Re: [PATCH] hw/block/nvme: fix aer logic

[Keith Busch]

On Mon, Oct 19, 2020 at 08:54:16AM +0200, Klaus Jensen wrote:
> @@ -844,6 +838,12 @@ static void nvme_enqueue_event(NvmeCtrl *n, uint8_t 
> event_type,
>          return;
>      }
>  
> +    /* ignore if masked (cqe posted, but event not cleared) */
> +    if (n->aer_mask & (1 << event_type)) {
> +        trace_pci_nvme_aer_masked(event_type, n->aer_mask);
> +        return;
> +    }

The 'mask' means the host hasn't yet acknowledged the AER with the
appropriate log. The controller should continue to internally enqueue
subsequent events of this type, but suppress sending the notification
for them until the host unlatches the event type.

>      event = g_new(NvmeAsyncEvent, 1);
>      event->result = (NvmeAerResult) {
>          .event_type = event_type,
> @@ -859,9 +859,15 @@ static void nvme_enqueue_event(NvmeCtrl *n, uint8_t 
> event_type,
>  
>  static void nvme_clear_events(NvmeCtrl *n, uint8_t event_type)
>  {
> +    NvmeAsyncEvent *event, *next;
> +
>      n->aer_mask &= ~(1 << event_type);
> -    if (!QTAILQ_EMPTY(&n->aer_queue)) {
> -        nvme_process_aers(n);
> +
> +    QTAILQ_FOREACH_SAFE(event, &n->aer_queue, entry, next) {
> +        if (event->result.event_type == event_type) {
> +            QTAILQ_REMOVE(&n->aer_queue, event, entry);

Memory leaking the 'event'?

> +            n->aer_queued--;
> +        }
>      }
>  }