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 X-Spam-Level: X-Spam-Status: No, score=-11.0 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 C654DC433E0 for ; Mon, 29 Mar 2021 11:49:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9F6736195C for ; Mon, 29 Mar 2021 11:49:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230434AbhC2Lsb (ORCPT ); Mon, 29 Mar 2021 07:48:31 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:59570 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231304AbhC2LsK (ORCPT ); Mon, 29 Mar 2021 07:48:10 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617018490; 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=XBBhbaK4RjgYEf7pYCtNqcj852KHocFegJV6ZZyHbik=; b=SUIb51kMGcZ7cwd/bpdwSb6/t0CPfyh1j/qBl3EGcDMv3GvfIVYMDZE1Uv88GeErPaw52E CRMc/CYRs2NsPmfoak9MwFTtmncV1CSqjnNBbkaXL/O7zrhPFcJqZlmAI7C/XKu6eatS1k 0W2NB8uF85H2FjI/p/KTgX9xuQJNOM0= 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-487-kZar8vd3PgO6U-y2Jj34Fw-1; Mon, 29 Mar 2021 07:48:08 -0400 X-MC-Unique: kZar8vd3PgO6U-y2Jj34Fw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CB0CC180FCA5; Mon, 29 Mar 2021 11:48:06 +0000 (UTC) Received: from vitty.brq.redhat.com (unknown [10.40.195.155]) by smtp.corp.redhat.com (Postfix) with ESMTP id 765FB1001B2C; Mon, 29 Mar 2021 11:48:01 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Wanpeng Li , Jim Mattson , Marcelo Tosatti Subject: [PATCH v2 0/2] KVM: x86: hyper-v: Fix TSC page update after KVM_SET_CLOCK(0) call Date: Mon, 29 Mar 2021 13:47:58 +0200 Message-Id: <20210329114800.164066-1-vkuznets@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Changes since v1: - Fix the issue by casting 'hv_clock->system_time' to s64 in compute_tsc_page_parameters() instead of clamping its value to zero in kvm_guest_time_update() [Paolo] Original description: I discovered that after KVM_SET_CLOCK(0) TSC page value in the guest can go through the roof and apparently we have a signedness issue when the update is performed. Fix the issue and add a selftest. Vitaly Kuznetsov (2): KVM: x86: hyper-v: Properly divide maybe-negative 'hv_clock->system_time' in compute_tsc_page_parameters() selftests: kvm: Check that TSC page value is small after KVM_SET_CLOCK(0) arch/x86/kvm/hyperv.c | 9 ++++++--- tools/testing/selftests/kvm/x86_64/hyperv_clock.c | 13 +++++++++++-- 2 files changed, 17 insertions(+), 5 deletions(-) -- 2.30.2