diff options
Diffstat (limited to 'hw/vhost.c')
| -rw-r--r-- | hw/vhost.c | 711 |
1 files changed, 711 insertions, 0 deletions
diff --git a/hw/vhost.c b/hw/vhost.c new file mode 100644 index 0000000..1e5bc69 --- /dev/null +++ b/hw/vhost.c @@ -0,0 +1,711 @@ +/* + * vhost support + * + * Copyright Red Hat, Inc. 2010 + * + * Authors: + * Michael S. Tsirkin <mst@redhat.com> + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + */ + +#include <linux/vhost.h> +#include <sys/ioctl.h> +#include <sys/eventfd.h> +#include "vhost.h" +#include "hw/hw.h" +/* For range_get_last */ +#include "pci.h" + +static void vhost_dev_sync_region(struct vhost_dev *dev, + uint64_t mfirst, uint64_t mlast, + uint64_t rfirst, uint64_t rlast) +{ + uint64_t start = MAX(mfirst, rfirst); + uint64_t end = MIN(mlast, rlast); + vhost_log_chunk_t *from = dev->log + start / VHOST_LOG_CHUNK; + vhost_log_chunk_t *to = dev->log + end / VHOST_LOG_CHUNK + 1; + uint64_t addr = (start / VHOST_LOG_CHUNK) * VHOST_LOG_CHUNK; + + assert(end / VHOST_LOG_CHUNK < dev->log_size); + assert(start / VHOST_LOG_CHUNK < dev->log_size); + if (end < start) { + return; + } + for (;from < to; ++from) { + vhost_log_chunk_t log; + int bit; + /* We first check with non-atomic: much cheaper, + * and we expect non-dirty to be the common case. */ + if (!*from) { + continue; + } + /* Data must be read atomically. We don't really + * need the barrier semantics of __sync + * builtins, but it's easier to use them than + * roll our own. */ + log = __sync_fetch_and_and(from, 0); + while ((bit = sizeof(log) > sizeof(int) ? + ffsll(log) : ffs(log))) { + bit -= 1; + cpu_physical_memory_set_dirty(addr + bit * VHOST_LOG_PAGE); + log &= ~(0x1ull << bit); + } + addr += VHOST_LOG_CHUNK; + } +} + +static int vhost_client_sync_dirty_bitmap(CPUPhysMemoryClient *client, + target_phys_addr_t start_addr, + target_phys_addr_t end_addr) +{ + struct vhost_dev *dev = container_of(client, struct vhost_dev, client); + int i; + if (!dev->log_enabled || !dev->started) { + return 0; + } + for (i = 0; i < dev->mem->nregions; ++i) { + struct vhost_memory_region *reg = dev->mem->regions + i; + vhost_dev_sync_region(dev, start_addr, end_addr, + reg->guest_phys_addr, + range_get_last(reg->guest_phys_addr, + reg->memory_size)); + } + for (i = 0; i < dev->nvqs; ++i) { + struct vhost_virtqueue *vq = dev->vqs + i; + vhost_dev_sync_region(dev, start_addr, end_addr, vq->used_phys, + range_get_last(vq->used_phys, vq->used_size)); + } + return 0; +} + +/* Assign/unassign. Keep an unsorted array of non-overlapping + * memory regions in dev->mem. */ +static void vhost_dev_unassign_memory(struct vhost_dev *dev, + uint64_t start_addr, + uint64_t size) +{ + int from, to, n = dev->mem->nregions; + /* Track overlapping/split regions for sanity checking. */ + int overlap_start = 0, overlap_end = 0, overlap_middle = 0, split = 0; + + for (from = 0, to = 0; from < n; ++from, ++to) { + struct vhost_memory_region *reg = dev->mem->regions + to; + uint64_t reglast; + uint64_t memlast; + uint64_t change; + + /* clone old region */ + if (to != from) { + memcpy(reg, dev->mem->regions + from, sizeof *reg); + } + + /* No overlap is simple */ + if (!ranges_overlap(reg->guest_phys_addr, reg->memory_size, + start_addr, size)) { + continue; + } + + /* Split only happens if supplied region + * is in the middle of an existing one. Thus it can not + * overlap with any other existing region. */ + assert(!split); + + reglast = range_get_last(reg->guest_phys_addr, reg->memory_size); + memlast = range_get_last(start_addr, size); + + /* Remove whole region */ + if (start_addr <= reg->guest_phys_addr && memlast >= reglast) { + --dev->mem->nregions; + --to; + assert(to >= 0); + ++overlap_middle; + continue; + } + + /* Shrink region */ + if (memlast >= reglast) { + reg->memory_size = start_addr - reg->guest_phys_addr; + assert(reg->memory_size); + assert(!overlap_end); + ++overlap_end; + continue; + } + + /* Shift region */ + if (start_addr <= reg->guest_phys_addr) { + change = memlast + 1 - reg->guest_phys_addr; + reg->memory_size -= change; + reg->guest_phys_addr += change; + reg->userspace_addr += change; + assert(reg->memory_size); + assert(!overlap_start); + ++overlap_start; + continue; + } + + /* This only happens if supplied region + * is in the middle of an existing one. Thus it can not + * overlap with any other existing region. */ + assert(!overlap_start); + assert(!overlap_end); + assert(!overlap_middle); + /* Split region: shrink first part, shift second part. */ + memcpy(dev->mem->regions + n, reg, sizeof *reg); + reg->memory_size = start_addr - reg->guest_phys_addr; + assert(reg->memory_size); + change = memlast + 1 - reg->guest_phys_addr; + reg = dev->mem->regions + n; + reg->memory_size -= change; + assert(reg->memory_size); + reg->guest_phys_addr += change; + reg->userspace_addr += change; + /* Never add more than 1 region */ + assert(dev->mem->nregions == n); + ++dev->mem->nregions; + ++split; + } +} + +/* Called after unassign, so no regions overlap the given range. */ +static void vhost_dev_assign_memory(struct vhost_dev *dev, + uint64_t start_addr, + uint64_t size, + uint64_t uaddr) +{ + int from, to; + struct vhost_memory_region *merged = NULL; + for (from = 0, to = 0; from < dev->mem->nregions; ++from, ++to) { + struct vhost_memory_region *reg = dev->mem->regions + to; + uint64_t prlast, urlast; + uint64_t pmlast, umlast; + uint64_t s, e, u; + + /* clone old region */ + if (to != from) { + memcpy(reg, dev->mem->regions + from, sizeof *reg); + } + prlast = range_get_last(reg->guest_phys_addr, reg->memory_size); + pmlast = range_get_last(start_addr, size); + urlast = range_get_last(reg->userspace_addr, reg->memory_size); + umlast = range_get_last(uaddr, size); + + /* check for overlapping regions: should never happen. */ + assert(prlast < start_addr || pmlast < reg->guest_phys_addr); + /* Not an adjacent or overlapping region - do not merge. */ + if ((prlast + 1 != start_addr || urlast + 1 != uaddr) && + (pmlast + 1 != reg->guest_phys_addr || + umlast + 1 != reg->userspace_addr)) { + continue; + } + + if (merged) { + --to; + assert(to >= 0); + } else { + merged = reg; + } + u = MIN(uaddr, reg->userspace_addr); + s = MIN(start_addr, reg->guest_phys_addr); + e = MAX(pmlast, prlast); + uaddr = merged->userspace_addr = u; + start_addr = merged->guest_phys_addr = s; + size = merged->memory_size = e - s + 1; + assert(merged->memory_size); + } + + if (!merged) { + struct vhost_memory_region *reg = dev->mem->regions + to; + memset(reg, 0, sizeof *reg); + reg->memory_size = size; + assert(reg->memory_size); + reg->guest_phys_addr = start_addr; + reg->userspace_addr = uaddr; + ++to; + } + assert(to <= dev->mem->nregions + 1); + dev->mem->nregions = to; +} + +static uint64_t vhost_get_log_size(struct vhost_dev *dev) +{ + uint64_t log_size = 0; + int i; + for (i = 0; i < dev->mem->nregions; ++i) { + struct vhost_memory_region *reg = dev->mem->regions + i; + uint64_t last = range_get_last(reg->guest_phys_addr, + reg->memory_size); + log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1); + } + for (i = 0; i < dev->nvqs; ++i) { + struct vhost_virtqueue *vq = dev->vqs + i; + uint64_t last = vq->used_phys + vq->used_size - 1; + log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1); + } + return log_size; +} + +static inline void vhost_dev_log_resize(struct vhost_dev* dev, uint64_t size) +{ + vhost_log_chunk_t *log; + uint64_t log_base; + int r; + if (size) { + log = qemu_mallocz(size * sizeof *log); + } else { + log = NULL; + } + log_base = (uint64_t)(unsigned long)log; + r = ioctl(dev->control, VHOST_SET_LOG_BASE, &log_base); + assert(r >= 0); + vhost_client_sync_dirty_bitmap(&dev->client, 0, + (target_phys_addr_t)~0x0ull); + if (dev->log) { + qemu_free(dev->log); + } + dev->log = log; + dev->log_size = size; +} + +static int vhost_verify_ring_mappings(struct vhost_dev *dev, + uint64_t start_addr, + uint64_t size) +{ + int i; + for (i = 0; i < dev->nvqs; ++i) { + struct vhost_virtqueue *vq = dev->vqs + i; + target_phys_addr_t l; + void *p; + + if (!ranges_overlap(start_addr, size, vq->ring_phys, vq->ring_size)) { + continue; + } + l = vq->ring_size; + p = cpu_physical_memory_map(vq->ring_phys, &l, 1); + if (!p || l != vq->ring_size) { + fprintf(stderr, "Unable to map ring buffer for ring %d\n", i); + return -ENOMEM; + } + if (p != vq->ring) { + fprintf(stderr, "Ring buffer relocated for ring %d\n", i); + return -EBUSY; + } + cpu_physical_memory_unmap(p, l, 0, 0); + } + return 0; +} + +static void vhost_client_set_memory(CPUPhysMemoryClient *client, + target_phys_addr_t start_addr, + ram_addr_t size, + ram_addr_t phys_offset) +{ + struct vhost_dev *dev = container_of(client, struct vhost_dev, client); + ram_addr_t flags = phys_offset & ~TARGET_PAGE_MASK; + int s = offsetof(struct vhost_memory, regions) + + (dev->mem->nregions + 1) * sizeof dev->mem->regions[0]; + uint64_t log_size; + int r; + dev->mem = qemu_realloc(dev->mem, s); + + assert(size); + + vhost_dev_unassign_memory(dev, start_addr, size); + if (flags == IO_MEM_RAM) { + /* Add given mapping, merging adjacent regions if any */ + vhost_dev_assign_memory(dev, start_addr, size, + (uintptr_t)qemu_get_ram_ptr(phys_offset)); + } else { + /* Remove old mapping for this memory, if any. */ + vhost_dev_unassign_memory(dev, start_addr, size); + } + + if (!dev->started) { + return; + } + + if (dev->started) { + r = vhost_verify_ring_mappings(dev, start_addr, size); + assert(r >= 0); + } + + if (!dev->log_enabled) { + r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem); + assert(r >= 0); + return; + } + log_size = vhost_get_log_size(dev); + /* We allocate an extra 4K bytes to log, + * to reduce the * number of reallocations. */ +#define VHOST_LOG_BUFFER (0x1000 / sizeof *dev->log) + /* To log more, must increase log size before table update. */ + if (dev->log_size < log_size) { + vhost_dev_log_resize(dev, log_size + VHOST_LOG_BUFFER); + } + r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem); + assert(r >= 0); + /* To log less, can only decrease log size after table update. */ + if (dev->log_size > log_size + VHOST_LOG_BUFFER) { + vhost_dev_log_resize(dev, log_size); + } +} + +static int vhost_virtqueue_set_addr(struct vhost_dev *dev, + struct vhost_virtqueue *vq, + unsigned idx, bool enable_log) +{ + struct vhost_vring_addr addr = { + .index = idx, + .desc_user_addr = (u_int64_t)(unsigned long)vq->desc, + .avail_user_addr = (u_int64_t)(unsigned long)vq->avail, + .used_user_addr = (u_int64_t)(unsigned long)vq->used, + .log_guest_addr = vq->used_phys, + .flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0, + }; + int r = ioctl(dev->control, VHOST_SET_VRING_ADDR, &addr); + if (r < 0) { + return -errno; + } + return 0; +} + +static int vhost_dev_set_features(struct vhost_dev *dev, bool enable_log) +{ + uint64_t features = dev->acked_features; + int r; + if (enable_log) { + features |= 0x1 << VHOST_F_LOG_ALL; + } + r = ioctl(dev->control, VHOST_SET_FEATURES, &features); + return r < 0 ? -errno : 0; +} + +static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log) +{ + int r, t, i; + r = vhost_dev_set_features(dev, enable_log); + if (r < 0) { + goto err_features; + } + for (i = 0; i < dev->nvqs; ++i) { + r = vhost_virtqueue_set_addr(dev, dev->vqs + i, i, + enable_log); + if (r < 0) { + goto err_vq; + } + } + return 0; +err_vq: + for (; i >= 0; --i) { + t = vhost_virtqueue_set_addr(dev, dev->vqs + i, i, + dev->log_enabled); + assert(t >= 0); + } + t = vhost_dev_set_features(dev, dev->log_enabled); + assert(t >= 0); +err_features: + return r; +} + +static int vhost_client_migration_log(CPUPhysMemoryClient *client, + int enable) +{ + struct vhost_dev *dev = container_of(client, struct vhost_dev, client); + int r; + if (!!enable == dev->log_enabled) { + return 0; + } + if (!dev->started) { + dev->log_enabled = enable; + return 0; + } + if (!enable) { + r = vhost_dev_set_log(dev, false); + if (r < 0) { + return r; + } + if (dev->log) { + qemu_free(dev->log); + } + dev->log = NULL; + dev->log_size = 0; + } else { + vhost_dev_log_resize(dev, vhost_get_log_size(dev)); + r = vhost_dev_set_log(dev, true); + if (r < 0) { + return r; + } + } + dev->log_enabled = enable; + return 0; +} + +static int vhost_virtqueue_init(struct vhost_dev *dev, + struct VirtIODevice *vdev, + struct vhost_virtqueue *vq, + unsigned idx) +{ + target_phys_addr_t s, l, a; + int r; + struct vhost_vring_file file = { + .index = idx, + }; + struct vhost_vring_state state = { + .index = idx, + }; + struct VirtQueue *vvq = virtio_get_queue(vdev, idx); + + if (!vdev->binding->set_guest_notifier) { + fprintf(stderr, "binding does not support guest notifiers\n"); + return -ENOSYS; + } + + if (!vdev->binding->set_host_notifier) { + fprintf(stderr, "binding does not support host notifiers\n"); + return -ENOSYS; + } + + vq->num = state.num = virtio_queue_get_num(vdev, idx); + r = ioctl(dev->control, VHOST_SET_VRING_NUM, &state); + if (r) { + return -errno; + } + + state.num = virtio_queue_get_last_avail_idx(vdev, idx); + r = ioctl(dev->control, VHOST_SET_VRING_BASE, &state); + if (r) { + return -errno; + } + + s = l = virtio_queue_get_desc_size(vdev, idx); + a = virtio_queue_get_desc_addr(vdev, idx); + vq->desc = cpu_physical_memory_map(a, &l, 0); + if (!vq->desc || l != s) { + r = -ENOMEM; + goto fail_alloc_desc; + } + s = l = virtio_queue_get_avail_size(vdev, idx); + a = virtio_queue_get_avail_addr(vdev, idx); + vq->avail = cpu_physical_memory_map(a, &l, 0); + if (!vq->avail || l != s) { + r = -ENOMEM; + goto fail_alloc_avail; + } + vq->used_size = s = l = virtio_queue_get_used_size(vdev, idx); + vq->used_phys = a = virtio_queue_get_used_addr(vdev, idx); + vq->used = cpu_physical_memory_map(a, &l, 1); + if (!vq->used || l != s) { + r = -ENOMEM; + goto fail_alloc_used; + } + + vq->ring_size = s = l = virtio_queue_get_ring_size(vdev, idx); + vq->ring_phys = a = virtio_queue_get_ring_addr(vdev, idx); + vq->ring = cpu_physical_memory_map(a, &l, 1); + if (!vq->ring || l != s) { + r = -ENOMEM; + goto fail_alloc_ring; + } + + r = vhost_virtqueue_set_addr(dev, vq, idx, dev->log_enabled); + if (r < 0) { + r = -errno; + goto fail_alloc; + } + r = vdev->binding->set_guest_notifier(vdev->binding_opaque, idx, true); + if (r < 0) { + fprintf(stderr, "Error binding guest notifier: %d\n", -r); + goto fail_guest_notifier; + } + + r = vdev->binding->set_host_notifier(vdev->binding_opaque, idx, true); + if (r < 0) { + fprintf(stderr, "Error binding host notifier: %d\n", -r); + goto fail_host_notifier; + } + + file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq)); + r = ioctl(dev->control, VHOST_SET_VRING_KICK, &file); + if (r) { + goto fail_kick; + } + + file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq)); + r = ioctl(dev->control, VHOST_SET_VRING_CALL, &file); + if (r) { + goto fail_call; + } + + return 0; + +fail_call: +fail_kick: + vdev->binding->set_host_notifier(vdev->binding_opaque, idx, false); +fail_host_notifier: + vdev->binding->set_guest_notifier(vdev->binding_opaque, idx, false); +fail_guest_notifier: +fail_alloc: + cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx), + 0, 0); +fail_alloc_ring: + cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx), + 0, 0); +fail_alloc_used: + cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx), + 0, 0); +fail_alloc_avail: + cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx), + 0, 0); +fail_alloc_desc: + return r; +} + +static void vhost_virtqueue_cleanup(struct vhost_dev *dev, + struct VirtIODevice *vdev, + struct vhost_virtqueue *vq, + unsigned idx) +{ + struct vhost_vring_state state = { + .index = idx, + }; + int r; + r = vdev->binding->set_guest_notifier(vdev->binding_opaque, idx, false); + if (r < 0) { + fprintf(stderr, "vhost VQ %d guest cleanup failed: %d\n", idx, r); + fflush(stderr); + } + assert (r >= 0); + + r = vdev->binding->set_host_notifier(vdev->binding_opaque, idx, false); + if (r < 0) { + fprintf(stderr, "vhost VQ %d host cleanup failed: %d\n", idx, r); + fflush(stderr); + } + assert (r >= 0); + r = ioctl(dev->control, VHOST_GET_VRING_BASE, &state); + if (r < 0) { + fprintf(stderr, "vhost VQ %d ring restore failed: %d\n", idx, r); + fflush(stderr); + } + virtio_queue_set_last_avail_idx(vdev, idx, state.num); + assert (r >= 0); + cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx), + 0, virtio_queue_get_ring_size(vdev, idx)); + cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx), + 1, virtio_queue_get_used_size(vdev, idx)); + cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx), + 0, virtio_queue_get_avail_size(vdev, idx)); + cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx), + 0, virtio_queue_get_desc_size(vdev, idx)); +} + +int vhost_dev_init(struct vhost_dev *hdev, int devfd) +{ + uint64_t features; + int r; + if (devfd >= 0) { + hdev->control = devfd; + } else { + hdev->control = open("/dev/vhost-net", O_RDWR); + if (hdev->control < 0) { + return -errno; + } + } + r = ioctl(hdev->control, VHOST_SET_OWNER, NULL); + if (r < 0) { + goto fail; + } + + r = ioctl(hdev->control, VHOST_GET_FEATURES, &features); + if (r < 0) { + goto fail; + } + hdev->features = features; + + hdev->client.set_memory = vhost_client_set_memory; + hdev->client.sync_dirty_bitmap = vhost_client_sync_dirty_bitmap; + hdev->client.migration_log = vhost_client_migration_log; + hdev->mem = qemu_mallocz(offsetof(struct vhost_memory, regions)); + hdev->log = NULL; + hdev->log_size = 0; + hdev->log_enabled = false; + hdev->started = false; + cpu_register_phys_memory_client(&hdev->client); + return 0; +fail: + r = -errno; + close(hdev->control); + return r; +} + +void vhost_dev_cleanup(struct vhost_dev *hdev) +{ + cpu_unregister_phys_memory_client(&hdev->client); + qemu_free(hdev->mem); + close(hdev->control); +} + +int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) +{ + int i, r; + + r = vhost_dev_set_features(hdev, hdev->log_enabled); + if (r < 0) { + goto fail; + } + r = ioctl(hdev->control, VHOST_SET_MEM_TABLE, hdev->mem); + if (r < 0) { + r = -errno; + goto fail; + } + if (hdev->log_enabled) { + hdev->log_size = vhost_get_log_size(hdev); + hdev->log = hdev->log_size ? + qemu_mallocz(hdev->log_size * sizeof *hdev->log) : NULL; + r = ioctl(hdev->control, VHOST_SET_LOG_BASE, + (uint64_t)(unsigned long)hdev->log); + if (r < 0) { + r = -errno; + goto fail; + } + } + + for (i = 0; i < hdev->nvqs; ++i) { + r = vhost_virtqueue_init(hdev, + vdev, + hdev->vqs + i, + i); + if (r < 0) { + goto fail_vq; + } + } + hdev->started = true; + + return 0; +fail_vq: + while (--i >= 0) { + vhost_virtqueue_cleanup(hdev, + vdev, + hdev->vqs + i, + i); + } +fail: + return r; +} + +void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) +{ + int i; + for (i = 0; i < hdev->nvqs; ++i) { + vhost_virtqueue_cleanup(hdev, + vdev, + hdev->vqs + i, + i); + } + vhost_client_sync_dirty_bitmap(&hdev->client, 0, + (target_phys_addr_t)~0x0ull); + hdev->started = false; + qemu_free(hdev->log); + hdev->log_size = 0; +} |