diff options
Diffstat (limited to 'contrib/libvhost-user/libvhost-user.c')
| -rw-r--r-- | contrib/libvhost-user/libvhost-user.c | 1499 |
1 files changed, 1499 insertions, 0 deletions
diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c new file mode 100644 index 0000000000..af4faad60b --- /dev/null +++ b/contrib/libvhost-user/libvhost-user.c @@ -0,0 +1,1499 @@ +/* + * Vhost User library + * + * Copyright IBM, Corp. 2007 + * Copyright (c) 2016 Red Hat, Inc. + * + * Authors: + * Anthony Liguori <aliguori@us.ibm.com> + * Marc-André Lureau <mlureau@redhat.com> + * Victor Kaplansky <victork@redhat.com> + * + * This work is licensed under the terms of the GNU GPL, version 2 or + * later. See the COPYING file in the top-level directory. + */ + +#include <qemu/osdep.h> +#include <sys/eventfd.h> +#include <linux/vhost.h> + +#include "qemu/atomic.h" + +#include "libvhost-user.h" + +#define VHOST_USER_HDR_SIZE offsetof(VhostUserMsg, payload.u64) + +/* The version of the protocol we support */ +#define VHOST_USER_VERSION 1 +#define LIBVHOST_USER_DEBUG 0 + +#define DPRINT(...) \ + do { \ + if (LIBVHOST_USER_DEBUG) { \ + fprintf(stderr, __VA_ARGS__); \ + } \ + } while (0) + +static const char * +vu_request_to_string(int req) +{ +#define REQ(req) [req] = #req + static const char *vu_request_str[] = { + REQ(VHOST_USER_NONE), + REQ(VHOST_USER_GET_FEATURES), + REQ(VHOST_USER_SET_FEATURES), + REQ(VHOST_USER_NONE), + REQ(VHOST_USER_GET_FEATURES), + REQ(VHOST_USER_SET_FEATURES), + REQ(VHOST_USER_SET_OWNER), + REQ(VHOST_USER_RESET_OWNER), + REQ(VHOST_USER_SET_MEM_TABLE), + REQ(VHOST_USER_SET_LOG_BASE), + REQ(VHOST_USER_SET_LOG_FD), + REQ(VHOST_USER_SET_VRING_NUM), + REQ(VHOST_USER_SET_VRING_ADDR), + REQ(VHOST_USER_SET_VRING_BASE), + REQ(VHOST_USER_GET_VRING_BASE), + REQ(VHOST_USER_SET_VRING_KICK), + REQ(VHOST_USER_SET_VRING_CALL), + REQ(VHOST_USER_SET_VRING_ERR), + REQ(VHOST_USER_GET_PROTOCOL_FEATURES), + REQ(VHOST_USER_SET_PROTOCOL_FEATURES), + REQ(VHOST_USER_GET_QUEUE_NUM), + REQ(VHOST_USER_SET_VRING_ENABLE), + REQ(VHOST_USER_SEND_RARP), + REQ(VHOST_USER_INPUT_GET_CONFIG), + REQ(VHOST_USER_MAX), + }; +#undef REQ + + if (req < VHOST_USER_MAX) { + return vu_request_str[req]; + } else { + return "unknown"; + } +} + +static void +vu_panic(VuDev *dev, const char *msg, ...) +{ + char *buf = NULL; + va_list ap; + + va_start(ap, msg); + (void)vasprintf(&buf, msg, ap); + va_end(ap); + + dev->broken = true; + dev->panic(dev, buf); + free(buf); + + /* FIXME: find a way to call virtio_error? */ +} + +/* Translate guest physical address to our virtual address. */ +void * +vu_gpa_to_va(VuDev *dev, uint64_t guest_addr) +{ + int i; + + /* Find matching memory region. */ + for (i = 0; i < dev->nregions; i++) { + VuDevRegion *r = &dev->regions[i]; + + if ((guest_addr >= r->gpa) && (guest_addr < (r->gpa + r->size))) { + return (void *)(uintptr_t) + guest_addr - r->gpa + r->mmap_addr + r->mmap_offset; + } + } + + return NULL; +} + +/* Translate qemu virtual address to our virtual address. */ +static void * +qva_to_va(VuDev *dev, uint64_t qemu_addr) +{ + int i; + + /* Find matching memory region. */ + for (i = 0; i < dev->nregions; i++) { + VuDevRegion *r = &dev->regions[i]; + + if ((qemu_addr >= r->qva) && (qemu_addr < (r->qva + r->size))) { + return (void *)(uintptr_t) + qemu_addr - r->qva + r->mmap_addr + r->mmap_offset; + } + } + + return NULL; +} + +static void +vmsg_close_fds(VhostUserMsg *vmsg) +{ + int i; + + for (i = 0; i < vmsg->fd_num; i++) { + close(vmsg->fds[i]); + } +} + +static bool +vu_message_read(VuDev *dev, int conn_fd, VhostUserMsg *vmsg) +{ + char control[CMSG_SPACE(VHOST_MEMORY_MAX_NREGIONS * sizeof(int))] = { }; + struct iovec iov = { + .iov_base = (char *)vmsg, + .iov_len = VHOST_USER_HDR_SIZE, + }; + struct msghdr msg = { + .msg_iov = &iov, + .msg_iovlen = 1, + .msg_control = control, + .msg_controllen = sizeof(control), + }; + size_t fd_size; + struct cmsghdr *cmsg; + int rc; + + do { + rc = recvmsg(conn_fd, &msg, 0); + } while (rc < 0 && (errno == EINTR || errno == EAGAIN)); + + if (rc <= 0) { + vu_panic(dev, "Error while recvmsg: %s", strerror(errno)); + return false; + } + + vmsg->fd_num = 0; + for (cmsg = CMSG_FIRSTHDR(&msg); + cmsg != NULL; + cmsg = CMSG_NXTHDR(&msg, cmsg)) + { + if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) { + fd_size = cmsg->cmsg_len - CMSG_LEN(0); + vmsg->fd_num = fd_size / sizeof(int); + memcpy(vmsg->fds, CMSG_DATA(cmsg), fd_size); + break; + } + } + + if (vmsg->size > sizeof(vmsg->payload)) { + vu_panic(dev, + "Error: too big message request: %d, size: vmsg->size: %u, " + "while sizeof(vmsg->payload) = %zu\n", + vmsg->request, vmsg->size, sizeof(vmsg->payload)); + goto fail; + } + + if (vmsg->size) { + do { + rc = read(conn_fd, &vmsg->payload, vmsg->size); + } while (rc < 0 && (errno == EINTR || errno == EAGAIN)); + + if (rc <= 0) { + vu_panic(dev, "Error while reading: %s", strerror(errno)); + goto fail; + } + + assert(rc == vmsg->size); + } + + return true; + +fail: + vmsg_close_fds(vmsg); + + return false; +} + +static bool +vu_message_write(VuDev *dev, int conn_fd, VhostUserMsg *vmsg) +{ + int rc; + uint8_t *p = (uint8_t *)vmsg; + + /* Set the version in the flags when sending the reply */ + vmsg->flags &= ~VHOST_USER_VERSION_MASK; + vmsg->flags |= VHOST_USER_VERSION; + vmsg->flags |= VHOST_USER_REPLY_MASK; + + do { + rc = write(conn_fd, p, VHOST_USER_HDR_SIZE); + } while (rc < 0 && (errno == EINTR || errno == EAGAIN)); + + do { + if (vmsg->data) { + rc = write(conn_fd, vmsg->data, vmsg->size); + } else { + rc = write(conn_fd, p + VHOST_USER_HDR_SIZE, vmsg->size); + } + } while (rc < 0 && (errno == EINTR || errno == EAGAIN)); + + if (rc <= 0) { + vu_panic(dev, "Error while writing: %s", strerror(errno)); + return false; + } + + return true; +} + +/* Kick the log_call_fd if required. */ +static void +vu_log_kick(VuDev *dev) +{ + if (dev->log_call_fd != -1) { + DPRINT("Kicking the QEMU's log...\n"); + if (eventfd_write(dev->log_call_fd, 1) < 0) { + vu_panic(dev, "Error writing eventfd: %s", strerror(errno)); + } + } +} + +static void +vu_log_page(uint8_t *log_table, uint64_t page) +{ + DPRINT("Logged dirty guest page: %"PRId64"\n", page); + atomic_or(&log_table[page / 8], 1 << (page % 8)); +} + +static void +vu_log_write(VuDev *dev, uint64_t address, uint64_t length) +{ + uint64_t page; + + if (!(dev->features & (1ULL << VHOST_F_LOG_ALL)) || + !dev->log_table || !length) { + return; + } + + assert(dev->log_size > ((address + length - 1) / VHOST_LOG_PAGE / 8)); + + page = address / VHOST_LOG_PAGE; + while (page * VHOST_LOG_PAGE < address + length) { + vu_log_page(dev->log_table, page); + page += VHOST_LOG_PAGE; + } + + vu_log_kick(dev); +} + +static void +vu_kick_cb(VuDev *dev, int condition, void *data) +{ + int index = (intptr_t)data; + VuVirtq *vq = &dev->vq[index]; + int sock = vq->kick_fd; + eventfd_t kick_data; + ssize_t rc; + + rc = eventfd_read(sock, &kick_data); + if (rc == -1) { + vu_panic(dev, "kick eventfd_read(): %s", strerror(errno)); + dev->remove_watch(dev, dev->vq[index].kick_fd); + } else { + DPRINT("Got kick_data: %016"PRIx64" handler:%p idx:%d\n", + kick_data, vq->handler, index); + if (vq->handler) { + vq->handler(dev, index); + } + } +} + +static bool +vu_get_features_exec(VuDev *dev, VhostUserMsg *vmsg) +{ + vmsg->payload.u64 = + 1ULL << VHOST_F_LOG_ALL | + 1ULL << VHOST_USER_F_PROTOCOL_FEATURES; + + if (dev->iface->get_features) { + vmsg->payload.u64 |= dev->iface->get_features(dev); + } + + vmsg->size = sizeof(vmsg->payload.u64); + + DPRINT("Sending back to guest u64: 0x%016"PRIx64"\n", vmsg->payload.u64); + + return true; +} + +static void +vu_set_enable_all_rings(VuDev *dev, bool enabled) +{ + int i; + + for (i = 0; i < VHOST_MAX_NR_VIRTQUEUE; i++) { + dev->vq[i].enable = enabled; + } +} + +static bool +vu_set_features_exec(VuDev *dev, VhostUserMsg *vmsg) +{ + DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64); + + dev->features = vmsg->payload.u64; + + if (!(dev->features & VHOST_USER_F_PROTOCOL_FEATURES)) { + vu_set_enable_all_rings(dev, true); + } + + if (dev->iface->set_features) { + dev->iface->set_features(dev, dev->features); + } + + return false; +} + +static bool +vu_set_owner_exec(VuDev *dev, VhostUserMsg *vmsg) +{ + return false; +} + +static void +vu_close_log(VuDev *dev) +{ + if (dev->log_table) { + if (munmap(dev->log_table, dev->log_size) != 0) { + perror("close log munmap() error"); + } + + dev->log_table = NULL; + } + if (dev->log_call_fd != -1) { + close(dev->log_call_fd); + dev->log_call_fd = -1; + } +} + +static bool +vu_reset_device_exec(VuDev *dev, VhostUserMsg *vmsg) +{ + vu_set_enable_all_rings(dev, false); + + return false; +} + +static bool +vu_set_mem_table_exec(VuDev *dev, VhostUserMsg *vmsg) +{ + int