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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D0229C4332F for ; Mon, 29 Nov 2021 09:49:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344036AbhK2Jwh (ORCPT ); Mon, 29 Nov 2021 04:52:37 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:46370 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244604AbhK2Jug (ORCPT ); Mon, 29 Nov 2021 04:50:36 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1638179239; 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=0qUJTyJu6gcW2XuY0aJhl0MQXWjW8+1IUhO0WvrIMxs=; b=IkTGibAwOoWiuRGwoG9tgYn+IHNLJFpVhotZocpGwVoYmXxyITukzc6up/7j912sGXBHKO 3wRpZsAkBlVJyeqpoHp3OMxrNqJZvxyVTssr8ay22GBSUne4IIDTr8VilgwmjJZ+bILiDU pDnpEXk3IFXFsH0xD4J7984g/tNuY0Y= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-564-Ysq5TsKkNoqgTxHGAaKEfg-1; Mon, 29 Nov 2021 04:47:17 -0500 X-MC-Unique: Ysq5TsKkNoqgTxHGAaKEfg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B4FED18C89D9; Mon, 29 Nov 2021 09:47:16 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.39.195.203]) by smtp.corp.redhat.com (Postfix) with ESMTP id 939C95D6B1; Mon, 29 Nov 2021 09:47:15 +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 v5 3/4] KVM: nVMX: Track whether changes in L0 require MSR bitmap for L2 to be rebuilt Date: Mon, 29 Nov 2021 10:47:03 +0100 Message-Id: <20211129094704.326635-4-vkuznets@redhat.com> In-Reply-To: <20211129094704.326635-1-vkuznets@redhat.com> References: <20211129094704.326635-1-vkuznets@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 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 95f3823b3a9d..2fe26fc4a4d5 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -672,6 +672,8 @@ static inline bool nested_vmx_prepare_msr_bitmap(struct kvm_vcpu *vcpu, kvm_vcpu_unmap(vcpu, &vmx->nested.msr_bitmap_map, false); + vmx->nested.force_msr_bitmap_recalc = false; + return true; } @@ -2029,10 +2031,13 @@ 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.force_msr_bitmap_recalc = true; + } + return EVMPTRLD_SUCCEEDED; } @@ -5258,6 +5263,7 @@ 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.force_msr_bitmap_recalc = true; } /* Emulate the VMPTRLD instruction */ @@ -6393,6 +6399,7 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu, goto error_guest_mode; vmx->nested.dirty_vmcs12 = true; + vmx->nested.force_msr_bitmap_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 4bd1c5746fe0..cf1368724540 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -3697,6 +3697,8 @@ static void vmx_msr_bitmap_l01_changed(struct vcpu_vmx *vmx) */ if (static_branch_unlikely(&enable_evmcs)) evmcs_touch_msr_bitmap(); + + vmx->nested.force_msr_bitmap_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 f978699480e3..6c2c1aff1c3d 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -158,6 +158,15 @@ 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 force_msr_bitmap_recalc; + /* * Indicates lazily loaded guest state has not yet been decached from * vmcs02. -- 2.33.1