Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755261AbaK0Mbi (ORCPT ); Thu, 27 Nov 2014 07:31:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:59875 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755174AbaK0Mbb (ORCPT ); Thu, 27 Nov 2014 07:31:31 -0500 Date: Thu, 27 Nov 2014 14:31:09 +0200 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Cc: David Miller , cornelia.huck@de.ibm.com, rusty@au1.ibm.com, nab@linux-iscsi.org, pbonzini@redhat.com, thuth@linux.vnet.ibm.com, dahi@linux.vnet.ibm.com, Rusty Russell , Pawel Moll , Ohad Ben-Cohen , virtualization@lists.linux-foundation.org Subject: [PATCH v5 13/45] virtio: add legacy feature table support Message-ID: <1417091078-24611-14-git-send-email-mst@redhat.com> References: <1417091078-24611-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1417091078-24611-1-git-send-email-mst@redhat.com> X-Mutt-Fcc: =sent Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org virtio-blk has some legacy feature bits that modern drivers must not negotiate, but are needed for old legacy hosts (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(-) diff --git a/include/linux/virtio.h b/include/linux/virtio.h index d6359a5..f70411e 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -130,6 +130,8 @@ int virtio_device_restore(struct virtio_device *dev); * @id_table: the ids serviced by this driver. * @feature_table: an array of feature numbers supported by this driver. * @feature_table_size: number of entries in the feature table array. + * @feature_table_legacy: same as feature_table but when working in legacy mode. + * @feature_table_size_legacy: number of entries in feature table legacy array. * @probe: the function to call when a device is found. Returns 0 or -errno. * @remove: the function to call when a device is removed. * @config_changed: optional function to call when the device configuration @@ -140,6 +142,8 @@ struct virtio_driver { const struct virtio_device_id *id_table; const unsigned int *feature_table; unsigned int feature_table_size; + const unsigned int *feature_table_legacy; + unsigned int feature_table_size_legacy; int (*probe)(struct virtio_device *dev); void (*scan)(struct virtio_device *dev); void (*remove)(struct virtio_device *dev); diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index 498bded..100b029 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -113,6 +113,13 @@ void virtio_check_driver_offered_feature(const struct virtio_device *vdev, for (i = 0; i < drv->feature_table_size; i++) if (drv->feature_table[i] == fbit) return; + + if (drv->feature_table_legacy) { + for (i = 0; i < drv->feature_table_size_legacy; i++) + if (drv->feature_table_legacy[i] == fbit) + return; + } + BUG(); } EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature); @@ -161,6 +168,7 @@ static int virtio_dev_probe(struct device *_d) struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); u64 device_features; u64 driver_features; + u64 driver_features_legacy; unsigned status; /* We have a driver! */ @@ -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 table for virtio v1.0 */ + 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; + } + + if (driver_features & device_features & (1ULL << VIRTIO_F_VERSION_1)) + dev->features = driver_features & device_features; + else + dev->features = driver_features_legacy & device_features; /* Transport features always preserved to pass to finalize_features. */ for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) -- MST -- 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/