diff options
| -rw-r--r-- | drivers/block/virtio_blk.c | 8 | ||||
| -rw-r--r-- | drivers/lguest/lguest_device.c | 48 | ||||
| -rw-r--r-- | drivers/net/virtio_net.c | 22 | ||||
| -rw-r--r-- | drivers/virtio/virtio.c | 38 | ||||
| -rw-r--r-- | drivers/virtio/virtio_balloon.c | 6 | ||||
| -rw-r--r-- | drivers/virtio/virtio_pci.c | 30 | ||||
| -rw-r--r-- | include/linux/virtio.h | 7 | ||||
| -rw-r--r-- | include/linux/virtio_config.h | 36 |
8 files changed, 142 insertions, 53 deletions
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index cc6d39383a3..78be6b8c89e 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -242,7 +242,7 @@ static int virtblk_probe(struct virtio_device *vdev) index++; /* If barriers are supported, tell block layer that queue is ordered */ - if (vdev->config->feature(vdev, VIRTIO_BLK_F_BARRIER)) + if (virtio_has_feature(vdev, VIRTIO_BLK_F_BARRIER)) blk_queue_ordered(vblk->disk->queue, QUEUE_ORDERED_TAG, NULL); /* Host must always specify the capacity. */ @@ -308,7 +308,13 @@ static struct virtio_device_id id_table[] = { { 0 }, }; +static unsigned int features[] = { + VIRTIO_BLK_F_BARRIER, VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, +}; + static struct virtio_driver virtio_blk = { + .feature_table = features, + .feature_table_size = ARRAY_SIZE(features), .driver.name = KBUILD_MODNAME, .driver.owner = THIS_MODULE, .id_table = id_table, diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c index 2bc9bf7e88e..7a643a6ee9a 100644 --- a/drivers/lguest/lguest_device.c +++ b/drivers/lguest/lguest_device.c @@ -85,27 +85,34 @@ static unsigned desc_size(const struct lguest_device_desc *desc) + desc->config_len; } -/* This tests (and acknowleges) a feature bit. */ -static bool lg_feature(struct virtio_device *vdev, unsigned fbit) +/* This gets the device's feature bits. */ +static u32 lg_get_features(struct virtio_device *vdev) { + unsigned int i; + u32 features = 0; + struct lguest_device_desc *desc = to_lgdev(vdev)->desc; + u8 *in_features = lg_features(desc); + + /* We do this the slow but generic way. */ + for (i = 0; i < min(desc->feature_len * 8, 32); i++) + if (in_features[i / 8] & (1 << (i % 8))) + features |= (1 << i); + + return features; +} + +static void lg_set_features(struct virtio_device *vdev, u32 features) +{ + unsigned int i; struct lguest_device_desc *desc = to_lgdev(vdev)->desc; - u8 *features; - - /* Obviously if they ask for a feature off the end of our feature - * bitmap, it's not set. */ - if (fbit / 8 > desc->feature_len) - return false; - - /* The feature bitmap comes after the virtqueues. */ - features = lg_features(desc); - if (!(features[fbit / 8] & (1 << (fbit % 8)))) - return false; - - /* We set the matching bit in the other half of the bitmap to tell the - * Host we want to use this feature. We don't use this yet, but we - * could in future. */ - features[desc->feature_len + fbit / 8] |= (1 << (fbit % 8)); - return true; + /* Second half of bitmap is features we accept. */ + u8 *out_features = lg_features(desc) + desc->feature_len; + + memset(out_features, 0, desc->feature_len); + for (i = 0; i < min(desc->feature_len * 8, 32); i++) { + if (features & (1 << i)) + out_features[i / 8] |= (1 << (i % 8)); + } } /* Once they've found a field, getting a copy of it is easy. */ @@ -286,7 +293,8 @@ static void lg_del_vq(struct virtqueue *vq) /* The ops structure which hooks everything together. */ static struct virtio_config_ops lguest_config_ops = { - .feature = lg_feature, + .get_features = lg_get_features, + .set_features = lg_set_features, .get = lg_get, .set = lg_set, .get_status = lg_get_status, diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index ad43421ab6f..f926b5ab3d0 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -378,26 +378,26 @@ static int virtnet_probe(struct virtio_device *vdev) SET_NETDEV_DEV(dev, &vdev->dev); /* Do we support "hardware" checksums? */ - if (csum && vdev->config->feature(vdev, VIRTIO_NET_F_CSUM)) { + if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { /* This opens up the world of extra features. */ dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; - if (gso && vdev->config->feature(vdev, VIRTIO_NET_F_GSO)) { + if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { dev->features |= NETIF_F_TSO | NETIF_F_UFO | NETIF_F_TSO_ECN | NETIF_F_TSO6; } /* Individual feature bits: what can host handle? */ - if (gso && vdev->config->feature(vdev, VIRTIO_NET_F_HOST_TSO4)) + if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4)) dev->features |= NETIF_F_TSO; - if (gso && vdev->config->feature(vdev, VIRTIO_NET_F_HOST_TSO6)) + if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6)) dev->features |= NETIF_F_TSO6; - if (gso && vdev->config->feature(vdev, VIRTIO_NET_F_HOST_ECN)) + if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN)) dev->features |= NETIF_F_TSO_ECN; - if (gso && vdev->config->feature(vdev, VIRTIO_NET_F_HOST_UFO)) + if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO)) dev->features |= NETIF_F_UFO; } /* Configuration may specify what MAC to use. Otherwise random. */ - if (vdev->config->feature(vdev, VIRTIO_NET_F_MAC)) { + if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) { vdev->config->get(vdev, offsetof(struct virtio_net_config, mac), dev->dev_addr, dev->addr_len); @@ -486,7 +486,15 @@ static struct virtio_device_id id_table[] = { { 0 }, }; +static unsigned int features[] = { + VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC, + VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, + VIRTIO_NET_F_HOST_ECN, +}; + static struct virtio_driver virtio_net = { + .feature_table = features, + .feature_table_size = ARRAY_SIZE(features), .driver.name = KBUILD_MODNAME, .driver.owner = THIS_MODULE, .id_table = id_table, diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index b535483bc55..13866789b35 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -80,19 +80,51 @@ static void add_status(struct virtio_device *dev, unsigned status) dev->config->set_status(dev, dev->config->get_status(dev) | status); } +void virtio_check_driver_offered_feature(const struct virtio_device *vdev, + unsigned int fbit) +{ + unsigned int i; + struct virtio_driver *drv = container_of(vdev->dev.driver, + struct virtio_driver, driver); + + for (i = 0; i < drv->feature_table_size; i++) + if (drv->feature_table[i] == fbit) + return; + BUG(); +} +EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature); + static int virtio_dev_probe(struct device *_d) { - int err; + int err, i; struct virtio_device *dev = container_of(_d,struct virtio_device,dev); struct virtio_driver *drv = container_of(dev->dev.driver, struct virtio_driver, driver); + u32 device_features; + /* We have a driver! */ add_status(dev, VIRTIO_CONFIG_S_DRIVER); + + /* 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)); + 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); + } + err = drv->probe(dev); if (err) add_status(dev, VIRTIO_CONFIG_S_FAILED); - else + else { add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK); + /* They should never have set feature bits beyond 32 */ + dev->config->set_features(dev, dev->features[0]); + } return err; } @@ -114,6 +146,8 @@ static int virtio_dev_remove(struct device *_d) int register_virtio_driver(struct virtio_driver *driver) { + /* Catch this early. */ + BUG_ON(driver->feature_table_size && !driver->feature_table); driver->driver.bus = &virtio_bus; driver->driver.probe = virtio_dev_probe; driver->driver.remove = virtio_dev_remove; diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index fef88d84cef..bfef604160d 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -227,7 +227,7 @@ static int virtballoon_probe(struct virtio_device *vdev) } vb->tell_host_first - = vdev->config->feature(vdev, VIRTIO_BALLOON_F_MUST_TELL_HOST); + = virtio_has_feature(vdev, VIRTIO_BALLOON_F_MUST_TELL_HOST); return 0; @@ -259,7 +259,11 @@ static void virtballoon_remove(struct virtio_device *vdev) kfree(vb); } +static unsigned int features[] = { VIRTIO_BALLOON_F_MUST_TELL_HOST }; + static struct virtio_driver virtio_balloon = { + .feature_table = features, + .feature_table_size = ARRAY_SIZE(features), .driver.name = KBUILD_MODNAME, .driver.owner = THIS_MODULE, .id_table = id_table, diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index de102a614e9..27e9fc9117c 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -87,23 +87,22 @@ static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev) return container_of(vdev, struct virtio_pci_device, vdev); } -/* virtio config->feature() implementation */ -static bool vp_feature(struct virtio_device *vdev, unsigned bit) +/* virtio config->get_features() implementation */ +static u32 vp_get_features(struct virtio_device *vdev) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + + /* When someone needs more than 32 feature bits, we'll need to + * steal a bit to indicate that the rest are somewhere else. */ + return ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES); +} + +/* virtio config->set_features() implementation */ +static void vp_set_features(struct virtio_device *vdev, u32 features) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); - u32 mask; - - /* Since this function is supposed to have the side effect of - * enabling a queried feature, we simulate that by doing a read - * from the host feature bitmask and then writing to the guest - * feature bitmask */ - mask = ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES); - if (mask & (1 << bit)) { - mask |= (1 << bit); - iowrite32(mask, vp_dev->ioaddr + VIRTIO_PCI_GUEST_FEATURES); - } - return !!