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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 232DDC433F5 for ; Wed, 13 Oct 2021 14:23:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 090F660E96 for ; Wed, 13 Oct 2021 14:23:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237511AbhJMOZh (ORCPT ); Wed, 13 Oct 2021 10:25:37 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:33274 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231980AbhJMOZW (ORCPT ); Wed, 13 Oct 2021 10:25:22 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1634134994; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=YcbIaIFmLcSI/vhU67IBzzFPXVlkOAtf5s1w+5KgaeI=; b=FaEonMi+0EoRsqa9puLDk4tnhvXqu21XQIYvv1q3vsXr+ZYsMAvkR+JQk2k3ldgl68bJmn ZnxZNnvogO3CyxWXYVSjTN8a/RpCBuzzz1enEvBdEgOID/s863Em8z8dOaOTHoWwrzcFSN rmSN+VJzNFCrTaOCW6EJiBEa+OJJdwY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-173-vt2A9PADP5Wtm2ncfClzmQ-1; Wed, 13 Oct 2021 10:23:10 -0400 X-MC-Unique: vt2A9PADP5Wtm2ncfClzmQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 747761006AA2; Wed, 13 Oct 2021 14:23:09 +0000 (UTC) Received: from vitty.brq.redhat.com (unknown [10.40.193.50]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5E42157CA5; Wed, 13 Oct 2021 14:23:07 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Wanpeng Li , Jim Mattson , Maxim Levitsky , linux-kernel@vger.kernel.org Subject: [PATCH v3 3/4] KVM: nVMX: Track whether changes in L0 require MSR bitmap for L2 to be rebuilt Date: Wed, 13 Oct 2021 16:22:57 +0200 Message-Id: <20211013142258.1738415-4-vkuznets@redhat.com> In-Reply-To: <20211013142258.1738415-1-vkuznets@redhat.com> References: <20211013142258.1738415-1-vkuznets@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Introduce a flag to keep track of whether MSR bitmap for L2 needs to be rebuilt due to changes in MSR bitmap for L1 or switching to a different L2. This information will be used for Enlightened MSR Bitmap feature for Hyper-V guests. Note, setting msr_bitmap_changed to 'true' from set_current_vmptr() is not really needed for Enlightened MSR Bitmap as the feature can only be used in conjunction with Enlightened VMCS but let's keep tracking information complete, it's cheap and in the future similar PV feature can easily be implemented for KVM on KVM too. No functional change intended. Signed-off-by: Vitaly Kuznetsov --- arch/x86/kvm/vmx/nested.c | 9 ++++++++- arch/x86/kvm/vmx/vmx.c | 2 ++ arch/x86/kvm/vmx/vmx.h | 9 +++++++++ 3 files changed, 19 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index af1bbb73430a..bf4fa63ed371 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -700,6 +700,8 @@ static inline bool nested_vmx_prepare_msr_bitmap(struct kvm_vcpu *vcpu, kvm_vcpu_unmap(vcpu, &to_vmx(vcpu)->nested.msr_bitmap_map, false); + vmx->nested.msr_bitmap_force_recalc = false; + return true; } @@ -2054,10 +2056,13 @@ static enum nested_evmptrld_status nested_vmx_handle_enlightened_vmptrld( * Clean fields data can't be used on VMLAUNCH and when we switch * between different L2 guests as KVM keeps a single VMCS12 per L1. */ - if (from_launch || evmcs_gpa_changed) + if (from_launch || evmcs_gpa_changed) { vmx->nested.hv_evmcs->hv_clean_fields &= ~HV_VMX_ENLIGHTENED_CLEAN_FIELD_ALL; + vmx->nested.msr_bitmap_force_recalc = true; + } + return EVMPTRLD_SUCCEEDED; } @@ -5274,6 +5279,7 @@ static void set_current_vmptr(struct vcpu_vmx *vmx, gpa_t vmptr) vmx->nested.need_vmcs12_to_shadow_sync = true; } vmx->nested.dirty_vmcs12 = true; + vmx->nested.msr_bitmap_force_recalc = true; } /* Emulate the VMPTRLD instruction */ @@ -6400,6 +6406,7 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu, goto error_guest_mode; vmx->nested.dirty_vmcs12 = true; + vmx->nested.msr_bitmap_force_recalc = true; ret = nested_vmx_enter_non_root_mode(vcpu, false); if (ret) goto error_guest_mode; diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 3fdaaef291e8..c78c315def59 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -3735,6 +3735,8 @@ static void vmx_msr_bitmap_l01_changed(struct vcpu_vmx *vmx) */ if (static_branch_unlikely(&enable_evmcs)) evmcs_touch_msr_bitmap(); + + vmx->nested.msr_bitmap_force_recalc = true; } void vmx_disable_intercept_for_msr(struct kvm_vcpu *vcpu, u32 msr, int type) diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index 592217fd7d92..2cdf66e6d1b0 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -148,6 +148,15 @@ struct nested_vmx { bool need_vmcs12_to_shadow_sync; bool dirty_vmcs12; + /* + * Indicates whether MSR bitmap for L2 needs to be rebuilt due to + * changes in MSR bitmap for L1 or switching to a different L2. Note, + * this flag can only be used reliably in conjunction with a paravirt L1 + * which informs L0 whether any changes to MSR bitmap for L2 were done + * on its side. + */ + bool msr_bitmap_force_recalc; + /* * Indicates lazily loaded guest state has not yet been decached from * vmcs02. -- 2.31.1