/*- * BSD LICENSE * * Copyright(c) 2010-2016 Intel Corporation. All rights reserved. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * Neither the name of Intel Corporation nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include "spdk/stdinc.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "spdk/env.h" #include "spdk/barrier.h" #include "spdk_internal/virtio.h" /* We use SMP memory barrier variants as all virtio_pci devices * are purely virtual. All MMIO is executed on a CPU core, so * there's no need to do full MMIO synchronization. */ #define virtio_mb() spdk_smp_mb() #define virtio_rmb() spdk_smp_rmb() #define virtio_wmb() spdk_smp_wmb() /* Chain all the descriptors in the ring with an END */ static inline void vring_desc_init(struct vring_desc *dp, uint16_t n) { uint16_t i; for (i = 0; i < n - 1; i++) { dp[i].next = (uint16_t)(i + 1); } dp[i].next = VQ_RING_DESC_CHAIN_END; } static void virtio_init_vring(struct virtqueue *vq) { int size = vq->vq_nentries; struct vring *vr = &vq->vq_ring; uint8_t *ring_mem = vq->vq_ring_virt_mem; /* * Reinitialise since virtio port might have been stopped and restarted */ memset(ring_mem, 0, vq->vq_ring_size); vring_init(vr, size, ring_mem, VIRTIO_PCI_VRING_ALIGN); vq->vq_used_cons_idx = 0; vq->vq_desc_head_idx = 0; vq->vq_avail_idx = 0; vq->vq_desc_tail_idx = (uint16_t)(vq->vq_nentries - 1); vq->vq_free_cnt = vq->vq_nentries; vq->req_start = VQ_RING_DESC_CHAIN_END; vq->req_end = VQ_RING_DESC_CHAIN_END; vq->reqs_finished = 0; memset(vq->vq_descx, 0, sizeof(struct vq_desc_extra) * vq->vq_nentries); vring_desc_init(vr->desc, size); /* Tell the backend not to interrupt us. * If F_EVENT_IDX is negotiated, we will always set incredibly high * used event idx, so that we will practically never receive an * interrupt. See virtqueue_req_flush() */ if (vq->vdev->negotiated_features & (1ULL << VIRTIO_RING_F_EVENT_IDX)) { vring_used_event(&vq->vq_ring) = UINT16_MAX; } else { vq->vq_ring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT; } } static int virtio_init_queue(struct virtio_dev *dev, uint16_t vtpci_queue_idx) { unsigned int vq_size, size; struct virtqueue *vq; int rc; SPDK_DEBUGLOG(SPDK_LOG_VIRTIO_DEV, "setting up queue: %"PRIu16"\n", vtpci_queue_idx); /* * Read the virtqueue size from the Queue Size field * Always power of 2 and if 0 virtqueue does not exist */ vq_size = virtio_dev_backend_ops(dev)->get_queue_size(dev, vtpci_queue_idx); SPDK_DEBUGLOG(SPDK_LOG_VIRTIO_DEV, "vq_size: %u\n", vq_size); if (vq_size == 0) { SPDK_ERRLOG("virtqueue %"PRIu16" does not exist\n", vtpci_queue_idx); return -EINVAL; } if (!rte_is_power_of_2(vq_size)) { SPDK_ERRLOG("virtqueue %"PRIu16" size (%u) is not powerof 2\n", vtpci_queue_idx, vq_size); return -EINVAL; } size = sizeof(*vq) + vq_size * sizeof(struct vq_desc_extra); if (posix_memalign((void **)&vq, RTE_CACHE_LINE_SIZE, size)) { SPDK_ERRLOG("can not allocate vq\n"); return -ENOMEM; } memset(vq, 0, size); dev->vqs[vtpci_queue_idx] = vq; vq->vdev = dev; vq->vq_queue_index = vtpci_queue_idx; vq->vq_nentries = vq_size; /* * Reserve a memzone for vring elements */ size = vring_size(vq_size, VIRTIO_PCI_VRING_ALIGN); vq->vq_ring_size = RTE_ALIGN_CEIL(size, VIRTIO_PCI_VRING_ALIGN); SPDK_DEBUGLOG(SPDK_LOG_VIRTIO_DEV, "vring_size: %u, rounded_vring_size: %u\n", size, vq->vq_ring_size); vq->owner_thread = NULL; rc = virtio_dev_backend_ops(dev)->setup_queue(dev, vq); if (rc < 0) { SPDK_ERRLOG("setup_queue failed\n"); free(vq); dev->vqs[vtpci_queue_idx] = NULL; return rc; } SPDK_DEBUGLOG(SPDK_LOG_VIRTIO_DEV, "vq->vq_ring_mem: 0x%" PRIx64 "\n", vq->vq_ring_mem); SPDK_DEBUGLOG(SPDK_LOG_VIRTIO_DEV, "vq->vq_ring_virt_mem: 0x%" PRIx64 "\n", (uint64_t)(uintptr_t)vq->vq_ring_virt_mem); virtio_init_vring(vq); return 0; } static void virtio_free_queues(struct virtio_dev *dev) { uint16_t nr_vq = dev->max_queues; struct virtqueue *vq; uint16_t i; if (dev->vqs == NULL) { return; } for (i = 0; i < nr_vq; i++) { vq = dev->vqs[i]; if (!vq) { continue; } virtio_dev_backend_ops(dev)->del_queue(dev, vq); free(vq); dev->vqs[i] = NULL; } free(dev->vqs); dev->vqs = NULL; } static int virtio_alloc_queues(struct virtio_dev *dev, uint16_t request_vq_num, uint16_t fixed_vq_num) { uint16_t nr_vq; uint16_t i; int ret; nr_vq = request_vq_num + fixed_vq_num; if (nr_vq == 0) { /* perfectly fine to have a device with no virtqueues. */ return 0; } assert(dev->vqs == NULL); dev->vqs = calloc(1, sizeof(struct virtqueue *) * nr_vq); if (!dev->vqs) { SPDK_ERRLOG("failed to allocate %"PRIu16" vqs\n", nr_vq); return -ENOMEM; } for (i = 0; i < nr_vq; i++) { ret = virtio_init_queue(dev, i); if (ret < 0) { virtio_free_queues(dev); return ret; } } dev->max_queues = nr_vq; dev->fixed_queues_num = fixed_vq_num; return 0; } /** * Negotiate virtio features. For virtio_user this will also set * dev->modern flag if VIRTIO_F_VERSION_1 flag is negotiated. */ static int virtio_negotiate_features(struct virtio_dev *dev, uint64_t req_features) { uint64_t host_features = virtio_dev_backend_ops(dev)->get_features(dev); int rc; SPDK_DEBUGLOG(SPDK_LOG_VIRTIO_DEV, "guest features = %" PRIx64 "\n", req_features); SPDK_DEBUGLOG(SPDK_LOG_VIRTIO_DEV, "device features = %" PRIx64 "\n", host_features); rc = virtio_dev_backend_ops(dev)->set_features(dev, req_features & host_features); if (rc != 0) { SPDK_ERRLOG("failed to negotiate device features.\n"); return rc; } SPDK_DEBUGLOG(SPDK_LOG_VIRTIO_DEV, "negotiated features = %" PRIx64 "\n", dev->negotiated_features); virtio_dev_set_status(dev, VIRTIO_CONFIG_S_FEATURES_OK); if (!(virtio_dev_get_status(dev) & VIRTIO_CONFIG_S_FEATURES_OK)) { SPDK_ERRLOG("failed to set FEATURES_OK status!\n"); /* either the device failed, or we offered some features that * depend on other, not offered features. */ return -EINVAL; } return 0; } int virtio_dev_construct(struct virtio_dev *vdev, const char *name, const struct virtio_dev_ops *ops, void *ctx) { int rc; vdev->name = strdup(name); if (vdev->name == NULL) { return -ENOMEM; } rc = pthread_mutex_init(&vdev->mutex, NULL); if (rc != 0) { free(vdev->name); return -rc; } vdev->backend_ops = ops; vdev->ctx = ctx; return 0; } int virtio_dev_reset(struct virtio_dev *dev, uint64_t req_features) { req_features |= (1ULL << VIRTIO_F_VERSION_1); virtio_dev_stop(dev); virtio_dev_set_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); if (!(virtio_dev_get_status(dev) & VIRTIO_CONFIG_S_ACKNOWLEDGE)) { SPDK_ERRLOG("Failed to set VIRTIO_CONFIG_S_ACKNOWLEDGE status.\n"); return -EIO; } virtio_dev_set_status(dev, VIRTIO_CONFIG_S_DRIVER); if (!(virtio_dev_get_status(dev) & VIRTIO_CONFIG_S_DRIVER)) { SPDK_ERRLOG("Failed to set VIRTIO_CONFIG_S_DRIVER status.