[PATCH v3 1/1] virtio_bt: Fix alignment in configuration struct

From: Igor Skalkin
Date: Tue Oct 18 2022 - 15:19:41 EST


The current version of the configuration structure has unaligned
16-bit fields, but according to the specification [1], access to
the configuration space must be aligned.

Add a second, aligned version of the configuration structure
and a new feature bit indicating that this version is being used.

[1] https://docs.oasis-open.org/virtio/virtio/v1.1/virtio-v1.1.pdf

Signed-off-by: Igor Skalkin <Igor.Skalkin@xxxxxxxxxxxxxxx>
---
drivers/bluetooth/virtio_bt.c | 16 +++++++++++++---
include/uapi/linux/virtio_bt.h | 8 ++++++++
2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/bluetooth/virtio_bt.c b/drivers/bluetooth/virtio_bt.c
index 67c21263f9e0..35f8041722c8 100644
--- a/drivers/bluetooth/virtio_bt.c
+++ b/drivers/bluetooth/virtio_bt.c
@@ -306,7 +306,12 @@ static int virtbt_probe(struct virtio_device *vdev)
if (virtio_has_feature(vdev, VIRTIO_BT_F_VND_HCI)) {
__u16 vendor;

- virtio_cread(vdev, struct virtio_bt_config, vendor, &vendor);
+ if (virtio_has_feature(vdev, VIRTIO_BT_F_CONFIG_V2))
+ virtio_cread(vdev, struct virtio_bt_config_v2,
+ vendor, &vendor);
+ else
+ virtio_cread(vdev, struct virtio_bt_config,
+ vendor, &vendor);

switch (vendor) {
case VIRTIO_BT_CONFIG_VENDOR_ZEPHYR:
@@ -339,8 +344,12 @@ static int virtbt_probe(struct virtio_device *vdev)
if (virtio_has_feature(vdev, VIRTIO_BT_F_MSFT_EXT)) {
__u16 msft_opcode;

- virtio_cread(vdev, struct virtio_bt_config,
- msft_opcode, &msft_opcode);
+ if (virtio_has_feature(vdev, VIRTIO_BT_F_CONFIG_V2))
+ virtio_cread(vdev, struct virtio_bt_config_v2,
+ msft_opcode, &msft_opcode);
+ else
+ virtio_cread(vdev, struct virtio_bt_config,
+ msft_opcode, &msft_opcode);

hci_set_msft_opcode(hdev, msft_opcode);
}
@@ -387,6 +396,7 @@ static const unsigned int virtbt_features[] = {
VIRTIO_BT_F_VND_HCI,
VIRTIO_BT_F_MSFT_EXT,
VIRTIO_BT_F_AOSP_EXT,
+ VIRTIO_BT_F_CONFIG_V2,
};

static struct virtio_driver virtbt_driver = {
diff --git a/include/uapi/linux/virtio_bt.h b/include/uapi/linux/virtio_bt.h
index a7bd48daa9a9..af798f4c9680 100644
--- a/include/uapi/linux/virtio_bt.h
+++ b/include/uapi/linux/virtio_bt.h
@@ -9,6 +9,7 @@
#define VIRTIO_BT_F_VND_HCI 0 /* Indicates vendor command support */
#define VIRTIO_BT_F_MSFT_EXT 1 /* Indicates MSFT vendor support */
#define VIRTIO_BT_F_AOSP_EXT 2 /* Indicates AOSP vendor support */
+#define VIRTIO_BT_F_CONFIG_V2 3 /* Use second version configuration */

enum virtio_bt_config_type {
VIRTIO_BT_CONFIG_TYPE_PRIMARY = 0,
@@ -28,4 +29,11 @@ struct virtio_bt_config {
__u16 msft_opcode;
} __attribute__((packed));

+struct virtio_bt_config_v2 {
+ __u8 type;
+ __u8 alignment;
+ __u16 vendor;
+ __u16 msft_opcode;
+};
+
#endif /* _UAPI_LINUX_VIRTIO_BT_H */
--
2.37.2


Please mind our privacy notice<https://www.opensynergy.com/datenschutzerklaerung/privacy-notice-for-business-partners-pursuant-to-article-13-of-the-general-data-protection-regulation-gdpr/> pursuant to Art. 13 GDPR. // Unsere Hinweise zum Datenschutz gem. Art. 13 DSGVO finden Sie hier.<https://www.opensynergy.com/de/datenschutzerklaerung/datenschutzhinweise-fuer-geschaeftspartner-gem-art-13-dsgvo/>