Subject: [PATCH net-next v20 01/12] virtio_pci: Remove supported_cap size build assert

From: Daniel Jurgens <[email-masked]>
Date: Thu, 5 Feb 2026 16:46:56 -0600

The cap ID list can be more than 64 bits. Remove the build assert. Also
remove caching of the supported caps, it wasn't used.

Signed-off-by: Daniel Jurgens <[email-masked]>
Reviewed-by: Parav Pandit <[email-masked]>
Reviewed-by: Xuan Zhuo <[email-masked]>

---
v4: New patch for V4
v5:
   - support_caps -> supported_caps (Alok Tiwari)
   - removed unused variable (test robot)

v12
   - Change supported_caps check to byte swap the constant. MST
---
 drivers/virtio/virtio_pci_common.h | 1 -
 drivers/virtio/virtio_pci_modern.c | 8 +-------
 2 files changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/virtio/virtio_pci_common.h b/drivers/virtio/virtio_pci_common.h
index 8cd01de27baf..fc26e035e7a6 100644
--- a/drivers/virtio/virtio_pci_common.h
+++ b/drivers/virtio/virtio_pci_common.h
@@ -48,7 +48,6 @@ struct virtio_pci_admin_vq {
 	/* Protects virtqueue access. */
 	spinlock_t lock;
 	u64 supported_cmds;
-	u64 supported_caps;
 	u8 max_dev_parts_objects;
 	struct ida dev_parts_ida;
 	/* Name of the admin queue: avq.$vq_index. */
diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index dd0e65f71d41..1675d6cda416 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -304,7 +304,6 @@ virtio_pci_admin_cmd_dev_parts_objects_enable(struct virtio_device *virtio_dev)
 
 static void virtio_pci_admin_cmd_cap_init(struct virtio_device *virtio_dev)
 {
-	struct virtio_pci_device *vp_dev = to_vp_device(virtio_dev);
 	struct virtio_admin_cmd_query_cap_id_result *data;
 	struct virtio_admin_cmd cmd = {};
 	struct scatterlist result_sg;
@@ -323,12 +322,7 @@ static void virtio_pci_admin_cmd_cap_init(struct virtio_device *virtio_dev)
 	if (ret)
 		goto end;
 
-	/* Max number of caps fits into a single u64 */
-	BUILD_BUG_ON(sizeof(data->supported_caps) > sizeof(u64));
-
-	vp_dev->admin_vq.supported_caps = le64_to_cpu(data->supported_caps[0]);
-
-	if (!(vp_dev->admin_vq.supported_caps & (1 << VIRTIO_DEV_PARTS_CAP)))
+	if (!(data->supported_caps[0] & cpu_to_le64(1 << VIRTIO_DEV_PARTS_CAP)))
 		goto end;
 
 	virtio_pci_admin_cmd_dev_parts_objects_enable(virtio_dev);
-- 
2.50.1