Hi Viresh,
On 24 Jul 2025, at 11:41, Viresh Kumar viresh.kumar@linaro.org wrote:
On 22-07-25, 10:38, Bertrand Marquis wrote:
+static void virtio_msg_get(struct virtio_device *vdev, unsigned int offset,
- void *buf, unsigned int len)
+{
- struct virtio_msg_device *vmdev = to_virtio_msg_device(vdev);
- struct get_config *req_payload = virtio_msg_payload(vmdev->request);
- struct get_config_resp *res_payload = virtio_msg_payload(vmdev->response);
- BUG_ON(len > 8);
So you only allow to retrieve 64bit at a time here. Why is that ?
This was copied from mmio which accepts on 8 bytes at a time. Modified as:
Sounds good yes, same should apply to set I would say.
Cheers Bertrand
diff --git a/drivers/virtio/virtio_msg.c b/drivers/virtio/virtio_msg.c index 207fa1f18bf9..8508a90551a6 100644 --- a/drivers/virtio/virtio_msg.c +++ b/drivers/virtio/virtio_msg.c @@ -170,8 +170,7 @@ static void virtio_msg_get(struct virtio_device *vdev, unsigned int offset, struct virtio_msg_device *vmdev = to_virtio_msg_device(vdev); struct get_config *req_payload = virtio_msg_payload(vmdev->request); struct get_config_resp *res_payload = virtio_msg_payload(vmdev->response);
BUG_ON(len > 8);
u32 i = 0, max; if (offset + len > vmdev->config_size) { dev_err(&vmdev->vdev.dev,@@ -180,16 +179,25 @@ static void virtio_msg_get(struct virtio_device *vdev, unsigned int offset, return; }
/* Max buffer size available in the response */max = vmdev->msg_size - sizeof(*vmdev->response) - sizeof(*res_payload);transport_msg_prepare(vmdev, VIRTIO_MSG_GET_CONFIG, sizeof(*req_payload));
req_payload->offset = cpu_to_le32(offset);req_payload->size = cpu_to_le32(len);if (virtio_msg_xfer(vmdev))return;
while (i != len) {u32 size = min(max, len - i);req_payload->offset = cpu_to_le32(offset + i);req_payload->size = cpu_to_le32(size);if (virtio_msg_xfer(vmdev))return;/* Buffer holds the data in little endian */memcpy(buf + i, res_payload->config, size);i += size;}
/* Buffer holds the data in little endian */if (buf)memcpy(buf, res_payload->config, len); vmdev->generation_count = le32_to_cpu(res_payload->generation);}
-- viresh
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