\n"); return -EIO; } return virtio_negotiate_features(dev, req_features); } int virtio_dev_start(struct virtio_dev *vdev, uint16_t max_queues, uint16_t fixed_queue_num) { int ret; ret = virtio_alloc_queues(vdev, max_queues, fixed_queue_num); if (ret < 0) { return ret; } virtio_dev_set_status(vdev, VIRTIO_CONFIG_S_DRIVER_OK); if (!(virtio_dev_get_status(vdev) & VIRTIO_CONFIG_S_DRIVER_OK)) { SPDK_ERRLOG("Failed to set VIRTIO_CONFIG_S_DRIVER_OK status.\n"); return -1; } return 0; } void virtio_dev_destruct(struct virtio_dev *dev) { virtio_dev_backend_ops(dev)->destruct_dev(dev); pthread_mutex_destroy(&dev->mutex); free(dev->name); } static void vq_ring_free_chain(struct virtqueue *vq, uint16_t desc_idx) { struct vring_desc *dp, *dp_tail; struct vq_desc_extra *dxp; uint16_t desc_idx_last = desc_idx; dp = &vq->vq_ring.desc[desc_idx]; dxp = &vq->vq_descx[desc_idx]; vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt + dxp->ndescs); if ((dp->flags & VRING_DESC_F_INDIRECT) == 0) { while (dp->flags & VRING_DESC_F_NEXT) { desc_idx_last = dp->next; dp = &vq->vq_ring.desc[dp->next]; } } dxp->ndescs = 0; /* * We must append the existing free chain, if any, to the end of * newly freed chain. If the virtqueue was completely used, then * head would be VQ_RING_DESC_CHAIN_END (ASSERTed above). */ if (vq->vq_desc_tail_idx == VQ_RING_DESC_CHAIN_END) { vq->vq_desc_head_idx = desc_idx; } else { dp_tail = &vq->vq_ring.desc[vq->vq_desc_tail_idx]; dp_tail->next = desc_idx; } vq->vq_desc_tail_idx = desc_idx_last; dp->next = VQ_RING_DESC_CHAIN_END; } static uint16_t virtqueue_dequeue_burst_rx(struct virtqueue *vq, void **rx_pkts, uint32_t *len, uint16_t num) { struct vring_used_elem *uep; void *cookie; uint16_t used_idx, desc_idx; uint16_t i; /* Caller does the check */ for (i = 0; i < num ; i++) { used_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1)); uep = &vq->vq_ring.used->ring[used_idx]; desc_idx = (uint16_t) uep->id; len[i] = uep->len; cookie = vq->vq_descx[desc_idx].cookie; if (spdk_unlikely(cookie == NULL)) { SPDK_WARNLOG("vring descriptor with no mbuf cookie at %"PRIu16"\n", vq->vq_used_cons_idx); break; } rte_prefetch0(cookie); rx_pkts[i] = cookie; vq->vq_used_cons_idx++; vq_ring_free_chain(vq, desc_idx); vq->vq_descx[desc_idx].cookie = NULL; } return i; } static void finish_req(struct virtqueue *vq) { struct vring_desc *desc; uint16_t avail_idx; desc = &vq->vq_ring.desc[vq->req_end]; desc->flags &= ~VRING_DESC_F_NEXT; /* * Place the head of the descriptor chain into the next slot and make * it usable to the host. The chain is made available now rather than * deferring to virtqueue_req_flush() in the hopes that if the host is * currently running on another CPU, we can keep it processing the new * descriptor. */ avail_idx = (uint16_t)(vq->vq_avail_idx & (vq->vq_nentries - 1)); vq->vq_ring.avail->ring[avail_idx] = vq->req_start; vq->vq_avail_idx++; vq->req_end = VQ_RING_DESC_CHAIN_END; virtio_wmb(); vq->vq_ring.avail->idx = vq->vq_avail_idx; vq->reqs_finished++; } int virtqueue_req_start(struct virtqueue *vq, void *cookie, int iovcnt) { struct vq_desc_extra *dxp; if (iovcnt > vq->vq_free_cnt) { return iovcnt > vq->vq_nentries ? -EINVAL : -ENOMEM; } if (vq->req_end != VQ_RING_DESC_CHAIN_END) { finish_req(vq); } vq->req_start = vq->vq_desc_head_idx; dxp = &vq->vq_descx[vq->req_start]; dxp->cookie = cookie; dxp->ndescs = 0; return 0; } void virtqueue_req_flush(struct virtqueue *vq) { uint16_t reqs_finished; if (vq->req_end == VQ_RING_DESC_CHAIN_END) { /* no non-empty requests have been started */ return; } finish_req(vq); virtio_mb(); reqs_finished = vq->reqs_finished; vq->reqs_finished = 0; if (vq->vdev->negotiated_features & (1ULL << VIRTIO_RING_F_EVENT_IDX)) { /* Set used event idx to a value the device will never reach. * This effectively disables interrupts. */ vring_used_event(&vq->vq_ring) = vq->vq_used_cons_idx - vq->vq_nentries - 1; if (!vring_need_event(vring_avail_event(&vq->vq_ring), vq->vq_avail_idx, vq->vq_avail_idx - reqs_finished)) { return; } } else if (vq->vq_ring.used->flags & VRING_USED_F_NO_NOTIFY) { return; } virtio_dev_backend_ops(vq->vdev)->notify_queue(vq->vdev, vq); SPDK_DEBUGLOG(SPDK_LOG_VIRTIO_DEV, "Notified backend after xmit\n"); } void virtqueue_req_abort(struct virtqueue *vq) { struct vring_desc *desc; if (vq->req_start == VQ_RING_DESC_CHAIN_END) { /* no requests have been started */ return; } desc = &vq->vq_ring.desc[vq->req_end]; desc->flags &= ~VRING_DESC_F_NEXT; vq_ring_free_chain(vq, vq->req_start); vq->req_start = VQ_RING_DESC_CHAIN_END; } void virtqueue_req_add_iovs(struct virtqueue *vq, struct iovec *iovs, uint16_t iovcnt, enum spdk_virtio_desc_type desc_type) { struct vring_desc *desc; struct vq_desc_extra *dxp; uint16_t i, prev_head, new_head; assert(vq->req_start != VQ_RING_DESC_CHAIN_END); assert(iovcnt <= vq->vq_free_cnt); /* TODO use indirect descriptors if iovcnt is high enough * or the caller specifies SPDK_VIRTIO_DESC_F_INDIRECT */ prev_head = vq->req_end; new_head = vq->vq_desc_head_idx; for (i = 0; i < iovcnt; ++i) { desc = &vq->vq_ring.desc[new_head]; if (!vq->vdev->is_hw) { desc->addr = (uintptr_t)iovs[i].iov_base; } else { desc->addr = spdk_vtophys(iovs[i].iov_base, NULL); } desc->len = iovs[i].iov_len; /* always set NEXT flag. unset it on the last descriptor * in the request-ending function. */ desc->flags = desc_type | VRING_DESC_F_NEXT; prev_head = new_head; new_head = desc->next; } dxp = &vq->vq_descx[vq->req_start]; dxp->ndescs += iovcnt; vq->req_end = prev_head; vq->vq_desc_head_idx = new_head; vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - iovcnt); if (vq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END) { assert(vq->vq_free_cnt == 0); vq->vq_desc_tail_idx = VQ_RING_DESC_CHAIN_END; } } #define DESC_PER_CACHELINE (RTE_CACHE_LINE_SIZE / sizeof(struct vring_desc)) uint16_t virtio_recv_pkts(struct virtqueue *vq, void **io, uint32_t *len, uint16_t nb_pkts) { uint16_t nb_used, num; nb_used = vq->vq_ring.used->idx - vq->vq_used_cons_idx; virtio_rmb(); num = (uint16_t)(spdk_likely(nb_used <= nb_pkts) ? nb_used : nb_pkts); if (spdk_likely(num > DESC_PER_CACHELINE)) { num = num - ((vq->vq_used_cons_idx + num) % DESC_PER_CACHELINE); } return virtqueue_dequeue_burst_rx(vq, io, len, num); } int virtio_dev_acquire_queue(struct virtio_dev *vdev, uint16_t index) { struct virtqueue *vq = NULL; if (index >= vdev->max_queues) { SPDK_ERRLOG("requested vq index %"PRIu16" exceeds max queue count %"PRIu16".