From patchwork Fri Jun 21 14:33:51 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cornelia Huck X-Patchwork-Id: 11010215 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 ECECF6C5 for ; Fri, 21 Jun 2019 14:34:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DB62128A29 for ; Fri, 21 Jun 2019 14:34:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CFE7928A70; Fri, 21 Jun 2019 14:34:23 +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 53FE228A29 for ; Fri, 21 Jun 2019 14:34:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726525AbfFUOeW (ORCPT ); Fri, 21 Jun 2019 10:34:22 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48048 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726519AbfFUOeW (ORCPT ); Fri, 21 Jun 2019 10:34:22 -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 E63FB30C31B9; Fri, 21 Jun 2019 14:34:21 +0000 (UTC) Received: from localhost (dhcp-192-192.str.redhat.com [10.33.192.192]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8FF38601B6; Fri, 21 Jun 2019 14:34:21 +0000 (UTC) From: Cornelia Huck To: Heiko Carstens , Vasily Gorbik , Christian Borntraeger Cc: Farhan Ali , Eric Farman , Halil Pasic , linux-s390@vger.kernel.org, kvm@vger.kernel.org, Cornelia Huck Subject: [PULL 10/14] vfio-ccw: Move guest_cp storage into common struct Date: Fri, 21 Jun 2019 16:33:51 +0200 Message-Id: <20190621143355.29175-11-cohuck@redhat.com> In-Reply-To: <20190621143355.29175-1-cohuck@redhat.com> References: <20190621143355.29175-1-cohuck@redhat.com> MIME-Version: 1.0 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 [10.5.110.40]); Fri, 21 Jun 2019 14:34:22 +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 From: Eric Farman Rather than allocating/freeing a piece of memory every time we try to figure out how long a CCW chain is, let's use a piece of memory allocated for each device. The io_mutex added with commit 4f76617378ee9 ("vfio-ccw: protect the I/O region") is held for the duration of the VFIO_CCW_EVENT_IO_REQ event that accesses/uses this space, so there should be no race concerns with another CPU attempting an (unexpected) SSCH for the same device. Suggested-by: Cornelia Huck Signed-off-by: Eric Farman Message-Id: <20190618202352.39702-2-farman@linux.ibm.com> Reviewed-by: Cornelia Huck Reviewed-by: Farhan Ali Signed-off-by: Cornelia Huck --- drivers/s390/cio/vfio_ccw_cp.c | 23 ++++------------------- drivers/s390/cio/vfio_ccw_cp.h | 7 +++++++ drivers/s390/cio/vfio_ccw_drv.c | 7 +++++++ 3 files changed, 18 insertions(+), 19 deletions(-) diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index 90d86e1354c1..f358502376be 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -16,12 +16,6 @@ #include "vfio_ccw_cp.h" -/* - * Max length for ccw chain. - * XXX: Limit to 256, need to check more? - */ -#define CCWCHAIN_LEN_MAX 256 - struct pfn_array { /* Starting guest physical I/O address. */ unsigned long pa_iova; @@ -386,7 +380,7 @@ static void ccwchain_cda_free(struct ccwchain *chain, int idx) */ static int ccwchain_calc_length(u64 iova, struct channel_program *cp) { - struct ccw1 *ccw, *p; + struct ccw1 *ccw = cp->guest_cp; int cnt; /* @@ -394,15 +388,9 @@ static int ccwchain_calc_length(u64 iova, struct channel_program *cp) * Currently the chain length is limited to CCWCHAIN_LEN_MAX (256). * So copying 2K is enough (safe). */ - p = ccw = kcalloc(CCWCHAIN_LEN_MAX, sizeof(*ccw), GFP_KERNEL); - if (!ccw) - return -ENOMEM; - cnt = copy_ccw_from_iova(cp, ccw, iova, CCWCHAIN_LEN_MAX); - if (cnt) { - kfree(ccw); + if (cnt) return cnt; - } cnt = 0; do { @@ -413,10 +401,8 @@ static int ccwchain_calc_length(u64 iova, struct channel_program *cp) * orb specified one of the unsupported formats, we defer * checking for IDAWs in unsupported formats to here. */ - if ((!cp->orb.cmd.c64 || cp->orb.cmd.i2k) && ccw_is_idal(ccw)) { - kfree(p); + if ((!cp->orb.cmd.c64 || cp->orb.cmd.i2k) && ccw_is_idal(ccw)) return -EOPNOTSUPP; - } /* * We want to keep counting if the current CCW has the @@ -435,7 +421,6 @@ static int ccwchain_calc_length(u64 iova, struct channel_program *cp) if (cnt == CCWCHAIN_LEN_MAX + 1) cnt = -EINVAL; - kfree(p); return cnt; } @@ -461,7 +446,7 @@ static int ccwchain_handle_ccw(u32 cda, struct channel_program *cp) struct ccwchain *chain; int len, ret; - /* Get chain length. */ + /* Copy the chain from cda to cp, and count the CCWs in it */ len = ccwchain_calc_length(cda, cp); if (len < 0) return len; diff --git a/drivers/s390/cio/vfio_ccw_cp.h b/drivers/s390/cio/vfio_ccw_cp.h index 3c20cd208da5..7cdc38049033 100644 --- a/drivers/s390/cio/vfio_ccw_cp.h +++ b/drivers/s390/cio/vfio_ccw_cp.h @@ -16,6 +16,12 @@ #include "orb.h" +/* + * Max length for ccw chain. + * XXX: Limit to 256, need to check more? + */ +#define CCWCHAIN_LEN_MAX 256 + /** * struct channel_program - manage information for channel program * @ccwchain_list: list head of ccwchains @@ -32,6 +38,7 @@ struct channel_program { union orb orb; struct device *mdev; bool initialized; + struct ccw1 *guest_cp; }; extern int cp_init(struct channel_program *cp, struct device *mdev, diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index 66a66ac1f3d1..34a9a5e3fd36 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -129,6 +129,11 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) if (!private) return -ENOMEM; + private->cp.guest_cp = kcalloc(CCWCHAIN_LEN_MAX, sizeof(struct ccw1), + GFP_KERNEL); + if (!private->cp.guest_cp) + goto out_free; + private->io_region = kmem_cache_zalloc(vfio_ccw_io_region, GFP_KERNEL | GFP_DMA); if (!private->io_region) @@ -169,6 +174,7 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region); if (private->io_region) kmem_cache_free(vfio_ccw_io_region, private->io_region); + kfree(private->cp.guest_cp); kfree(private); return ret; } @@ -185,6 +191,7 @@ static int vfio_ccw_sch_remove(struct subchannel *sch) kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region); kmem_cache_free(vfio_ccw_io_region, private->io_region); + kfree(private->cp.guest_cp); kfree(private); return 0;