From patchwork Thu Oct 4 20:49:05 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eduardo Habkost X-Patchwork-Id: 1548211 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 2AB9240D2D for ; Thu, 4 Oct 2012 20:49:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757512Ab2JDUs7 (ORCPT ); Thu, 4 Oct 2012 16:48:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57767 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757319Ab2JDUsP (ORCPT ); Thu, 4 Oct 2012 16:48:15 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q94KmDNp001227 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 4 Oct 2012 16:48:13 -0400 Received: from blackpad.lan.raisama.net (vpn1-7-183.gru2.redhat.com [10.97.7.183]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id q94KmCge008175; Thu, 4 Oct 2012 16:48:12 -0400 Received: by blackpad.lan.raisama.net (Postfix, from userid 500) id 26628203634; Thu, 4 Oct 2012 17:49:13 -0300 (BRT) From: Eduardo Habkost To: qemu-devel@nongnu.org Cc: kvm@vger.kernel.org, Igor Mammedov , Avi Kivity , Gleb Natapov , Marcelo Tosatti , =?UTF-8?q?Andreas=20F=C3=A4rber?= Subject: [PATCH 13/15] i386: kvm: filter CPUID feature words earlier, on cpu.c Date: Thu, 4 Oct 2012 17:49:05 -0300 Message-Id: <1349383747-19383-14-git-send-email-ehabkost@redhat.com> In-Reply-To: <1349383747-19383-1-git-send-email-ehabkost@redhat.com> References: <1349383747-19383-1-git-send-email-ehabkost@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org cpu.c contains the code that will check if all requested CPU features are available, so the filtering of KVM features must be there, so we can implement "check" and "enforce" properly. The only point where kvm_arch_init_vcpu() is called on i386 is: - cpu_x86_init() - x86_cpu_realize() (after cpu_x86_register() is called) - qemu_init_vcpu() - qemu_kvm_start_vcpu() - qemu_kvm_thread_fn() (on a new thread) - kvm_init_vcpu() - kvm_arch_init_vcpu() With this patch, the filtering will be done earlier, at: - cpu_x86_init() - cpu_x86_register() (before x86_cpu_realize() is called) Also, the KVM CPUID filtering will now be done at the same place where the TCG CPUID feature filtering is done. Later, the code can be changed to use the same filtering code for the "check" and "enforce" modes, as now the cpu.c code knows exactly which CPU features are going to be exposed to the guest (and much earlier). One thing I was worrying about when doing this is that kvm_arch_get_supported_cpuid() depends on kvm_irqchip_in_kernel(), and maybe the 'kvm_kernel_irqchip' global variable wasn't initialized yet at CPU creation time. But kvm_kernel_irqchip is initialized during kvm_init(), that is called very early (much earlier than the machine init function), and kvm_init() is already a requirement to run the GET_SUPPORTED_CPUID ioctl() (as kvm_init() initializes the kvm_state global variable). Side note: it would be nice to keep KVM-specific code inside kvm.c. The problem is that properly implementing -cpu check/enforce code (that's inside cpu.c) depends directly on the feature bit filtering done using kvm_arch_get_supported_cpuid(). Currently -cpu check/enforce is broken because it simply uses the host CPU feature bits instead of GET_SUPPORTED_CPUID, and we need to fix that. Signed-off-by: Eduardo Habkost --- kvm.h | 1 + target-i386/cpu.c | 30 ++++++++++++++++++++++++++++++ target-i386/kvm.c | 18 ------------------ 3 files changed, 31 insertions(+), 18 deletions(-) diff --git a/kvm.h b/kvm.h index dea2998..150f95d 100644 --- a/kvm.h +++ b/kvm.h @@ -20,6 +20,7 @@ #ifdef CONFIG_KVM #include +#include #endif extern int kvm_allowed; diff --git a/target-i386/cpu.c b/target-i386/cpu.c index bb1e44e..a5c1628 100644 --- a/target-i386/cpu.c +++ b/target-i386/cpu.c @@ -1360,6 +1360,32 @@ CpuDefinitionInfoList *arch_query_cpu_definitions(Error **errp) return cpu_list; } +#ifdef CONFIG_KVM +static void filter_features_for_kvm(X86CPU *cpu) +{ + CPUX86State *env = &cpu->env; + KVMState *s = kvm_state; + + env->cpuid_features &= kvm_arch_get_supported_cpuid(s, 1, 0, R_EDX); + + env->cpuid_ext_features &= kvm_arch_get_supported_cpuid(s, 1, 0, R_ECX); + + env->cpuid_ext2_features &= kvm_arch_get_supported_cpuid(s, 0x80000001, + 0, R_EDX); + env->cpuid_ext3_features &= kvm_arch_get_supported_cpuid(s, 0x80000001, + 0, R_ECX); + env->cpuid_svm_features &= kvm_arch_get_supported_cpuid(s, 0x8000000A, + 0, R_EDX); + + env->cpuid_kvm_features &= + kvm_arch_get_supported_cpuid(s, KVM_CPUID_FEATURES, 0, R_EAX); + + env->cpuid_ext4_features &= kvm_arch_get_supported_cpuid(s, 0xC0000001, + 0, R_EDX); + +} +#endif + int cpu_x86_register(X86CPU *cpu, const char *cpu_model) { CPUX86State *env = &cpu->env; @@ -1417,6 +1443,10 @@ int cpu_x86_register(X86CPU *cpu, const char *cpu_model) ); env->cpuid_ext3_features &= TCG_EXT3_FEATURES; env->cpuid_svm_features &= TCG_SVM_FEATURES; + } else { +#ifdef CONFIG_KVM + filter_features_for_kvm(cpu); +#endif } object_property_set_str(OBJECT(cpu), def->model_id, "model-id", &error); if (error_is_set(&error)) { diff --git a/target-i386/kvm.c b/target-i386/kvm.c index 335b3e7..0257083 100644 --- a/target-i386/kvm.c +++ b/target-i386/kvm.c @@ -410,30 +410,12 @@ int kvm_arch_init_vcpu(CPUX86State *env) struct kvm_cpuid2 cpuid; struct kvm_cpuid_entry2 entries[100]; } QEMU_PACKED cpuid_data; - KVMState *s = env->kvm_state; uint32_t limit, i, j, cpuid_i; uint32_t unused; struct kvm_cpuid_entry2 *c; uint32_t signature[3]; int r; - env->cpuid_features &= kvm_arch_get_supported_cpuid(s, 1, 0, R_EDX); - - env->cpuid_ext_features &= kvm_arch_get_supported_cpuid(s, 1, 0, R_ECX); - - env->cpuid_ext2_features &= kvm_arch_get_supported_cpuid(s, 0x80000001, - 0, R_EDX); - env->cpuid_ext3_features &= kvm_arch_get_supported_cpuid(s, 0x80000001, - 0, R_ECX); - env->cpuid_svm_features &= kvm_arch_get_supported_cpuid(s, 0x8000000A, - 0, R_EDX); - - env->cpuid_kvm_features &= - kvm_arch_get_supported_cpuid(s, KVM_CPUID_FEATURES, 0, R_EAX); - - env->cpuid_ext4_features &= kvm_arch_get_supported_cpuid(s, 0xC0000001, - 0, R_EDX); - cpuid_i = 0; /* Paravirtualization CPUIDs */