idpf: fix issue with ethtool -n command display

idpf: fix issue with ethtool -n command display

When ethtool -n is executed on an interface to display the flow steering
rules, "rxclass: Unknown flow type" error is generated.

The flow steering list maintained in the driver currently stores only the
location and q_index but other fields of the ethtool_rx_flow_spec are not
stored. This may be enough for the virtchnl command to delete the entry.
However, when the ethtool -n command is used to query the flow steering
rules, the ethtool_rx_flow_spec returned is not complete causing the
error below.

Resolve this by storing the flow spec (fsp) when rules are added and
returning the complete flow spec when rules are queried.

Also, change the return value from EINVAL to ENOENT when flow steering
entry is not found during query by location or when deleting an entry.

Add logic to detect and reject duplicate filter entries at the same
location and change logic to perform upfront validation of all error
conditions before adding flow rules through virtchnl. This avoids the
need for additional virtchnl delete messages when subsequent operations
fail, which was missing in the original upstream code.

Example:
Before the fix:
ethtool -n eth1
2 RX rings available
Total 2 rules

rxclass: Unknown flow type
rxclass: Unknown flow type

After the fix:
ethtool -n eth1
2 RX rings available
Total 2 rules

Filter: 0
        Rule Type: TCP over IPv4
        Src IP addr: 10.0.0.1 mask: 0.0.0.0
        Dest IP addr: 0.0.0.0 mask: 255.255.255.255
        TOS: 0x0 mask: 0xff
        Src port: 0 mask: 0xffff
        Dest port: 0 mask: 0xffff
        Action: Direct to queue 0

Filter: 1
        Rule Type: UDP over IPv4
        Src IP addr: 10.0.0.1 mask: 0.0.0.0
        Dest IP addr: 0.0.0.0 mask: 255.255.255.255
        TOS: 0x0 mask: 0xff
        Src port: 0 mask: 0xffff
        Dest port: 0 mask: 0xffff
        Action: Direct to queue 0

Fixes: ada3e24b84a0 ("idpf: add flow steering support")
Signed-off-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.com>
Co-developed-by: Sreedevi Joshi <sreedevi.joshi@intel.com>
Signed-off-by: Sreedevi Joshi <sreedevi.joshi@intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Mina Almasry <almasrymina@google.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>