Re: [dpdk-dev] [PATCH 1/2] mbuf: fix bitmask of Tx offload flags

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> -----Original Message-----
> From: Olivier MATZ [mailto:olivier.matz@6wind.com]
> Sent: Thursday, January 26, 2017 3:58 PM
> To: Ananyev, Konstantin <konstantin.ananyev@intel.com>
> Cc: Olivier MATZ <olivier.matz@6wind.com>; Wu, Jingjing <jingjing.wu@intel.com>; dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH 1/2] mbuf: fix bitmask of Tx offload flags
> 
> On Thu, 26 Jan 2017 15:35:29 +0000, "Ananyev, Konstantin"
> <konstantin.ananyev@intel.com> wrote:
> > Hi Olivier,
> >
> > > -----Original Message-----
> > > From: Olivier MATZ [mailto:olivier.matz@6wind.com]
> > > Sent: Thursday, January 26, 2017 3:05 PM
> > > To: Ananyev, Konstantin <konstantin.ananyev@intel.com>
> > > Cc: Wu, Jingjing <jingjing.wu@intel.com>; dev@dpdk.org
> > > Subject: Re: [dpdk-dev] [PATCH 1/2] mbuf: fix bitmask of Tx offload
> > > flags
> > >
> > > On Thu, 26 Jan 2017 14:58:08 +0000, "Ananyev, Konstantin"
> > > <konstantin.ananyev@intel.com> wrote:
> > > > Hi Jingjng,
> > > >
> > > > > -----Original Message-----
> > > > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Jingjing Wu
> > > > > Sent: Tuesday, January 24, 2017 11:48 AM
> > > > > To: dev@dpdk.org
> > > > > Cc: Wu, Jingjing <jingjing.wu@intel.com>
> > > > > Subject: [dpdk-dev] [PATCH 1/2] mbuf: fix bitmask of Tx offload
> > > > > flags
> > > > >
> > > > > Some Tx offload flags are missed in Bitmask of all supported
> > > > > packet Tx offload features flags.
> > > > > This patch fixes it.
> > > >
> > > > Not sure what it exactly fixes?
> > > > As I remember these flags don't specify any TX offload for HW to
> > > > perform, But just provide information to the TX function.
> > > > Again, why only i40e code is modified?
> > > > As I remember we have the same code in other PMDs too.
> > > > Konstantin
> > > >
> > > > >
> > > > > Fixes: 4fb7e803eb1a ("ethdev: add Tx preparation")
> > > > > Signed-off-by: Jingjing Wu <jingjing.wu@intel.com>
> > > > > ---
> > > > >  lib/librte_mbuf/rte_mbuf.h | 4 ++++
> > > > >  1 file changed, 4 insertions(+)
> > > > >
> > > > > diff --git a/lib/librte_mbuf/rte_mbuf.h
> > > > > b/lib/librte_mbuf/rte_mbuf.h index bfce9f4..e57a4d2 100644
> > > > > --- a/lib/librte_mbuf/rte_mbuf.h
> > > > > +++ b/lib/librte_mbuf/rte_mbuf.h
> > > > > @@ -295,8 +295,12 @@ extern "C" {
> > > > >   */
> > > > >  #define PKT_TX_OFFLOAD_MASK (    \
> > > > >  		PKT_TX_IP_CKSUM |        \
> > > > > +		PKT_TX_IPV4 |            \
> > > > > +		PKT_TX_IPV6 |            \
> > > > >  		PKT_TX_L4_MASK |         \
> > > > >  		PKT_TX_OUTER_IP_CKSUM |  \
> > > > > +		PKT_TX_OUTER_IPV4 |      \
> > > > > +		PKT_TX_OUTER_IPV6 |      \
> > > > >  		PKT_TX_TCP_SEG |         \
> > > > >  		PKT_TX_QINQ_PKT |        \
> > > > >  		PKT_TX_VLAN_PKT |        \
> > > > > --
> > > > > 2.4.11
> > > >
> > >
> > > Also, it looks like MACSEC is missing. To avoid forgetting flags in
> > > the future, what do you think about doing the following (not
> > > tested)?
> > >
> > >
> > > diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
> > > index b3cccfc..aa1dc76 100644
> > > --- a/lib/librte_mbuf/rte_mbuf.h
> > > +++ b/lib/librte_mbuf/rte_mbuf.h
> > > @@ -182,9 +182,11 @@ extern "C" {
> > >   */
> > >  #define PKT_RX_TIMESTAMP     (1ULL << 17)
> > >
> > > -/* add new RX flags here */
> > > +/* add new RX flags here, and update __PKT_RX_NEXT */
> > > +#define __PKT_RX_NEXT        (1ULL << 18)
> > >
> > > -/* add new TX flags here */
> > > +/* add new TX flags here, and update __PKT_TX_NEXT */
> > > +#define __PKT_TX_NEXT        (1ULL << 43)
> > >
> > >  /**
> > >   * Offload the MACsec. This flag must be set by the application to
> > > enable @@ -295,17 +297,16 @@ extern "C" {
> > >  #define PKT_TX_OUTER_IPV6    (1ULL << 60)
> > >
> > >  /**
> > > + * Bitmask of all supported packet Rx offload features flags,
> > > + * which can be set for packet.
> > > + */
> > > +#define PKT_RX_OFFLOAD_MASK (__PKT_RX_NEXT - 1)
> > > +
> > > +/**
> > >   * Bitmask of all supported packet Tx offload features flags,
> > >   * which can be set for packet.
> > >   */
> > > -#define PKT_TX_OFFLOAD_MASK (    \
> > > -               PKT_TX_IP_CKSUM |        \
> > > -               PKT_TX_L4_MASK |         \
> > > -               PKT_TX_OUTER_IP_CKSUM |  \
> > > -               PKT_TX_TCP_SEG |         \
> > > -               PKT_TX_QINQ_PKT |        \
> > > -               PKT_TX_VLAN_PKT |        \
> > > -               PKT_TX_TUNNEL_MASK)
> > > +#define PKT_TX_OFFLOAD_MASK ((~(__PKT_TX_NEXT - 1)) &
> > > 0x1fffffffffffffff)
> >
> > I see your point but should, let say, PKT_TX_IPV4 be part of
> > PKT_TX_OFFLOAD_MASK at all? It doesn't really define any offload for
> > PMD/HW to perform. It just provide extra information for  PMD so it
> > can successfully process other offload requests. Konstantin
> 
> Yes, that's right. On the other hand, differentiating them may confuse
> the PMD developpers (that's probably the case for this patch).
> 
> Having PKT_TX_MASK that includes all TX flags automatically would also
> do the job (knowing PMDs must be updated), 

Yes, all other PMDs that do use PKT_TX_OFFLOAD_MASK have to be updated in that case...
But ok, I agree what do you propose might help to avoid confusion. 

>and would avoid to forget
> flags in the future... if we decide to do it, it would be better before
> 17.02, because PKT_TX_OFFLOAD_MASK was added after 16.11, so it is not
> yet part of the API.

Agree.

> 
> In any case, we need a patch to fix the missing PKT_TX_MACSEC in
> PKT_TX_OFFLOAD_MASK.
> 
> 

Yes, we do.
Konstantin