On Wed, Feb 05, 2020 at 08:59:05PM +0200, Yuri Benditovich wrote:
> Fixes:
https://github.com/oasis-tcs/virtio-spec/issues/66> Define respective feature bit for virtio-net.
> Extend packet layout to populate hash value and type.
> Move the definition of IP/TCP/UDP header fields to
> calculate the hash out of RSS section to common network
> device section.
>
> Signed-off-by: Yuri Benditovich <
yuri.benditovich@daynix.com>
Looks good to me.
Minor typos/tweaks.
Otherwise
Acked-by: Michael S. Tsirkin <
mst@redhat.com>
> ---
> content.tex | 347 ++++++++++++++++++++++++++++++++++------------------
> 1 file changed, 228 insertions(+), 119 deletions(-)
>
> diff --git a/content.tex b/content.tex
> index fb10061..20d598d 100644
> --- a/content.tex
> +++ b/content.tex
> @@ -2895,6 +2895,9 @@ \subsection{Feature bits}\label{sec:Device Types / Network Device / Feature bits
> \item[VIRTIO_NET_F_CTRL_MAC_ADDR(23)] Set MAC address through control
> channel.
>
> +\item[VIRTIO_NET_F_HASH_REPORT(58)] Device can report per-packet hash
> + value and a type of calculated hash.
> +
> \item[VIRTIO_NET_F_GUEST_HDRLEN(59)] Driver can provide the exact \field{hdr_len}
> value. Device benefits from knowing the exact header length.
>
> @@ -2981,35 +2984,17 @@ \subsection{Device configuration layout}\label{sec:Device Types / Network Device
> le32 supported_hash_types;
> };
> \end{lstlisting}
> -\label{sec:Device Types / Network Device / Device configuration layout / RSS}
> -Three following fields, \field{rss_max_key_size}, \field{rss_max_indirection_table_length}
> -and \field{supported_hash_types} only exist if VIRTIO_NET_F_RSS is set.
> +The following field, \field{rss_max_key_size} only exist if VIRTIO_NET_F_RSS or VIRTIO_NET_F_HASH_REPORT is set.
> +It specifies the maximal supported length of RSS key in bytes.
>
> -Field \field{rss_max_key_size} specifies the maximal supported length of RSS key in bytes.
> +The following field, \field{rss_max_indirection_table_length} only exist if VIRTIO_NET_F_RSS is set.
> +It specifies the maximal number of 16-bit entries in RSS indirection table.
>
> -Field \field{rss_max_indirection_table_length} specifies the maximal number of 16-bit entries in RSS indirection table.
> +The next field, \field{supported_hash_types} exists only if the device supports hash calculation,
> +i.e. if VIRTIO_NET_F_RSS of VIRTIO_NET_F_HASH_REPORT is set.
of -> or?
>
> -Field \field{supported_hash_types} contains the bitmask of supported RSS hash types.
> -
> -Hash types applicable for IPv4 packets:
> -\begin{lstlisting}
> -#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)
> -\end{lstlisting}
> -Hash types applicable for IPv6 packets without extension headers
> -\begin{lstlisting}
> -#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)
> -\end{lstlisting}
> -Hash types applicable for IPv6 packets with extension headers
> -\begin{lstlisting}
> -#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)
> -\end{lstlisting}
> -For the exact meaning of VIRTIO_NET_RSS_HASH_TYPE_ flags see \ref{sec:Device Types / Network Device / Device Operation / Control Virtqueue / Receive-side scaling (RSS) / RSS hash types}.
> +Field \field{supported_hash_types} contains the bitmask of supported hash types.
> +See \ref{sec:Device Types / Network Device / Device Operation / Processing of Incoming Packets / Hash calculation for incoming packets / Supported/enabled hash types} for details of supported hash types.
>
> \devicenormative{\subsubsection}{Device configuration layout}{Device Types / Network Device / Device configuration layout}
>
> @@ -3034,7 +3019,7 @@ \subsection{Device configuration layout}\label{sec:Device Types / Network Device
> negotiated.
