From patchwork Wed Apr 21 14:06:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vineeth Pillai X-Patchwork-Id: 12216201 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=-21.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 E72D2C43617 for ; Wed, 21 Apr 2021 14:07:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B9BD361457 for ; Wed, 21 Apr 2021 14:07:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243371AbhDUOHp (ORCPT ); Wed, 21 Apr 2021 10:07:45 -0400 Received: from linux.microsoft.com ([13.77.154.182]:36978 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243323AbhDUOHi (ORCPT ); Wed, 21 Apr 2021 10:07:38 -0400 Received: from viremana-dev.fwjladdvyuiujdukmejncen4mf.xx.internal.cloudapp.net (unknown [13.66.132.26]) by linux.microsoft.com (Postfix) with ESMTPSA id A031020B8001; Wed, 21 Apr 2021 07:07:04 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com A031020B8001 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1619014024; bh=Cg5t1YQVX4cxqUdMwABIBhBs50zuYp0RIByfae1cQIs=; h=From:To:Cc:Subject:Date:From; b=sNmmAB3BcY0o93b9qcSFnOEbwY3ph/E3Kh64eWsqihR8XQP0ycLXgMHqIdofeuiXp fxwdd95sbKFEvYMd1dc9Pxf9XxNwOvnVYAHuhnMugcCoj8TmKxZWq9qHje2uznlzrU Wwm7Kws0hrjCsyJvQmgpafYqzb/fD2ZDzXKFIH5o= From: Vineeth Pillai To: Lan Tianyu , Michael Kelley , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Wei Liu , Stephen Hemminger , Haiyang Zhang Cc: Vineeth Pillai , "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "K. Y. Srinivasan" , x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org Subject: [PATCH v3 0/7] Hyper-V nested virt enlightenments for SVM Date: Wed, 21 Apr 2021 14:06:47 +0000 Message-Id: X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org This patch series enables the nested virtualization enlightenments for SVM. This is very similar to the enlightenments for VMX except for the fact that there is no enlightened VMCS. For SVM, VMCB is already an architectural in-memory data structure. The supported enlightenments are: Enlightened TLB Flush: If this is enabled, ASID invalidations invalidate only gva -> hpa entries. To flush entries derived from NPT, hyper-v provided hypercalls (HvFlushGuestPhysicalAddressSpace or HvFlushGuestPhysicalAddressList) should be used. Enlightened MSR bitmap(TLFS 16.5.3): "When enabled, L0 hypervisor does not monitor the MSR bitmaps for changes. Instead, the L1 hypervisor must invalidate the corresponding clean field after making changes to one of the MSR bitmaps." Direct Virtual Flush(TLFS 16.8): The hypervisor exposes hypercalls (HvFlushVirtualAddressSpace, HvFlushVirtualAddressSpaceEx, HvFlushVirtualAddressList, and HvFlushVirtualAddressListEx) that allow operating systems to more efficiently manage the virtual TLB. The L1 hypervisor can choose to allow its guest to use those hypercalls and delegate the responsibility to handle them to the L0 hypervisor. This requires the use of a partition assist page." L2 Windows boot time was measured with and without the patch. Time was measured from power on to the login screen and was averaged over a consecutive 5 trials: Without the patch: 42 seconds With the patch: 29 seconds --- Changes from v2: - Refactored the Remote TLB Flush logic into separate hyperv specific source files (kvm_onhyperv.[ch]). - Reverted the VMCB Clean bits macro changes as it is no longer needed. Changes from v1: - Move the remote TLB flush related fields from kvm_vcpu_hv and kvm_hv to kvm_vcpu_arch and kvm_arch. - Modify the VMCB clean mask runtime based on whether L1 hypervisor is running on Hyper-V or not. - Detect Hyper-V nested enlightenments based on HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS. - Address other minor review comments. --- Vineeth Pillai (7): hyperv: Detect Nested virtualization support for SVM hyperv: SVM enlightened TLB flush support flag KVM: x86: hyper-v: Move the remote TLB flush logic out of vmx KVM: SVM: hyper-v: Nested enlightenments in VMCB KVM: SVM: hyper-v: Remote TLB flush for SVM KVM: SVM: hyper-v: Enlightened MSR-Bitmap support KVM: SVM: hyper-v: Direct Virtual Flush support arch/x86/include/asm/hyperv-tlfs.h | 9 +++ arch/x86/include/asm/kvm_host.h | 14 ++++ arch/x86/include/asm/svm.h | 24 +++++- arch/x86/kernel/cpu/mshyperv.c | 10 ++- arch/x86/kvm/Makefile | 5 ++ arch/x86/kvm/kvm_onhyperv.c | 94 ++++++++++++++++++++++ arch/x86/kvm/kvm_onhyperv.h | 31 ++++++++ arch/x86/kvm/svm/svm.c | 121 +++++++++++++++++++++++++++++ arch/x86/kvm/svm/svm.h | 12 ++- arch/x86/kvm/vmx/vmx.c | 97 ++--------------------- arch/x86/kvm/vmx/vmx.h | 10 --- arch/x86/kvm/x86.c | 8 ++ 12 files changed, 330 insertions(+), 105 deletions(-) create mode 100644 arch/x86/kvm/kvm_onhyperv.c create mode 100644 arch/x86/kvm/kvm_onhyperv.h