Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751222AbaKYRxu (ORCPT ); Tue, 25 Nov 2014 12:53:50 -0500 Received: from e06smtp12.uk.ibm.com ([195.75.94.108]:51717 "EHLO e06smtp12.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750964AbaKYRxt (ORCPT ); Tue, 25 Nov 2014 12:53:49 -0500 Date: Tue, 25 Nov 2014 18:53:42 +0100 From: Cornelia Huck To: "Michael S. Tsirkin" Cc: linux-kernel@vger.kernel.org, David Miller , rusty@au1.ibm.com, nab@linux-iscsi.org, pbonzini@redhat.com, Rusty Russell , Pawel Moll , Ohad Ben-Cohen , virtualization@lists.linux-foundation.org Subject: Re: [PATCH v4 11/42] virtio: add legacy feature table support Message-ID: <20141125185342.761bf72e.cornelia.huck@de.ibm.com> In-Reply-To: <1416933600-21398-12-git-send-email-mst@redhat.com> References: <1416933600-21398-1-git-send-email-mst@redhat.com> <1416933600-21398-12-git-send-email-mst@redhat.com> Organization: IBM Deutschland Research & Development GmbH Vorsitzende des Aufsichtsrats: Martina Koederitz =?UTF-8?B?R2VzY2jDpGZ0c2bDvGhydW5nOg==?= Dirk Wittkopp Sitz der Gesellschaft: =?UTF-8?B?QsO2Ymxpbmdlbg==?= Registergericht: Amtsgericht Stuttgart, HRB 243294 X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14112517-0009-0000-0000-00000223054F Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 25 Nov 2014 18:42:09 +0200 "Michael S. Tsirkin" wrote: > virtio blk has some legacy feature bits that modern drivers virtio-blk > must not negotiate, but are needed for old legacy hosts > (e.g. that dn't support virtio scsi). (that e.g. don't support virtio-scsi) > Allow a separate legacy feature table for such cases. > > Signed-off-by: Michael S. Tsirkin > --- > include/linux/virtio.h | 4 ++++ > drivers/virtio/virtio.c | 25 ++++++++++++++++++++++++- > 2 files changed, 28 insertions(+), 1 deletion(-) > > @@ -177,7 +185,22 @@ static int virtio_dev_probe(struct device *_d) > driver_features |= (1ULL << f); > } > > - dev->features = driver_features & device_features; > + /* Some drivers have a separate feature tables for virtio v1.0 */ /* some drivers have a separate feature table for legacy virtio */ ? > + if (drv->feature_table_legacy) { > + driver_features_legacy = 0; > + for (i = 0; i < drv->feature_table_size_legacy; i++) { > + unsigned int f = drv->feature_table_legacy[i]; > + BUG_ON(f >= 64); > + driver_features_legacy |= (1ULL << f); > + } > + } else { > + driver_features_legacy = driver_features; > + } (...) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/