From patchwork Mon May 17 13:50:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 12262035 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=-11.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 23D7EC433B4 for ; Mon, 17 May 2021 13:51:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 03DB061209 for ; Mon, 17 May 2021 13:51:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237549AbhEQNwR (ORCPT ); Mon, 17 May 2021 09:52:17 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:59811 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233139AbhEQNwR (ORCPT ); Mon, 17 May 2021 09:52:17 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1621259460; 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=C+tg4c3vND5Z6+PsNiPP16d8jOHSNadBgt74LgH79DM=; b=EYDrNMP92yCUa6d3wixDYUGfjhqrJsktX7HJob+vAMJPguJZFXrEQ+RNkfkaaL1vdw1r4i 1QQtOrdibo7XXNXHiGcQi2ja0zKEiYakBmc+OH0lHJpEzLzqQbskYarDCA5XDUDN4m54iy mBnCt2cGez/sBBFxhXUVsniwl4usQ1Q= 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-248-6QNT2PQ7MiqH4mdwbB0tGg-1; Mon, 17 May 2021 09:50:59 -0400 X-MC-Unique: 6QNT2PQ7MiqH4mdwbB0tGg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CC973801106; Mon, 17 May 2021 13:50:57 +0000 (UTC) Received: from vitty.brq.redhat.com (unknown [10.40.194.112]) by smtp.corp.redhat.com (Postfix) with ESMTP id C08985C1A1; Mon, 17 May 2021 13:50:55 +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 v2 0/7] KVM: nVMX: Fixes for nested state migration when eVMCS is in use Date: Mon, 17 May 2021 15:50:47 +0200 Message-Id: <20210517135054.1914802-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Changes since v1 (Sean): - Drop now-unneeded curly braces in nested_sync_vmcs12_to_shadow(). - Pass 'evmcs->hv_clean_fields' instead of 'bool from_vmentry' to copy_enlightened_to_vmcs12(). Commit f5c7e8425f18 ("KVM: nVMX: Always make an attempt to map eVMCS after migration") fixed the most obvious reason why Hyper-V on KVM (e.g. Win10 + WSL2) was crashing immediately after migration. It was also reported that we have more issues to fix as, while the failure rate was lowered signifincatly, it was still possible to observe crashes after several dozens of migration. Turns out, the issue arises when we manage to issue KVM_GET_NESTED_STATE right after L2->L2 VMEXIT but before L1 gets a chance to run. This state is tracked with 'need_vmcs12_to_shadow_sync' flag but the flag itself is not part of saved nested state. A few other less significant issues are fixed along the way. While there's no proof this series fixes all eVMCS related problems, Win10+WSL2 was able to survive 3333 (thanks, Max!) migrations without crashing in testing. Patches are based on the current kvm/next tree. Vitaly Kuznetsov (7): KVM: nVMX: Introduce nested_evmcs_is_used() KVM: nVMX: Release enlightened VMCS on VMCLEAR KVM: nVMX: Ignore 'hv_clean_fields' data when eVMCS data is copied in vmx_get_nested_state() KVM: nVMX: Force enlightened VMCS sync from nested_vmx_failValid() KVM: nVMX: Reset eVMCS clean fields data from prepare_vmcs02() KVM: nVMX: Request to sync eVMCS from VMCS12 after migration KVM: selftests: evmcs_test: Test that KVM_STATE_NESTED_EVMCS is never lost arch/x86/kvm/vmx/nested.c | 110 ++++++++++++------ .../testing/selftests/kvm/x86_64/evmcs_test.c | 64 +++++----- 2 files changed, 115 insertions(+), 59 deletions(-)