From patchwork Tue May 14 23:42:44 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Farman X-Patchwork-Id: 10944073 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 243EC1398 for ; Tue, 14 May 2019 23:43:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 14485288FD for ; Tue, 14 May 2019 23:43:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 089A528987; Tue, 14 May 2019 23:43:03 +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 7DDCF288FD for ; Tue, 14 May 2019 23:43:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726775AbfENXnB (ORCPT ); Tue, 14 May 2019 19:43:01 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:54390 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726677AbfENXm6 (ORCPT ); Tue, 14 May 2019 19:42:58 -0400 Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x4ENLtDH042043 for ; Tue, 14 May 2019 19:42:57 -0400 Received: from e06smtp03.uk.ibm.com (e06smtp03.uk.ibm.com [195.75.94.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 2sg4n9xa9v-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 14 May 2019 19:42:56 -0400 Received: from localhost by e06smtp03.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 15 May 2019 00:42:53 +0100 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x4ENgpuJ39059610 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 14 May 2019 23:42:51 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8E6ED11C054; Tue, 14 May 2019 23:42:51 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 768C911C04C; Tue, 14 May 2019 23:42:51 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Tue, 14 May 2019 23:42:51 +0000 (GMT) Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 4958) id 31B09E13D1; Wed, 15 May 2019 01:42:51 +0200 (CEST) From: Eric Farman To: Cornelia Huck , Farhan Ali Cc: Halil Pasic , Pierre Morel , linux-s390@vger.kernel.org, kvm@vger.kernel.org, Eric Farman Subject: [PATCH v2 3/7] s390/cio: Split pfn_array_alloc_pin into pieces Date: Wed, 15 May 2019 01:42:44 +0200 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190514234248.36203-1-farman@linux.ibm.com> References: <20190514234248.36203-1-farman@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 19051423-0012-0000-0000-0000031BB7C2 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19051423-0013-0000-0000-000021545247 Message-Id: <20190514234248.36203-4-farman@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-05-14_13:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=2 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=720 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905140153 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The pfn_array_alloc_pin routine is doing too much. Today, it does the alloc of the pfn_array struct and its member arrays, builds the iova address lists out of a contiguous piece of guest memory, and asks vfio to pin the resulting pages. Let's effectively revert a significant portion of commit 5c1cfb1c3948 ("vfio: ccw: refactor and improve pfn_array_alloc_pin()") such that we break pfn_array_alloc_pin() into its component pieces, and have one routine that allocates/populates the pfn_array structs, and another that actually pins the memory. In the future, we will be able to handle scenarios where pinning memory isn't actually appropriate. Signed-off-by: Eric Farman Reviewed-by: Farhan Ali --- drivers/s390/cio/vfio_ccw_cp.c | 64 ++++++++++++++++++++++++---------- 1 file changed, 46 insertions(+), 18 deletions(-) diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index 41f48b8790bc..60aa784717c5 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -50,28 +50,25 @@ struct ccwchain { }; /* - * pfn_array_alloc_pin() - alloc memory for PFNs, then pin user pages in memory + * pfn_array_alloc() - alloc