From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932334AbbIUNLM (ORCPT ); Mon, 21 Sep 2015 09:11:12 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:35493 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932179AbbIUNLJ (ORCPT ); Mon, 21 Sep 2015 09:11:09 -0400 From: Boris Ostrovsky To: konrad.wilk@oracle.com, david.vrabel@citrix.com Cc: xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, boris.ostrovsky@oracle.com Subject: [PATCH] xen/x86: Don't try to write syscall-related MSRs for PV guests Date: Mon, 21 Sep 2015 09:09:28 -0400 Message-Id: <1442840968-23052-1-git-send-email-boris.ostrovsky@oracle.com> X-Mailer: git-send-email 2.1.0 X-Source-IP: aserv0022.oracle.com [141.146.126.234] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For PV guests these registers are set up by hypervisor and thus should not be written by the guest. The comment in xen_write_msr_safe() says so but we still write the MSRs, causing the hypervisor to print a warning. Signed-off-by: Boris Ostrovsky --- arch/x86/xen/enlighten.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 30d12af..1f1dbd2 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1077,6 +1077,7 @@ static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high) /* Fast syscall setup is all done in hypercalls, so these are all ignored. Stub them out here to stop Xen console noise. */ + break; default: if (!pmu_msr_write(msr, low, high, &ret)) -- 2.1.0