i; + VhostUserMemory *memory = &vmsg->payload.memory; + dev->nregions = memory->nregions; + + DPRINT("Nregions: %d\n", memory->nregions); + for (i = 0; i < dev->nregions; i++) { + void *mmap_addr; + VhostUserMemoryRegion *msg_region = &memory->regions[i]; + VuDevRegion *dev_region = &dev->regions[i]; + + DPRINT("Region %d\n", i); + DPRINT(" guest_phys_addr: 0x%016"PRIx64"\n", + msg_region->guest_phys_addr); + DPRINT(" memory_size: 0x%016"PRIx64"\n", + msg_region->memory_size); + DPRINT(" userspace_addr 0x%016"PRIx64"\n", + msg_region->userspace_addr); + DPRINT(" mmap_offset 0x%016"PRIx64"\n", + msg_region->mmap_offset); + + dev_region->gpa = msg_region->guest_phys_addr; + dev_region->size = msg_region->memory_size; + dev_region->qva = msg_region->userspace_addr; + dev_region->mmap_offset = msg_region->mmap_offset; + + /* We don't use offset argument of mmap() since the + * mapped address has to be page aligned, and we use huge + * pages. */ + mmap_addr = mmap(0, dev_region->size + dev_region->mmap_offset, + PROT_READ | PROT_WRITE, MAP_SHARED, + vmsg->fds[i], 0); + + if (mmap_addr == MAP_FAILED) { + vu_panic(dev, "region mmap error: %s", strerror(errno)); + } else { + dev_region->mmap_addr = (uint64_t)(uintptr_t)mmap_addr; + DPRINT(" mmap_addr: 0x%016"PRIx64"\n", + dev_region->mmap_addr); + } + + close(vmsg->fds[i]); + } + + return false; +} + +static bool +vu_set_log_base_exec(VuDev *dev, VhostUserMsg *vmsg) +{ + int fd; + uint64_t log_mmap_size, log_mmap_offset; + void *rc; + + if (vmsg->fd_num != 1 || + vmsg->size != sizeof(vmsg->payload.log)) { + vu_panic(dev, "Invalid log_base message"); + return true; + } + + fd = vmsg->fds[0]; + log_mmap_offset = vmsg->payload.log.mmap_offset; + log_mmap_size = vmsg->payload.log.mmap_size; + DPRINT("Log mmap_offset: %"PRId64"\n", log_mmap_offset); + DPRINT("Log mmap_size: %"PRId64"\n", log_mmap_size); + + rc = mmap(0, log_mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, + log_mmap_offset); + if (rc == MAP_FAILED) { + perror("log mmap error"); + } + dev->log_table = rc; + dev->log_size = log_mmap_size; + + vmsg->size = sizeof(vmsg->payload.u64); + + return true; +} + +static bool +vu_set_log_fd_exec(VuDev *dev, VhostUserMsg *vmsg) +{ + if (vmsg->fd_num != 1) { + vu_panic(dev, "Invalid log_fd message"); + return false; + } + + if (dev->log_call_fd != -1) { + close(dev->log_call_fd); + } + dev->log_call_fd = vmsg->fds[0]; + DPRINT("Got log_call_fd: %d\n", vmsg->fds[0]); + + return false; +} + +static bool +vu_set_vring_num_exec(VuDev *dev, VhostUserMsg *vmsg) +{ + unsigned int index = vmsg->payload.state.index; + unsigned int num = vmsg->payload.state.num; + + DPRINT("State.index: %d\n", index); + DPRINT("State.num: %d\n", num); + dev->vq[index].vring.num = num; + + return false; +} + +static bool +vu_set_vring_addr_exec(VuDev *dev, VhostUserMsg *vmsg) +{ + struct vhost_vring_addr *vra = &vmsg->payload.addr; + unsigned int index = vra->index; + VuVirtq *vq = &dev->vq[index]; + + DPRINT("vhost_vring_addr:\n"); + DPRINT(" index: %d\n", vra->index); + DPRINT(" flags: %d\n", vra->flags); + DPRINT(" desc_user_addr: 0x%016llx\n", vra->desc_user_addr); + DPRINT(" used_user_addr: 0x%016llx\n", vra->used_user_addr); + DPRINT(" avail_user_addr: 0x%016llx\n", vra->avail_user_addr); + DPRINT(" log_guest_addr: 0x%016llx\n", vra->log_guest_addr); + + vq->vring.flags = vra->flags; + vq->vring.desc = qva_to_va(dev, vra->desc_user_addr); + vq->vring.used = qva_to_va(dev, vra->used_user_addr); + vq->vring.avail = qva_to_va(dev, vra->avail_user_addr); + vq->vring.log_guest_addr = vra->log_guest_addr; + + DPRINT("Setting virtq addresses:\n"); + DPRINT(" vring_desc at %p\n", vq->vring.desc); + DPRINT(" vring_used at %p\n", vq->vring.used); + DPRINT(" vring_avail at %p\n", vq->vring.avail); + + if (!