Re: [PATCH v2 08/15] vsock/virtio: use virtqueue_add_inbuf_cache_clean for events
From: Stefano Garzarella <sgarzare@redhat.com>
Date: 2026-01-08 14:08:40
Also in:
kvm, linux-crypto, linux-doc, linux-iommu, linux-scsi, lkml, virtualization
On Mon, Jan 05, 2026 at 03:23:21AM -0500, Michael S. Tsirkin wrote:
The event_list array contains 8 small (4-byte) events that share cachelines with each other. When CONFIG_DMA_API_DEBUG is enabled, this can trigger warnings about overlapping DMA mappings within the same cacheline. The previous patch isolated event_list in its own cache lines so the warnings are spurious. Use virtqueue_add_inbuf_cache_clean() to indicate that the CPU does not write into these fields, suppressing the warnings. Reported-by: Cong Wang <redacted> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- net/vmw_vsock/virtio_transport.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
quoted hunk ↗ jump to hunk
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c index bb94baadfd8b..ef983c36cb66 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c@@ -392,7 +392,7 @@ static int virtio_vsock_event_fill_one(struct virtio_vsock *vsock,sg_init_one(&sg, event, sizeof(*event)); - return virtqueue_add_inbuf(vq, &sg, 1, event, GFP_KERNEL); + return virtqueue_add_inbuf_cache_clean(vq, &sg, 1, event, GFP_KERNEL); } /* event_lock must be held */ -- MST