diff options
Diffstat (limited to 'src/hw/virtio/vhost.c')
| -rw-r--r-- | src/hw/virtio/vhost.c | 1271 |
1 files changed, 1271 insertions, 0 deletions
diff --git a/src/hw/virtio/vhost.c b/src/hw/virtio/vhost.c new file mode 100644 index 0000000..90c60a7 --- /dev/null +++ b/src/hw/virtio/vhost.c @@ -0,0 +1,1271 @@ +/* + * 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. + * + * Contributions after 2012-01-13 are licensed under the terms of the + * GNU GPL, version 2 or (at your option) any later version. + */ + +#include "hw/virtio/vhost.h" +#include "hw/hw.h" +#include "qemu/atomic.h" +#include "qemu/range.h" +#include "qemu/error-report.h" +#include "qemu/memfd.h" +#include <linux/vhost.h> +#include "exec/address-spaces.h" +#include "hw/virtio/virtio-bus.h" +#include "hw/virtio/virtio-access.h" +#include "migration/migration.h" + +static struct vhost_log *vhost_log; +static struct vhost_log *vhost_log_shm; + +static unsigned int used_memslots; +static QLIST_HEAD(, vhost_dev) vhost_devices = + QLIST_HEAD_INITIALIZER(vhost_devices); + +bool vhost_has_free_slot(void) +{ + unsigned int slots_limit = ~0U; + struct vhost_dev *hdev; + + QLIST_FOREACH(hdev, &vhost_devices, entry) { + unsigned int r = hdev->vhost_ops->vhost_backend_memslots_limit(hdev); + slots_limit = MIN(slots_limit, r); + } + return slots_limit > used_memslots; +} + +static void vhost_dev_sync_region(struct vhost_dev *dev, + MemoryRegionSection *section, + uint64_t mfirst, uint64_t mlast, + uint64_t rfirst, uint64_t rlast) +{ + vhost_log_chunk_t *log = dev->log->log; + + uint64_t start = MAX(mfirst, rfirst); + uint64_t end = MIN(mlast, rlast); + vhost_log_chunk_t *from = log + start / VHOST_LOG_CHUNK; + vhost_log_chunk_t *to = log + end / VHOST_LOG_CHUNK + 1; + uint64_t addr = (start / VHOST_LOG_CHUNK) * VHOST_LOG_CHUNK; + + if (end < start) { + return; + } + assert(end / VHOST_LOG_CHUNK < dev->log_size); + assert(start / VHOST_LOG_CHUNK < dev->log_size); + + for (;from < to; ++from) { + vhost_log_chunk_t log; + /* We first check with non-atomic: much cheaper, + * and we expect non-dirty to be the common case. */ + if (!*from) { + addr += VHOST_LOG_CHUNK; + continue; + } + /* Data must be read atomically. We don't really need barrier semantics + * but it's easier to use atomic_* than roll our own. */ + log = atomic_xchg(from, 0); + while (log) { + int bit = ctzl(log); + hwaddr page_addr; + hwaddr section_offset; + hwaddr mr_offset; + page_addr = addr + bit * VHOST_LOG_PAGE; + section_offset = page_addr - section->offset_within_address_space; + mr_offset = section_offset + section->offset_within_region; + memory_region_set_dirty(section->mr, mr_offset, VHOST_LOG_PAGE); + log &= ~(0x1ull << bit); + } + addr += VHOST_LOG_CHUNK; + } +} + +static int vhost_sync_dirty_bitmap(struct vhost_dev *dev, + MemoryRegionSection *section, + hwaddr first, + hwaddr last) +{ + int i; + hwaddr start_addr; + hwaddr end_addr; + + if (!dev->log_enabled || !dev->started) { + return 0; + } + start_addr = section->offset_within_address_space; + end_addr = range_get_last(start_addr, int128_get64(section->size)); + start_addr = MAX(first, start_addr); + end_addr = MIN(last, end_addr); + + for (i = 0; i < dev->mem->nregions; ++i) { + struct vhost_memory_region *reg = dev->mem->regions + i; + vhost_dev_sync_region(dev, section, 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, section, start_addr, end_addr, vq->used_phys, + range_get_last(vq->used_phys, vq->used_size)); + } + return 0; +} + +static void vhost_log_sync(MemoryListener *listener, + MemoryRegionSection *section) +{ + struct vhost_dev *dev = container_of(listener, struct vhost_dev, + memory_listener); + vhost_sync_dirty_bitmap(dev, section, 0x0, ~0x0ULL); +} + +static void vhost_log_sync_range(struct vhost_dev *dev, + hwaddr first, hwaddr last) +{ + int i; + /* FIXME: this is N^2 in number of sections */ + for (i = 0; i < dev->n_mem_sections; ++i) { + MemoryRegionSection *section = &dev->mem_sections[i]; + vhost_sync_dirty_bitmap(dev, section, first, last); + } +} + +/* 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; + ++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 (dev->vhost_ops->vhost_backend_can_merge && + !dev->vhost_ops->vhost_backend_can_merge(dev, uaddr, size, + reg->userspace_addr, + reg->memory_size)) { + 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 struct vhost_log *vhost_log_alloc(uint64_t size, bool share) +{ + struct vhost_log *log; + uint64_t logsize = size * sizeof(*(log->log)); + int fd = -1; + + log = g_new0(struct vhost_log, 1); + if (share) { + log->log = qemu_memfd_alloc("vhost-log", logsize, + F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL, + &fd); + memset(log->log, 0, logsize); + } else { + log->log = g_malloc0(logsize); + } + + log->size = size; + log->refcnt = 1; + log->fd = fd; + + return log; +} + +static struct vhost_log *vhost_log_get(uint64_t size, bool share) +{ + struct vhost_log *log = share ? vhost_log_shm : vhost_log; + + if (!log || log->size != size) { + log = vhost_log_alloc(size, share); + if (share) { + vhost_log_shm = log; + } else { + vhost_log = log; + } + } else { + ++log->refcnt; + } + + return log; +} + +static void vhost_log_put(struct vhost_dev *dev, bool sync) +{ + struct vhost_log *log = dev->log; + + if (!log) { + return; + } + + --log->refcnt; + if (log->refcnt == 0) { + /* Sync only the range covered by the old log */ + if (dev->log_size && sync) { + vhost_log_sync_range(dev, 0, dev->log_size * VHOST_LOG_CHUNK - 1); + } + + if (vhost_log == log) { + g_free(log->log); + vhost_log = NULL; + } else if (vhost_log_shm == log) { + qemu_memfd_free(log->log, log->size * sizeof(*(log->log)), + log->fd); + vhost_log_shm = NULL; + } + + g_free(log); + } +} + +static bool vhost_dev_log_is_shared(struct vhost_dev *dev) +{ + return dev->vhost_ops->vhost_requires_shm_log && + dev->vhost_ops->vhost_requires_shm_log(dev); +} + +static inline void vhost_dev_log_resize(struct vhost_dev *dev, uint64_t size) +{ + struct vhost_log *log = vhost_log_get(size, vhost_dev_log_is_shared(dev)); + uint64_t log_base = (uintptr_t)log->log; + int r; + + /* inform backend of log switching, this must be done before + releasing the current log, to ensure no logging is lost */ + r = dev->vhost_ops->vhost_set_log_base(dev, log_base, log); + assert(r >= 0); + vhost_log_put(dev, true); + 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; + int r = 0; + + for (i = 0; !r && i < dev->nvqs; ++i) { + struct vhost_virtqueue *vq = dev->vqs + i; + hwaddr 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); + r = -ENOMEM; + } + if (p != vq->ring) { + fprintf(stderr, "Ring buffer relocated for ring %d\n", i); + r = -EBUSY; + } + cpu_physical_memory_unmap(p, l, 0, 0); + } + return r; +} + +static struct vhost_memory_region *vhost_dev_find_reg(struct vhost_dev *dev, + uint64_t start_addr, + uint64_t size) +{ + int i, n = dev->mem->nregions; + for (i = 0; i < n; ++i) { + struct vhost_memory_region *reg = dev->mem->regions + i; + if (ranges_overlap(reg->guest_phys_addr, reg->memory_size, + start_addr, size)) { + return reg; + } + } + return NULL; +} + +static bool vhost_dev_cmp_memory(struct vhost_dev *dev, + uint64_t start_addr, + uint64_t size, + uint64_t uaddr) +{ + struct vhost_memory_region *reg = vhost_dev_find_reg(dev, start_addr, size); + uint64_t reglast; + uint64_t memlast; + + if (!reg) { + return true; + } + + reglast = range_get_last(reg->guest_phys_addr, reg->memory_size); + memlast = range_get_last(start_addr, size); + + /* Need to extend region? */ + if (start_addr < reg->guest_phys_addr || memlast > reglast) { + return true; + } + /* userspace_addr changed? */ + return uaddr != reg->userspace_addr + start_addr - reg->guest_phys_addr; +} + +static void vhost_set_memory(MemoryListener *listener, + MemoryRegionSection *section, + bool add) +{ + struct vhost_dev *dev = container_of(listener, struct vhost_dev, + memory_listener); + hwaddr start_addr = section->offset_within_address_space; + ram_addr_t size = int128_get64(section->size); + bool log_dirty = + memory_region_get_dirty_log_mask(section->mr) & ~(1 << DIRTY_MEMORY_MIGRATION); + int s = offsetof(struct vhost_memory, regions) + + (dev->mem->nregions + 1) * sizeof dev->mem->regions[0]; + void *ram; + + dev->mem = g_realloc(dev->mem, s); + + if (log_dirty) { + add = false; + } + + assert(size); + + /* Optimize no-change case. At least cirrus_vga does this a lot at this time. */ + ram = memory_region_get_ram_ptr(section->mr) + section->offset_within_region; + if (add) { + if (!vhost_dev_cmp_memory(dev, start_addr, size, (uintptr_t)ram)) { + /* Region exists with same address. Nothing to do. */ + return; + } + } else { + if (!vhost_dev_find_reg(dev, start_addr, size)) { + /* Removing region that we don't access. Nothing to do. */ + return; + } + } + + vhost_dev_unassign_memory(dev, start_addr, size); + if (add) { + /* Add given mapping, merging adjacent regions if any */ + vhost_dev_assign_memory(dev, start_addr, size, (uintptr_t)ram); + } else { + /* Remove old mapping for this memory, if any. */ + vhost_dev_unassign_memory(dev, start_addr, size); + } + dev->mem_changed_start_addr = MIN(dev->mem_changed_start_addr, start_addr); + dev->mem_changed_end_addr = MAX(dev->mem_changed_end_addr, start_addr + size - 1); + dev->memory_changed = true; + used_memslots = dev->mem->nregions; +} + +static bool vhost_section(MemoryRegionSection *section) +{ + return memory_region_is_ram(section->mr); +} + +static void vhost_begin(MemoryListener *listener) +{ + struct vhost_dev *dev = container_of(listener, struct vhost_dev, + memory_listener); + dev->mem_changed_end_addr = 0; + dev->mem_changed_start_addr = -1; +} + +static void vhost_commit(MemoryListener *listener) +{ + struct vhost_dev *dev = container_of(listener, struct vhost_dev, + memory_listener); + hwaddr start_addr = 0; + ram_addr_t size = 0; + uint64_t log_size; + int r; + + if (!dev->memory_changed) { + return; + } + if (!dev->started) { + return; + } + if (dev->mem_changed_start_addr > dev->mem_changed_end_addr) { + return; + } + + if (dev->started) { + start_addr = dev->mem_changed_start_addr; + size = dev->mem_changed_end_addr - dev->mem_changed_start_addr + 1; + + r = vhost_verify_ring_mappings(dev, start_addr, size); + assert(r >= 0); + } + + if (!dev->log_enabled) { + r = dev->vhost_ops->vhost_set_mem_table(dev, dev->mem); + assert(r >= 0); + dev->memory_changed = false; + 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 = dev->vhost_ops->vhost_set_mem_table(dev, 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); + } + dev->memory_changed = false; +} + +static void vhost_region_add(MemoryListener *listener, + MemoryRegionSection *section) +{ + struct vhost_dev *dev = container_of(listener, struct