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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 CD7F7C55189 for ; Wed, 22 Apr 2020 10:04:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A2C392076C for ; Wed, 22 Apr 2020 10:04:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587549870; bh=8lUSKtyzTf9clAUJMci6xV8dZ8QUMoDtmqALs+WfH1Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=fMr3RM7lcCWaMdlRB+p1yDmfgymg6wvdOwWqXsUcUVDKawxCcCO8l2Uf4+2s1YLkb cLFH/LawCCHCVAuMnjHKdgb+vYh9DndQ6VRjm2oBo1YPpueuF4Yznl1upiVdlC2vWG rkZWPFqErVTrkTBD1Aqy6xJOMzPNwNDsGD55twKc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728024AbgDVKE3 (ORCPT ); Wed, 22 Apr 2020 06:04:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:54704 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726717AbgDVKEW (ORCPT ); Wed, 22 Apr 2020 06:04:22 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.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 66AA72075A; Wed, 22 Apr 2020 10:04:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587549860; bh=8lUSKtyzTf9clAUJMci6xV8dZ8QUMoDtmqALs+WfH1Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TkIbly/rrTzVYye6Hl+qdqCLahBkUltNItxKdIpdGlCS34CyzCzbIGnd1kFipGd1R Z2uzvFmpXbbne4ayfGvr1Xj8jDCVMpRpPTzM6BzoJfFfuBoWFhEhWPaOrMe+hoJbua VroG3FY+6EU2/5Qsvb4jqnkR2SLr5ODTJEKhV/44= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Hildenbrand , Claudio Imbrenda , Christian Borntraeger Subject: [PATCH 4.9 036/125] KVM: s390: vsie: Fix delivery of addressing exceptions Date: Wed, 22 Apr 2020 11:55:53 +0200 Message-Id: <20200422095039.294486317@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095032.909124119@linuxfoundation.org> References: <20200422095032.909124119@linuxfoundation.org> User-Agent: quilt/0.66 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 From: David Hildenbrand commit 4d4cee96fb7a3cc53702a9be8299bf525be4ee98 upstream. Whenever we get an -EFAULT, we failed to read in guest 2 physical address space. Such addressing exceptions are reported via a program intercept to the nested hypervisor. We faked the intercept, we have to return to guest 2. Instead, right now we would be returning -EFAULT from the intercept handler, eventually crashing the VM. the correct thing to do is to return 1 as rc == 1 is the internal representation of "we have to go back into g2". Addressing exceptions can only happen if the g2->g3 page tables reference invalid g2 addresses (say, either a table or the final page is not accessible - so something that basically never happens in sane environments. Identified by manual code inspection. Fixes: a3508fbe9dc6 ("KVM: s390: vsie: initial support for nested virtualization") Cc: # v4.8+ Signed-off-by: David Hildenbrand Link: https://lore.kernel.org/r/20200403153050.20569-3-david@redhat.com Reviewed-by: Claudio Imbrenda Reviewed-by: Christian Borntraeger [borntraeger@de.ibm.com: fix patch description] Signed-off-by: Christian Borntraeger Signed-off-by: Greg Kroah-Hartman --- arch/s390/kvm/vsie.c | 1 + 1 file changed, 1 insertion(+) --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -947,6 +947,7 @@ static int vsie_run(struct kvm_vcpu *vcp scb_s->iprcc = PGM_ADDRESSING; scb_s->pgmilc = 4; scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, 4); + rc = 1; } return rc; }