From 33cdfa1936a0a50086b766fffaa8124ecafdc1ac Mon Sep 17 00:00:00 2001 From: Xiao Wang Date: Mon, 15 Apr 2019 15:56:23 +0800 Subject: [PATCH] net/ifc: do not relay for Tx queue Relay for Tx queue doesn't provide any benefit, since the packet buffer in Tx queue is read-only, there's no dirty page logging for Tx buffer. This change further reduces CPU usage and improves throughput. Signed-off-by: Xiao Wang --- drivers/net/ifc/ifcvf_vdpa.c | 88 +++++++++++++++++++----------------- 1 file changed, 46 insertions(+), 42 deletions(-) diff --git a/drivers/net/ifc/ifcvf_vdpa.c b/drivers/net/ifc/ifcvf_vdpa.c index 921a7e0585..619cdc245c 100644 --- a/drivers/net/ifc/ifcvf_vdpa.c +++ b/drivers/net/ifc/ifcvf_vdpa.c @@ -66,6 +66,8 @@ struct ifcvf_internal { bool sw_fallback_running; /* mediated vring for sw fallback */ struct vring m_vring[IFCVF_MAX_QUEUES * 2]; + /* eventfd for used ring interrupt */ + int intr_fd[IFCVF_MAX_QUEUES * 2]; }; struct internal_list { @@ -334,7 +336,7 @@ vdpa_ifcvf_stop(struct ifcvf_internal *internal) #define MSIX_IRQ_SET_BUF_LEN (sizeof(struct vfio_irq_set) + \ sizeof(int) * (IFCVF_MAX_QUEUES * 2 + 1)) static int -vdpa_enable_vfio_intr(struct ifcvf_internal *internal) +vdpa_enable_vfio_intr(struct ifcvf_internal *internal, bool m_rx) { int ret; uint32_t i, nr_vring; @@ -342,6 +344,7 @@ vdpa_enable_vfio_intr(struct ifcvf_internal *internal) struct vfio_irq_set *irq_set; int *fd_ptr; struct rte_vhost_vring vring; + int fd; nr_vring = rte_vhost_get_vring_num(internal->vid); @@ -355,9 +358,22 @@ vdpa_enable_vfio_intr(struct ifcvf_internal *internal) fd_ptr = (int *)&irq_set->data; fd_ptr[RTE_INTR_VEC_ZERO_OFFSET] = internal->pdev->intr_handle.fd; + for (i = 0; i < nr_vring; i++) + internal->intr_fd[i] = -1; + for (i = 0; i < nr_vring; i++) { rte_vhost_get_vhost_vring(internal->vid, i, &vring); fd_ptr[RTE_INTR_VEC_RXTX_OFFSET + i] = vring.callfd; + if ((i & 1) == 0 && m_rx == true) { + fd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC); + if (fd < 0) { + DRV_LOG(ERR, "can't setup eventfd: %s", + strerror(errno)); + return -1; + } + internal->intr_fd[i] = fd; + fd_ptr[RTE_INTR_VEC_RXTX_OFFSET + i] = fd; + } } ret = ioctl(internal->vfio_dev_fd, VFIO_DEVICE_SET_IRQS, irq_set); @@ -374,6 +390,7 @@ static int vdpa_disable_vfio_intr(struct ifcvf_internal *internal) { int ret; + uint32_t i, nr_vring; char irq_set_buf[MSIX_IRQ_SET_BUF_LEN]; struct vfio_irq_set *irq_set; @@ -384,6 +401,13 @@ vdpa_disable_vfio_intr(struct ifcvf_internal *internal) irq_set->index = VFIO_PCI_MSIX_IRQ_INDEX; irq_set->start = 0; + nr_vring = rte_vhost_get_vring_num(internal->vid); + for (i = 0; i < nr_vring; i++) { + if (internal->intr_fd[i] >= 0) + close(internal->intr_fd[i]); + internal->intr_fd[i] = -1; + } + ret = ioctl(internal->vfio_dev_fd, VFIO_DEVICE_SET_IRQS, irq_set); if (ret) { DRV_LOG(ERR, "Error disabling MSI-X interrupts: %s", @@ -505,7 +529,7 @@ update_datapath(struct ifcvf_internal *internal) if (ret) goto err; - ret = vdpa_enable_vfio_intr(internal); + ret = vdpa_enable_vfio_intr(internal, 0); if (ret) goto err; @@ -591,9 +615,19 @@ m_ifcvf_start(struct ifcvf_internal *internal) } hw->vring[i].avail = gpa; - hw->vring[i].used = m_vring_iova + - (char *)internal->m_vring[i].used - - (char *)internal->m_vring[i].desc; + /* Direct I/O for Tx queue, relay for Rx queue */ + if (i & 1) { + gpa = hva_to_gpa(vid, (uint64_t)(uintptr_t)vq.used); + if (gpa == 0) { + DRV_LOG(ERR, "Fail to get GPA for used ring."); + return -1; + } + hw->vring[i].used = gpa; + } else { + hw->vring[i].used = m_vring_iova + + (char *)internal->m_vring[i].used - + (char *)internal->m_vring[i].desc; + } hw->vring[i].size = vq.size; @@ -647,35 +681,6 @@ m_ifcvf_stop(struct ifcvf_internal *internal) return 0; } -static int -m_enable_vfio_intr(struct ifcvf_internal *internal) -{ - uint32_t nr_vring; - struct rte_intr_handle *intr_handle = &internal->pdev->intr_handle; - int ret; - - nr_vring = rte_vhost_get_vring_num(internal->vid); - - ret = rte_intr_efd_enable(intr_handle, nr_vring); - if (ret) - return -1; - - ret = rte_intr_enable(intr_handle); - if (ret) - return -1; - - return 0; -} - -static void -m_disable_vfio_intr(struct ifcvf_internal *internal) -{ - struct rte_intr_handle *intr_handle = &internal->pdev->intr_handle; - - rte_intr_efd_disable(intr_handle); - rte_intr_disable(intr_handle); -} - static void update_used_ring(struct ifcvf_internal *internal, uint16_t qid) { @@ -689,7 +694,6 @@ vring_relay(void *arg) int i, vid, epfd, fd, nfds; struct ifcvf_internal *internal = (struct ifcvf_internal *)arg; struct rte_vhost_vring vring; - struct rte_intr_handle *intr_handle; uint16_t qid, q_num; struct epoll_event events[IFCVF_MAX_QUEUES * 4]; struct epoll_event ev; @@ -722,12 +726,12 @@ vring_relay(void *arg) } } - intr_handle = &internal->pdev->intr_handle; - for (qid = 0; qid < q_num; qid++) { + for (qid = 0; qid < q_num; qid += 2) { ev.events = EPOLLIN | EPOLLPRI; + /* leave a flag to mark it's for interrupt */ ev.data.u64 = 1 | qid << 1 | - (uint64_t)intr_handle->efds[qid] << 32; - if (epoll_ctl(epfd, EPOLL_CTL_ADD, intr_handle->efds[qid], &ev) + (uint64_t)internal->intr_fd[qid] << 32; + if (epoll_ctl(epfd, EPOLL_CTL_ADD, internal->intr_fd[qid], &ev) < 0) { DRV_LOG(ERR, "epoll add error: %s", strerror(errno)); return NULL; @@ -824,7 +828,7 @@ ifcvf_sw_fallback_switchover(struct ifcvf_internal *internal) goto error; /* set up interrupt for interrupt relay */ - ret = m_enable_vfio_intr(internal); + ret = vdpa_enable_vfio_intr(internal, 1); if (ret) goto unmap; @@ -847,7 +851,7 @@ ifcvf_sw_fallback_switchover(struct ifcvf_internal *internal) stop_vf: m_ifcvf_stop(internal); unset_intr: - m_disable_vfio_intr(internal); + vdpa_disable_vfio_intr(internal); unmap: ifcvf_dma_map(internal, 0); error: @@ -903,7 +907,7 @@ ifcvf_dev_close(int vid) m_ifcvf_stop(internal); /* remove interrupt setting */ - m_disable_vfio_intr(internal); + vdpa_disable_vfio_intr(internal); /* unset DMA map for guest memory */ ifcvf_dma_map(internal, 0); -- 2.20.1