>
> The device MUST set \field{rss_max_key_size} to at least 40, if it offers
> -VIRTIO_NET_F_RSS.
> +VIRTIO_NET_F_RSS or VIRTIO_NET_F_HASH_REPORT.
>
> The device MUST set \field{rss_max_indirection_table_length} to at least 128, if it offers
> VIRTIO_NET_F_RSS.
> @@ -3159,6 +3144,8 @@ \subsection{Device Operation}\label{sec:Device Types / Network Device / Device O
> le16 csum_start;
> le16 csum_offset;
> le16 num_buffers;
> + le32 hash_value; (Only if VIRTIO_NET_F_HASH_REPORT negotiated)
> + le16 hash_type; (Only if VIRTIO_NET_F_HASH_REPORT negotiated)
> };
> \end{lstlisting}
>
> @@ -3481,6 +3468,12 @@ \subsubsection{Processing of Incoming Packets}\label{sec:Device Types / Network
>
> \end{enumerate}
>
> +If applicable, the device calculates per-packet hash for incoming packets as
> +defined in \ref{sec:Device Types / Network Device / Device Operation / Processing of Incoming Packets / Hash calculation for incoming packets}.
> +
> +If applicable, the device reports hash information for incoming packets as
> +defined in \ref{sec:Device Types / Network Device / Device Operation / Processing of Incoming Packets / Hash reporting for incoming packets}.
> +
> \devicenormative{\paragraph}{Processing of Incoming Packets}{Device Types / Network Device / Device Operation / Processing of Incoming Packets}
> \label{devicenormative:Device Types / Network Device / Device Operation / Processing of Packets}%old label for latexdiff
>
> @@ -3583,6 +3576,181 @@ \subsubsection{Processing of Incoming Packets}\label{sec:Device Types / Network
> If neither VIRTIO_NET_HDR_F_NEEDS_CSUM nor
> VIRTIO_NET_HDR_F_DATA_VALID is set, the driver MUST NOT
> rely on the packet checksum being correct.
> +
> +\paragraph{Hash calculation for incoming packets}
> +\label{sec:Device Types / Network Device / Device Operation / Processing of Incoming Packets / Hash calculation for incoming packets}
> +
> +A device attempts to calculate a per-packet hash in the following cases:
> +\begin{itemize}
> +\item The feature VIRTIO_NET_F_RSS was negotiated. The device uses the hash to determine the receive virtqueue to place incoming packets.
> +\item The feature VIRTIO_NET_F_HASH_REPORT was negotiated. The device reports the hash value and the hash type with the packet.
> +\end{itemize}
below mentions structures that were never mentioned earlier.
We should say a couple of words here.
E.g.
the driver configures the hash calculation by sending
either the virtio_net_rss_config structure as described in
... or the
virtio_net_hash_config structure as described in ... to the device.
> +If the feature VIRTIO_NET_F_RSS was negotiated:
> +\begin{itemize}
> +\item The device uses \field{hash_types} of the virtio_net_rss_config structure as the 'Enabled hash types' bitmask.
> +\item The device uses \field{hash_key_data} of the virtio_net_rss_config structure.
.. as ... ?
Also what about key length field?
We should document all fields.
Also I would maybe repeat this near where the structure itself is defined.
> +\end{itemize}
> +See the definition of virtio_net_rss_config structure in \ref{sec:Device Types / Network Device / Device Operation / Control Virtqueue / Receive-side scaling (RSS) / Setting RSS parameters}
I would just add a link where virtio_net_rss_config is mentioned.
E.g.
The device uses \field{hash_key_data} of the virtio_net_rss_config
structure (See \ref{...}).
> +
> +If the feature VIRTIO_NET_F_RSS was not negotiated:
> +\begin{itemize}
> +\item The device uses \field{hash_types} of the virtio_net_hash_config structure as the 'Enabled hash types' bitmask.
> +\item The device uses \field{hash_key_data} of the virtio_net_hash_config structure.
