| /* |
| * 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 "qemu/osdep.h" |
| #include "qapi/error.h" |
| #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 */ |
| } |
| |
| /* The vhost driver natively knows how to handle the vrings of non |
| * cross-endian legacy devices and modern devices. Only legacy devices |
| * exposed to a bi-endian guest may require the vhost driver to use a |
| * specific endianness. |
| */ |
| static inline bool vhost_needs_vring_endian(VirtIODevice *vdev) |
| { |
| if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { |
| return false; |
| } |
| #ifdef HOST_WORDS_BIGENDIAN |
| return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_LITTLE; |
| #else |
| return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG; |
| #endif |
| } |
| |
| 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 (vhost_needs_vring_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); |
| |
| /* Init vring in unmasked state, unless guest_notifier_mask |
| * will do it later. |
| */ |
| if (!vdev->use_guest_notifier_mask) { |
| /* TODO: check and handle errors. */ |
| vhost_virtqueue_mask(dev, vdev, idx, false); |
| } |
| |
| 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 (vhost_needs_vring_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_set_busyloop_timeout(struct vhost_dev *dev, |
| int n, uint32_t timeout) |
| { |
| int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, n); |
| struct vhost_vring_state state = { |
| .index = vhost_vq_index, |
| .num = timeout, |
| }; |
| int r; |
| |
| if (!dev->vhost_ops->vhost_set_vring_busyloop_timeout) { |
| return -EINVAL; |
| } |
| |
| r = dev->vhost_ops->vhost_set_vring_busyloop_timeout(dev, &state); |
| if (r) { |
| return r; |
| } |
| |
| return 0; |
| } |
| |
| 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, uint32_t busyloop_timeout) |
| { |
| 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; |
| } |
| } |
| |
| if (busyloop_timeout) { |
| for (i = 0; i < hdev->nvqs; ++i) { |
| r = vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, |
| busyloop_timeout); |
| if (r < 0) { |
| goto fail_busyloop; |
| } |
| } |
| } |
| |
| 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_busyloop: |
| while (--i >= 0) { |
| vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 0); |
| } |
| i = hdev->nvqs; |
| 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->ioeventfd_started) { |
| fprintf(stderr, "binding does not support host notifiers\n"); |
| r = -ENOSYS; |
| goto fail; |
| } |
| |
| for (i = 0; i < hdev->nvqs; ++i) { |
| r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), 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 = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), 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))); |
| int i, r; |
| |
| for (i = 0; i < hdev->nvqs; ++i) { |
| r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), 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) { |
| assert(vdev->use_guest_notifier_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; |
| } |
| |