(vq->vring.desc && vq->vring.used && vq->vring.avail)) { + vu_panic(dev, "Invalid vring_addr message"); + return false; + } + + vq->used_idx = vq->vring.used->idx; + + return false; +} + +static bool +vu_set_vring_base_exec(VuDev *dev, VhostUserMsg *vmsg) +{ + unsigned int index = vmsg->payload.state.index; + unsigned int num = vmsg->payload.state.num; + + DPRINT("State.index: %d\n", index); + DPRINT("State.num: %d\n", num); + dev->vq[index].shadow_avail_idx = dev->vq[index].last_avail_idx = num; + + return false; +} + +static bool +vu_get_vring_base_exec(VuDev *dev, VhostUserMsg *vmsg) +{ + unsigned int index = vmsg->payload.state.index; + + DPRINT("State.index: %d\n", index); + vmsg->payload.state.num = dev->vq[index].last_avail_idx; + vmsg->size = sizeof(vmsg->payload.state); + + dev->vq[index].started = false; + if (dev->iface->queue_set_started) { + dev->iface->queue_set_started(dev, index, false); + } + + if (dev->vq[index].call_fd != -1) { + close(dev->vq[index].call_fd); + dev->vq[index].call_fd = -1; + } + if (dev->vq[index].kick_fd != -1) { + dev->remove_watch(dev, dev->vq[index].kick_fd); + close(dev->vq[index].kick_fd); + dev->vq[index].kick_fd = -1; + } + + return true; +} + +static bool +vu_check_queue_msg_file(VuDev *dev, VhostUserMsg *vmsg) +{ + int index = vmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK; + + if (index >= VHOST_MAX_NR_VIRTQUEUE) { + vmsg_close_fds(vmsg); + vu_panic(dev, "Invalid queue index: %u", index); + return false; + } + + if (vmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK || + vmsg->fd_num != 1) { + vmsg_close_fds(vmsg); + vu_panic(dev, "Invalid fds in request: %d", vmsg->request); + return false; + } + + return true; +} + +static bool +vu_set_vring_kick_exec(VuDev *dev, VhostUserMsg *vmsg) +{ + int index = vmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK; + + DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64); + + if (!vu_check_queue_msg_file(dev, vmsg)) { + return false; + } + + if (dev->vq[index].kick_fd != -1) { + dev->remove_watch(dev, dev->vq[index].kick_fd); + close(dev->vq[index].kick_fd); + dev->vq[index].kick_fd = -1; + } + + if (!(vmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK)) { + dev->vq[index].kick_fd = vmsg->fds[0]; + DPRINT("Got kick_fd: %d for vq: %d\n", vmsg->fds[0], index); + } + + dev->vq[index].started = true; + if (dev->iface->queue_set_started) { + dev->iface->queue_set_started(dev, index, true); + } + + if (dev->vq[index].kick_fd != -1 && dev->vq[index].handler) { + dev->set_watch(dev, dev->vq[index].kick_fd, VU_WATCH_IN, + vu_kick_cb, (void *)(long)index); + + DPRINT("Waiting for kicks on fd: %d for vq: %d\n", + dev->vq[index].kick_fd, index); + } + + return false; +} + +void vu_set_queue_handler(VuDev *dev, VuVirtq *vq, + vu_queue_handler_cb handler) +{ + int qidx = vq - dev->vq; + + vq->handler = handler; + if (vq->kick_fd >= 0) { + if (handler) { + dev->set_watch(dev, vq->kick_fd, VU_WATCH_IN, + vu_kick_cb, (void *)(long)qidx); + } else { + dev->remove_watch(dev, vq->kick_fd); + } + } +} + +static bool +vu_set_vring_call_exec(VuDev *dev, VhostUserMsg *vmsg) +{ + int index = vmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK; + + DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64); + + if (!vu_check_queue_msg_file(dev, vmsg)) { + return false; + } + + if (dev->vq[index].call_fd != -1) { + close(dev->vq[index].call_fd); + dev->vq[index].call_fd = -1; + } + + if (!(vmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK)) { + dev->vq[index].call_fd = vmsg->fds[0]; + } + + DPRINT("Got call_fd: %d for vq: %d\n", vmsg->fds[0], index); + + return false; +} + +static bool +vu_set_vring_err_exec(VuDev *dev, VhostUserMsg *vmsg) +{ + int index = vmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK; + + DPRINT("u64: 0x%016"PRIx64"\n", vmsg->payload.u64); + + if (!vu_check_queue_msg_file(dev, vmsg)) { + return false; + } + + if (dev->vq[index].err_fd != -1) { + close(dev->vq[index].err_fd); + dev->vq[index].err_fd = -1; + } + + if (!(vmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK)) { + dev->vq[index].err_fd = vmsg->fds[0]; + } + + return false; +} + +static bool +vu_get_protocol_features_exec(VuDev *dev, VhostUserMsg *vmsg) +{ + uint64_t features = 1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD; + + if (dev->iface->get_protocol_features) { + features |= dev->iface->get_protocol_features(dev); + } + + vmsg->payload.u64 = features; + vmsg->size = sizeof(vmsg->payload.u64); + + return true; +} + +static bool +vu_set_protocol_features_exec(VuDev *dev, VhostUserMsg *vmsg) +{ + uint64_t features = vmsg->payload.u64; + + DPRINT("u64: 0x%016"PRIx64"\n", features); + + dev->protocol_features = vmsg->payload.u64; + + if (dev->iface->set_protocol_features) { + dev->iface->set_protocol_features(dev, features); + } + + return false; +} + +static bool +vu_get_queue_num_exec(VuDev *dev, VhostUserMsg *vmsg) +{ + DPRINT("Function %s() not implemented yet.