> +\end{itemize}
> +See the definition of virtio_net_hash_config structure in \ref{sec:Device Types / Network Device / Device Operation / Control Virtqueue / Automatic receive steering in multiqueue mode / Hash calculation}.
> +
> +Note that if the device offers VIRTIO_NET_F_HASH_REPORT, even if it supports only one pair of virtqueues, it SHOULD support
> +at least one of commands of VIRTIO_NET_CTRL_MQ class to configure reported hash parameters:
> +\begin{itemize}
> +\item If the device offers VIRTIO_NET_F_RSS, it MUST support VIRTIO_NET_CTRL_MQ_RSS_CONFIG command per
> + \ref{sec:Device Types / Network Device / Device Operation / Control Virtqueue / Receive-side scaling (RSS) / Setting RSS parameters}.
> +\item Otherwise the device SHOULD support VIRTIO_NET_CTRL_MQ_HASH_CONFIG command per
> + \ref{sec:Device Types / Network Device / Device Operation / Control Virtqueue / Automatic receive steering in multiqueue mode / Hash calculation}.
> +\end{itemize}
> +
> +\subparagraph{Supported/enabled hash types}
> +\label{sec:Device Types / Network Device / Device Operation / Processing of Incoming Packets / Hash calculation for incoming packets / Supported/enabled hash types}
> +Hash types applicable for IPv4 packets:
> +\begin{lstlisting}
> +#define VIRTIO_NET_HASH_TYPE_IPv4 (1 << 0)
> +#define VIRTIO_NET_HASH_TYPE_TCPv4 (1 << 1)
> +#define VIRTIO_NET_HASH_TYPE_UDPv4 (1 << 2)
> +\end{lstlisting}
> +Hash types applicable for IPv6 packets without extension headers
> +\begin{lstlisting}
> +#define VIRTIO_NET_HASH_TYPE_IPv6 (1 << 3)
> +#define VIRTIO_NET_HASH_TYPE_TCPv6 (1 << 4)
> +#define VIRTIO_NET_HASH_TYPE_UDPv6 (1 << 5)
> +\end{lstlisting}
> +Hash types applicable for IPv6 packets with extension headers
> +\begin{lstlisting}
> +#define VIRTIO_NET_HASH_TYPE_IP_EX (1 << 6)
> +#define VIRTIO_NET_HASH_TYPE_TCP_EX (1 << 7)
> +#define VIRTIO_NET_HASH_TYPE_UDP_EX (1 << 8)
> +\end{lstlisting}
> +
> +\subparagraph{IPv4 packets}
> +\label{sec:Device Types / Network Device / Device Operation / Processing of Incoming Packets / Hash calculation for incoming packets / IPv4 packets}
> +The device calculates the hash on IPv4 packets according to 'Enabled hash types' bitmask as follows:
> +\begin{itemize}
> +\item If VIRTIO_NET_HASH_TYPE_TCPv4 is set and the packet has
> +a TCP header, the hash is calculated over the following fields:
> +\begin{itemize}
> +\item Source IP address
> +\item Destination IP address
> +\item Source TCP port
> +\item Destination TCP port
> +\end{itemize}
> +\item Else if VIRTIO_NET_HASH_TYPE_UDPv4 is set and the
> +packet has a UDP header, the hash is calculated over the following fields:
> +\begin{itemize}
> +\item Source IP address
> +\item Destination IP address
> +\item Source UDP port
> +\item Destination UDP port
> +\end{itemize}
> +\item Else if VIRTIO_NET_HASH_TYPE_IPv4 is set, the hash is
> +calculated over the following fields:
> +\begin{itemize}
> +\item Source IP address
> +\item Destination IP address
> +\end{itemize}
> +\item Else the device does not calculate the hash
> +\end{itemize}
> +
> +\subparagraph{IPv6 packets without extension header}
> +\label{sec:Device Types / Network Device / Device Operation / Processing of Incoming Packets / Hash calculation for incoming packets / IPv6 packets without extension header}
> +The device calculates the hash on IPv6 packets without extension
> +headers according to 'Enabled hash types' bitmask as follows:
> +\begin{itemize}
> +\item If VIRTIO_NET_HASH_TYPE_TCPv6 is set and the packet has
> +a TCPv6 header, the hash is calculated over the following fields:
