* [PATCH bpf 1/3] i40e: Relax i40e_xsk_wakeup's return value when PF is busy
2020-02-05 4:58 [PATCH bpf 0/3] XSK related fixes Maciej Fijalkowski
@ 2020-02-05 4:58 ` Maciej Fijalkowski
2020-02-05 4:58 ` [PATCH bpf 2/3] samples: bpf: drop doubled variable declaration in xdpsock Maciej Fijalkowski
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Maciej Fijalkowski @ 2020-02-05 4:58 UTC (permalink / raw)
To: ast, daniel; +Cc: netdev, bpf, bjorn.topel, magnus.karlsson, maximmi
Return -EAGAIN instead of -ENETDOWN to provide a slightly milder
information to user space so that an application will know to retry the
syscall when __I40E_CONFIG_BUSY bit is set on pf->state.
Fixes: b3873a5be757 ("net/i40e: Fix concurrency issues between config flow and XSK")
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
---
drivers/net/ethernet/intel/i40e/i40e_xsk.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index 42058fad6..0b7d29192 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -791,7 +791,7 @@ int i40e_xsk_wakeup(struct net_device *dev, u32 queue_id, u32 flags)
struct i40e_ring *ring;
if (test_bit(__I40E_CONFIG_BUSY, pf->state))
- return -ENETDOWN;
+ return -EAGAIN;
if (test_bit(__I40E_VSI_DOWN, vsi->state))
return -ENETDOWN;
--
2.20.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH bpf 2/3] samples: bpf: drop doubled variable declaration in xdpsock
2020-02-05 4:58 [PATCH bpf 0/3] XSK related fixes Maciej Fijalkowski
2020-02-05 4:58 ` [PATCH bpf 1/3] i40e: Relax i40e_xsk_wakeup's return value when PF is busy Maciej Fijalkowski
@ 2020-02-05 4:58 ` Maciej Fijalkowski
2020-02-05 4:58 ` [PATCH bpf 3/3] samples: bpf: allow for -ENETDOWN " Maciej Fijalkowski
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Maciej Fijalkowski @ 2020-02-05 4:58 UTC (permalink / raw)
To: ast, daniel; +Cc: netdev, bpf, bjorn.topel, magnus.karlsson, maximmi
Seems that by accident there is a doubled declaration of global variable
opt_xdp_bind_flags in xdpsock_user.c. The second one is uninitialized so
compiler was simply ignoring it.
To keep things clean, drop the doubled variable.
Fixes: c543f5469822 ("samples/bpf: add unaligned chunks mode support to xdpsock")
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
---
samples/bpf/xdpsock_user.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c
index 0b5acd722..bab7a850e 100644
--- a/samples/bpf/xdpsock_user.c
+++ b/samples/bpf/xdpsock_user.c
@@ -83,7 +83,6 @@ static u32 opt_xdp_bind_flags = XDP_USE_NEED_WAKEUP;
static u32 opt_umem_flags;
static int opt_unaligned_chunks;
static int opt_mmap_flags;
-static u32 opt_xdp_bind_flags;
static int opt_xsk_frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE;
static int opt_timeout = 1000;
static bool opt_need_wakeup = true;
--
2.20.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH bpf 3/3] samples: bpf: allow for -ENETDOWN in xdpsock
2020-02-05 4:58 [PATCH bpf 0/3] XSK related fixes Maciej Fijalkowski
2020-02-05 4:58 ` [PATCH bpf 1/3] i40e: Relax i40e_xsk_wakeup's return value when PF is busy Maciej Fijalkowski
2020-02-05 4:58 ` [PATCH bpf 2/3] samples: bpf: drop doubled variable declaration in xdpsock Maciej Fijalkowski
@ 2020-02-05 4:58 ` Maciej Fijalkowski
2020-02-05 21:21 ` [PATCH bpf 0/3] XSK related fixes Daniel Borkmann
2020-02-06 13:58 ` Maxim Mikityanskiy
4 siblings, 0 replies; 6+ messages in thread
From: Maciej Fijalkowski @ 2020-02-05 4:58 UTC (permalink / raw)
To: ast, daniel; +Cc: netdev, bpf, bjorn.topel, magnus.karlsson, maximmi
ndo_xsk_wakeup() can return -ENETDOWN and there's no particular reason
to bail the whole application out on that case. Let's check in kick_tx()
whether errno was set to mentioned value and basically allow application
to further process frames.
Fixes: 248c7f9c0e21 ("samples/bpf: convert xdpsock to use libbpf for AF_XDP access")
Reported-by: Cameron Elliott <cameron@cameronelliott.com>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
---
samples/bpf/xdpsock_user.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c
index bab7a850e..c91e91362 100644
--- a/samples/bpf/xdpsock_user.c
+++ b/samples/bpf/xdpsock_user.c
@@ -788,7 +788,8 @@ static void kick_tx(struct xsk_socket_info *xsk)
int ret;
ret = sendto(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL, 0);
- if (ret >= 0 || errno == ENOBUFS || errno == EAGAIN || errno == EBUSY)
+ if (ret >= 0 || errno == ENOBUFS || errno == EAGAIN ||
+ errno == EBUSY || errno == ENETDOWN)
return;
exit_with_error(errno);
}
--
2.20.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH bpf 0/3] XSK related fixes
2020-02-05 4:58 [PATCH bpf 0/3] XSK related fixes Maciej Fijalkowski
` (2 preceding siblings ...)
