[dpdk-dev] [RFC 24/24] WORKAROUND examples/vhost_scsi: avoid broken EVENT_IDX

Michael S. Tsirkin mst at redhat.com
Fri Jan 19 20:31:32 CET 2018


On Fri, Jan 19, 2018 at 01:44:44PM +0000, Stefan Hajnoczi wrote:
> The EVENT_IDX code in DPDK is broken.  It's missing the
> signalled_used_valid flag that handles the corner cases (startup and
> wrapping).  Disable it for now.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha at redhat.com>

FYI signalled_used_valid isn't strictly required,
there are ways to handle event idx without that,
e.g. like virtio within guest.

> ---
>  examples/vhost_scsi/vhost_scsi.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/examples/vhost_scsi/vhost_scsi.c b/examples/vhost_scsi/vhost_scsi.c
> index 61001cadb..7106dc6d2 100644
> --- a/examples/vhost_scsi/vhost_scsi.c
> +++ b/examples/vhost_scsi/vhost_scsi.c
> @@ -22,7 +22,6 @@
>  #include "scsi_spec.h"
>  
>  #define VIRTIO_SCSI_FEATURES ((1 << VIRTIO_F_NOTIFY_ON_EMPTY) |\
> -			      (1 << VIRTIO_RING_F_EVENT_IDX) |\
>  			      (1 << VIRTIO_SCSI_F_INOUT) |\
>  			      (1 << VIRTIO_SCSI_F_CHANGE))
>  
> -- 
> 2.14.3


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