> +\begin{itemize}
> +\item Source IPv6 address
> +\item Destination IPv6 address
> +\item Source TCP port
> +\item Destination TCP port
> +\end{itemize}
> +\item Else if VIRTIO_NET_HASH_TYPE_UDPv6 is set and the
> +packet has a UDPv6 header, the hash is calculated over the following fields:
> +\begin{itemize}
> +\item Source IPv6 address
> +\item Destination IPv6 address
> +\item Source UDP port
> +\item Destination UDP port
> +\end{itemize}
> +\item Else if VIRTIO_NET_HASH_TYPE_IPv6 is set, the hash is
> +calculated over the following fields:
> +\begin{itemize}
> +\item Source IPv6 address
> +\item Destination IPv6 address
> +\end{itemize}
> +\item Else the device does not calculate the hash
> +\end{itemize}
> +
> +\subparagraph{IPv6 packets with extension header}
> +\label{sec:Device Types / Network Device / Device Operation / Processing of Incoming Packets / Hash calculation for incoming packets / IPv6 packets with extension header}
> +The device calculates the hash on IPv6 packets with extension
> +headers according to 'Enabled hash types' bitmask as follows:
> +\begin{itemize}
> +\item If VIRTIO_NET_HASH_TYPE_TCP_EX is set and the packet
> +has a TCPv6 header, the hash is calculated over the following fields:
> +\begin{itemize}
> +\item Home address from the home address option in the IPv6 destination options header. If the extension header is not present, use the Source IPv6 address.
> +\item IPv6 address that is contained in the Routing-Header-Type-2 from the associated extension header. If the extension header is not present, use the Destination IPv6 address.
> +\item Source TCP port
> +\item Destination TCP port
> +\end{itemize}
> +\item Else if VIRTIO_NET_HASH_TYPE_UDP_EX is set and the
> +packet has a UDPv6 header, the hash is calculated over the following fields:
> +\begin{itemize}
> +\item Home address from the home address option in the IPv6 destination options header. If the extension header is not present, use the Source IPv6 address.
> +\item IPv6 address that is contained in the Routing-Header-Type-2 from the associated extension header. If the extension header is not present, use the Destination IPv6 address.
> +\item Source UDP port
> +\item Destination UDP port
> +\end{itemize}
> +\item Else if VIRTIO_NET_HASH_TYPE_IP_EX is set, the hash is
> +calculated over the following fields:
> +\begin{itemize}
> +\item Home address from the home address option in the IPv6 destination options header. If the extension header is not present, use the Source IPv6 address.
> +\item IPv6 address that is contained in the Routing-Header-Type-2 from the associated extension header. If the extension header is not present, use the Destination IPv6 address.
> +\end{itemize}
> +\item Else skip IPv6 extension headers and calculate the hash as
> +defined for an IPv6 packet without extension headers
> +(see \ref{sec:Device Types / Network Device / Device Operation / Processing of Incoming Packets / Hash calculation for incoming packets / IPv6 packets without extension header}).
> +\end{itemize}
> +
> +\paragraph{Hash reporting for incoming packets}
> +\label{sec:Device Types / Network Device / Device Operation / Processing of Incoming Packets / Hash reporting for incoming packets}%old label for latexdiff
I doubt it's an old label
> +
> +If feature VIRTIO_NET_F_HASH_REPORT
If feature VIRTIO_NET_F_HASH_REPORT -> If VIRTIO_NET_F_HASH_REPORT
> was negotiated and
> + the device has calculated the hash for the packet, the device fills \field{hash_type} with the type of calculated hash
> +and \field{hash_value} with the value of calculated hash.