(mask & (1 << bit)); + iowrite32(features, vp_dev->ioaddr + VIRTIO_PCI_GUEST_FEATURES); } /* virtio config->get() implementation */ @@ -293,7 +292,6 @@ static void vp_del_vq(struct virtqueue *vq) } static struct virtio_config_ops virtio_pci_config_ops = { - .feature = vp_feature, .get = vp_get, .set = vp_set, .get_status = vp_get_status, @@ -301,6 +299,8 @@ static struct virtio_config_ops virtio_pci_config_ops = { .reset = vp_reset, .find_vq = vp_find_vq, .del_vq = vp_del_vq, + .get_features = vp_get_features, + .set_features = vp_set_features, }; /* the PCI probing function */ diff --git a/include/linux/virtio.h b/include/linux/virtio.h index e7d10845b3c..06005fa9e98 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -76,6 +76,7 @@ struct virtqueue_ops { * @dev: underlying device. * @id: the device type identification (used to match it with a driver). * @config: the configuration ops for this device. + * @features: the features supported by both driver and device. * @priv: private pointer for the driver's use. */ struct virtio_device @@ -84,6 +85,8 @@ struct virtio_device struct device dev; struct virtio_device_id id; struct virtio_config_ops *config; + /* Note that this is a Linux set_bit-style bitmap. */ + unsigned long features[1]; void *priv; }; @@ -94,6 +97,8 @@ void unregister_virtio_device(struct virtio_device *dev); * virtio_driver - operations for a virtio I/O driver * @driver: underlying device driver (populate name and owner). * @id_table: the ids serviced by this driver. + * @feature_table: an array of feature numbers supported by this device. + * @feature_table_size: number of entries in the feature table array. * @probe: the function to call when a device is found. Returns a token for * remove, or PTR_ERR(). * @remove: the function when a device is removed. @@ -103,6 +108,8 @@ void unregister_virtio_device(struct virtio_device *dev); struct virtio_driver { struct device_driver driver; const struct virtio_device_id *id_table; + const unsigned int *feature_table; + unsigned int feature_table_size; int (*probe)(struct virtio_device *dev); void (*remove)(struct virtio_device *dev); void (*config_changed)(struct virtio_device *dev); diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index 475572e976f..50db245c81a 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -20,11 +20,6 @@ /** * virtio_config_ops - operations for configuring a virtio device - * @feature: search for a feature in this config - * vdev: the virtio_device - * bit: the feature bit - * Returns true if the feature is supported. Acknowledges the feature - * so the host can see it. * @get: read the value of a configuration field * vdev: the virtio_device * offset: the offset of the configuration field @@ -50,10 +45,15 @@ * callback: the virqtueue callback * Returns the new virtqueue or ERR_PTR() (eg. -ENOENT). * @del_vq: free a virtqueue found by find_vq(). + * @get_features: get the array of feature bits for this device. + * vdev: the virtio_device + * Returns the first 32 feature bits (all we currently need). + * @set_features: confirm what device features we'll be using. + * vdev: the virtio_device + * feature: the first 32 feature bits */ struct virtio_config_ops { - bool (*feature)(struct virtio_device *vdev, unsigned bit); void (*get)(struct virtio_device *vdev, unsigned offset, void *buf, unsigned len); void (*set)(struct virtio_device *vdev, unsigned offset, @@ -65,8 +65,30 @@ struct virtio_config_ops unsigned index, void (*callback)(struct virtqueue *)); void (*del_vq)(struct virtqueue *vq); + u32 (*get_features)(struct virtio_device *vdev); + void (*set_features)(struct virtio_device *vdev, u32 features); }; +/* If driver didn't advertise the feature, it will never appear. */ +void virtio_check_driver_offered_feature(const struct virtio_device *vdev, + unsigned int fbit); + +/** + * virtio_has_feature - helper to determine if this device has this feature. + * @vdev: the device + * @fbit: the feature bit + */ +static inline bool virtio_has_feature(const struct virtio_device *vdev, + unsigned int fbit) +{ + /* Did you forget to fix assumptions on max features? */ + if (__builtin_constant_p(fbit)) + BUILD_BUG_ON(fbit >= 32); + + virtio_check_driver_offered_feature(vdev, fbit); + return test_bit(fbit, vdev->features); +} + /** * virtio_config_val - look for a feature and get a virtio config entry. * @vdev: the virtio device @@ -84,7 +106,7 @@ static inline int virtio_config_buf(struct virtio_device *vdev, unsigned int offset, void *buf, unsigned len) { - if (!vdev->config->feature(vdev, fbit)) + if (!virtio_has_feature(vdev, fbit)) return -ENOENT; vdev->config->get(vdev, offset, buf, len); |