Re: [PATCH 1/1] virtio: add VIRTIO_F_IN_ORDER to header file
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2021-09-05 15:09:25
Also in:
kvm
On Sun, Sep 05, 2021 at 03:09:11PM +0300, Max Gurtovoy wrote:
For now only add this definition from the spec. In the future, The drivers should negotiate this feature to optimize the performance. Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
So I think IN_ORDER was a mistake since it breaks ability to do pagefaults efficiently without stopping the ring. I think that VIRTIO_F_PARTIAL_ORDER is a better option - am working on finalizing that proposal, will post RSN now.
quoted hunk
--- include/uapi/linux/virtio_config.h | 6 ++++++ 1 file changed, 6 insertions(+)diff --git a/include/uapi/linux/virtio_config.h b/include/uapi/linux/virtio_config.h index b5eda06f0d57..3fcdc4ab6f19 100644 --- a/include/uapi/linux/virtio_config.h +++ b/include/uapi/linux/virtio_config.h@@ -82,6 +82,12 @@ /* This feature indicates support for the packed virtqueue layout. */ #define VIRTIO_F_RING_PACKED 34 +/* + * This feature indicates that all buffers are used by the device in the same + * order in which they have been made available. + */ +#define VIRTIO_F_IN_ORDER 35 + /* * This feature indicates that memory accesses by the driver and the * device are ordered in a way described by the platform.-- 2.18.1
_______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization