@ 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, @@ -2757,10 +2756,9 @@ 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 | @@ -2788,10 +2786,9 @@ 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 | --=20 2.19.1 --=20 Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.