[PATCH v7 12/46] virtio: set FEATURES_OK

Michael S. Tsirkin
2014-11-30T15:22:08Z

set FEATURES_OK as per virtio 1.0 spec

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
include/uapi/linux/virtio_config.h | 2 ++
drivers/virtio/virtio.c | 29 ++++++++++++++++++++++-------
2 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/include/uapi/linux/virtio_config.h b/include/uapi/linux/virtio_config.h
index 80e7381..4d05671 100644
--- a/include/uapi/linux/virtio_config.h
+++ b/include/uapi/linux/virtio_config.h
@@ -38,6 +38,8 @@
#define VIRTIO_CONFIG_S_DRIVER 2
/* Driver has used its parts of the config, and is happy */
#define VIRTIO_CONFIG_S_DRIVER_OK 4
+/* Driver has finished configuring features */
+#define VIRTIO_CONFIG_S_FEATURES_OK 8
/* We've given up on this device. */
#define VIRTIO_CONFIG_S_FAILED 0x80

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 746d350..9248125 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -160,6 +160,7 @@ static int virtio_dev_probe(struct device *_d)
struct virtio_device *dev = dev_to_virtio(_d);
struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
u64 device_features;
+ unsigned status;

/* We have a driver! */
add_status(dev, VIRTIO_CONFIG_S_DRIVER);
@@ -183,18 +184,32 @@ static int virtio_dev_probe(struct device *_d)

dev->config->finalize_features(dev);

+ if (virtio_has_feature(dev, VIRTIO_F_VERSION_1)) {
+ add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK);
+ status = dev->config->get_status(dev);
+ if (!(status & VIRTIO_CONFIG_S_FEATURES_OK)) {
+ dev_err(_d, "virtio: device refuses features: %x\n",
+ status);
+ err = -ENODEV;
+ 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)
--
MST