From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1A2D4C43382 for ; Tue, 25 Sep 2018 17:59:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C2C4520896 for ; Tue, 25 Sep 2018 17:58:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C2C4520896 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727166AbeIZAHh (ORCPT ); Tue, 25 Sep 2018 20:07:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:1342 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726163AbeIZAHh (ORCPT ); Tue, 25 Sep 2018 20:07:37 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D9E7F86672; Tue, 25 Sep 2018 17:58:57 +0000 (UTC) Received: from vitty.brq.redhat.com (ovpn-204-21.brq.redhat.com [10.40.204.21]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9487560BF6; Tue, 25 Sep 2018 17:58:47 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org Cc: Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Jim Mattson , Liran Alon , Sean Christopherson , linux-kernel@vger.kernel.org Subject: [PATCH v2 0/9] x86/kvm/nVMX: optimize MMU switch between L1 and L2 Date: Tue, 25 Sep 2018 19:58:35 +0200 Message-Id: <20180925175844.20277-1-vkuznets@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Tue, 25 Sep 2018 17:58:57 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Changes since v1 [Sean Christopherson]: - drop now unneded local 'vmx' variable from vmx_free_vcpu_nested() - Rename: kvm_mmu_scache -> kvm_mmu_extended_role mmu_role.scache -> mmu_role.ext mmu_role.base_role -> mmu_role.base - Add BUILD_BUG_ONs checking MMU role unions sizes. Original description: Currently, when we switch from L1 to L2 (VMX) we do the following: - Re-initialize L1 MMU as shadow EPT MMU (nested_ept_init_mmu_context()) - Re-initialize 'nested' MMU (nested_vmx_load_cr3() -> init_kvm_nested_mmu()) When we switch back we do: - Re-initialize L1 MMU (nested_vmx_load_cr3() -> init_kvm_tdp_mmu()) This seems to be sub-optimal. Initializing MMU is expensive (thanks to update_permission_bitmask(), update_pkru_bitmask(),..) Try solving the issue by splitting L1-normal and L1-nested MMUs and checking if MMU reset is really needed. This spares us about 1000 cpu cycles on nested vmexit. Brief look at SVM makes me think it can be optimized the exact same way. I'll do this in a separate series if nobody objects. Paolo Bonzini (1): x86/kvm/mmu: get rid of redundant kvm_mmu_setup() Vitaly Kuznetsov (8): x86/kvm/mmu: make vcpu->mmu a pointer to the current MMU x86/kvm/mmu.c: set get_pdptr hook in kvm_init_shadow_ept_mmu() x86/kvm/mmu.c: add kvm_mmu parameter to kvm_mmu_free_roots() x86/kvm/mmu: introduce guest_mmu x86/kvm/mmu: make space for source data caching in struct kvm_mmu x86/kvm/nVMX: introduce source data cache for kvm_init_shadow_ept_mmu() x86/kvm/mmu: check if tdp/shadow MMU reconfiguration is needed x86/kvm/mmu: check if MMU reconfiguration is needed in init_kvm_nested_mmu() arch/x86/include/asm/kvm_host.h | 44 +++- arch/x86/kvm/mmu.c | 345 +++++++++++++++++++------------- arch/x86/kvm/mmu.h | 8 +- arch/x86/kvm/mmu_audit.c | 12 +- arch/x86/kvm/paging_tmpl.h | 15 +- arch/x86/kvm/svm.c | 14 +- arch/x86/kvm/vmx.c | 46 +++-- arch/x86/kvm/x86.c | 22 +- 8 files changed, 305 insertions(+), 201 deletions(-) -- 2.17.1