\n", __func__); + return false; +} + +static bool +vu_set_vring_enable_exec(VuDev *dev, VhostUserMsg *vmsg) +{ + unsigned int index = vmsg->payload.state.index; + unsigned int enable = vmsg->payload.state.num; + + DPRINT("State.index: %d\n", index); + DPRINT("State.enable: %d\n", enable); + + if (index >= VHOST_MAX_NR_VIRTQUEUE) { + vu_panic(dev, "Invalid vring_enable index: %u", index); + return false; + } + + dev->vq[index].enable = enable; + return false; +} + +static bool +vu_process_message(VuDev *dev, VhostUserMsg *vmsg) +{ + int do_reply = 0; + + /* Print out generic part of the request. */ + DPRINT("================ Vhost user message ================\n"); + DPRINT("Request: %s (%d)\n", vu_request_to_string(vmsg->request), + vmsg->request); + DPRINT("Flags: 0x%x\n", vmsg->flags); + DPRINT("Size: %d\n", vmsg->size); + + if (vmsg->fd_num) { + int i; + DPRINT("Fds:"); + for (i = 0; i < vmsg->fd_num; i++) { + DPRINT(" %d", vmsg->fds[i]); + } + DPRINT("\n"); + } + + if (dev->iface->process_msg && + dev->iface->process_msg(dev, vmsg, &do_reply)) { + return do_reply; + } + + switch (vmsg->request) { + case VHOST_USER_GET_FEATURES: + return vu_get_features_exec(dev, vmsg); + case VHOST_USER_SET_FEATURES: + return vu_set_features_exec(dev, vmsg); + case VHOST_USER_GET_PROTOCOL_FEATURES: + return vu_get_protocol_features_exec(dev, vmsg); + case VHOST_USER_SET_PROTOCOL_FEATURES: + return vu_set_protocol_features_exec(dev, vmsg); + case VHOST_USER_SET_OWNER: + return vu_set_owner_exec(dev, vmsg); + case VHOST_USER_RESET_OWNER: + return vu_reset_device_exec(dev, vmsg); + case VHOST_USER_SET_MEM_TABLE: + return vu_set_mem_table_exec(dev, vmsg); + case VHOST_USER_SET_LOG_BASE: + return vu_set_log_base_exec(dev, vmsg); + case VHOST_USER_SET_LOG_FD: + return vu_set_log_fd_exec(dev, vmsg); + case VHOST_USER_SET_VRING_NUM: + return vu_set_vring_num_exec(dev, vmsg); + case VHOST_USER_SET_VRING_ADDR: + return vu_set_vring_addr_exec(dev, vmsg); + case VHOST_USER_SET_VRING_BASE: + return vu_set_vring_base_exec(dev, vmsg); + case VHOST_USER_GET_VRING_BASE: + return vu_get_vring_base_exec(dev, vmsg); + case VHOST_USER_SET_VRING_KICK: + return vu_set_vring_kick_exec(dev, vmsg); + case VHOST_USER_SET_VRING_CALL: + return vu_set_vring_call_exec(dev, vmsg); + case VHOST_USER_SET_VRING_ERR: + return vu_set_vring_err_exec(dev, vmsg); + case VHOST_USER_GET_QUEUE_NUM: + return vu_get_queue_num_exec(dev, vmsg); + case VHOST_USER_SET_VRING_ENABLE: + return vu_set_vring_enable_exec(dev, vmsg); + default: + vmsg_close_fds(vmsg); + vu_panic(dev, "Unhandled request: %d", vmsg->request); + } + + return false; +} + +bool +vu_dispatch(VuDev *dev) +{ + VhostUserMsg vmsg = { 0, }; + int reply_requested; + bool success = false; + + if (!vu_message_read(dev, dev->sock, &vmsg)) { + goto end; + } + + reply_requested = vu_process_message(dev, &vmsg); + if (!reply_requested) { + success = true; + goto end; + } + + if (!vu_message_write(dev, dev->sock, &vmsg)) { + goto end; + } + + success = true; + +end: + g_free(vmsg.data); + return success; +} + +void +vu_deinit(VuDev *dev) +{ + int i; + + for (i = 0; i < dev->nregions; i++) { + VuDevRegion *r = &dev->regions[i]; + void *m = (void *) (uintptr_t) r->mmap_addr; + if (m != MAP_FAILED) { + munmap(m, r->size + r->mmap_offset); + } + } + dev->nregions = 0; + + for (i = 0; i < VHOST_MAX_NR_VIRTQUEUE; i++) { + VuVirtq *vq = &dev->vq[i]; + + if (vq->call_fd != -1) { + close(vq->call_fd); + vq->call_fd = -1; + } + + if (vq->kick_fd != -1) { + close(vq->kick_fd); + vq->kick_fd = -1; + } + + if (vq->err_fd != -1) { + close(vq->err_fd); + vq->err_fd = -1; + } + } + + + vu_close_log(dev); + + if (dev->sock != -1) { + close(dev->sock); + } +} + +void +vu_init(VuDev *dev, + int socket, + vu_panic_cb panic, + vu_set_watch_cb set_watch, + vu_remove_watch_cb remove_watch, + const VuDevIface *iface) +{ + int i; + + assert(socket >= 0); + assert(set_watch); + assert(remove_watch); + assert(iface); + assert(panic); + + memset(dev, 0, sizeof(*dev)); + + dev->sock = socket; + dev->panic = panic; + dev->set_watch = set_watch; + dev->remove_watch = remove_watch; + dev->iface = iface; + dev->log_call_fd = -1; + for (i = 0; i < VHOST_MAX_NR_VIRTQUEUE; i++) { + dev->vq[i] = (VuVirtq) { + .call_fd = -1, .kick_fd = -1, .err_fd = -1, + .notification = true, + }; + } +} + +VuVirtq * +vu_get_queue(VuDev *dev, int qidx) +{ + assert(qidx < VHOST_MAX_NR_VIRTQUEUE); + return &dev->vq[qidx]; +} + +bool +vu_queue_enabled(VuDev *dev, VuVirtq *vq) +{ + return vq->enable; +} + +static inline uint16_t +vring_avail_flags(VuVirtq *vq) +{ + return vq->vring.avail->flags; +} + +static inline uint16_t +vring_avail_idx(VuVirtq *vq) +{ + vq->shadow_avail_idx = vq->vring.avail->idx; + + return vq->shadow_avail_idx; +} + +static inline uint16_t +vring_avail_ring(VuVirtq *vq, int i) +{ + return vq->vring.avail->ring[i]; +} + +static inline uint16_t +vring_get_used_event(VuVirtq *vq) +{ + return vring_avail_ring(vq, vq->vring.num); +} + +static int +virtqueue_num_heads(VuDev *dev, VuVirtq *vq, unsigned int idx) +{ + uint16_t num_heads = vring_avail_idx(vq) - idx; + + /* Check it isn't doing very strange things with descriptor numbers. */ + if (num_heads > vq->vring.num) { + vu_panic(dev, "Guest moved used index from %u to %u", + idx, vq->shadow_avail_idx); + return -1; + } + if (num_heads) { + /* On success, callers read a descriptor at vq->last_avail_idx. + * Make sure descriptor read does not bypass avail index read. */ + smp_rmb(); + } + + return num_heads; +} + +static bool +virtqueue_get_head(VuDev *dev, VuVirtq *vq, + unsigned int idx, unsigned int *head) +{ + /* Grab the next descriptor number they're advertising, and increment + * the index we've seen. */ + *head = vring_avail_ring(vq, idx % vq->vring.num); + + /* If their number is silly, that's a fatal mistake. */ + if (*head >= vq->vring.num) { + vu_panic(dev, "Guest says index %u is available", head); + return false; + } + + return true; +} + +enum { + VIRTQUEUE_READ_DESC_ERROR = -1, + VIRTQUEUE_READ_DESC_DONE = 0, /* end of chain */ + VIRTQUEUE_READ_DESC_MORE = 1, /* more buffers in chain */ +}; + +static int +virtqueue_read_next_desc(VuDev *dev, struct vring_desc *desc, + int i, unsigned int max, unsigned int *next) +{ + /* If this descriptor says it doesn't chain, we're done. */ + if (!(desc[i].flags & VRING_DESC_F_NEXT)) { + return VIRTQUEUE_READ_DESC_DONE; + } + + /* Check they're not leading us off end of descriptors. */ + *next = desc[i].next; + /* Make sure compiler knows to grab that: we don't want it changing! */ + smp_wmb(); + + if (*next >= max) { + vu_panic(dev, "Desc next is %u", next); + return VIRTQUEUE_READ_DESC_ERROR; + } + + return VIRTQUEUE_READ_DESC_MORE; +} + +void +vu_queue_get_avail_bytes(VuDev *dev, VuVirtq *vq, unsigned int *in_bytes, + unsigned int *out_bytes, + unsigned max_in_bytes, unsigned max_out_bytes) +{ + unsigned int idx; + unsigned int total_bufs, in_total, out_total; + int rc; + + idx = vq->last_avail_idx; + + total_bufs = in_total = out_total = 0; + while ((rc = virtqueue_num_heads(dev, vq, idx)) > 0) { + unsigned int max, num_bufs, indirect = 0; + struct vring_desc *desc; + unsigned int i; + + max = vq->vring.num; + num_bufs = total_bufs; + if (!virtqueue_get_head(dev, vq, idx++, &i)) { + goto err; + } + desc = vq->vring.desc; + + if (desc[i].flags & VRING_DESC_F_INDIRECT) { + if (desc[i].len % sizeof(struct vring_desc)) { + vu_panic(dev, "Invalid size for indirect buffer table"); + goto err; + } + + /* If we've got too many, that implies a descriptor loop. */ + if (num_bufs >= max) { + vu_panic(dev, "Looped descriptor"); + goto err; + } + + /* loop over the indirect descriptor table */ + indirect = 1; + max = desc[i].len / sizeof(struct vring_desc); + desc = vu_gpa_to_va(dev, desc[i].addr); + num_bufs = i = 0; + } + + do { + /* If we've got too many, that implies a descriptor loop. */ + if (++num_bufs > max) { + vu_panic(dev, "Looped descriptor"); + goto err; + } + + if (desc[i].flags & VRING_DESC_F_WRITE) { + in_total += desc[i].len; + } else { + out_total += desc[i].len; + } + if (in_total >= max_in_bytes && out_total >= max_out_bytes) { + goto done; + } + rc = virtqueue_read_next_desc(dev, desc, i, max, &i); + } while (rc == VIRTQUEUE_READ_DESC_MORE); + + if (rc == VIRTQUEUE_READ_DESC_ERROR) { + goto err; + } + + if (!indirect) { + total_bufs = num_bufs; + } else { + total_bufs++; + } + } + if (rc < 0) { + goto err; + } +done: + if (in_bytes) { + *in_bytes = in_total; + } + if (out_bytes) { + *out_bytes = out_total; + } + return; + +err: + in_total = out_total = 0; + goto done; +} + +bool +vu_queue_avail_bytes(VuDev *dev, VuVirtq *vq, unsigned int in_bytes, + unsigned int out_bytes) +{ + unsigned int in_total, out_total; + + vu_queue_get_avail_bytes(dev, vq, &in_total, &out_total, + in_bytes, out_bytes); + + return in_bytes <= in_total && out_bytes <= out_total; +} + +/* Fetch avail_idx from VQ memory only when we really need to know if + * guest has added some buffers. */ +int +vu_queue_empty(VuDev *dev, VuVirtq *vq) +{ + if (vq->shadow_avail_idx != vq->last_avail_idx) { + return 0; + } + + return vring_avail_idx(vq) == vq->last_avail_idx; +} + +static inline +bool has_feature(uint64_t features, unsigned int fbit) +{ + assert(fbit < 64); + return !!