From patchwork Wed May 20 20:27:54 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liang Li X-Patchwork-Id: 6443171 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 7D9759F318 for ; Wed, 20 May 2015 08:38:04 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 9A928203B7 for ; Wed, 20 May 2015 08:38:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B3A8F203DB for ; Wed, 20 May 2015 08:38:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752369AbbETIhm (ORCPT ); Wed, 20 May 2015 04:37:42 -0400 Received: from mga03.intel.com ([134.134.136.65]:38563 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750934AbbETIhj (ORCPT ); Wed, 20 May 2015 04:37:39 -0400 Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga103.jf.intel.com with ESMTP; 20 May 2015 01:37:40 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.13,464,1427785200"; d="scan'208";a="495949800" Received: from ll.sh.intel.com (HELO localhost) ([10.239.13.40]) by FMSMGA003.fm.intel.com with ESMTP; 20 May 2015 01:37:37 -0700 From: Liang Li To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: pbonzini@redhat.com, gleb@kernel.org, mtosatt@redhat.com, Liang Li , Yang Zhang Subject: [v2] kvm/fpu: Enable eager restore kvm FPU for MPX Date: Thu, 21 May 2015 04:27:54 +0800 Message-Id: <1432153674-10398-1-git-send-email-liang.z.li@intel.com> X-Mailer: git-send-email 1.9.1 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-5.0 required=5.0 tests=BAYES_00, DATE_IN_FUTURE_06_12, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The MPX feature requires eager KVM FPU restore support. We have verified that MPX cannot work correctly with the current lazy KVM FPU restore mechanism. Eager KVM FPU restore should be enabled if the MPX feature is exposed to VM. Signed-off-by: Liang Li Signed-off-by: Yang Zhang --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/cpuid.c | 4 ++++ arch/x86/kvm/cpuid.h | 8 ++++++++ arch/x86/kvm/vmx.c | 4 ++++ arch/x86/kvm/x86.c | 3 ++- 5 files changed, 19 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index e61c3a4..4cb39d4 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -401,6 +401,7 @@ struct kvm_vcpu_arch { struct kvm_mmu_memory_cache mmu_page_header_cache; struct fpu guest_fpu; + bool eager_fpu; u64 xcr0; u64 guest_supported_xcr0; u32 guest_xstate_size; diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 59b69f6..5ac5e4d 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -95,6 +95,10 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu) if (best && (best->eax & (F(XSAVES) | F(XSAVEC)))) best->ebx = xstate_required_size(vcpu->arch.xcr0, true); + if (guest_cpuid_has_mpx(vcpu)) + vcpu->arch.eager_fpu = true; + else + vcpu->arch.eager_fpu = false; /* * The existing code assumes virtual address is 48-bit in the canonical * address checks; exit if it is ever changed. diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h index c3b1ad9..496b369 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -117,4 +117,12 @@ static inline bool guest_cpuid_has_rtm(struct kvm_vcpu *vcpu) best = kvm_find_cpuid_entry(vcpu, 7, 0); return best && (best->ebx & bit(X86_FEATURE_RTM)); } + +static inline bool guest_cpuid_has_mpx(struct kvm_vcpu *vcpu) +{ + struct kvm_cpuid_entry2 *best; + + best = kvm_find_cpuid_entry(vcpu, 7, 0); + return best && (best->ebx & bit(X86_FEATURE_MPX)); +} #endif diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index f7b6168..030c1475 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -8445,6 +8445,10 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) goto free_vmcs; } + /* activate fpu here is okay, because it will be deactivated soon if the + * lazy fpu restore mode is used. + */ + vmx_fpu_activate(&vmx->vcpu); return &vmx->vcpu; free_vmcs: diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 5f38188..4d9f8e9 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7060,7 +7060,8 @@ void kvm_put_guest_fpu(struct kvm_vcpu *vcpu) fpu_save_init(&vcpu->arch.guest_fpu); __kernel_fpu_end(); ++vcpu->stat.fpu_reload; - kvm_make_request(KVM_REQ_DEACTIVATE_FPU, vcpu); + if (!vcpu->arch.eager_fpu) + kvm_make_request(KVM_REQ_DEACTIVATE_FPU, vcpu); trace_kvm_fpu(0); }