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| author | Michael S. Tsirkin <mst@redhat.com> | 2014-10-23 18:07:47 +0300 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2014-12-09 12:05:26 +0200 |
| commit | b3bb62d11950eb6ac87403cacd667f84fa9495bc (patch) | |
| tree | f3aee72f5e622722d19c484c7f5925990e97cffb /drivers/virtio | |
| parent | c102659d690d382171bd2e40f35c5c811f0cdcac (diff) | |
| download | linux-b3bb62d11950eb6ac87403cacd667f84fa9495bc.tar.bz2 | |
virtio: add legacy feature table support
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 <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Diffstat (limited to 'drivers/virtio')
| -rw-r--r-- | drivers/virtio/virtio.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index 3e78f4bcfa8e..f9ad99c8b352 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++) |