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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 860C5C38A2F for ; Sat, 18 Apr 2020 14:53:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 534D9206D6 for ; Sat, 18 Apr 2020 14:53:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587221623; bh=Z7KdvEPwnuQWnkjL+BM3WAvJLHQISfNthr7UMBLVDas=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=HbI8SO0F3x7uh0M4Fu3IpxiuBoSyF5k/FNvuPnrN2IugBSzBVrOi3hC3tF4c3h/HP nfRH23gDw6sOKLD1X9G3dLOruFXP5P+acgbX3aKnIFd34gm8dSW09J81dHln4EHEZt ught6II5pQkbH9SiR3bl6VcNkH1a42R6XRGqXZB8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728981AbgDROxm (ORCPT ); Sat, 18 Apr 2020 10:53:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:51630 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728197AbgDROl5 (ORCPT ); Sat, 18 Apr 2020 10:41:57 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B364321D82; Sat, 18 Apr 2020 14:41:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587220916; bh=Z7KdvEPwnuQWnkjL+BM3WAvJLHQISfNthr7UMBLVDas=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rhJn0kgWvOGuMa0Y3i8mg2lj+N7vhFiskwT84YvqTvf8d87lrrqJAKIWY42yt0bp9 OGb1blYhCze6nj9/uyo2OO8KTeSHGQrhgs+lvqCk1JQdthJXs+488Z1HyEK1VPSK6F wxIu7Qe4HU2q8q+0PhptOW4ygj8qQU+R7hQdyOC4= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: David Hildenbrand , Claudio Imbrenda , Christian Borntraeger , Sasha Levin , kvm@vger.kernel.org, linux-s390@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 55/78] KVM: s390: vsie: Fix delivery of addressing exceptions Date: Sat, 18 Apr 2020 10:40:24 -0400 Message-Id: <20200418144047.9013-55-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200418144047.9013-1-sashal@kernel.org> References: <20200418144047.9013-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 [ Upstream commit 4d4cee96fb7a3cc53702a9be8299bf525be4ee98 ] 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: Sasha Levin --- arch/s390/kvm/vsie.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c index 076090f9e666c..4f6c22d72072a 100644 --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -1202,6 +1202,7 @@ static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) scb_s->iprcc = PGM_ADDRESSING; scb_s->pgmilc = 4; scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, 4); + rc = 1; } return rc; } -- 2.20.1