[PATCH v4 1/2] virtio: let arch validate VIRTIO features

Pierre Morel
2020-07-07T08:44:59Z

An architecture may need to validate the VIRTIO devices features
based on architecture specificities.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
drivers/virtio/virtio.c | 19 +++++++++++++++++++
include/linux/virtio_config.h | 1 +
2 files changed, 20 insertions(+)

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index a977e32a88f2..3179a8aa76f5 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -167,6 +167,21 @@ void virtio_add_status(struct virtio_device *dev, unsigned int status)
}
EXPORT_SYMBOL_GPL(virtio_add_status);

+/*
+ * arch_needs_virtio_iommu_platform - provide arch specific hook when finalizing
+ * features for VIRTIO device dev
+ * @dev: the VIRTIO device being added
+ *
+ * Permits the platform to provide architecture specific functionality when
+ * devices features are finalized. This is the default implementation.
+ * Architecture implementations can override this.
+ */
+
+int __weak arch_validate_virtio_features(struct virtio_device *dev)
+{
+ return 0;
+}
+
int virtio_finalize_features(struct virtio_device *dev)
{
int ret = dev->config->finalize_features(dev);
@@ -176,6 +191,10 @@ int virtio_finalize_features(struct virtio_device *dev)
if (ret)
return ret;

+ ret = arch_validate_virtio_features(dev);
+ if (ret)
+ return ret;
+
if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1))
return 0;

diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index bb4cc4910750..3f4117adf311 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -459,4 +459,5 @@ static inline void virtio_cwrite64(struct virtio_device *vdev,
_r; \
})

+int arch_validate_virtio_features(struct virtio_device *dev);
#endif /* _LINUX_VIRTIO_CONFIG_H */
--
2.25.1