[PATCH 5.15 356/731] i40e: Fix the inability to attach XDP program on downed interface

Greg Kroah-Hartman
2022-12-28T15:14:22Z

From: Bartosz Staszewski <bartoszx.staszewski@intel.com>

[ Upstream commit 0c87b545a2ed5cd8a6318011f1c92b188c2d74bc ]

Whenever trying to load XDP prog on downed interface, function i40e_xdp
was passing vsi->rx_buf_len field to i40e_xdp_setup() which was equal 0.
i40e_open() calls i40e_vsi_configure_rx() which configures that field,
but that only happens when interface is up. When it is down, i40e_open()
is not being called, thus vsi->rx_buf_len is not set.

Solution for this is calculate buffer length in newly created
function - i40e_calculate_vsi_rx_buf_len() that return actual buffer
length. Buffer length is being calculated based on the same rules
applied previously in i40e_vsi_configure_rx() function.

Fixes: 613142b0bb88 ("i40e: Log error for oversized MTU on device")
Fixes: 0c8493d90b6b ("i40e: add XDP support for pass and drop actions")
Signed-off-by: Bartosz Staszewski <bartoszx.staszewski@intel.com>
Signed-off-by: Mateusz Palczewski <mateusz.palczewski@intel.com>
Tested-by: Shwetha Nagaraju <Shwetha.nagaraju@intel.com>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Reviewed-by: Saeed Mahameed <saeed@kernel.com>
Link: https://lore.kernel.org/r/20221209185411.2519898-1-anthony.l.nguyen@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/intel/i40e/i40e_main.c | 36 ++++++++++++++-------
1 file changed, 24 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index ed2c961902b6..c013d86559af 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -3548,6 +3548,24 @@ static int i40e_vsi_configure_tx(struct i40e_vsi *vsi)
return err;
}

+/**
+ * i40e_calculate_vsi_rx_buf_len - Calculates buffer length
+ *
+ * @vsi: VSI to calculate rx_buf_len from
+ */
+static u16 i40e_calculate_vsi_rx_buf_len(struct i40e_vsi *vsi)
+{
+ if (!vsi->netdev || (vsi->back->flags & I40E_FLAG_LEGACY_RX))
+ return I40E_RXBUFFER_2048;
+
+#if (PAGE_SIZE < 8192)
+ if (!I40E_2K_TOO_SMALL_WITH_PADDING && vsi->netdev->mtu <= ETH_DATA_LEN)
+ return I40E_RXBUFFER_1536 - NET_IP_ALIGN;
+#endif
+
+ return PAGE_SIZE < 8192 ? I40E_RXBUFFER_3072 : I40E_RXBUFFER_2048;
+}
+
/**
* i40e_vsi_configure_rx - Configure the VSI for Rx
* @vsi: the VSI being configured
@@ -3559,20 +3577,14 @@ static int i40e_vsi_configure_rx(struct i40e_vsi *vsi)
int err = 0;
u16 i;

- if (!vsi->netdev || (vsi->back->flags & I40E_FLAG_LEGACY_RX)) {
- vsi->max_frame = I40E_MAX_RXBUFFER;
- vsi->rx_buf_len = I40E_RXBUFFER_2048;
+ vsi->max_frame = I40E_MAX_RXBUFFER;
+ vsi->rx_buf_len = i40e_calculate_vsi_rx_buf_len(vsi);
+
#if (PAGE_SIZE < 8192)
- } else if (!I40E_2K_TOO_SMALL_WITH_PADDING &&
- (vsi->netdev->mtu <= ETH_DATA_LEN)) {
+ if (vsi->netdev && !I40E_2K_TOO_SMALL_WITH_PADDING &&
+ vsi->netdev->mtu <= ETH_DATA_LEN)
vsi->max_frame = I40E_RXBUFFER_1536 - NET_IP_ALIGN;
- vsi->rx_buf_len = I40E_RXBUFFER_1536 - NET_IP_ALIGN;
#endif
- } else {
- vsi->max_frame = I40E_MAX_RXBUFFER;
- vsi->rx_buf_len = (PAGE_SIZE < 8192) ? I40E_RXBUFFER_3072 :
- I40E_RXBUFFER_2048;
- }

/* set up individual rings */
for (i = 0; i < vsi->num_queue_pairs && !err; i++)
@@ -13147,7 +13159,7 @@ static int i40e_xdp_setup(struct i40e_vsi *vsi, struct bpf_prog *prog,
int i;

/* Don't allow frames that span over multiple buffers */
- if (frame_size > vsi->rx_buf_len) {
+ if (frame_size > i40e_calculate_vsi_rx_buf_len(vsi)) {
NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP");
return -EINVAL;
}
--
2.35.1