From: Or Gerlitz <hidden> Date: 2012-10-09 09:41:50
Hi Ben,
Looking on kernel ethtool flow steering APIs in the context of a device
which is used as the uplink of a virtual switch, the admin should be able
to provide flow specification and action (e.g drop) that relates to traffic
coming from a specific port of the switch e.g that relates to a certain VM,etc.
For that end, we need to be able to specify both the L3/L4 attributes of
the flow and an L2 spec, that is the L2 spec containing the destination MAC
can't be assumed as the one of that device.
Specifically, in struct ethtool_rx_ntuple_flow_spec, I think we should let the
to provide an ethhdr even when L3/L4 spec is given, make sense? if yes, how
would you like to see this change, add a union entry that contains both, or in
another way?
Or.
From: Ben Hutchings <hidden> Date: 2012-10-09 16:48:39
On Tue, 2012-10-09 at 11:37 +0200, Or Gerlitz wrote:
Hi Ben,
Looking on kernel ethtool flow steering APIs in the context of a device
which is used as the uplink of a virtual switch, the admin should be able
to provide flow specification and action (e.g drop) that relates to traffic
coming from a specific port of the switch e.g that relates to a certain
VM,etc.
For that end, we need to be able to specify both the L3/L4 attributes of
the flow and an L2 spec, that is the L2 spec containing the destination MAC
can't be assumed as the one of that device.
Specifically, in struct ethtool_rx_ntuple_flow_spec, I think we should
let the
to provide an ethhdr even when L3/L4 spec is given, make sense?
Yes, but the ethertype looks redundant - the inner type is implied by
the L3 flow type and the outer type for a VLAN-encapsulated packet
should be matched against ethtool_flow_ext::vlan_etype. Might be better
to avoid confusion by just specifying the L2 addresses.
if yes, how
would you like to see this change, add a union entry that contains both,
or in
another way?
struct ethtool_rx_ntuple_flow_spec is obsolete; struct
ethtool_rx_flow_spec is what we have to consider. That effectively has:
union ethtool_flow_union {
struct ethtool_tcpip4_spec tcp_ip4_spec;
struct ethtool_tcpip4_spec udp_ip4_spec;
struct ethtool_tcpip4_spec sctp_ip4_spec;
struct ethtool_ah_espip4_spec ah_ip4_spec;
struct ethtool_ah_espip4_spec esp_ip4_spec;
struct ethtool_usrip4_spec usr_ip4_spec;
struct ethhdr ether_spec;
/* above are up to 16 bytes long */
__u8 hdata[60];
} h_u;
struct ethtool_flow_ext {
__be16 vlan_etype;
__be16 vlan_tci;
__be32 data[2];
} h_ext;
union ethtool_flow_union m_u;
struct ethtool_flow_ext m_ext;
So ethtool_flow_union::hdata currently provides 44 bytes of padding
between the per-protocol flow specs and ethtool_flow_ext, which can be
reallocated to the *beginning* of ethtool_flow_ext. At some point we'll
presumably want to add IPv6 flow specs, which will use up 24 bytes of
that padding at the front. So we can potentially extend
ethtool_flow_ext by up to 20 bytes.
Ben.
--
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.
From: Or Gerlitz <hidden> Date: 2012-10-10 14:19:02
On 09/10/2012 18:48, Ben Hutchings wrote:
On Tue, 2012-10-09 at 11:37 +0200, Or Gerlitz wrote:
quoted
Hi Ben,
Looking on kernel ethtool flow steering APIs in the context of a device
which is used as the uplink of a virtual switch, the admin should be able
to provide flow specification and action (e.g drop) that relates to traffic
coming from a specific port of the switch e.g that relates to a certain
VM,etc.
For that end, we need to be able to specify both the L3/L4 attributes of
the flow and an L2 spec, that is the L2 spec containing the destination MAC
can't be assumed as the one of that device.
Specifically, in struct ethtool_rx_ntuple_flow_spec, I think we should
let the
to provide an ethhdr even when L3/L4 spec is given, make sense?
