From patchwork Mon Mar 11 16:26:56 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cornelia Huck X-Patchwork-Id: 10847799 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D700814DE for ; Mon, 11 Mar 2019 16:27:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C1E8C28446 for ; Mon, 11 Mar 2019 16:27:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B545A291CE; Mon, 11 Mar 2019 16:27:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5988328446 for ; Mon, 11 Mar 2019 16:27:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727758AbfCKQ1C (ORCPT ); Mon, 11 Mar 2019 12:27:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:12731 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727599AbfCKQ1C (ORCPT ); Mon, 11 Mar 2019 12:27:02 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 543DDC0467E4; Mon, 11 Mar 2019 16:27:02 +0000 (UTC) Received: from localhost (ovpn-117-96.ams2.redhat.com [10.36.117.96]) by smtp.corp.redhat.com (Postfix) with ESMTPS id DC25160123; Mon, 11 Mar 2019 16:27:01 +0000 (UTC) From: Cornelia Huck To: Martin Schwidefsky , Heiko Carstens Cc: Farhan Ali , Eric Farman , Halil Pasic , linux-s390@vger.kernel.org, kvm@vger.kernel.org, Cornelia Huck , stable@vger.kernel.org Subject: [PULL 1/1] vfio: ccw: only free cp on final interrupt Date: Mon, 11 Mar 2019 17:26:56 +0100 Message-Id: <20190311162656.10067-2-cohuck@redhat.com> In-Reply-To: <20190311162656.10067-1-cohuck@redhat.com> References: <20190311162656.10067-1-cohuck@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Mon, 11 Mar 2019 16:27:02 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When we get an interrupt for a channel program, it is not necessarily the final interrupt; for example, the issuing guest may request an intermediate interrupt by specifying the program-controlled-interrupt flag on a ccw. We must not switch the state to idle if the interrupt is not yet final; even more importantly, we must not free the translated channel program if the interrupt is not yet final, or the host can crash during cp rewind. Fixes: e5f84dbaea59 ("vfio: ccw: return I/O results asynchronously") Cc: stable@vger.kernel.org # v4.12+ Reviewed-by: Eric Farman Signed-off-by: Cornelia Huck --- drivers/s390/cio/vfio_ccw_drv.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index a10cec0e86eb..0b3b9de45c60 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -72,20 +72,24 @@ static void vfio_ccw_sch_io_todo(struct work_struct *work) { struct vfio_ccw_private *private; struct irb *irb; + bool is_final; private = container_of(work, struct vfio_ccw_private, io_work); irb = &private->irb; + is_final = !(scsw_actl(&irb->scsw) & + (SCSW_ACTL_DEVACT | SCSW_ACTL_SCHACT)); if (scsw_is_solicited(&irb->scsw)) { cp_update_scsw(&private->cp, &irb->scsw); - cp_free(&private->cp); + if (is_final) + cp_free(&private->cp); } memcpy(private->io_region->irb_area, irb, sizeof(*irb)); if (private->io_trigger) eventfd_signal(private->io_trigger, 1); - if (private->mdev) + if (private->mdev && is_final) private->state = VFIO_CCW_STATE_IDLE; }