2020-02-05 4:58 ` [PATCH bpf 3/3] samples: bpf: allow for -ENETDOWN " Maciej Fijalkowski
@ 2020-02-05 21:21 ` Daniel Borkmann
2020-02-06 13:58 ` Maxim Mikityanskiy
4 siblings, 0 replies; 6+ messages in thread
From: Daniel Borkmann @ 2020-02-05 21:21 UTC (permalink / raw)
To: Maciej Fijalkowski
Cc: ast, netdev, bpf, bjorn.topel, magnus.karlsson, maximmi
On Wed, Feb 05, 2020 at 05:58:31AM +0100, Maciej Fijalkowski wrote:
> Cameron reported [0] that on fresh bpf-next he could not run multiple
> xdpsock instances in Tx-only mode on single network interface with i40e
> driver.
>
> Turns out that Maxim's series [1] which was adding RCU protection around
> ndo_xsk_wakeup added check against the __I40E_CONFIG_BUSY being set on
> pf->state within i40e_xsk_wakeup() - if it's set, return -ENETDOWN.
> Since this bit is set per PF when UMEM is being enabled/disabled, the
> situation Cameron stumbled upon was that when he launched second xdpsock
> instance, second UMEM was being registered, hence set __I40E_CONFIG_BUSY
> which is now observed by first xdpsock and therefore xdpsock's kick_tx()
> gets -ENETDOWN as errno.
>
> -ENETDOWN currently is not allowed in kick_tx(), so we were exiting the
> first application. Such exit means also XDP program being unloaded and
> its dedicated resources, which caused an -ENXIO being return in the
> second xdpsock instance.
>
> Let's fix the issue from both sides - protect ourselves from future
> xdpsock crashes by allowing for -ENETDOWN errno being set in kick_tx()
> (patch 3) and from driver side, return -EAGAIN for the case where PF is
> busy (patch 1).
>
> Remove also doubled variable from xdpsock_user.c (patch 2).
>
> Note that ixgbe seems not to be affected since UMEM registration sets
> the busy/disable bit per ring, not per PF.
>
> Thanks!
> Maciej
>
> [0]: https://www.spinics.net/lists/xdp-newbies/msg01558.html
> [1]: https://lore.kernel.org/netdev/20191217162023.16011-1-maximmi@mellanox.com/
Applied, thanks!
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH bpf 0/3] XSK related fixes
2020-02-05 4:58 [PATCH bpf 0/3] XSK related fixes Maciej Fijalkowski
` (3 preceding siblings ...)
2020-02-05 21:21 ` [PATCH bpf 0/3] XSK related fixes Daniel Borkmann
@ 2020-02-06 13:58 ` Maxim Mikityanskiy
4 siblings, 0 replies; 6+ messages in thread
From: Maxim Mikityanskiy @ 2020-02-06 13:58 UTC (permalink / raw)
To: Maciej Fijalkowski, daniel; +Cc: ast, netdev, bpf, bjorn.topel, magnus.karlsson
On 2020-02-05 06:58, Maciej Fijalkowski wrote:
> Cameron reported [0] that on fresh bpf-next he could not run multiple
> xdpsock instances in Tx-only mode on single network interface with i40e
> driver.
>
> Turns out that Maxim's series [1] which was adding RCU protection around
> ndo_xsk_wakeup added check against the __I40E_CONFIG_BUSY being set on
> pf->state within i40e_xsk_wakeup() - if it's set, return -ENETDOWN.
> Since this bit is set per PF when UMEM is being enabled/disabled, the
> situation Cameron stumbled upon was that when he launched second xdpsock
> instance, second UMEM was being registered, hence set __I40E_CONFIG_BUSY
> which is now observed by first xdpsock and therefore xdpsock's kick_tx()
> gets -ENETDOWN as errno.
>
> -ENETDOWN currently is not allowed in kick_tx(), so we were exiting the
> first application. Such exit means also XDP program being unloaded and
> its dedicated resources, which caused an -ENXIO being return in the
> second xdpsock instance.
>
> Let's fix the issue from both sides - protect ourselves from future
> xdpsock crashes by allowing for -ENETDOWN errno being set in kick_tx()
> (patch 3) and from driver side, return -EAGAIN for the case where PF is
> busy (patch 1).
>
> Remove also doubled variable from xdpsock_user.c (patch 2).
>
> Note that ixgbe seems not to be affected since UMEM registration sets
> the busy/disable bit per ring, not per PF.
>
> Thanks!
> Maciej
>
> [0]: https://www.spinics.net/lists/xdp-newbies/msg01558.html
> [1]: https://lore.kernel.org/netdev/20191217162023.16011-1-maximmi@mellanox.com/
>
> Maciej Fijalkowski (3):
> i40e: Relax i40e_xsk_wakeup's return value when PF is busy
> samples: bpf: drop doubled variable declaration in xdpsock
> samples: bpf: allow for -ENETDOWN in xdpsock
>
> drivers/net/ethernet/intel/i40e/i40e_xsk.c | 2 +-
> samples/bpf/xdpsock_user.c | 4 ++--
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
Acked-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Though it's already merged (that was too fast).
^ permalink raw reply [flat|nested] 6+ messages in thread