[PATCH 0/3] virtio-net: introduce features defined in the spec

[PATCH 0/3] virtio-net: introduce features defined in the spec

[Yuri Benditovich]

This series introduce virtio-net features VIRTIO_NET_F_RSC_EXT,
VIRTIO_NET_F_RSS and VIRTIO_NET_F_HASH_REPORT.

Yuri Benditovich (3):
  virtio-net: Introduce extended RSC feature
  virtio-net: Introduce RSS receive steering feature
  virtio-net: Introduce hash report feature

 include/uapi/linux/virtio_net.h | 90 +++++++++++++++++++++++++++++++--
 1 file changed, 86 insertions(+), 4 deletions(-)

-- 
2.17.1

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

[Yuri Benditovich]

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 <yuri.benditovich@daynix.com>
---
 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

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

[Michael S. Tsirkin]

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 <yuri.benditovich@daynix.com>
> ---
>  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

[PATCH 2/3] virtio-net: Introduce RSS receive steering feature

[Yuri Benditovich]

RSS (Receive-side scaling) defines hash calculation
rules and decision on receive virtqueue according to
the calculated hash, provided mask to apply and
provided indirection table containing indices of
receive virqueues. The driver sends the control
command to enable multiqueue and provide parameters
for receive steering.

Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
---
 include/uapi/linux/virtio_net.h | 42 +++++++++++++++++++++++++++++++--
 1 file changed, 40 insertions(+), 2 deletions(-)

diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
index 6e26a2cc6ad0..7a342657fb6c 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_RSS	  60	/* Supports RSS RX steering */
 #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.
@@ -70,6 +71,17 @@
 #define VIRTIO_NET_S_LINK_UP	1	/* Link is up */
 #define VIRTIO_NET_S_ANNOUNCE	2	/* Announcement is needed */
 
+/* supported/enabled hash types */
+#define VIRTIO_NET_RSS_HASH_TYPE_IPv4          (1 << 0)
+#define VIRTIO_NET_RSS_HASH_TYPE_TCPv4         (1 << 1)
+#define VIRTIO_NET_RSS_HASH_TYPE_UDPv4         (1 << 2)
+#define VIRTIO_NET_RSS_HASH_TYPE_IPv6          (1 << 3)
+#define VIRTIO_NET_RSS_HASH_TYPE_TCPv6         (1 << 4)
+#define VIRTIO_NET_RSS_HASH_TYPE_UDPv6         (1 << 5)
+#define VIRTIO_NET_RSS_HASH_TYPE_IP_EX         (1 << 6)
+#define VIRTIO_NET_RSS_HASH_TYPE_TCP_EX        (1 << 7)
+#define VIRTIO_NET_RSS_HASH_TYPE_UDP_EX        (1 << 8)
+
 struct virtio_net_config {
 	/* The config defining mac address (if VIRTIO_NET_F_MAC) */
 	__u8 mac[ETH_ALEN];
@@ -93,6 +105,12 @@ struct virtio_net_config {
 	 * Any other value stands for unknown.
 	 */
 	__u8 duplex;
+	/* maximal size of RSS key */
+	__u8 rss_max_key_size;
+	/* maximal number of indirection table entries */
+	__u16 rss_max_indirection_table_length;
+	/* bitmask of supported VIRTIO_NET_RSS_HASH_ types */
+	__u32 supported_hash_types;
 } __attribute__((packed));
 
 /*
@@ -236,7 +254,9 @@ struct virtio_net_ctrl_mac {
 
 /*
  * Control Receive Flow Steering
- *
+ */
+#define VIRTIO_NET_CTRL_MQ   4
+/*
  * The command VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET
  * enables Receive Flow Steering, specifying the number of the transmit and
  * receive queues that will be used. After the command is consumed and acked by
@@ -249,11 +269,29 @@ struct virtio_net_ctrl_mq {
 	__virtio16 virtqueue_pairs;
 };
 
-#define VIRTIO_NET_CTRL_MQ   4
  #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET        0
  #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN        1
  #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX        0x8000
 
