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=-12.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 8C1CEC388F7 for ; Tue, 20 Oct 2020 21:56:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3FC862237B for ; Tue, 20 Oct 2020 21:56:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2438843AbgJTV4T (ORCPT ); Tue, 20 Oct 2020 17:56:19 -0400 Received: from mga12.intel.com ([192.55.52.136]:61050 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2438807AbgJTV4P (ORCPT ); Tue, 20 Oct 2020 17:56:15 -0400 IronPort-SDR: DgidWhlLCBLF7+k4p74s2OuFdrhjW+Fjzs2QHeYgewr7HTDRoxPsgoP3ujbuYcy4Wy9aXHLhvl PqfSfoQdNLaA== X-IronPort-AV: E=McAfee;i="6000,8403,9780"; a="146576323" X-IronPort-AV: E=Sophos;i="5.77,399,1596524400"; d="scan'208";a="146576323" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Oct 2020 14:56:15 -0700 IronPort-SDR: cOUZ6k3xd/1OjjHJci/Y239nTI5oJaJQAJtOg4YdcQ8HxkLyBG5dpNAkcRKdqlPn7A/hDxiCts LKO/gnnJGhRw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,399,1596524400"; d="scan'208";a="301827717" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.160]) by fmsmga008.fm.intel.com with ESMTP; 20 Oct 2020 14:56:14 -0700 From: Sean Christopherson To: Paolo Bonzini Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 01/10] KVM: VMX: Track common EPTP for Hyper-V's paravirt TLB flush Date: Tue, 20 Oct 2020 14:56:04 -0700 Message-Id: <20201020215613.8972-2-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201020215613.8972-1-sean.j.christopherson@intel.com> References: <20201020215613.8972-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Explicitly track the EPTP that is common to all vCPUs instead of grabbing vCPU0's EPTP when invoking Hyper-V's paravirt TLB flush. Tracking the EPTP will allow optimizing the checks when loading a new EPTP and will also allow dropping ept_pointer_match, e.g. by marking the common EPTP as invalid. This also technically fixes a bug where KVM could theoretically flush an invalid GPA if all vCPUs have an invalid root. In practice, it's likely impossible to trigger a remote TLB flush in such a scenario. In any case, the superfluous flush is completely benign. Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/vmx.c | 19 ++++++++----------- arch/x86/kvm/vmx/vmx.h | 1 + 2 files changed, 9 insertions(+), 11 deletions(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index bcc097bb8321..6d53bcc4a1a9 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -486,6 +486,7 @@ static void check_ept_pointer_match(struct kvm *kvm) } } + to_kvm_vmx(kvm)->hv_tlb_eptp = tmp_eptp; to_kvm_vmx(kvm)->ept_pointers_match = EPT_POINTERS_MATCH; } @@ -498,21 +499,18 @@ static int kvm_fill_hv_flush_list_func(struct hv_guest_mapping_flush_list *flush range->pages); } -static inline int __hv_remote_flush_tlb_with_range(struct kvm *kvm, - struct kvm_vcpu *vcpu, struct kvm_tlb_range *range) +static inline int hv_remote_flush_eptp(u64 eptp, struct kvm_tlb_range *range) { - u64 ept_pointer = to_vmx(vcpu)->ept_pointer; - /* * FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE hypercall needs address * of the base of EPT PML4 table, strip off EPT configuration * information. */ if (range) - return hyperv_flush_guest_mapping_range(ept_pointer & PAGE_MASK, + return hyperv_flush_guest_mapping_range(eptp & PAGE_MASK, kvm_fill_hv_flush_list_func, (void *)range); else - return hyperv_flush_guest_mapping(ept_pointer & PAGE_MASK); + return hyperv_flush_guest_mapping(eptp & PAGE_MASK); } static int hv_remote_flush_tlb_with_range(struct kvm *kvm, @@ -530,12 +528,11 @@ static int hv_remote_flush_tlb_with_range(struct kvm *kvm, kvm_for_each_vcpu(i, vcpu, kvm) { /* If ept_pointer is invalid pointer, bypass flush request. */ if (VALID_PAGE(to_vmx(vcpu)->ept_pointer)) - ret |= __hv_remote_flush_tlb_with_range( - kvm, vcpu, range); + ret |= hv_remote_flush_eptp(to_vmx(vcpu)->ept_pointer, + range); } - } else { - ret = __hv_remote_flush_tlb_with_range(kvm, - kvm_get_vcpu(kvm, 0), range); + } else if (VALID_PAGE(to_kvm_vmx(kvm)->hv_tlb_eptp)) { + ret = hv_remote_flush_eptp(to_kvm_vmx(kvm)->hv_tlb_eptp, range); } spin_unlock(&to_kvm_vmx(kvm)->ept_pointer_lock); diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index 5961cb897125..3d557a065c01 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -301,6 +301,7 @@ struct kvm_vmx { bool ept_identity_pagetable_done; gpa_t ept_identity_map_addr; + hpa_t hv_tlb_eptp; enum ept_pointers_status ept_pointers_match; spinlock_t ept_pointer_lock; }; -- 2.28.0