[PATCH 5.11 535/775] ice: Account for port VLAN in VF max packet size calculation

From: Greg Kroah-Hartman
Date: Tue Mar 02 2021 - 00:55:41 EST


From: Brett Creeley <brett.creeley@xxxxxxxxx>

[ Upstream commit a6aa7c8f998f4afddd73410aa043dad38162ce9e ]

Currently if an AVF driver doesn't account for the possibility of a
port VLAN when determining its max packet size then packets at MTU will
be dropped. It is not the VF driver's responsibility to account for a
port VLAN so fix this. To fix this, do the following:

1. Add a function that determines the max packet size a VF is allowed by
using the port's max packet size and whether the VF is in a port
VLAN. If a port VLAN is configured then a VF's max packet size will
always be the port's max packet size minus VLAN_HLEN. Otherwise it
will be the port's max packet size.

2. Use this function to verify the max packet size from the VF.

3. If there is a port VLAN configured then add 4 bytes (VLAN_HLEN) to
the VF's max packet size configuration.

Also, the VIRTCHNL_OP_GET_VF_RESOURCES message provides the capability
to communicate a VF's max packet size. Use the new function for this
purpose.

Fixes: 1071a8358a28 ("ice: Implement virtchnl commands for AVF support")
Signed-off-by: Brett Creeley <brett.creeley@xxxxxxxxx>
Tested-by: Tony Brelinski <tonyx.brelinski@xxxxxxxxx>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
.../net/ethernet/intel/ice/ice_virtchnl_pf.c | 33 ++++++++++++++++++-
1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c b/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c
index ec7f6c64132ee..b3161c5def465 100644
--- a/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c
@@ -1878,6 +1878,29 @@ static int ice_vc_get_ver_msg(struct ice_vf *vf, u8 *msg)
sizeof(struct virtchnl_version_info));
}

+/**
+ * ice_vc_get_max_frame_size - get max frame size allowed for VF
+ * @vf: VF used to determine max frame size
+ *
+ * Max frame size is determined based on the current port's max frame size and
+ * whether a port VLAN is configured on this VF. The VF is not aware whether
+ * it's in a port VLAN so the PF needs to account for this in max frame size
+ * checks and sending the max frame size to the VF.
+ */
+static u16 ice_vc_get_max_frame_size(struct ice_vf *vf)
+{
+ struct ice_vsi *vsi = vf->pf->vsi[vf->lan_vsi_idx];
+ struct ice_port_info *pi = vsi->port_info;
+ u16 max_frame_size;
+
+ max_frame_size = pi->phy.link_info.max_frame_size;
+
+ if (vf->port_vlan_info)
+ max_frame_size -= VLAN_HLEN;
+
+ return max_frame_size;
+}
+
/**
* ice_vc_get_vf_res_msg
* @vf: pointer to the VF info
@@ -1960,6 +1983,7 @@ static int ice_vc_get_vf_res_msg(struct ice_vf *vf, u8 *msg)
vfres->max_vectors = pf->num_msix_per_vf;
vfres->rss_key_size = ICE_VSIQF_HKEY_ARRAY_SIZE;
vfres->rss_lut_size = ICE_VSIQF_HLUT_ARRAY_SIZE;
+ vfres->max_mtu = ice_vc_get_max_frame_size(vf);

vfres->vsi_res[0].vsi_id = vf->lan_vsi_num;
vfres->vsi_res[0].vsi_type = VIRTCHNL_VSI_SRIOV;
@@ -2952,6 +2976,8 @@ static int ice_vc_cfg_qs_msg(struct ice_vf *vf, u8 *msg)

/* copy Rx queue info from VF into VSI */
if (qpi->rxq.ring_len > 0) {
+ u16 max_frame_size = ice_vc_get_max_frame_size(vf);
+
num_rxq++;
vsi->rx_rings[i]->dma = qpi->rxq.dma_ring_addr;
vsi->rx_rings[i]->count = qpi->rxq.ring_len;
@@ -2964,7 +2990,7 @@ static int ice_vc_cfg_qs_msg(struct ice_vf *vf, u8 *msg)
}
vsi->rx_buf_len = qpi->rxq.databuffer_size;
vsi->rx_rings[i]->rx_buf_len = vsi->rx_buf_len;
- if (qpi->rxq.max_pkt_size >= (16 * 1024) ||
+ if (qpi->rxq.max_pkt_size > max_frame_size ||
qpi->rxq.max_pkt_size < 64) {
v_ret = VIRTCHNL_STATUS_ERR_PARAM;
goto error_param;
@@ -2972,6 +2998,11 @@ static int ice_vc_cfg_qs_msg(struct ice_vf *vf, u8 *msg)
}

vsi->max_frame = qpi->rxq.max_pkt_size;
+ /* add space for the port VLAN since the VF driver is not
+ * expected to account for it in the MTU calculation
+ */
+ if (vf->port_vlan_info)
+ vsi->max_frame += VLAN_HLEN;
}

/* VF can request to configure less than allocated queues or default
--
2.27.0