ice: set MSI-X vector count on VF

Implement ops needed to set MSI-X vector count on VF.

sriov_get_vf_total_msix() should return total number of MSI-X that can
be used by the VFs. Return the value set by devlink resources API
(pf->req_msix.vf).

sriov_set_msix_vec_count() will set number of MSI-X on particular VF.
Disable VF register mapping, rebuild VSI with new MSI-X and queues
values and enable new VF register mapping.

For best performance set number of queues equal to number of MSI-X.

Signed-off-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/intel/ice/ice_main.c

@@ -5635,6 +5635,8 @@ static struct pci_driver ice_driver = {
 #endif /* CONFIG_PM */
 	.shutdown = ice_shutdown,
 	.sriov_configure = ice_sriov_configure,
+	.sriov_get_vf_total_msix = ice_sriov_get_vf_total_msix,
+	.sriov_set_msix_vec_count = ice_sriov_set_msix_vec_count,
 	.err_handler = &ice_pci_err_handler
 };
 

drivers/net/ethernet/intel/ice/ice_sriov.c

@@ -987,6 +987,75 @@ static int ice_check_sriov_allowed(struct ice_pf *pf)
 	return 0;
 }
 
+/**
+ * ice_sriov_get_vf_total_msix - return number of MSI-X used by VFs
+ * @pdev: pointer to pci_dev struct
+ *
+ * The function is called via sysfs ops
+ */
+u32 ice_sriov_get_vf_total_msix(struct pci_dev *pdev)
+{
+	struct ice_pf *pf = pci_get_drvdata(pdev);
+
+	return pf->sriov_irq_size - ice_get_max_used_msix_vector(pf);
+}
+
+/**
+ * ice_sriov_set_msix_vec_count
+ * @vf_dev: pointer to pci_dev struct of VF device
+ * @msix_vec_count: new value for MSI-X amount on this VF
+ *
+ * Set requested MSI-X, queues and registers for @vf_dev.
+ *
+ * First do some sanity checks like if there are any VFs, if the new value
+ * is correct etc. Then disable old mapping (MSI-X and queues registers), change
+ * MSI-X and queues, rebuild VSI and enable new mapping.
+ *
+ * If it is possible (driver not binded to VF) try to remap also other VFs to
+ * linearize irqs register usage.
+ */
+int ice_sriov_set_msix_vec_count(struct pci_dev *vf_dev, int msix_vec_count)
+{
+	struct pci_dev *pdev = pci_physfn(vf_dev);
+	struct ice_pf *pf = pci_get_drvdata(pdev);
+	struct ice_vf *vf;
+	u16 queues;
+	int id;
+
+	if (!ice_get_num_vfs(pf))
+		return -ENOENT;
+
+	if (!msix_vec_count)
+		return 0;
+
+	queues = msix_vec_count;
+	/* add 1 MSI-X for OICR */
+	msix_vec_count += 1;
+
+	/* Transition of PCI VF function number to function_id */
+	for (id = 0; id < pci_num_vf(pdev); id++) {
+		if (vf_dev->devfn == pci_iov_virtfn_devfn(pdev, id))
+			break;
+	}
+
+	if (id == pci_num_vf(pdev))
+		return -ENOENT;
+
+	vf = ice_get_vf_by_id(pf, id);
+
+	if (!vf)
+		return -ENOENT;
+
+	ice_dis_vf_mappings(vf);
+	vf->num_msix = msix_vec_count;
+	vf->num_vf_qs = queues;
+	ice_vsi_rebuild(ice_get_vf_vsi(vf), ICE_VSI_FLAG_NO_INIT);
+	ice_ena_vf_mappings(vf);
+	ice_put_vf(vf);
+
+	return 0;
+}
+
 /**
  * ice_sriov_configure - Enable or change number of VFs via sysfs
  * @pdev: pointer to a pci_dev structure

drivers/net/ethernet/intel/ice/ice_sriov.h

@@ -60,6 +60,8 @@ void ice_print_vfs_mdd_events(struct ice_pf *pf);
 void ice_print_vf_rx_mdd_event(struct ice_vf *vf);
 bool
 ice_vc_validate_pattern(struct ice_vf *vf, struct virtchnl_proto_hdrs *proto);
+u32 ice_sriov_get_vf_total_msix(struct pci_dev *pdev);
+int ice_sriov_set_msix_vec_count(struct pci_dev *vf_dev, int msix_vec_count);
 #else /* CONFIG_PCI_IOV */
 static inline void ice_process_vflr_event(struct ice_pf *pf) { }
 static inline void ice_free_vfs(struct ice_pf *pf) { }
@@ -142,5 +144,16 @@ ice_get_vf_stats(struct net_device __always_unused *netdev,
 {
 	return -EOPNOTSUPP;
 }
+
+static inline u32 ice_sriov_get_vf_total_msix(struct pci_dev *pdev)
+{
+	return 0;
+}
+
+static inline int
+ice_sriov_set_msix_vec_count(struct pci_dev *vf_dev, int msix_vec_count)
+{
+	return -EOPNOTSUPP;
+}
 #endif /* CONFIG_PCI_IOV */
 #endif /* _ICE_SRIOV_H_ */