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 E5FD4C433F5 for ; Mon, 29 Nov 2021 09:49:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343627AbhK2Jwd (ORCPT ); Mon, 29 Nov 2021 04:52:33 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:36417 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238670AbhK2Jua (ORCPT ); Mon, 29 Nov 2021 04:50:30 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1638179232; 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; bh=mwp0gBwc6gvcsvlfC3q+oEEiELWsgNE32DBmNySkG/Y=; b=Qiv5CECZ5Ynm75FUllfaPBK3FTAbjvVT3e/ontYYDHHo/lTm4+U0Olgi6n9bpYhRHl69ta DY8j9EIgYnRU2kkT/BJdGeVd9QgTz8b6APN1tNjddIdXNyIe8Emq95KwHGY/OQiVZd5ywn 4EpVT6r3EJyV3OVDIbu9Ll0cWITLvqQ= 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-120-eM9-RiCANdaAlYaBqO-uFw-1; Mon, 29 Nov 2021 04:47:09 -0500 X-MC-Unique: eM9-RiCANdaAlYaBqO-uFw-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 3924183DD20; Mon, 29 Nov 2021 09:47:08 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.39.195.203]) by smtp.corp.redhat.com (Postfix) with ESMTP id 814465D6B1; Mon, 29 Nov 2021 09:47:06 +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 0/4] KVM: nVMX: Enlightened MSR Bitmap feature for Hyper-V on KVM Date: Mon, 29 Nov 2021 10:47:00 +0100 Message-Id: <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 Changes since "[PATCH v4 0/8] KVM: nVMX: Enlightened MSR Bitmap feature for Hyper-V on KVM (+ KVM: x86: MSR filtering and related fixes)": - Drop Sean's "KVM: x86: MSR filtering and related fixes" as they're already queued, rebase to the latest kvm/queue. Original description of the feature: Updating MSR bitmap for L2 is not cheap and rearly needed. TLFS for Hyper-V offers 'Enlightened MSR Bitmap' feature which allows L1 hypervisor to inform L0 when it changes MSR bitmap, this eliminates the need to examine L1's MSR bitmap for L2 every time when 'real' MSR bitmap for L2 gets constructed. When the feature is enabled for Win10+WSL2, it shaves off around 700 CPU cycles from a nested vmexit cost (tight cpuid loop test). First patch of the series is unrelated to the newly implemented feature, it fixes a bug in Enlightened MSR Bitmap usage when KVM runs as a nested hypervisor on top of Hyper-V. Vitaly Kuznetsov (4): KVM: nVMX: Don't use Enlightened MSR Bitmap for L3 KVM: VMX: Introduce vmx_msr_bitmap_l01_changed() helper KVM: nVMX: Track whether changes in L0 require MSR bitmap for L2 to be rebuilt KVM: nVMX: Implement Enlightened MSR Bitmap feature arch/x86/kvm/hyperv.c | 2 ++ arch/x86/kvm/vmx/nested.c | 23 +++++++++++++++++++++- arch/x86/kvm/vmx/vmx.c | 41 ++++++++++++++++++++++++++------------- arch/x86/kvm/vmx/vmx.h | 9 +++++++++ 4 files changed, 61 insertions(+), 14 deletions(-) -- 2.33.1