Yes, but the ethertype looks redundant - the inner type is implied by
the L3 flow type and the outer type for a VLAN-encapsulated packet
should be matched against ethtool_flow_ext::vlan_etype. Might be better
to avoid confusion by just specifying the L2 addresses.
quoted
if yes, how
would you like to see this change, add a union entry that contains both,
or in
another way?
struct ethtool_rx_ntuple_flow_spec is obsolete; struct
ethtool_rx_flow_spec is what we have to consider. That effectively has:
union ethtool_flow_union {
struct ethtool_tcpip4_spec tcp_ip4_spec;
struct ethtool_tcpip4_spec udp_ip4_spec;
struct ethtool_tcpip4_spec sctp_ip4_spec;
struct ethtool_ah_espip4_spec ah_ip4_spec;
struct ethtool_ah_espip4_spec esp_ip4_spec;
struct ethtool_usrip4_spec usr_ip4_spec;
struct ethhdr ether_spec;
/* above are up to 16 bytes long */
__u8 hdata[60];
} h_u;
struct ethtool_flow_ext {
__be16 vlan_etype;
__be16 vlan_tci;
__be32 data[2];
} h_ext;
union ethtool_flow_union m_u;
struct ethtool_flow_ext m_ext;
So ethtool_flow_union::hdata currently provides 44 bytes of padding
between the per-protocol flow specs and ethtool_flow_ext, which can be
reallocated to the *beginning* of ethtool_flow_ext. At some point we'll
presumably want to add IPv6 flow specs, which will use up 24 bytes of
that padding at the front. So we can potentially extend
ethtool_flow_ext by up to 20 bytes.
Ben.
Ben,
Thanks for setting the sketch of a plan here... so if we go little bit into details, we can safely move 20 bytes from the hadata[60] field into the beginning of struct ethtool_flow_ext, which will still allow old
user space to work with newer kernels. As for newer uses space that would like to set mac addresses within
ethtool_flow_ext, how are they supposed to identify if the kernel supports this extension (of the extension...)? this might be newbee question, I didn't made many ethtool patches so far.
Also on a related note, what does the 64bit data field of ethtool_flow_ext used for?
Or.
From: Ben Hutchings <hidden> Date: 2012-10-10 14:28:34
On Wed, 2012-10-10 at 16:16 +0200, Or Gerlitz wrote:
[...]
Thanks for setting the sketch of a plan here... so if we go little bit
into details, we can safely move 20 bytes from the hadata[60] field into
the beginning of struct ethtool_flow_ext, which will still allow old
user space to work with newer kernels. As for newer uses space that
would like to set mac addresses within
ethtool_flow_ext, how are they supposed to identify if the kernel
supports this extension (of the extension...)?
Well they can't tell in advance, but we can define another flag in
flow_type like FLOW_EXT and existing drivers will reject flow specs with
that flag set.
this might be newbee
question, I didn't made many ethtool patches so far.
Also on a related note, what does the 64bit data field of
ethtool_flow_ext used for?
Driver-dependent. ixgbe uses it for something.
Ben.
--
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.
From: Or Gerlitz <hidden> Date: 2012-10-10 14:34:07
On 10/10/2012 16:28, Ben Hutchings wrote:
On Wed, 2012-10-10 at 16:16 +0200, Or Gerlitz wrote:
[...]
quoted
quoted
Thanks for setting the sketch of a plan here... so if we go little bit
into details, we can safely move 20 bytes from the hadata[60] field into
the beginning of struct ethtool_flow_ext, which will still allow old
user space to work with newer kernels. As for newer uses space that
would like to set mac addresses within
ethtool_flow_ext, how are they supposed to identify if the kernel
supports this extension (of the extension...)?
Well they can't tell in advance, but we can define another flag in
flow_type like FLOW_EXT and existing drivers will reject flow specs with
that flag set.
I understand what we can add a flag which will be rejected by driver's that don't support this ext,
can the same/similar flag be used for newer user space code to mark they want this ext?
Or.
From: Ben Hutchings <hidden> Date: 2012-10-10 17:27:32
On Wed, 2012-10-10 at 16:31 +0200, Or Gerlitz wrote:
On 10/10/2012 16:28, Ben Hutchings wrote:
quoted
On Wed, 2012-10-10 at 16:16 +0200, Or Gerlitz wrote:
[...]
quoted
quoted
Thanks for setting the sketch of a plan here... so if we go little bit
into details, we can safely move 20 bytes from the hadata[60] field into
the beginning of struct ethtool_flow_ext, which will still allow old
user space to work with newer kernels. As for newer uses space that
would like to set mac addresses within
ethtool_flow_ext, how are they supposed to identify if the kernel
supports this extension (of the extension...)?
Well they can't tell in advance, but we can define another flag in
flow_type like FLOW_EXT and existing drivers will reject flow specs with
that flag set.
I understand what we can add a flag which will be rejected by driver's
that don't support this ext,
can the same/similar flag be used for newer user space code to mark they
want this ext?
Exactly.
Ben.
--
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.