vhost_dev, + memory_listener); + + if (!vhost_section(section)) { + return; + } + + ++dev->n_mem_sections; + dev->mem_sections = g_renew(MemoryRegionSection, dev->mem_sections, + dev->n_mem_sections); + dev->mem_sections[dev->n_mem_sections - 1] = *section; + memory_region_ref(section->mr); + vhost_set_memory(listener, section, true); +} + +static void vhost_region_del(MemoryListener *listener, + MemoryRegionSection *section) +{ + struct vhost_dev *dev = container_of(listener, struct vhost_dev, + memory_listener); + int i; + + if (!vhost_section(section)) { + return; + } + + vhost_set_memory(listener, section, false); + memory_region_unref(section->mr); + for (i = 0; i < dev->n_mem_sections; ++i) { + if (dev->mem_sections[i].offset_within_address_space + == section->offset_within_address_space) { + --dev->n_mem_sections; + memmove(&dev->mem_sections[i], &dev->mem_sections[i+1], + (dev->n_mem_sections - i) * sizeof(*dev->mem_sections)); + break; + } + } +} + +static void vhost_region_nop(MemoryListener *listener, + MemoryRegionSection *section) +{ +} + +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 = (uint64_t)(unsigned long)vq->desc, + .avail_user_addr = (uint64_t)(unsigned long)vq->avail, + .used_user_addr = (uint64_t)(unsigned long)vq->used, + .log_guest_addr = vq->used_phys, + .flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0, + }; + int r = dev->vhost_ops->vhost_set_vring_addr(dev, &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 |= 0x1ULL << VHOST_F_LOG_ALL; + } + r = dev->vhost_ops->vhost_set_features(dev, features); + return r < 0 ? -errno : 0; +} + +static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log) +{ + int r, t, i, idx; + r = vhost_dev_set_features(dev, enable_log); + if (r < 0) { + goto err_features; + } + for (i = 0; i < dev->nvqs; ++i) { + idx = dev->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + i); + r = vhost_virtqueue_set_addr(dev, dev->vqs + i, idx, + enable_log); + if (r < 0) { + goto err_vq; + } + } + return 0; +err_vq: + for (; i >= 0; --i) { + idx = dev->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + i); + t = vhost_virtqueue_set_addr(dev, dev->vqs + i, idx, + 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_migration_log(MemoryListener *listener, int enable) +{ + struct vhost_dev *dev = container_of(listener, struct vhost_dev, + memory_listener); + 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; + } + vhost_log_put(dev, false); + 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 void vhost_log_global_start(MemoryListener *listener) +{ + int r; + + r = vhost_migration_log(listener, true); + if (r < 0) { + abort(); + } +} + +static void vhost_log_global_stop(MemoryListener *listener) +{ + int r; + + r = vhost_migration_log(listener, false); + if (r < 0) { + abort(); + } +} + +static void vhost_log_start(MemoryListener *listener, + MemoryRegionSection *section, + int old, int new) +{ + /* FIXME: implement */ +} + +static void vhost_log_stop(MemoryListener *listener, + MemoryRegionSection *section, + int old, int new) +{ + /* FIXME: implement */ +} + +static int vhost_virtqueue_set_vring_endian_legacy(struct vhost_dev *dev, + bool is_big_endian, + int vhost_vq_index) +{ + struct vhost_vring_state s = { + .index = vhost_vq_index, + .num = is_big_endian + }; + + if (!dev->vhost_ops->vhost_set_vring_endian(dev, &s)) { + return 0; + } + + if (errno == ENOTTY) { + error_report("vhost does not support cross-endian"); + return -ENOSYS; + } + + return -errno; +} + +static int vhost_virtqueue_start(struct vhost_dev *dev, + struct VirtIODevice *vdev, + struct vhost_virtqueue *vq, + unsigned idx) +{ + hwaddr s, l, a; + int r; + int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); + struct vhost_vring_file file = { + .index = vhost_vq_index + }; + struct vhost_vring_state state = { + .index = vhost_vq_index + }; + struct VirtQueue *vvq = virtio_get_queue(vdev, idx); + + + vq->num = state.num = virtio_queue_get_num(vdev, idx); + r = dev->vhost_ops->vhost_set_vring_num(dev, &state); + if (r) { + return -errno; + } + + state.num = virtio_queue_get_last_avail_idx(vdev, idx); + r = dev->vhost_ops->vhost_set_vring_base(dev, &state); + if (r) { + return -errno; + } + + if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1) && + virtio_legacy_is_cross_endian(vdev)) { + r = vhost_virtqueue_set_vring_endian_legacy(dev, + virtio_is_big_endian(vdev), + vhost_vq_index); + 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, vhost_vq_index, dev->log_enabled); + if (r < 0) { + r = -errno; + goto fail_alloc; + } + + file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq)); + r = dev->vhost_ops->vhost_set_vring_kick(dev, &file); + if (r) { + r = -errno; + goto fail_kick; + } + + /* Clear and discard previous events if any. */ + event_notifier_test_and_clear(&vq->masked_notifier); + + return 0; + +fail_kick: +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_stop(struct vhost_dev *dev, + struct VirtIODevice *vdev, + struct vhost_virtqueue *vq, + unsigned idx) +{ + int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx); + struct vhost_vring_state state = { + .index = vhost_vq_index, + }; + int r; + + r = dev->vhost_ops->vhost_get_vring_base(dev, &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); + virtio_queue_invalidate_signalled_used(vdev, idx); + + /* In the cross-endian case, we need to reset the vring endianness to + * native as legacy devices expect so by default. + */ + if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1) && + virtio_legacy_is_cross_endian(vdev)) { + r = vhost_virtqueue_set_vring_endian_legacy(dev, + !virtio_is_big_endian(vdev), + vhost_vq_index); + if (r < 0) { + error_report("failed to reset vring endianness"); + } + } + + 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)); +} + +static void vhost_eventfd_add(MemoryListener *listener, + MemoryRegionSection *section, + bool match_data, uint64_t data, EventNotifier *e) +{ +} + +static void vhost_eventfd_del(MemoryListener *listener, + MemoryRegionSection *section, + bool match_data, uint64_t data, EventNotifier *e) +{ +} + +static int vhost_virtqueue_init(struct vhost_dev *dev, + struct vhost_virtqueue *vq, int n) +{ + int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); + struct vhost_vring_file file = { + .index = vhost_vq_index, + }; + int r = event_notifier_init(&vq->masked_notifier, 0); + if (r < 0) { + return r; + } + + file.fd = event_notifier_get_fd(&vq->masked_notifier); + r = dev->vhost_ops->vhost_set_vring_call(dev, &file); + if (r) { + r = -errno; + goto fail_call; + } + return 0; +fail_call: + event_notifier_cleanup(&vq->masked_notifier); + return r; +} + +static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq) +{ + event_notifier_cleanup(&vq->masked_notifier); +} + +int vhost_dev_init(struct vhost_dev *hdev, void *opaque, + VhostBackendType backend_type) +{ + uint64_t features; + int i, r; + + hdev->migration_blocker = NULL; + + if (vhost_set_backend_type(hdev, backend_type) < 0) { + close((uintptr_t)opaque); + return -1; + } + + if (hdev->vhost_ops->vhost_backend_init(hdev, opaque) < 0) { + close((uintptr_t)opaque); + return -errno; + } + + if (used_memslots > hdev->vhost_ops->vhost_backend_memslots_limit(hdev)) { + fprintf(stderr, "vhost backend memory slots limit is less" + " than current number of present memory slots\n"); + close((uintptr_t)opaque); + return -1; + } + QLIST_INSERT_HEAD(&vhost_devices, hdev, entry); + + r = hdev->vhost_ops->vhost_set_owner(hdev); + if (r < 0) { + goto fail; + } + + r = hdev->vhost_ops->vhost_get_features(hdev, &features); + if (r < 0) { + goto fail; + } + + for (i = 0; i < hdev->nvqs; ++i) { + r = vhost_virtqueue_init(hdev, hdev->vqs + i, hdev->vq_index + i); + if (r < 0) { + goto fail_vq; + } + } + hdev->features = features; + + hdev->memory_listener = (MemoryListener) { + .begin = vhost_begin, + .commit = vhost_commit, + .region_add = vhost_region_add, + .region_del = vhost_region_del, + .region_nop = vhost_region_nop, + .log_start = vhost_log_start, + .log_stop = vhost_log_stop, + .log_sync = vhost_log_sync, + .log_global_start = vhost_log_global_start, + .log_global_stop = vhost_log_global_stop, + .eventfd_add = vhost_eventfd_add, + .eventfd_del = vhost_eventfd_del, + .priority = 10 + }; + + if (hdev->migration_blocker == NULL) { + if (!(hdev->features & (0x1ULL << VHOST_F_LOG_ALL))) { + error_setg(&hdev->migration_blocker, + "Migration disabled: vhost lacks VHOST_F_LOG_ALL feature."); + } else if (!qemu_memfd_check()) { + error_setg(&hdev->migration_blocker, + "Migration disabled: failed to allocate shared memory"); + } + } + + if (hdev->migration_blocker != NULL) { + migrate_add_blocker(hdev->migration_blocker); + } + + hdev->mem = g_malloc0(offsetof(struct vhost_memory, regions)); + hdev->n_mem_sections = 0; + hdev->mem_sections = NULL; + hdev->log = NULL; + hdev->log_size = 0; + hdev->log_enabled = false; + hdev->started = false; + hdev->memory_changed = false; + memory_listener_register(&hdev->memory_listener, &address_space_memory); + return 0; +fail_vq: + while (--i >= 0) { + vhost_virtqueue_cleanup(hdev->vqs + i); + } +fail: + r = -errno; + hdev->vhost_ops->vhost_backend_cleanup(hdev); + QLIST_REMOVE(hdev, entry); + return r; +} + +void vhost_dev_cleanup(struct vhost_dev *hdev) +{ + int i; + for (i = 0; i < hdev->nvqs; ++i) { + vhost_virtqueue_cleanup(hdev->vqs + i); + } + memory_listener_unregister(&hdev->memory_listener); + if (hdev->migration_blocker) { + migrate_del_blocker(hdev->migration_blocker); + error_free(hdev->migration_blocker); + } + g_free(hdev->mem); + g_free(hdev->mem_sections); + hdev->vhost_ops->vhost_backend_cleanup(hdev); + QLIST_REMOVE(hdev, entry); +} + +/* Stop processing guest IO notifications in qemu. + * Start processing them in vhost in kernel. + */ +int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) +{ + BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); + VirtioBusState *vbus = VIRTIO_BUS(qbus); + VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); + int i, r, e; + if (!k->set_host_notifier) { + fprintf(stderr, "binding does not support host notifiers\n"); + r = -ENOSYS; + goto fail; + } + + for (i = 0; i < hdev->nvqs; ++i) { + r = k->set_host_notifier(qbus->parent, hdev->vq_index + i, true); + if (r < 0) { + fprintf(stderr, "vhost VQ %d notifier binding failed: %d\n", i, -r); + goto fail_vq; + } + } + + return 0; +fail_vq: + while (--i >= 0) { + e = k->set_host_notifier(qbus->parent, hdev->vq_index + i, false); + if (e < 0) { + fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, -r); + fflush(stderr); + } + assert (e >= 0); + } +fail: + return r; +} + +/* Stop processing guest IO notifications in vhost. + * Start processing them in qemu. + * This might actually run