From patchwork Tue Jan 16 18:26:54 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 10167869 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4041E603B5 for ; Tue, 16 Jan 2018 18:27:52 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3DE44262AE for ; Tue, 16 Jan 2018 18:27:52 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3229026538; Tue, 16 Jan 2018 18:27:52 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EB36F262AE for ; Tue, 16 Jan 2018 18:27:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751487AbeAPS1f (ORCPT ); Tue, 16 Jan 2018 13:27:35 -0500 Received: from mx1.redhat.com ([209.132.183.28]:44224 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751465AbeAPS1d (ORCPT ); Tue, 16 Jan 2018 13:27:33 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5E5BB780DE; Tue, 16 Jan 2018 18:27:23 +0000 (UTC) Received: from vitty.brq.redhat.com (unknown [10.43.2.155]) by smtp.corp.redhat.com (Postfix) with ESMTP id 366856A82C; Tue, 16 Jan 2018 18:27:15 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, x86@kernel.org Cc: Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , "Michael Kelley (EOSG)" , Andy Lutomirski , Mohammed Gamal , Cathy Avery , Roman Kagan , linux-kernel@vger.kernel.org, devel@linuxdriverproject.org Subject: [PATCH v3 1/7] x86/hyper-v: check for required priviliges in hyperv_init() Date: Tue, 16 Jan 2018 19:26:54 +0100 Message-Id: <20180116182700.1042-2-vkuznets@redhat.com> In-Reply-To: <20180116182700.1042-1-vkuznets@redhat.com> References: <20180116182700.1042-1-vkuznets@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Tue, 16 Jan 2018 18:27:33 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In hyperv_init() we presume we always have access to VP index and hypercall MSRs while according to the specification we should check if we're allowed to access the corresponding MSRs before accessing them. Signed-off-by: Vitaly Kuznetsov Reviewed-by: Thomas Gleixner --- arch/x86/hyperv/hv_init.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index 189a398290db..21f9d53d9f00 100644 --- a/arch/x86/hyperv/hv_init.c +++ b/arch/x86/hyperv/hv_init.c @@ -110,12 +110,19 @@ static int hv_cpu_init(unsigned int cpu) */ void hyperv_init(void) { - u64 guest_id; + u64 guest_id, required_msrs; union hv_x64_msr_hypercall_contents hypercall_msr; if (x86_hyper_type != X86_HYPER_MS_HYPERV) return; + /* Absolutely required MSRs */ + required_msrs = HV_X64_MSR_HYPERCALL_AVAILABLE | + HV_X64_MSR_VP_INDEX_AVAILABLE; + + if ((ms_hyperv.features & required_msrs) != required_msrs) + return; + /* Allocate percpu VP index */ hv_vp_index = kmalloc_array(num_possible_cpus(), sizeof(*hv_vp_index), GFP_KERNEL);