memory for PFNs * @pa: pfn_array on which to perform the operation - * @mdev: the mediated device to perform pin/unpin operations * @iova: target guest physical address * @len: number of bytes that should be pinned from @iova * - * Attempt to allocate memory for PFNs, and pin user pages in memory. + * Attempt to allocate memory for PFNs. * * Usage of pfn_array: * We expect (pa_nr == 0) and (pa_iova_pfn == NULL), any field in * this structure will be filled in by this function. * * Returns: - * Number of pages pinned on success. - * If @pa->pa_nr is not 0, or @pa->pa_iova_pfn is not NULL initially, - * returns -EINVAL. - * If no pages were pinned, returns -errno. + * 0 if PFNs are allocated + * -EINVAL if pa->pa_nr is not initially zero, or pa->pa_iova_pfn is not NULL + * -ENOMEM if alloc failed */ -static int pfn_array_alloc_pin(struct pfn_array *pa, struct device *mdev, - u64 iova, unsigned int len) +static int pfn_array_alloc(struct pfn_array *pa, u64 iova, unsigned int len) { - int i, ret = 0; + int i; if (!len) return 0; @@ -97,6 +94,22 @@ static int pfn_array_alloc_pin(struct pfn_array *pa, struct device *mdev, for (i = 1; i < pa->pa_nr; i++) pa->pa_iova_pfn[i] = pa->pa_iova_pfn[i - 1] + 1; + return 0; +} + +/* + * pfn_array_pin() - Pin user pages in memory + * @pa: pfn_array on which to perform the operation + * @mdev: the mediated device to perform pin operations + * + * Returns number of pages pinned upon success. + * If the pin request partially succeeds, or fails completely, + * all pages are left unpinned and a negative error value is returned. + */ +static int pfn_array_pin(struct pfn_array *pa, struct device *mdev) +{ + int ret = 0; + ret = vfio_pin_pages(mdev, pa->pa_iova_pfn, pa->pa_nr, IOMMU_READ | IOMMU_WRITE, pa->pa_pfn); @@ -112,8 +125,6 @@ static int pfn_array_alloc_pin(struct pfn_array *pa, struct device *mdev, err_out: pa->pa_nr = 0; - kfree(pa->pa_iova_pfn); - pa->pa_iova_pfn = NULL; return ret; } @@ -121,7 +132,9 @@ static int pfn_array_alloc_pin(struct pfn_array *pa, struct device *mdev, /* Unpin the pages before releasing the memory. */ static void pfn_array_unpin_free(struct pfn_array *pa, struct device *mdev) { - vfio_unpin_pages(mdev, pa->pa_iova_pfn, pa->pa_nr); + /* Only unpin if any pages were pinned to begin with */ + if (pa->pa_nr) + vfio_unpin_pages(mdev, pa->pa_iova_pfn, pa->pa_nr); pa->pa_nr = 0; kfree(pa->pa_iova_pfn); } @@ -209,10 +222,16 @@ static long copy_from_iova(struct device *mdev, int i, ret; unsigned long l, m; - ret = pfn_array_alloc_pin(&pa, mdev, iova, n); - if (ret <= 0) + ret = pfn_array_alloc(&pa, iova, n); + if (ret < 0) return ret; + ret = pfn_array_pin(&pa, mdev); + if (ret < 0) { + pfn_array_unpin_free(&pa, mdev); + return ret; + } + l = n; for (i = 0; i < pa.pa_nr; i++) { from = pa.pa_pfn[i] << PAGE_SHIFT; @@ -559,7 +578,11 @@ static int ccwchain_fetch_direct(struct ccwchain *chain, if (ret) goto out_init; - ret = pfn_array_alloc_pin(pat->pat_pa, cp->mdev, ccw->cda, ccw->count); + ret = pfn_array_alloc(pat->pat_pa, ccw->cda, ccw->count); + if (ret < 0) + goto out_unpin; + + ret = pfn_array_pin(pat->pat_pa, cp->mdev); if (ret < 0) goto out_unpin; @@ -589,6 +612,7 @@ static int ccwchain_fetch_idal(struct ccwchain *chain, { struct ccw1 *ccw; struct pfn_array_table *pat; + struct pfn_array *pa; unsigned long *idaws; u64 idaw_iova; unsigned int idaw_nr, idaw_len; @@ -627,9 +651,13 @@ static int ccwchain_fetch_idal(struct ccwchain *chain, for (i = 0; i < idaw_nr; i++) { idaw_iova = *(idaws + i); + pa = pat->pat_pa + i; + + ret = pfn_array_alloc(pa, idaw_iova, 1); + if (ret < 0) + goto out_free_idaws; - ret = pfn_array_alloc_pin(pat->pat_pa + i, cp->mdev, - idaw_iova, 1); + ret = pfn_array_pin(pa, cp->mdev); if (ret < 0) goto out_free_idaws; }