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| author | Jose Ignacio Tornos Martinez <jtornosm@redhat.com> | 2026-05-15 11:24:09 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-05-18 19:00:43 -0700 |
| commit | 3ba4dd024d26372733d1c02e13e076c6016e3320 (patch) | |
| tree | 020ad137f8b413a7a526c9bf73e83294b8e8dc8f /drivers/net | |
| parent | 89bbff099bfc94888eb942d5b981592bbbe0c856 (diff) | |
| download | lwn-3ba4dd024d26372733d1c02e13e076c6016e3320.tar.gz lwn-3ba4dd024d26372733d1c02e13e076c6016e3320.zip | |
ice: fix VF queue configuration with low MTU values
The ice driver's VF queue configuration validation rejects
databuffer_size values below 1024 bytes, which prevents VFs from
using MTU values below 871 bytes.
The iavf driver calculates databuffer_size based on the MTU using:
databuffer_size = ALIGN(MTU + LIBETH_RX_LL_LEN, 128)
where LIBETH_RX_LL_LEN = 26 (ETH_HLEN + 2*VLAN_HLEN + ETH_FCS_LEN).
For MTU values below 871:
MTU 870: 870 + 26 = 896, aligned to 128 = 896 (< 1024, rejected)
MTU 871: 871 + 26 = 897, aligned to 128 = 1024 (>= 1024, accepted)
The 1024-byte minimum seems unnecessarily restrictive, because the hardware
supports databuffer_size as low as 128 bytes (the alignment boundary),
which should allow MTU values down to the standard minimum of 68 bytes.
I haven't found the reason why the limit was configured in the commit
9c7dd7566d18 ("ice: add validation in OP_CONFIG_VSI_QUEUES VF message"), so
with no more information and since it is working, change the minimum
databuffer_size validation from 1024 to 128 bytes to allow standard low
MTU values while still preventing invalid configurations.
Fixes: 9c7dd7566d18 ("ice: add validation in OP_CONFIG_VSI_QUEUES VF message")
cc: stable@vger.kernel.org
Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://patch.msgid.link/20260515182419.1597859-3-anthony.l.nguyen@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/ethernet/intel/ice/virt/queues.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/ethernet/intel/ice/virt/queues.c b/drivers/net/ethernet/intel/ice/virt/queues.c index f73d5a3e83d4..31be2f76181c 100644 --- a/drivers/net/ethernet/intel/ice/virt/queues.c +++ b/drivers/net/ethernet/intel/ice/virt/queues.c @@ -840,7 +840,7 @@ int ice_vc_cfg_qs_msg(struct ice_vf *vf, u8 *msg) if (qpi->rxq.databuffer_size != 0 && (qpi->rxq.databuffer_size > ((16 * 1024) - 128) || - qpi->rxq.databuffer_size < 1024)) + qpi->rxq.databuffer_size < 128)) goto error_param; ring->rx_buf_len = qpi->rxq.databuffer_size; |