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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 D5F85C43218 for ; Tue, 11 Jun 2019 10:17:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BA5132089E for ; Tue, 11 Jun 2019 10:17:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405417AbfFKKRj (ORCPT ); Tue, 11 Jun 2019 06:17:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:62859 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405412AbfFKKRh (ORCPT ); Tue, 11 Jun 2019 06:17:37 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id DA365308425B; Tue, 11 Jun 2019 10:17:36 +0000 (UTC) Received: from gondolin (ovpn-204-147.brq.redhat.com [10.40.204.147]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0ECA61001B0A; Tue, 11 Jun 2019 10:17:26 +0000 (UTC) Date: Tue, 11 Jun 2019 12:17:21 +0200 From: Cornelia Huck To: Halil Pasic Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org, Sebastian Ott , Heiko Carstens , virtualization@lists.linux-foundation.org, "Michael S. Tsirkin" , Christoph Hellwig , Thomas Huth , Christian Borntraeger , Viktor Mihajlovski , Vasily Gorbik , Janosch Frank , Michael Mueller , Claudio Imbrenda , Farhan Ali , Eric Farman , "Jason J. Herne" Subject: Re: [PATCH v4 4/8] s390/airq: use DMA memory for adapter interrupts Message-ID: <20190611121721.61bf09b4.cohuck@redhat.com> In-Reply-To: <20190606115127.55519-5-pasic@linux.ibm.com> References: <20190606115127.55519-1-pasic@linux.ibm.com> <20190606115127.55519-5-pasic@linux.ibm.com> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.40]); Tue, 11 Jun 2019 10:17:37 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, 6 Jun 2019 13:51:23 +0200 Halil Pasic wrote: > Protected virtualization guests have to use shared pages for airq > notifier bit vectors, because hypervisor needs to write these bits. > > Let us make sure we allocate DMA memory for the notifier bit vectors by > replacing the kmem_cache with a dma_cache and kalloc() with > cio_dma_zalloc(). > > Signed-off-by: Halil Pasic > Reviewed-by: Sebastian Ott > --- > arch/s390/include/asm/airq.h | 2 ++ > drivers/s390/cio/airq.c | 32 ++++++++++++++++++++------------ > drivers/s390/cio/cio.h | 2 ++ > drivers/s390/cio/css.c | 1 + > 4 files changed, 25 insertions(+), 12 deletions(-) > (...) > @@ -295,12 +303,12 @@ unsigned long airq_iv_scan(struct airq_iv *iv, unsigned long start, > } > EXPORT_SYMBOL(airq_iv_scan); > > -static int __init airq_init(void) > +int __init airq_init(void) > { > - airq_iv_cache = kmem_cache_create("airq_iv_cache", cache_line_size(), > - cache_line_size(), 0, NULL); > + airq_iv_cache = dma_pool_create("airq_iv_cache", cio_get_dma_css_dev(), > + cache_line_size(), > + cache_line_size(), PAGE_SIZE); > if (!airq_iv_cache) > return -ENOMEM; Sorry about not noticing that in the last iteration; but you may return an error here if airq_iv_cache could not be allocated... > return 0; > } > -subsys_initcall(airq_init); (...) > diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c > index 6fc91d534af1..7901c8ed3597 100644 > --- a/drivers/s390/cio/css.c > +++ b/drivers/s390/cio/css.c > @@ -1182,6 +1182,7 @@ static int __init css_bus_init(void) > ret = cio_dma_pool_init(); > if (ret) > goto out_unregister_pmn; > + airq_init(); ...but don't check the return code here. Probably a pathological case, but shouldn't you handle that error as well? > css_init_done = 1; > > /* Enable default isc for I/O subchannels. */