(features & (1ULL << fbit)); +} + +static inline +bool vu_has_feature(VuDev *dev, + unsigned int fbit) +{ + return has_feature(dev->features, fbit); +} + +static bool +vring_notify(VuDev *dev, VuVirtq *vq) +{ + uint16_t old, new; + bool v; + + /* We need to expose used array entries before checking used event. */ + smp_mb(); + + /* Always notify when queue is empty (when feature acknowledge) */ + if (vu_has_feature(dev, VIRTIO_F_NOTIFY_ON_EMPTY) && + !vq->inuse && vu_queue_empty(dev, vq)) { + return true; + } + + if (!vu_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) { + return !(vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT); + } + + v = vq->signalled_used_valid; + vq->signalled_used_valid = true; + old = vq->signalled_used; + new = vq->signalled_used = vq->used_idx; + return !v || vring_need_event(vring_get_used_event(vq), new, old); +} + +void +vu_queue_notify(VuDev *dev, VuVirtq *vq) +{ + if (unlikely(dev->broken)) { + return; + } + + if (!vring_notify(dev, vq)) { + DPRINT("skipped notify...\n"); + return; + } + + if (eventfd_write(vq->call_fd, 1) < 0) { + vu_panic(dev, "Error writing eventfd: %s", strerror(errno)); + } +} + +static inline void +vring_used_flags_set_bit(VuVirtq *vq, int mask) +{ + uint16_t *flags; + + flags = (uint16_t *)((char*)vq->vring.used + + offsetof(struct vring_used, flags)); + *flags |= mask; +} + +static inline void +vring_used_flags_unset_bit(VuVirtq *vq, int mask) +{ + uint16_t *flags; + + flags = (uint16_t *)((char*)vq->vring.used + + offsetof(struct vring_used, flags)); + *flags &= ~mask; +} + +static inline void +vring_set_avail_event(VuVirtq *vq, uint16_t val) +{ + if (!vq->notification) { + return; + } + + *((uint16_t *) &vq->vring.used->ring[vq->vring.num]) = val; +} + +void +vu_queue_set_notification(VuDev *dev, VuVirtq *vq, int enable) +{ + vq->notification = enable; + if (vu_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) { + vring_set_avail_event(vq, vring_avail_idx(vq)); + } else if (enable) { + vring_used_flags_unset_bit(vq, VRING_USED_F_NO_NOTIFY); + } else { + vring_used_flags_set_bit(vq, VRING_USED_F_NO_NOTIFY); + } + if (enable) { + /* Expose avail event/used flags before caller checks the avail idx. */ + smp_mb(); + } +} + +static void +virtqueue_map_desc(VuDev *dev, + unsigned int *p_num_sg, struct iovec *iov, + unsigned int max_num_sg, bool is_write, + uint64_t pa, size_t sz) +{ + unsigned num_sg = *p_num_sg; + + assert(num_sg <= max_num_sg); + + if (!sz) { + vu_panic(dev, "virtio: zero sized buffers are not allowed"); + return; + } + + iov[num_sg].iov_base = vu_gpa_to_va(dev, pa); + iov[num_sg].iov_len = sz; + num_sg++; + + *p_num_sg = num_sg; +} + +/* Round number down to multiple */ +#define ALIGN_DOWN(n, m) ((n) / (m) * (m)) + +/* Round number up to multiple */ +#define ALIGN_UP(n, m) ALIGN_DOWN((n) + (m) - 1, (m)) + +static void * +virtqueue_alloc_element(size_t sz, + unsigned out_num, unsigned in_num) +{ + VuVirtqElement *elem; + size_t in_sg_ofs = ALIGN_UP(sz, __alignof__(elem->in_sg[0])); + size_t out_sg_ofs = in_sg_ofs + in_num * sizeof(elem->in_sg[0]); + size_t out_sg_end = out_sg_ofs + out_num * sizeof(elem->out_sg[0]); + + assert(sz >= sizeof(VuVirtqElement)); + elem = malloc(out_sg_end); + elem->out_num = out_num; + elem->in_num = in_num; + elem->in_sg = (void *)elem + in_sg_ofs; + elem->out_sg = (void *)elem + out_sg_ofs; + return elem; +} + +void * +vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz) +{ + unsigned int i, head, max; + VuVirtqElement *elem; + unsigned out_num, in_num; + struct iovec iov[VIRTQUEUE_MAX_SIZE]; + struct vring_desc *desc; + int rc; + + if (unlikely(dev->broken)) { + return NULL; + } + + if (vu_queue_empty(dev, vq)) { + return NULL; + } + /* Needed after virtio_queue_empty(), see comment in + * virtqueue_num_heads(). */ + smp_rmb(); + + /* When we start there are none of either input nor output. */ + out_num = in_num = 0; + + max = vq->vring.num; + if (vq->inuse >= vq->vring.num) { + vu_panic(dev, "Virtqueue size exceeded"); + return NULL; + } + + if (!virtqueue_get_head(dev, vq, vq->last_avail_idx++, &head)) { + return NULL; + } + + if (vu_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) { + vring_set_avail_event(vq, vq->last_avail_idx); + } + + i = head; + desc = vq->vring.desc; + if (desc[i].flags & VRING_DESC_F_INDIRECT) { + if (desc[i].len % sizeof(struct vring_desc)) { + vu_panic(dev, "Invalid size for indirect buffer table"); + } + + /* loop over the indirect descriptor table */ + max = desc[i].len / sizeof(struct vring_desc); + desc = vu_gpa_to_va(dev, desc[i].addr); + i = 0; + } + + /* Collect all the descriptors */ + do { + if (desc[i].flags & VRING_DESC_F_WRITE) { + virtqueue_map_desc(dev, &in_num, iov + out_num, + VIRTQUEUE_MAX_SIZE - out_num, true, + desc[i].addr, desc[i].len); + } else { + if (in_num) { + vu_panic(dev, "Incorrect order for descriptors"); + return NULL; + } + virtqueue_map_desc(dev, &out_num, iov, + VIRTQUEUE_MAX_SIZE, false, + desc[i].addr, desc[i].len); + } + + /* If we've got too many, that implies a descriptor loop. */ + if ((in_num + out_num) > max) { + vu_panic(dev, "Looped descriptor"); + } + rc = virtqueue_read_next_desc(dev, desc, i, max, &i); + } while (rc == VIRTQUEUE_READ_DESC_MORE); + + if (rc == VIRTQUEUE_READ_DESC_ERROR) { + return NULL; + } + + /* Now copy what we have collected and mapped */ + elem = virtqueue_alloc_element(sz, out_num, in_num); + elem->index = head; + for (i = 0; i < out_num; i++) { + elem->out_sg[i] = iov[i]; + } + for (i = 0; i < in_num; i++) { + elem->in_sg[i] = iov[out_num + i]; + } + + vq->inuse++; + + return elem; +} + +bool +vu_queue_rewind(VuDev *dev, VuVirtq *vq, unsigned int num) +{ + if (num > vq->inuse) { + return false; + } + vq->last_avail_idx -= num; + vq->inuse -= num; + return true; +} + +static inline +void vring_used_write(VuDev *dev, VuVirtq *vq, + struct vring_used_elem *uelem, int i) +{ + struct vring_used *used = vq->vring.used; + + used->ring[i] = *uelem; + vu_log_write(dev, vq->vring.log_guest_addr + + offsetof(struct vring_used, ring[i]), + sizeof(used->ring[i])); +} + + +static void +vu_log_queue_fill(VuDev *dev, VuVirtq *vq, + const VuVirtqElement *elem, + unsigned int len) +{ + struct vring_desc *desc = vq->vring.desc; + unsigned int i, max, min; + unsigned num_bufs = 0; + + max = vq->vring.num; + i = elem->index; + + if (desc[i].flags & VRING_DESC_F_INDIRECT) { + if (desc[i].len % sizeof(struct vring_desc)) { + vu_panic(dev, "Invalid size for indirect buffer table"); + } + + /* loop over the indirect descriptor table */ + max = desc[i].len / sizeof(struct vring_desc); + desc = vu_gpa_to_va(dev, desc[i].addr); + i = 0; + } + + do { + if (++num_bufs > max) { + vu_panic(dev, "Looped descriptor"); + return; + } + + if (desc[i].flags & VRING_DESC_F_WRITE) { + min = MIN(desc[i].len, len); + vu_log_write(dev, desc[i].addr, min); + len -= min; + } + + } while (len > 0 && + (virtqueue_read_next_desc(dev, desc, i, max, &i) + == VIRTQUEUE_READ_DESC_MORE)); +} + +void +vu_queue_fill(VuDev *dev, VuVirtq *vq, + const VuVirtqElement *elem, + unsigned int len, unsigned int idx) +{ + struct vring_used_elem uelem; + + if (unlikely(dev->broken)) { + return; + } + + vu_log_queue_fill(dev, vq, elem, len); + + idx = (idx + vq->used_idx) % vq->vring.num; + + uelem.id = elem->index; + uelem.len = len; + vring_used_write(dev, vq, &uelem, idx); +} + +static inline +void vring_used_idx_set(VuDev *dev, VuVirtq *vq, uint16_t val) +{ + vq->vring.used->idx = val; + vu_log_write(dev, + vq->vring.log_guest_addr + offsetof(struct vring_used, idx), + sizeof(vq->vring.used->idx)); + + vq->used_idx = val; +} + +void +vu_queue_flush(VuDev *dev, VuVirtq *vq, unsigned int count) +{ + uint16_t old, new; + + if (unlikely(dev->broken)) { + return; + } + + /* Make sure buffer is written before we update index. */ + smp_wmb(); + + old = vq->used_idx; + new = old + count; + vring_used_idx_set(dev, vq, new); + vq->inuse -= count; + if (unlikely((int16_t)(new - vq->signalled_used) < (uint16_t)(new - old))) { + vq->signalled_used_valid = false; + } +} + +void +vu_queue_push(VuDev *dev, VuVirtq *vq, + const VuVirtqElement *elem, unsigned int len) +{ + vu_queue_fill(dev, vq, elem, len, 0); + vu_queue_flush(dev, vq, 1); +} |