> +
> +If VIRTIO_NET_F_HASH_REPORT was negotiated but due to any reason the
> +hash was not calculated, the device sets \field{hash_type} to VIRTIO_NET_HASH_REPORT_NONE.
> +
> +Possible values that the device can report in \field{hash_type} are defined below.
> +They correspond to supported hash types defined in
> +\ref{sec:Device Types / Network Device / Device Operation / Processing of Incoming Packets / Hash calculation for incoming packets / Supported/enabled hash types}
> +as follows:
> +
> +VIRTIO_NET_HASH_TYPE_XXX = 1 << (VIRTIO_NET_HASH_REPORT_XXX - 1)
> +
> +\begin{lstlisting}
> +#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
> +\end{lstlisting}
> +
> \subsubsection{Control Virtqueue}\label{sec:Device Types / Network Device / Device Operation / Control Virtqueue}
>
> The driver uses the control virtqueue (if VIRTIO_NET_F_CTRL_VQ is
> @@ -3860,6 +4028,7 @@ \subsubsection{Control Virtqueue}\label{sec:Device Types / Network Device / Devi
> #define VIRTIO_NET_CTRL_MQ 4
> #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET 0 (for automatic receive steering)
> #define VIRTIO_NET_CTRL_MQ_RSS_CONFIG 1 (for configurable receive steering)
> + #define VIRTIO_NET_CTRL_MQ_HASH_CONFIG 2 (for configurable hash calculation)
> \end{lstlisting}
>
> If more than one multiqueue mode is negotiated, the resulting device configuration is defined by the last command sent by the driver.
> @@ -3925,10 +4094,37 @@ \subsubsection{Control Virtqueue}\label{sec:Device Types / Network Device / Devi
> according to the native endian of the guest rather than
> (necessarily when not using the legacy interface) little-endian.
>
> +\subparagraph{Hash calculation}\label{sec:Device Types / Network Device / Device Operation / Control Virtqueue / Automatic receive steering in multiqueue mode / Hash calculation}
> +If VIRTIO_NET_F_HASH_REPORT negotiated
negotiated -> was negotiated
> and the device uses automatic receive steering,
> +the device SHOULD support a command to configure hash calculation parameters.
SHOULD and not MUST do drivers must expect failure and handle
gracefully?
> +
> +The driver provides parameters for hash calculation as follows:
> +
> +\field{class} VIRTIO_NET_CTRL_MQ, \field{command} VIRTIO_NET_CTRL_MQ_HASH_CONFIG.
> +
> +The \field{command-specific-data} has following format:
> +\begin{lstlisting}
> +struct virtio_net_hash_config {
> + le32 hash_types;
> + le16 reserved[4];
> + u8 hash_key_length;
> + u8 hash_key_data[hash_key_length];
> +};
> +\end{lstlisting}
> +Field \field{hash_types} contains a bitmask of allowed hash types as
> +defined in
> +\ref{sec:Device Types / Network Device / Device Operation / Processing of Incoming Packets / Hash calculation for incoming packets / Supported/enabled hash types}.
> +Initially the device has all hash types disabled and reports only VIRTIO_NET_HASH_REPORT_NONE.
> +
> +Field \field{reserved} MUST contain zeroes. It is defined to make the structure to look similar
look similar -> match the layout of
> to virtio_net_rss_config structure,
> +defined in \ref{sec:Device Types / Network Device / Device Operation / Control Virtqueue / Receive-side scaling (RSS)}.
> +
> +Fields \field{hash_key_length} and \field{hash_key_data} define the key to be used in hash calculation.
> +
> \paragraph{Receive-side scaling (RSS)}\label{sec:Device Types / Network Device / Device Operation / Control Virtqueue / Receive-side scaling (RSS)}
> A device offers the feature VIRTIO_NET_F_RSS if it supports RSS receive steering with Toeplitz hash calculation and configurable parameters.