+/*
+ * The command VIRTIO_NET_CTRL_MQ_RSS_CONFIG has the same effect as
+ * VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET does and additionally configures
+ * the receive steering to use a hash calculated for incoming packet
+ * to decide on receive virtqueue to place the packet. The command
+ * also provides parameters to calculate a hash and receive virtqueue.
+ */
+struct virtio_net_rss_config {
+	__virtio32 hash_types;
+	__virtio16 indirection_table_mask;
+	__virtio16 unclassified_queue;
+	__virtio16 indirection_table[1/* + indirection_table_mask*/];
+	__virtio16 max_tx_vq;
+	__u8 hash_key_length;
+	__u8 hash_key_data[/*hash_key_length*/];
+};
+
+ #define VIRTIO_NET_CTRL_MQ_RSS_CONFIG          1
+
 /*
  * Control network offloads
  *
-- 
2.17.1

Re: [PATCH 2/3] virtio-net: Introduce RSS receive steering feature

[Michael S. Tsirkin]

On Sat, Feb 29, 2020 at 07:13:00PM +0200, Yuri Benditovich wrote:
> RSS (Receive-side scaling) defines hash calculation
> rules and decision on receive virtqueue according to
> the calculated hash, provided mask to apply and
> provided indirection table containing indices of
> receive virqueues. The driver sends the control
> command to enable multiqueue and provide parameters
> for receive steering.
> 
> Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
> ---
>  include/uapi/linux/virtio_net.h | 42 +++++++++++++++++++++++++++++++--
>  1 file changed, 40 insertions(+), 2 deletions(-)
> 
> diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
> index 6e26a2cc6ad0..7a342657fb6c 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_RSS	  60	/* Supports RSS RX steering */
>  #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.
> @@ -70,6 +71,17 @@
>  #define VIRTIO_NET_S_LINK_UP	1	/* Link is up */
>  #define VIRTIO_NET_S_ANNOUNCE	2	/* Announcement is needed */
>  
> +/* supported/enabled hash types */
> +#define VIRTIO_NET_RSS_HASH_TYPE_IPv4          (1 << 0)
> +#define VIRTIO_NET_RSS_HASH_TYPE_TCPv4         (1 << 1)
> +#define VIRTIO_NET_RSS_HASH_TYPE_UDPv4         (1 << 2)
> +#define VIRTIO_NET_RSS_HASH_TYPE_IPv6          (1 << 3)
> +#define VIRTIO_NET_RSS_HASH_TYPE_TCPv6         (1 << 4)
> +#define VIRTIO_NET_RSS_HASH_TYPE_UDPv6         (1 << 5)
> +#define VIRTIO_NET_RSS_HASH_TYPE_IP_EX         (1 << 6)
> +#define VIRTIO_NET_RSS_HASH_TYPE_TCP_EX        (1 << 7)
> +#define VIRTIO_NET_RSS_HASH_TYPE_UDP_EX        (1 << 8)
> +
>  struct virtio_net_config {
>  	/* The config defining mac address (if VIRTIO_NET_F_MAC) */
>  	__u8 mac[ETH_ALEN];
> @@ -93,6 +105,12 @@ struct virtio_net_config {
>  	 * Any other value stands for unknown.
>  	 */
>  	__u8 duplex;
> +	/* maximal size of RSS key */
> +	__u8 rss_max_key_size;
> +	/* maximal number of indirection table entries */
> +	__u16 rss_max_indirection_table_length;

This mirrors spec language. However I just stumbled upon this:

https://en.wikipedia.org/wiki/Maximal_and_minimal_elements

which seems to say maximal means "local maximum".
So I think we should fix both the spec and this header to
say "maximum" instead of "maximal".

Thanks!



