This patch mainly allocates structure to store queue/irq mapping,
and configure queue/irq mapping down through PCI ops. It also creates
eventfds for each Rx queue and tell the kernel about the eventfd/intr
binding.
Mostly importantly, different from previous NICs (usually implements
these logic in dev_start()), virtio's interrupt settings should be
configured down to QEMU before sending DRIVER_OK notification.
Note: We only support 1:1 queue/irq mapping so far, which means, each
rx queue has one exclusive interrupt (corresponding to irqfd in the
qemu/kvm) to get notified when packets are available on that queue.
Signed-off-by: Jianfeng Tan <jianfeng....@intel.com>
---
drivers/net/virtio/virtio_ethdev.c | 89 ++++++++++++++++++++++++++++++++++++++
1 file changed, 89 insertions(+)
diff --git a/drivers/net/virtio/virtio_ethdev.c
b/drivers/net/virtio/virtio_ethdev.c
index 3f8b90c..082346b 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -1206,6 +1206,76 @@ rx_func_get(struct rte_eth_dev *eth_dev)
eth_dev->rx_pkt_burst = &virtio_recv_pkts;
}
+/* Only support 1:1 queue/interrupt mapping so far.
+ * TODO: under below cases, lsc and rxq interrupt share one interrupt.
+ * a) binded to uio, igb_uio, vfio (type1);
+ * b) device only has one vec, see _vectors_ option in -device virtio-net-pci.
+ * TODO: support n:1 queue/interrupt mapping.
+ */
+static int
+virtio_queues_bind_intr(struct rte_eth_dev *dev)
+{
+ uint32_t i;
+ struct rte_intr_handle *intr_handle = &dev->pci_dev->intr_handle;
+ struct virtio_hw *hw = dev->data->dev_private;
+
+ PMD_INIT_LOG(INFO, "queue/interrupt binding\n");
+ for (i = 0; i < dev->data->nb_rx_queues; ++i) {
+ intr_handle->intr_vec[i] = i + 1;
+ if (vtpci_irq_queue(hw->vqs[i * VTNET_CQ], i + 1) ==
+ VIRTIO_MSI_NO_VECTOR) {
+ PMD_DRV_LOG(ERR, "failed to set queue vector");
+ return -EBUSY;
+ }
+ }
+
+ return 0;
+}
+
+static int
+virtio_configure_intr(struct rte_eth_dev *dev)
+{
+ uint32_t intr_vector;
+ struct rte_intr_handle *intr_handle = &dev->pci_dev->intr_handle;
+
+ /* check if rxq interrupt is enabled */
+ if (!rte_intr_cap_multiple(intr_handle)) {
+ PMD_INIT_LOG(ERR, "Multiple intr vector not supported");
+ return -ENOTSUP;
+ }
+
+ intr_vector = dev->data->nb_rx_queues;
+ if (rte_intr_efd_enable(intr_handle, intr_vector)) {
+ PMD_INIT_LOG(ERR, "Fail to create eventfd");
+ return -1;
+ }
+
+ if (!intr_handle->intr_vec) {
+ intr_handle->intr_vec =
+ rte_zmalloc("intr_vec", intr_vector * sizeof(int), 0);
+ if (!intr_handle->intr_vec) {
+ PMD_INIT_LOG(ERR, "Failed to allocate %d rxq vectors",
+ intr_vector);
+ return -ENOMEM;
+ }
+ }
+
+ if (virtio_queues_bind_intr(dev) < 0) {
+ PMD_INIT_LOG(ERR, "Failed to bind queue/interrupt");
+ return -1;
+ }
+
+ /* DO NOT try remove this! This function will enable msix, or QEMU
+ * will encounter SIGSEGV.
+ */
+ if (rte_intr_enable(intr_handle) < 0) {
+ PMD_DRV_LOG(ERR, "interrupt enable failed");
+ return -1;
+ }
+
+ return 0;
+}
+
/* reset device and renegotiate features if needed */
static int
virtio_init_device(struct rte_eth_dev *eth_dev, uint64_t req_features)
@@ -1299,6 +1369,17 @@ virtio_init_device(struct rte_eth_dev *eth_dev, uint64_t
req_features)
ret = virtio_alloc_queues(eth_dev);
if (ret < 0)
return ret;
+
+ /* Make sure rxq interrupt is configured before sending DRIVER_OK,
+ * so that QEMU can properly set those irq into kvm.
+ */
+ if (eth_dev->data->dev_conf.intr_conf.rxq) {
+ if (virtio_configure_intr(eth_dev) < 0) {
+ PMD_INIT_LOG(ERR, "failed to configure interrupt");
+ return -1;
+ }
+ }
+
vtpci_reinit_complete(hw);
if (pci_dev)
@@ -1503,7 +1584,15 @@ virtio_dev_start(struct rte_eth_dev *dev)
PMD_DRV_LOG(ERR, "link status not supported by host");
return -ENOTSUP;
}
+ }
+ /* Enable uio/vfio intr/eventfd mapping: althrough we already did that
+ * in device configure, but it could be unmapped when device is
+ * stopped.
+ */
+ if (dev->data->dev_conf.intr_conf.lsc ||
+ dev->data->dev_conf.intr_conf.rxq) {
+ rte_intr_disable(&dev->pci_dev->intr_handle);
if (rte_intr_enable(&dev->pci_dev->intr_handle) < 0) {
PMD_DRV_LOG(ERR, "interrupt enable failed");
return -EIO;
--
2.7.4