>
> -A driver queries RSS capabilities of the device by reading device configuration as defined in \ref{sec:Device Types / Network Device / Device configuration layout / RSS}
> +A driver queries RSS capabilities of the device by reading device configuration as defined in \ref{sec:Device Types / Network Device / Device configuration layout}
>
> \subparagraph{Setting RSS parameters}\label{sec:Device Types / Network Device / Device Operation / Control Virtqueue / Receive-side scaling (RSS) / Setting RSS parameters}
>
> @@ -3945,7 +4141,8 @@ \subsubsection{Control Virtqueue}\label{sec:Device Types / Network Device / Devi
> };
> \end{lstlisting}
> Field \field{hash_types} contains a bitmask of allowed hash types as
> -defined in \ref{sec:Device Types / Network Device / Device Operation / Control Virtqueue / Receive-side scaling (RSS) / RSS hash types}.
> +defined in
> +\ref{sec:Device Types / Network Device / Device Operation / Processing of Incoming Packets / Hash calculation for incoming packets / Supported/enabled hash types}.
>
> Field \field{indirection_table_mask} is a mask to be applied to
> the calculated hash to produce an index in the
> @@ -3959,94 +4156,6 @@ \subsubsection{Control Virtqueue}\label{sec:Device Types / Network Device / Devi
>
> A driver sets \field{max_tx_vq} to inform a device how many transmit virtqueues it may use (transmitq1\ldots transmitq \field{max_tx_vq}).
>
> -\subparagraph{RSS hash types}\label{sec:Device Types / Network Device / Device Operation / Control Virtqueue / Receive-side scaling (RSS) / RSS hash types}
> -
> -The device calculates the hash on IPv4 packets according to the
> -field \field{hash_types} of the virtio_net_rss_config structure as follows:
> -\begin{itemize}
> -\item If VIRTIO_NET_RSS_HASH_TYPE_TCPv4 is set and the packet has
> -a TCP header, the hash is calculated over the following fields:
> -\begin{itemize}
> -\item Source IP address
> -\item Destination IP address
> -\item Source TCP port
> -\item Destination TCP port
> -\end{itemize}
> -\item Else if VIRTIO_NET_RSS_HASH_TYPE_UDPv4 is set and the
> -packet has a UDP header, the hash is calculated over the following fields:
> -\begin{itemize}
> -\item Source IP address
> -\item Destination IP address
> -\item Source UDP port
> -\item Destination UDP port
> -\end{itemize}
> -\item Else if VIRTIO_NET_RSS_HASH_TYPE_IPv4 is set, the hash is
> -calculated over the following fields:
> -\begin{itemize}
> -\item Source IP address
> -\item Destination IP address
> -\end{itemize}
> -\item Else the device does not calculate the hash
> -\end{itemize}
> -
> -\label{itm:Device Types / Network Device / Device Operation / Control Virtqueue / Receive-side scaling (RSS) / RSS hash types/hash on IPv6 packets without extension headers}
> -The device calculates the hash on IPv6 packets without extension
> -headers according to the field \field{hash_types} of the virtio_net_rss_config structure as follows:
> -\begin{itemize}
> -\item If VIRTIO_NET_RSS_HASH_TYPE_TCPv6 is set and the packet has
> -a TCPv6 header, the hash is calculated over the following fields:
> -\begin{itemize}
> -\item Source IPv6 address
> -\item Destination IPv6 address
> -\item Source TCP port
> -\item Destination TCP port
> -\end{itemize}
> -\item Else if VIRTIO_NET_RSS_HASH_TYPE_UDPv6 is set and the
> -packet has a UDPv6 header, the hash is calculated over the following fields:
> -\begin{itemize}
> -\item Source IPv6 address
> -\item Destination IPv6 address
> -\item Source UDP port
> -\item Destination UDP port
> -\end{itemize}
> -\item Else if VIRTIO_NET_RSS_HASH_TYPE_IPv6 is set, the hash is
> -calculated over the following fields:
> -\begin{itemize}
> -\item Source IPv6 address
> -\item Destination IPv6 address
> -\end{itemize}
> -\item Else the device does not calculate the hash
> -\end{itemize}
> -
> -The device calculates the hash on IPv6 packets with extension
> -headers according to the field \field{hash_types} of the virtio_net_rss_config structure as follows:
> -\begin{itemize}
> -\item If VIRTIO_NET_RSS_HASH_TYPE_TCP_EX is set and the packet
> -has a TCPv6 header, the hash is calculated over the following fields:
> -\begin{itemize}
> -\item Home address from the home address option in the IPv6 destination options header. If the extension header is not present, use the Source IPv6 address.
