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=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 F3C2DC6786C for ; Fri, 14 Dec 2018 12:18:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BAE632133F for ; Fri, 14 Dec 2018 12:18:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1544789902; bh=JMn3SSFj0g8NHb+MFh7WUwRpo0MvSNUGV1q8RiDG0zc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=vmO3ohn9HyNKRNp52nPOmMMMAmYDmj0bqb+yWcODhmmrvVo+SXHP8gSN9Aw3vPkCs z1hzVjEaUJJ+QB71j7EFgpbAAfyvkgN2zt4tHOXuEjmxsRsMsIs60Wa0jB9gZk7sH9 8u0FJ3iHJdQDLtpM+kPn7vMv5Rg4BXixvDKk//nU= DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BAE632133F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732783AbeLNMQh (ORCPT ); Fri, 14 Dec 2018 07:16:37 -0500 Received: from mail.kernel.org ([198.145.29.99]:36796 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732264AbeLNMQe (ORCPT ); Fri, 14 Dec 2018 07:16:34 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2E185214AE; Fri, 14 Dec 2018 12:16:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1544789793; bh=JMn3SSFj0g8NHb+MFh7WUwRpo0MvSNUGV1q8RiDG0zc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wQ6hwG0wgqMKpB0XNpslLnJGNgov8+AlBuS9FJGqmE3xYIW+0NS7itERAIvDt/mmB McovjY6qVrXsplwC1Pn6QE68BR6ET9A2B3hrtYdqCTL/qYesSJwPJSDHBbIs4A0CKk JHdLmsWiEN2phUpIauwruZdAUynlCb6NOuAiLT8s= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Gleixner , Borislav Petkov , Konrad Rzeszutek Wilk , Paolo Bonzini , David Woodhouse , Ben Hutchings Subject: [PATCH 4.4 58/88] KVM: SVM: Move spec control call after restore of GS Date: Fri, 14 Dec 2018 13:00:32 +0100 Message-Id: <20181214115707.259654951@linuxfoundation.org> X-Mailer: git-send-email 2.20.0 In-Reply-To: <20181214115702.151309521@linuxfoundation.org> References: <20181214115702.151309521@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Gleixner commit 15e6c22fd8e5a42c5ed6d487b7c9fe44c2517765 upstream. svm_vcpu_run() invokes x86_spec_ctrl_restore_host() after VMEXIT, but before the host GS is restored. x86_spec_ctrl_restore_host() uses 'current' to determine the host SSBD state of the thread. 'current' is GS based, but host GS is not yet restored and the access causes a triple fault. Move the call after the host GS restore. Fixes: 885f82bfbc6f x86/process: Allow runtime control of Speculative Store Bypass Signed-off-by: Thomas Gleixner Reviewed-by: Borislav Petkov Reviewed-by: Konrad Rzeszutek Wilk Acked-by: Paolo Bonzini Signed-off-by: David Woodhouse Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/svm.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -3998,6 +3998,18 @@ static void svm_vcpu_run(struct kvm_vcpu #endif ); + /* Eliminate branch target predictions from guest mode */ + vmexit_fill_RSB(); + +#ifdef CONFIG_X86_64 + wrmsrl(MSR_GS_BASE, svm->host.gs_base); +#else + loadsegment(fs, svm->host.fs); +#ifndef CONFIG_X86_32_LAZY_GS + loadsegment(gs, svm->host.gs); +#endif +#endif + /* * We do not use IBRS in the kernel. If this vCPU has used the * SPEC_CTRL MSR it may have left it on; save the value and @@ -4018,18 +4030,6 @@ static void svm_vcpu_run(struct kvm_vcpu x86_spec_ctrl_restore_host(svm->spec_ctrl); - /* Eliminate branch target predictions from guest mode */ - vmexit_fill_RSB(); - -#ifdef CONFIG_X86_64 - wrmsrl(MSR_GS_BASE, svm->host.gs_base); -#else - loadsegment(fs, svm->host.fs); -#ifndef CONFIG_X86_32_LAZY_GS - loadsegment(gs, svm->host.gs); -#endif -#endif - reload_tss(vcpu); local_irq_disable();