From patchwork Wed Dec 12 20:08:03 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Borislav Petkov X-Patchwork-Id: 10727067 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 20CCF91E for ; Wed, 12 Dec 2018 20:08:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0F5A62B7D5 for ; Wed, 12 Dec 2018 20:08:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 024232BA2A; Wed, 12 Dec 2018 20:08:20 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DF1362B7D5 for ; Wed, 12 Dec 2018 20:08:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726980AbeLLUIJ (ORCPT ); Wed, 12 Dec 2018 15:08:09 -0500 Received: from mail.skyhub.de ([5.9.137.197]:34094 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726247AbeLLUIJ (ORCPT ); Wed, 12 Dec 2018 15:08:09 -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 From: Borislav Petkov To: Eduardo Habkost Cc: Daniel =?utf-8?b?UC4gQmVycmFuZ8Op?= , Paolo Bonzini , =?utf-8?b?SsO2cmcgUsO2ZGVs?= , Andre Przywara , kvm ML , lkml , Tom Lendacky , Eric Blake , qemu-devel@nongnu.org Subject: [PATCH -v2] target-i386: Reenable RDTSCP support on Opteron_G[345] CPU models CPU models 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) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Wed, Dec 12, 2018 at 05:52:35PM -0200, Eduardo Habkost wrote: > Why did you remove this entry from PC_COMPAT_2_4? > > 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 >= 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 *); #define PC_COMPAT_3_1 \ HW_COMPAT_3_1 \ + {\ + .driver = "Opteron_G3" "-" TYPE_X86_CPU,\ + .property = "rdtscp",\ + .value = "off",\ + },{\ + .driver = "Opteron_G4" "-" TYPE_X86_CPU,\ + .property = "rdtscp",\ + .value = "off",\ + },{\ + .driver = "Opteron_G5" "-" TYPE_X86_CPU,\ + .property = "rdtscp",\ + .value = "off",\ + }, #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 +@node System requirements +@chapter System requirements + +@section KVM kernel module + +On x86_64 hosts, the default set of CPU features enabled by the KVM accelerator +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. @include qemu-tech.texi 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[] = { CPUID_DE | CPUID_FP87, .features[FEAT_1_ECX] = CPUID_EXT_CX16 | CPUID_EXT_SSE3, - /* Missing: CPUID_EXT2_RDTSCP */ .features[FEAT_8000_0001_EDX] = CPUID_EXT2_LM | CPUID_EXT2_NX | CPUID_EXT2_SYSCALL, .features[FEAT_8000_0001_ECX] = @@ -2730,9 +2729,9 @@ static X86CPUDefinition builtin_x86_defs[] = { .features[FEAT_1_ECX] = CPUID_EXT_POPCNT | CPUID_EXT_CX16 | CPUID_EXT_MONITOR | CPUID_EXT_SSE3, - /* Missing: CPUID_EXT2_RDTSCP */ .features[FEAT_8000_0001_EDX] = - 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] = 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[] = { 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] = CPUID_EXT2_LM | CPUID_EXT2_PDPE1GB | CPUID_EXT2_NX | - CPUID_EXT2_SYSCALL, + CPUID_EXT2_SYSCALL | CPUID_EXT2_RDTSCP, .features[FEAT_8000_0001_ECX] = CPUID_EXT3_FMA4 | CPUID_EXT3_XOP | CPUID_EXT3_3DNOWPREFETCH | CPUID_EXT3_MISALIGNSSE | @@ -2788,10 +2786,9 @@ static X86CPUDefinition builtin_x86_defs[] = { 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] = CPUID_EXT2_LM | CPUID_EXT2_PDPE1GB | CPUID_EXT2_NX | - CPUID_EXT2_SYSCALL, + CPUID_EXT2_SYSCALL | CPUID_EXT2_RDTSCP, .features[FEAT_8000_0001_ECX] = CPUID_EXT3_TBM | CPUID_EXT3_FMA4 | CPUID_EXT3_XOP | CPUID_EXT3_3DNOWPREFETCH | CPUID_EXT3_MISALIGNSSE |