From a5203b53d4fa227560333b890d3e79fc220d1bfd Mon Sep 17 00:00:00 2001 From: Mohsin Kazmi Date: Mon, 12 Oct 2020 13:01:24 +0200 Subject: virtio: run process to send interrupts to input nodes Type: improvement virtio interfaces support packet coalescing and buffering which depends on timer expiry to flush the stored packets periodically. virtio input node checks timer expiry and schedules tx queue accordingly. In poll mode, timer expiry is handled naturally, as input node runs periodically. In interrupt mode, virtio input node depends on the interrupts send from backend. Stored packets could starve, if there would not be interrupts to input node. This patch implements a process node which periodically sends interrupt to virtio input node given coalescing or buffering feature is enabled on an interface. Change-Id: Ic38f749f74b001073d4d0579dca149d0a4cea039 Signed-off-by: Mohsin Kazmi --- src/vnet/devices/virtio/device.c | 34 +++++++++++++++++----------------- 1 file changed, 17 insertions(+), 17 deletions(-) (limited to 'src/vnet/devices/virtio/device.c') diff --git a/src/vnet/devices/virtio/device.c b/src/vnet/devices/virtio/device.c index 084be962ed7..521d76a8da4 100644 --- a/src/vnet/devices/virtio/device.c +++ b/src/vnet/devices/virtio/device.c @@ -761,11 +761,11 @@ static clib_error_t * virtio_interface_rx_mode_change (vnet_main_t * vnm, u32 hw_if_index, u32 qid, vnet_hw_if_rx_mode mode) { + vlib_main_t *vm = vnm->vlib_main; virtio_main_t *mm = &virtio_main; vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index); virtio_if_t *vif = pool_elt_at_index (mm->interfaces, hw->dev_instance); virtio_vring_t *rx_vring = vec_elt_at_index (vif->rxq_vrings, qid); - virtio_vring_t *tx_vring = 0; if (vif->type == VIRTIO_IF_TYPE_PCI && !(vif->support_int_mode)) { @@ -775,32 +775,32 @@ virtio_interface_rx_mode_change (vnet_main_t * vnm, u32 hw_if_index, u32 qid, if (mode == VNET_HW_IF_RX_MODE_POLLING) { - vec_foreach (tx_vring, vif->txq_vrings) - { - /* only enable packet coalesce in poll mode */ - gro_flow_table_set_is_enable (tx_vring->flow_table, 1); - /* only enable packet buffering in poll mode */ - virtio_vring_buffering_set_is_enable (tx_vring->buffering, 1); - } + if (vif->packet_coalesce || vif->packet_buffering) + { + if (mm->interrupt_queues_count > 0) + mm->interrupt_queues_count--; + if (mm->interrupt_queues_count == 0) + vlib_process_signal_event (vm, + virtio_send_interrupt_node.index, + VIRTIO_EVENT_STOP_TIMER, 0); + } rx_vring->avail->flags |= VRING_AVAIL_F_NO_INTERRUPT; } else { if (vif->packet_coalesce || vif->packet_buffering) { - virtio_log_warning (vif, - "interface %U is in interrupt mode, disabling packet coalescing or buffering", - format_vnet_sw_if_index_name, vnet_get_main (), - vif->sw_if_index); - vec_foreach (tx_vring, vif->txq_vrings) - { - gro_flow_table_set_is_enable (tx_vring->flow_table, 0); - virtio_vring_buffering_set_is_enable (tx_vring->buffering, 0); - } + mm->interrupt_queues_count++; + if (mm->interrupt_queues_count == 1) + vlib_process_signal_event (vm, + virtio_send_interrupt_node.index, + VIRTIO_EVENT_START_TIMER, 0); } rx_vring->avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT; } + rx_vring->mode = mode; + return 0; } -- cgit 1.2.3-korg