> +	/* bitmask of supported VIRTIO_NET_RSS_HASH_ types */
> +	__u32 supported_hash_types;
>  } __attribute__((packed));
>  
>  /*
> @@ -236,7 +254,9 @@ struct virtio_net_ctrl_mac {
>  
>  /*
>   * Control Receive Flow Steering
> - *
> + */
> +#define VIRTIO_NET_CTRL_MQ   4
> +/*
>   * The command VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET
>   * enables Receive Flow Steering, specifying the number of the transmit and
>   * receive queues that will be used. After the command is consumed and acked by
> @@ -249,11 +269,29 @@ struct virtio_net_ctrl_mq {
>  	__virtio16 virtqueue_pairs;
>  };
>  
> -#define VIRTIO_NET_CTRL_MQ   4
>   #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET        0
>   #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN        1
>   #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX        0x8000
>  
> +/*
> + * The command VIRTIO_NET_CTRL_MQ_RSS_CONFIG has the same effect as
> + * VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET does and additionally configures
> + * the receive steering to use a hash calculated for incoming packet
> + * to decide on receive virtqueue to place the packet. The command
> + * also provides parameters to calculate a hash and receive virtqueue.
> + */
> +struct virtio_net_rss_config {
> +	__virtio32 hash_types;
> +	__virtio16 indirection_table_mask;
> +	__virtio16 unclassified_queue;
> +	__virtio16 indirection_table[1/* + indirection_table_mask*/];
> +	__virtio16 max_tx_vq;
> +	__u8 hash_key_length;
> +	__u8 hash_key_data[/*hash_key_length*/];
> +};


Should use __le and not __virtio.
__virtio is for legacy types which sometimes have variable endian-ness.


> +
> + #define VIRTIO_NET_CTRL_MQ_RSS_CONFIG          1
> +
>  /*
>   * Control network offloads
>   *
> -- 
> 2.17.1

[PATCH 3/3] virtio-net: Introduce hash report feature

[Yuri Benditovich]

The feature VIRTIO_NET_F_HASH_REPORT extends the
layout of the packet and requests the device to
calculate hash on incoming packets and report it
in the packet header.

Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
---
 include/uapi/linux/virtio_net.h | 36 +++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
index 7a342657fb6c..6d7230469c57 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_HASH_REPORT  57	/* Supports hash report */
 #define VIRTIO_NET_F_RSS	  60	/* Supports RSS RX steering */
 #define VIRTIO_NET_F_RSC_EXT	  61	/* extended coalescing info */
 #define VIRTIO_NET_F_STANDBY	  62	/* Act as standby for another device
@@ -144,6 +145,23 @@ struct virtio_net_hdr_v1 {
 	__virtio16 num_buffers;	/* Number of merged rx buffers */
 };
 
+struct virtio_net_hdr_v1_hash {
+	struct virtio_net_hdr_v1 hdr;
+	__virtio32 hash_value;
+#define VIRTIO_NET_HASH_REPORT_NONE            0
+#define VIRTIO_NET_HASH_REPORT_IPv4            1
+#define VIRTIO_NET_HASH_REPORT_TCPv4           2
+#define VIRTIO_NET_HASH_REPORT_UDPv4           3
+#define VIRTIO_NET_HASH_REPORT_IPv6            4
+#define VIRTIO_NET_HASH_REPORT_TCPv6           5
+#define VIRTIO_NET_HASH_REPORT_UDPv6           6
+#define VIRTIO_NET_HASH_REPORT_IPv6_EX         7
+#define VIRTIO_NET_HASH_REPORT_TCPv6_EX        8
+#define VIRTIO_NET_HASH_REPORT_UDPv6_EX        9
+	__virtio16 hash_report;
+	__virtio16 padding;
+};
+
 #ifndef VIRTIO_NET_NO_LEGACY
 /* This header comes first in the scatter-gather list.
  * For legacy virtio, if VIRTIO_F_ANY_LAYOUT is not negotiated, it must
@@ -292,6 +310,24 @@ struct virtio_net_rss_config {
 