\n", index, vdev->max_queues); return -1; } pthread_mutex_lock(&vdev->mutex); vq = vdev->vqs[index]; if (vq == NULL || vq->owner_thread != NULL) { pthread_mutex_unlock(&vdev->mutex); return -1; } vq->owner_thread = spdk_get_thread(); pthread_mutex_unlock(&vdev->mutex); return 0; } int32_t virtio_dev_find_and_acquire_queue(struct virtio_dev *vdev, uint16_t start_index) { struct virtqueue *vq = NULL; uint16_t i; pthread_mutex_lock(&vdev->mutex); for (i = start_index; i < vdev->max_queues; ++i) { vq = vdev->vqs[i]; if (vq != NULL && vq->owner_thread == NULL) { break; } } if (vq == NULL || i == vdev->max_queues) { SPDK_ERRLOG("no more unused virtio queues with idx >= %"PRIu16".\n", start_index); pthread_mutex_unlock(&vdev->mutex); return -1; } vq->owner_thread = spdk_get_thread(); pthread_mutex_unlock(&vdev->mutex); return i; } struct spdk_thread * virtio_dev_queue_get_thread(struct virtio_dev *vdev, uint16_t index) { struct spdk_thread *thread = NULL; if (index >= vdev->max_queues) { SPDK_ERRLOG("given vq index %"PRIu16" exceeds max queue count %"PRIu16"\n", index, vdev->max_queues); abort(); /* This is not recoverable */ } pthread_mutex_lock(&vdev->mutex); thread = vdev->vqs[index]->owner_thread; pthread_mutex_unlock(&vdev->mutex); return thread; } bool virtio_dev_queue_is_acquired(struct virtio_dev *vdev, uint16_t index) { return virtio_dev_queue_get_thread(vdev, index) != NULL; } void virtio_dev_release_queue(struct virtio_dev *vdev, uint16_t index) { struct virtqueue *vq = NULL; if (index >= vdev->max_queues) { SPDK_ERRLOG("given vq index %"PRIu16" exceeds max queue count %"PRIu16".\n", index, vdev->max_queues); return; } pthread_mutex_lock(&vdev->mutex); vq = vdev->vqs[index]; if (vq == NULL) { SPDK_ERRLOG("virtqueue at index %"PRIu16" is not initialized.\n", index); pthread_mutex_unlock(&vdev->mutex); return; } assert(vq->owner_thread == spdk_get_thread()); vq->owner_thread = NULL; pthread_mutex_unlock(&vdev->mutex); } int virtio_dev_read_dev_config(struct virtio_dev *dev, size_t offset, void *dst, int length) { return virtio_dev_backend_ops(dev)->read_dev_cfg(dev, offset, dst, length); } int virtio_dev_write_dev_config(struct virtio_dev *dev, size_t offset, const void *src, int length) { return virtio_dev_backend_ops(dev)->write_dev_cfg(dev, offset, src, length); } void virtio_dev_stop(struct virtio_dev *dev) { virtio_dev_backend_ops(dev)->set_status(dev, VIRTIO_CONFIG_S_RESET); /* flush status write */ virtio_dev_backend_ops(dev)->get_status(dev); virtio_free_queues(dev); } void virtio_dev_set_status(struct virtio_dev *dev, uint8_t status) { if (status != VIRTIO_CONFIG_S_RESET) { status |= virtio_dev_backend_ops(dev)->get_status(dev); } virtio_dev_backend_ops(dev)->set_status(dev, status); } uint8_t virtio_dev_get_status(struct virtio_dev *dev) { return virtio_dev_backend_ops(dev)->get_status(dev); } const struct virtio_dev_ops * virtio_dev_backend_ops(struct virtio_dev *dev) { return dev->backend_ops; } void virtio_dev_dump_json_info(struct virtio_dev *hw, struct spdk_json_write_ctx *w) { spdk_json_write_named_object_begin(w, "virtio"); spdk_json_write_named_uint32(w, "vq_count", hw->max_queues); spdk_json_write_named_uint32(w, "vq_size", virtio_dev_backend_ops(hw)->get_queue_size(hw, 0)); virtio_dev_backend_ops(hw)->dump_json_info(hw, w); spdk_json_write_object_end(w); } SPDK_LOG_REGISTER_COMPONENT("virtio_dev", SPDK_LOG_VIRTIO_DEV)