diff options
Diffstat (limited to 'drivers/virtio/virtio.c')
| -rw-r--r-- | drivers/virtio/virtio.c | 111 |
1 files changed, 87 insertions, 24 deletions
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index df598dd8c5c8..b9f70dfc4751 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -3,6 +3,7 @@ #include <linux/virtio_config.h> #include <linux/module.h> #include <linux/idr.h> +#include <uapi/linux/virtio_ids.h> /* Unique numbering for virtio devices. */ static DEFINE_IDA(virtio_index_ida); @@ -49,9 +50,9 @@ static ssize_t features_show(struct device *_d, /* We actually represent this as a bitstring, as it could be * arbitrary length in future. */ - for (i = 0; i < ARRAY_SIZE(dev->features)*BITS_PER_LONG; i++) + for (i = 0; i < sizeof(dev->features)*8; i++) len += sprintf(buf+len, "%c", - test_bit(i, dev->features) ? '1' : '0'); + __virtio_test_bit(dev, i) ? '1' : '0'); len += sprintf(buf+len, "\n"); return len; } @@ -113,6 +114,13 @@ 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); @@ -154,12 +162,35 @@ static void virtio_config_enable(struct virtio_device *dev) spin_unlock_irq(&dev->config_lock); } +static int virtio_finalize_features(struct virtio_device *dev) +{ + int ret = dev->config->finalize_features(dev); + unsigned status; + + if (ret) + return ret; + + if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) + return 0; + + add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK); + status = dev->config->get_status(dev); + if (!(status & VIRTIO_CONFIG_S_FEATURES_OK)) { + dev_err(&dev->dev, "virtio: device refuses features: %x\n", + status); + return -ENODEV; + } + return 0; +} + static int virtio_dev_probe(struct device *_d) { int err, i; struct virtio_device *dev = dev_to_virtio(_d); struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); - u32 device_features; + u64 device_features; + u64 driver_features; + u64 driver_features_legacy; /* We have a driver! */ add_status(dev, VIRTIO_CONFIG_S_DRIVER); @@ -167,34 +198,55 @@ static int virtio_dev_probe(struct device *_d) /* Figure out what features the device supports. */ device_features = dev->config->get_features(dev); - /* Features supported by both device and driver into dev->features. */ - memset(dev->features, 0, sizeof(dev->features)); + /* Figure out what features the driver supports. */ + driver_features = 0; for (i = 0; i < drv->feature_table_size; i++) { unsigned int f = drv->feature_table[i]; - BUG_ON(f >= 32); - if (device_features & (1 << f)) - set_bit(f, dev->features); + BUG_ON(f >= 64); + driver_features |= (1ULL << f); + } + + /* 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 (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++) - if (device_features & (1 << i)) - set_bit(i, dev->features); + if (device_features & (1ULL << i)) + __virtio_set_bit(dev, i); - dev->config->finalize_features(dev); + err = virtio_finalize_features(dev); + if (err) + goto err; err = drv->probe(dev); if (err) - add_status(dev, VIRTIO_CONFIG_S_FAILED); - else { - add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK); - if (drv->scan) - drv->scan(dev); + goto err; - virtio_config_enable(dev); - } + add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK); + if (drv->scan) + drv->scan(dev); + + virtio_config_enable(dev); + return 0; +err: + add_status(dev, VIRTIO_CONFIG_S_FAILED); return err; + } static int virtio_dev_remove(struct device *_d) @@ -223,6 +275,12 @@ static struct bus_type virtio_bus = { .remove = virtio_dev_remove, }; +bool virtio_device_is_legacy_only(struct virtio_device_id id) +{ + return id.device == VIRTIO_ID_BALLOON; +} +EXPORT_SYMBOL_GPL(virtio_device_is_legacy_only); + int register_virtio_driver(struct virtio_driver *driver) { /* Catch this early. */ @@ -303,6 +361,7 @@ EXPORT_SYMBOL_GPL(virtio_device_freeze); int virtio_device_restore(struct virtio_device *dev) { struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); + int ret; /* We always start by resetting the device, in case a previous * driver messed it up. */ @@ -322,14 +381,14 @@ int virtio_device_restore(struct virtio_device *dev) /* We have a driver! */ add_status(dev, VIRTIO_CONFIG_S_DRIVER); - dev->config->finalize_features(dev); + ret = virtio_finalize_features(dev); + if (ret) + goto err; if (drv->restore) { - int ret = drv->restore(dev); - if (ret) { - add_status(dev, VIRTIO_CONFIG_S_FAILED); - return ret; - } + ret = drv->restore(dev); + if (ret) + goto err; } /* Finally, tell the device we're all set */ @@ -338,6 +397,10 @@ int virtio_device_restore(struct virtio_device *dev) virtio_config_enable(dev); return 0; + +err: + add_status(dev, VIRTIO_CONFIG_S_FAILED); + return ret; } EXPORT_SYMBOL_GPL(virtio_device_restore); #endif |