  #define VIRTIO_NET_CTRL_MQ_RSS_CONFIG          1
 
+/*
+ * The command VIRTIO_NET_CTRL_MQ_HASH_CONFIG requests the device
+ * to include in the virtio header of the packet the value of the
+ * calculated hash and the report type of hash. It also provides
+ * parameters for hash calculation. The command requires feature
+ * VIRTIO_NET_F_HASH_REPORT to be negotiated to extend the
+ * layout of virtio header as defined in virtio_net_hdr_v1_hash.
+ */
+struct virtio_net_hash_config {
+	__virtio32 hash_types;
+	/* for compatibility with virtio_net_rss_config */
+	__virtio16 reserved[4];
+	__u8 hash_key_length;
+	__u8 hash_key_data[/*hash_key_length*/];
+};
+
+ #define VIRTIO_NET_CTRL_MQ_HASH_CONFIG         2
+
 /*
  * Control network offloads
  *
-- 
2.17.1

Re: [PATCH 3/3] virtio-net: Introduce hash report feature

[Michael S. Tsirkin]

On Sat, Feb 29, 2020 at 07:13:01PM +0200, Yuri Benditovich wrote:
> The feature VIRTIO_NET_F_HASH_REPORT extends the
> layout of the packet and requests the device to
> calculate hash on incoming packets and report it
> in the packet header.
> 
> Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
> ---
>  include/uapi/linux/virtio_net.h | 36 +++++++++++++++++++++++++++++++++
>  1 file changed, 36 insertions(+)
> 
> diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
> index 7a342657fb6c..6d7230469c57 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_HASH_REPORT  57	/* Supports hash report */
>  #define VIRTIO_NET_F_RSS	  60	/* Supports RSS RX steering */
>  #define VIRTIO_NET_F_RSC_EXT	  61	/* extended coalescing info */
>  #define VIRTIO_NET_F_STANDBY	  62	/* Act as standby for another device
> @@ -144,6 +145,23 @@ struct virtio_net_hdr_v1 {
>  	__virtio16 num_buffers;	/* Number of merged rx buffers */
>  };
>  
> +struct virtio_net_hdr_v1_hash {
> +	struct virtio_net_hdr_v1 hdr;
> +	__virtio32 hash_value;
> +#define VIRTIO_NET_HASH_REPORT_NONE            0
> +#define VIRTIO_NET_HASH_REPORT_IPv4            1
> +#define VIRTIO_NET_HASH_REPORT_TCPv4           2
> +#define VIRTIO_NET_HASH_REPORT_UDPv4           3
> +#define VIRTIO_NET_HASH_REPORT_IPv6            4
> +#define VIRTIO_NET_HASH_REPORT_TCPv6           5
> +#define VIRTIO_NET_HASH_REPORT_UDPv6           6
> +#define VIRTIO_NET_HASH_REPORT_IPv6_EX         7
> +#define VIRTIO_NET_HASH_REPORT_TCPv6_EX        8
> +#define VIRTIO_NET_HASH_REPORT_UDPv6_EX        9
> +	__virtio16 hash_report;
> +	__virtio16 padding;
> +};
> +
>  #ifndef VIRTIO_NET_NO_LEGACY
>  /* This header comes first in the scatter-gather list.
>   * For legacy virtio, if VIRTIO_F_ANY_LAYOUT is not negotiated, it must
> @@ -292,6 +310,24 @@ struct virtio_net_rss_config {
>  
>   #define VIRTIO_NET_CTRL_MQ_RSS_CONFIG          1
>  
> +/*
> + * The command VIRTIO_NET_CTRL_MQ_HASH_CONFIG requests the device
> + * to include in the virtio header of the packet the value of the
> + * calculated hash and the report type of hash. It also provides
> + * parameters for hash calculation. The command requires feature
> + * VIRTIO_NET_F_HASH_REPORT to be negotiated to extend the
> + * layout of virtio header as defined in virtio_net_hdr_v1_hash.
> + */
> +struct virtio_net_hash_config {
> +	__virtio32 hash_types;
> +	/* for compatibility with virtio_net_rss_config */
> +	__virtio16 reserved[4];

I expect these should all be le32/le16 respectively.

> +	__u8 hash_key_length;
> +	__u8 hash_key_data[/*hash_key_length*/];
> +};

Should be /* hash_key_length */ as per coding style.

> +
> + #define VIRTIO_NET_CTRL_MQ_HASH_CONFIG         2
> +
>  /*
>   * Control network offloads
>   *
> -- 
> 2.17.1