diff options
| author | Michael S. Tsirkin <mst@redhat.com> | 2025-12-29 18:24:36 -0500 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2026-01-08 09:54:26 -0500 |
| commit | 95c7b0ad6c69d1c0608ff0bbd358a546856beaf3 (patch) | |
| tree | f4fed8c40e9fcb26c48004ddf5dec6fcefa9598e | |
| parent | db191ba0c8564ff84877e5b1c9553e991feca239 (diff) | |
virtio_input: fix DMA alignment for evts
On non-cache-coherent platforms, when a structure contains a buffer
used for DMA alongside fields that the CPU writes to, cacheline sharing
can cause data corruption.
The evts array is used for DMA_FROM_DEVICE operations via
virtqueue_add_inbuf(). The adjacent lock and ready fields are written
by the CPU during normal operation. If these share cachelines with evts,
CPU writes can corrupt DMA data.
Add __dma_from_device_group_begin()/end() annotations to ensure evts is
isolated in its own cachelines.
Message-ID: <cd328233198a76618809bb5cd9a6ddcaa603a8a1.1767601130.git.mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| -rw-r--r-- | drivers/virtio/virtio_input.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_input.c b/drivers/virtio/virtio_input.c index d0728285b6ce..9f13de1f1d77 100644 --- a/drivers/virtio/virtio_input.c +++ b/drivers/virtio/virtio_input.c @@ -4,6 +4,7 @@ #include <linux/virtio_config.h> #include <linux/input.h> #include <linux/slab.h> +#include <linux/dma-mapping.h> #include <uapi/linux/virtio_ids.h> #include <uapi/linux/virtio_input.h> @@ -16,7 +17,9 @@ struct virtio_input { char serial[64]; char phys[64]; struct virtqueue *evt, *sts; + __dma_from_device_group_begin(); struct virtio_input_event evts[64]; + __dma_from_device_group_end(); spinlock_t lock; bool ready; }; |