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-rw-r--r--qemu/hw/virtio/vhost.c1186
1 files changed, 1186 insertions, 0 deletions
diff --git a/qemu/hw/virtio/vhost.c b/qemu/hw/virtio/vhost.c
new file mode 100644
index 000000000..2712c6fc0
--- /dev/null
+++ b/qemu/hw/virtio/vhost.c
@@ -0,0 +1,1186 @@
+/*
+ * 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 <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 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 (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)
+{
+ struct vhost_log *log = g_malloc0(sizeof *log + size * sizeof(*(log->log)));
+
+ log->size = size;
+ log->refcnt = 1;
+
+ return log;
+}
+
+static struct vhost_log *vhost_log_get(uint64_t size)
+{
+ if (!vhost_log || vhost_log->size != size) {
+ vhost_log = vhost_log_alloc(size);
+ } else {
+ ++vhost_log->refcnt;
+ }
+
+ return vhost_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) {
+ vhost_log = NULL;
+ }
+ g_free(log);
+ }
+}
+
+static inline void vhost_dev_log_resize(struct vhost_dev* dev, uint64_t size)
+{
+ struct vhost_log *log = vhost_log_get(size);
+ uint64_t log_base = (uintptr_t)log->log;
+ int r;
+
+ r = dev->vhost_ops->vhost_call(dev, VHOST_SET_LOG_BASE, &log_base);
+ 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;
+}
+
+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_call(dev, VHOST_SET_MEM_TABLE, 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_call(dev, 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);
+ }
+ 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_call(dev, 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 |= 0x1ULL << VHOST_F_LOG_ALL;
+ }
+ r = dev->vhost_ops->vhost_call(dev, 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_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_call(dev, VHOST_SET_VRING_ENDIAN, &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 = idx - dev->vq_index;
+ 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);
+
+ assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs);
+
+ vq->num = state.num = virtio_queue_get_num(vdev, idx);
+ r = dev->vhost_ops->vhost_call(dev, VHOST_SET_VRING_NUM, &state);
+ if (r) {
+ return -errno;
+ }
+
+ state.num = virtio_queue_get_last_avail_idx(vdev, idx);
+ r = dev->vhost_ops->vhost_call(dev, VHOST_SET_VRING_BASE, &state);
+ if (r) {
+ return -errno;
+ }
+
+ if (!virtio_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_call(dev, VHOST_SET_VRING_KICK, &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 = idx - dev->vq_index;
+ struct vhost_vring_state state = {
+ .index = vhost_vq_index,
+ };
+ int r;
+ assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs);
+ r = dev->vhost_ops->vhost_call(dev, 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);
+ 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_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)
+{
+ struct vhost_vring_file file = {
+ .index = n,
+ };
+ 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_call(dev, VHOST_SET_VRING_CALL, &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;
+
+ 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;
+ }
+
+ r = hdev->vhost_ops->vhost_call(hdev, VHOST_SET_OWNER, NULL);
+ if (r < 0) {
+ goto fail;
+ }
+
+ r = hdev->vhost_ops->vhost_call(hdev, VHOST_GET_FEATURES, &features);
+ if (r < 0) {
+ goto fail;
+ }
+
+ for (i = 0; i < hdev->nvqs; ++i) {
+ r = vhost_virtqueue_init(hdev, hdev->vqs + i, 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
+ };
+ 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.");
+ 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);
+ 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);
+}
+
+/* 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;
+
+ assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs);
+
+ struct vhost_vring_file file = {
+ .index = index
+ };
+ 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));
+ }
+ r = hdev->vhost_ops->vhost_call(hdev, VHOST_SET_VRING_CALL, &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_call(hdev, VHOST_SET_MEM_TABLE, 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);
+ log_base = (uintptr_t)hdev->log->log;
+ r = hdev->vhost_ops->vhost_call(hdev, VHOST_SET_LOG_BASE,
+ hdev->log_size ? &log_base : NULL);
+ 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;
+}
+