2020-02-29 17:15:23

by Yuri Benditovich

Subject: [PATCH 1/3] virtio-net: Introduce extended RSC feature

VIRTIO_NET_F_RSC_EXT feature bit indicates that the device
is able to provide extended RSC information. When the feature
is negotiatede and 'gso_type' field in received packet is not
GSO_NONE, the device reports number of coalesced packets in
'csum_start' field and number of duplicated acks in 'csum_offset'
field and sets VIRTIO_NET_HDR_F_RSC_INFO in 'flags' field.

Signed-off-by: Yuri Benditovich <[email protected]>
---
include/uapi/linux/virtio_net.h | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
index a3715a3224c1..6e26a2cc6ad0 100644
--- a/include/uapi/linux/virtio_net.h
+++ b/include/uapi/linux/virtio_net.h
@@ -57,6 +57,7 @@
* Steering */
#define VIRTIO_NET_F_CTRL_MAC_ADDR 23 /* Set MAC address */

+#define VIRTIO_NET_F_RSC_EXT 61 /* extended coalescing info */
#define VIRTIO_NET_F_STANDBY 62 /* Act as standby for another device
* with the same MAC.
*/
@@ -104,6 +105,7 @@ struct virtio_net_config {
struct virtio_net_hdr_v1 {
#define VIRTIO_NET_HDR_F_NEEDS_CSUM 1 /* Use csum_start, csum_offset */
#define VIRTIO_NET_HDR_F_DATA_VALID 2 /* Csum is valid */
+#define VIRTIO_NET_HDR_F_RSC_INFO 4 /* rsc info in csum_ fields */
__u8 flags;
#define VIRTIO_NET_HDR_GSO_NONE 0 /* Not a GSO frame */
#define VIRTIO_NET_HDR_GSO_TCPV4 1 /* GSO frame, IPv4 TCP (TSO) */
@@ -113,8 +115,14 @@ struct virtio_net_hdr_v1 {
__u8 gso_type;
__virtio16 hdr_len; /* Ethernet + IP + tcp/udp hdrs */
__virtio16 gso_size; /* Bytes to append to hdr_len per frame */
- __virtio16 csum_start; /* Position to start checksumming from */
- __virtio16 csum_offset; /* Offset after that to place checksum */
+ union {
+ __virtio16 csum_start; /* Position to start checksumming from */
+ __virtio16 rsc_ext_num_packets; /* num of coalesced packets */
+ };
+ union {
+ __virtio16 csum_offset; /* Offset after that to place checksum */
+ __virtio16 rsc_ext_num_dupacks; /* num of duplicated acks */
+ };
__virtio16 num_buffers; /* Number of merged rx buffers */
};

--
2.17.1

2020-03-01 08:45:59

by Michael S. Tsirkin

Subject: Re: [PATCH 1/3] virtio-net: Introduce extended RSC feature

On Sat, Feb 29, 2020 at 07:12:59PM +0200, Yuri Benditovich wrote:
> VIRTIO_NET_F_RSC_EXT feature bit indicates that the device
> is able to provide extended RSC information. When the feature
> is negotiatede and 'gso_type' field in received packet is not
> GSO_NONE, the device reports number of coalesced packets in
> 'csum_start' field and number of duplicated acks in 'csum_offset'
> field and sets VIRTIO_NET_HDR_F_RSC_INFO in 'flags' field.
>
> Signed-off-by: Yuri Benditovich <[email protected]>
> ---
> include/uapi/linux/virtio_net.h | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
> index a3715a3224c1..6e26a2cc6ad0 100644
> --- a/include/uapi/linux/virtio_net.h
> +++ b/include/uapi/linux/virtio_net.h
> @@ -57,6 +57,7 @@
> * Steering */
> #define VIRTIO_NET_F_CTRL_MAC_ADDR 23 /* Set MAC address */
>
> +#define VIRTIO_NET_F_RSC_EXT 61 /* extended coalescing info */
> #define VIRTIO_NET_F_STANDBY 62 /* Act as standby for another device
> * with the same MAC.
> */
> @@ -104,6 +105,7 @@ struct virtio_net_config {
> struct virtio_net_hdr_v1 {
> #define VIRTIO_NET_HDR_F_NEEDS_CSUM 1 /* Use csum_start, csum_offset */
> #define VIRTIO_NET_HDR_F_DATA_VALID 2 /* Csum is valid */
> +#define VIRTIO_NET_HDR_F_RSC_INFO 4 /* rsc info in csum_ fields */
> __u8 flags;
> #define VIRTIO_NET_HDR_GSO_NONE 0 /* Not a GSO frame */
> #define VIRTIO_NET_HDR_GSO_TCPV4 1 /* GSO frame, IPv4 TCP (TSO) */
> @@ -113,8 +115,14 @@ struct virtio_net_hdr_v1 {
> __u8 gso_type;
> __virtio16 hdr_len; /* Ethernet + IP + tcp/udp hdrs */
> __virtio16 gso_size; /* Bytes to append to hdr_len per frame */
> - __virtio16 csum_start; /* Position to start checksumming from */
> - __virtio16 csum_offset; /* Offset after that to place checksum */
> + union {
> + __virtio16 csum_start; /* Position to start checksumming from */
> + __virtio16 rsc_ext_num_packets; /* num of coalesced packets */
> + };
> + union {
> + __virtio16 csum_offset; /* Offset after that to place checksum */
> + __virtio16 rsc_ext_num_dupacks; /* num of duplicated acks */
> + };
> __virtio16 num_buffers; /* Number of merged rx buffers */
> };


New fields should all be __le, not __virtio.

>
> --
> 2.17.1