the qemu handlers right away, + * so virtio in qemu must be completely setup when this is called. + */ +void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) +{ + BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); + VirtioBusState *vbus = VIRTIO_BUS(qbus); + VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); + int i, r; + + for (i = 0; i < hdev->nvqs; ++i) { + r = k->set_host_notifier(qbus->parent, hdev->vq_index + i, false); + if (r < 0) { + fprintf(stderr, "vhost VQ %d notifier cleanup failed: %d\n", i, -r); + fflush(stderr); + } + assert (r >= 0); + } +} + +/* Test and clear event pending status. + * Should be called after unmask to avoid losing events. + */ +bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n) +{ + struct vhost_virtqueue *vq = hdev->vqs + n - hdev->vq_index; + assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs); + return event_notifier_test_and_clear(&vq->masked_notifier); +} + +/* Mask/unmask events from this vq. */ +void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, + bool mask) +{ + struct VirtQueue *vvq = virtio_get_queue(vdev, n); + int r, index = n - hdev->vq_index; + struct vhost_vring_file file; + + if (mask) { + file.fd = event_notifier_get_fd(&hdev->vqs[index].masked_notifier); + } else { + file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq)); + } + + file.index = hdev->vhost_ops->vhost_get_vq_index(hdev, n); + r = hdev->vhost_ops->vhost_set_vring_call(hdev, &file); + assert(r >= 0); +} + +uint64_t vhost_get_features(struct vhost_dev *hdev, const int *feature_bits, + uint64_t features) +{ + const int *bit = feature_bits; + while (*bit != VHOST_INVALID_FEATURE_BIT) { + uint64_t bit_mask = (1ULL << *bit); + if (!(hdev->features & bit_mask)) { + features &= ~bit_mask; + } + bit++; + } + return features; +} + +void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits, + uint64_t features) +{ + const int *bit = feature_bits; + while (*bit != VHOST_INVALID_FEATURE_BIT) { + uint64_t bit_mask = (1ULL << *bit); + if (features & bit_mask) { + hdev->acked_features |= bit_mask; + } + bit++; + } +} + +/* Host notifiers must be enabled at this point. */ +int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) +{ + int i, r; + + hdev->started = true; + + r = vhost_dev_set_features(hdev, hdev->log_enabled); + if (r < 0) { + goto fail_features; + } + r = hdev->vhost_ops->vhost_set_mem_table(hdev, hdev->mem); + if (r < 0) { + r = -errno; + goto fail_mem; + } + for (i = 0; i < hdev->nvqs; ++i) { + r = vhost_virtqueue_start(hdev, + vdev, + hdev->vqs + i, + hdev->vq_index + i); + if (r < 0) { + goto fail_vq; + } + } + + if (hdev->log_enabled) { + uint64_t log_base; + + hdev->log_size = vhost_get_log_size(hdev); + hdev->log = vhost_log_get(hdev->log_size, + vhost_dev_log_is_shared(hdev)); + log_base = (uintptr_t)hdev->log->log; + r = hdev->vhost_ops->vhost_set_log_base(hdev, + hdev->log_size ? log_base : 0, + hdev->log); + if (r < 0) { + r = -errno; + goto fail_log; + } + } + + return 0; +fail_log: + vhost_log_put(hdev, false); +fail_vq: + while (--i >= 0) { + vhost_virtqueue_stop(hdev, + vdev, + hdev->vqs + i, + hdev->vq_index + i); + } + i = hdev->nvqs; +fail_mem: +fail_features: + + hdev->started = false; + return r; +} + +/* Host notifiers must be enabled at this point. */ +void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) +{ + int i; + + for (i = 0; i < hdev->nvqs; ++i) { + vhost_virtqueue_stop(hdev, + vdev, + hdev->vqs + i, + hdev->vq_index + i); + } + + vhost_log_put(hdev, true); + hdev->started = false; + hdev->log = NULL; + hdev->log_size = 0; +} + |
