From patchwork Thu Apr 2 18:48:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 11471257 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E296B1668 for ; Thu, 2 Apr 2020 18:48:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C023C20719 for ; Thu, 2 Apr 2020 18:48:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="HhC0fdYM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389891AbgDBSs5 (ORCPT ); Thu, 2 Apr 2020 14:48:57 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:33370 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2389894AbgDBSsd (ORCPT ); Thu, 2 Apr 2020 14:48:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1585853312; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=J1iTHN+tnT2p+g/fi18lrfKuFFUGCiTi5w5obFOSEB4=; b=HhC0fdYMDipAnzG7GMxd4xvkNFeTtl4ybkCcV9Imsby0G7yNTez7ynRWb/nKRFrA8XI8Yu gKmG4TgBwmLwH9zf7q/NewmZMAjWGvs3M1NFTG4Fo6BZQhF8XNcPXhgQ8xSqz674rsjWRm Rswm9XOdz3kxSf60HCXEUoMvHJ2wwoU= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-283-ggkVwfV3P3KDHLgJNeELUA-1; Thu, 02 Apr 2020 14:48:31 -0400 X-MC-Unique: ggkVwfV3P3KDHLgJNeELUA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C55AC1926DA5; Thu, 2 Apr 2020 18:48:29 +0000 (UTC) Received: from t480s.redhat.com (ovpn-114-29.ams2.redhat.com [10.36.114.29]) by smtp.corp.redhat.com (Postfix) with ESMTP id B900360BF3; Thu, 2 Apr 2020 18:48:27 +0000 (UTC) From: David Hildenbrand To: kvm@vger.kernel.org Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, Vasily Gorbik , Heiko Carstens , Cornelia Huck , Janosch Frank , Christian Borntraeger , David Hildenbrand , stable@vger.kernel.org Subject: [PATCH v1 2/5] KVM: s390: vsie: Fix delivery of addressing exceptions Date: Thu, 2 Apr 2020 20:48:16 +0200 Message-Id: <20200402184819.34215-3-david@redhat.com> In-Reply-To: <20200402184819.34215-1-david@redhat.com> References: <20200402184819.34215-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org 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. 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 Reviewed-by: Christian Borntraeger --- 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 076090f9e666..4f6c22d72072 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; }