> -\item IPv6 address that is contained in the Routing-Header-Type-2 from the associated extension header. If the extension header is not present, use the Destination IPv6 address.
> -\item Source TCP port
> -\item Destination TCP port
> -\end{itemize}
> -\item Else if VIRTIO_NET_RSS_HASH_TYPE_UDP_EX is set and the
> -packet has a UDPv6 header, the hash is calculated over the following fields:
> -\begin{itemize}
> -\item Home address from the home address option in the IPv6 destination options header. If the extension header is not present, use the Source IPv6 address.
> -\item IPv6 address that is contained in the Routing-Header-Type-2 from the associated extension header. If the extension header is not present, use the Destination IPv6 address.
> -\item Source UDP port
> -\item Destination UDP port
> -\end{itemize}
> -\item Else if VIRTIO_NET_RSS_HASH_TYPE_IP_EX is set, the hash is
> -calculated over the following fields:
> -\begin{itemize}
> -\item Home address from the home address option in the IPv6 destination options header. If the extension header is not present, use the Source IPv6 address.
> -\item IPv6 address that is contained in the Routing-Header-Type-2 from the associated extension header. If the extension header is not present, use the Destination IPv6 address.
> -\end{itemize}
> -\item Else skip IPv6 extension headers and calculate the hash as
> -defined for an IPv6 packet without extension headers (see \ref{itm:Device Types / Network Device / Device Operation / Control Virtqueue / Receive-side scaling (RSS) / RSS hash types/hash on IPv6 packets without extension headers}).
> -\end{itemize}
> -
> \drivernormative{\subparagraph}{Setting RSS parameters}{Device Types / Network Device / Device Operation / Control Virtqueue / Receive-side scaling (RSS) }
>
> A driver MUST NOT send the VIRTIO_NET_CTRL_MQ_RSS_CONFIG command if the feature VIRTIO_NET_F_RSS has not been negotiated.
> @@ -4057,12 +4166,12 @@ \subsubsection{Control Virtqueue}\label{sec:Device Types / Network Device / Devi
>
> A driver MUST use \field{indirection_table_mask} values that are less than \field{rss_max_indirection_table_length} reported by a device.
>
> -A driver MUST NOT set any VIRTIO_NET_RSS_HASH_TYPE_ flags that are not supported by a device.
> +A driver MUST NOT set any VIRTIO_NET_HASH_TYPE_ flags that are not supported by a device.
>
> \devicenormative{\subparagraph}{RSS processing}{Device Types / Network Device / Device Operation / Control Virtqueue / Receive-side scaling (RSS) / RSS processing}
> The device MUST determine the destination queue for a network packet as follows:
> \begin{itemize}
> -\item Calculate the hash of the packet as defined in \ref{sec:Device Types / Network Device / Device Operation / Control Virtqueue / Receive-side scaling (RSS) / RSS hash types}
> +\item Calculate the hash of the packet as defined in \ref{sec:Device Types / Network Device / Device Operation / Processing of Incoming Packets / Hash calculation for incoming packets}.
> \item If the device did not calculate the hash for the specific packet, the device directs the packet to the receiveq specified by \field{unclassified_queue} of virtio_net_rss_config structure (value of 0 corresponds to receiveq1).
> \item Apply \field{indirection_table_mask} to the calculated hash and use the result as the index in the indirection table to get 0-based number of destination receiveq (value of 0 corresponds to receiveq1).
> \end{itemize}
> --
> 2.17.1