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vhost.c
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/*
* 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 "qemu/atomic.h"
#include "qemu/range.h"
#include "qemu/error-report.h"
#include "qemu/memfd.h"
#include "standard-headers/linux/vhost_types.h"
#include "exec/address-spaces.h"
#include "hw/virtio/virtio-bus.h"
#include "hw/virtio/virtio-access.h"
#include "migration/blocker.h"
#include "migration/qemu-file-types.h"
#include "sysemu/dma.h"
#include "sysemu/tcg.h"
#include "trace.h"
/* enabled until disconnected backend stabilizes */
#define _VHOST_DEBUG 1
#ifdef _VHOST_DEBUG
#define VHOST_OPS_DEBUG(fmt, ...) \
do { error_report(fmt ": %s (%d)", ## __VA_ARGS__, \
strerror(errno), errno); } while (0)
#else
#define VHOST_OPS_DEBUG(fmt, ...) \
do { } while (0)
#endif
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 = QEMU_ALIGN_DOWN(start, 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 = qatomic_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;
if (!vq->used_phys && !vq->used_size) {
continue;
}
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);
}
}
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);
}
return log_size;
}
static struct vhost_log *vhost_log_alloc(uint64_t size, bool share)
{
Error *err = NULL;
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, &err);
if (err) {
error_report_err(err);
g_free(log);
return NULL;
}
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);
}
dev->log = NULL;
dev->log_size = 0;
}
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);
if (r < 0) {
VHOST_OPS_DEBUG("vhost_set_log_base failed");
}
vhost_log_put(dev, true);
dev->log = log;
dev->log_size = size;
}
static int vhost_dev_has_iommu(struct vhost_dev *dev)
{
VirtIODevice *vdev = dev->vdev;
/*
* For vhost, VIRTIO_F_IOMMU_PLATFORM means the backend support
* incremental memory mapping API via IOTLB API. For platform that
* does not have IOMMU, there's no need to enable this feature
* which may cause unnecessary IOTLB miss/update trnasactions.
*/
return vdev->dma_as != &address_space_memory &&
virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM);
}
static void *vhost_memory_map(struct vhost_dev *dev, hwaddr addr,
hwaddr *plen, bool is_write)
{
if (!vhost_dev_has_iommu(dev)) {
return cpu_physical_memory_map(addr, plen, is_write);
} else {
return (void *)(uintptr_t)addr;
}
}
static void vhost_memory_unmap(struct vhost_dev *dev, void *buffer,
hwaddr len, int is_write,
hwaddr access_len)
{
if (!vhost_dev_has_iommu(dev)) {
cpu_physical_memory_unmap(buffer, len, is_write, access_len);
}
}
static int vhost_verify_ring_part_mapping(void *ring_hva,
uint64_t ring_gpa,
uint64_t ring_size,
void *reg_hva,
uint64_t reg_gpa,
uint64_t reg_size)
{
uint64_t hva_ring_offset;
uint64_t ring_last = range_get_last(ring_gpa, ring_size);
uint64_t reg_last = range_get_last(reg_gpa, reg_size);
if (ring_last < reg_gpa || ring_gpa > reg_last) {
return 0;
}
/* check that whole ring's is mapped */
if (ring_last > reg_last) {
return -ENOMEM;
}
/* check that ring's MemoryRegion wasn't replaced */
hva_ring_offset = ring_gpa - reg_gpa;
if (ring_hva != reg_hva + hva_ring_offset) {
return -EBUSY;
}
return 0;
}
static int vhost_verify_ring_mappings(struct vhost_dev *dev,
void *reg_hva,
uint64_t reg_gpa,
uint64_t reg_size)
{
int i, j;
int r = 0;
const char *part_name[] = {
"descriptor table",
"available ring",
"used ring"
};
if (vhost_dev_has_iommu(dev)) {
return 0;
}
for (i = 0; i < dev->nvqs; ++i) {
struct vhost_virtqueue *vq = dev->vqs + i;
if (vq->desc_phys == 0) {
continue;
}
j = 0;
r = vhost_verify_ring_part_mapping(
vq->desc, vq->desc_phys, vq->desc_size,
reg_hva, reg_gpa, reg_size);
if (r) {
break;
}
j++;
r = vhost_verify_ring_part_mapping(
vq->avail, vq->avail_phys, vq->avail_size,
reg_hva, reg_gpa, reg_size);
if (r) {
break;
}
j++;
r = vhost_verify_ring_part_mapping(
vq->used, vq->used_phys, vq->used_size,
reg_hva, reg_gpa, reg_size);
if (r) {
break;
}
}
if (r == -ENOMEM) {
error_report("Unable to map %s for ring %d", part_name[j], i);
} else if (r == -EBUSY) {
error_report("%s relocated for ring %d", part_name[j], i);
}
return r;
}
/*
* vhost_section: identify sections needed for vhost access
*
* We only care about RAM sections here (where virtqueue and guest
* internals accessed by virtio might live). If we find one we still
* allow the backend to potentially filter it out of our list.
*/
static bool vhost_section(struct vhost_dev *dev, MemoryRegionSection *section)
{
MemoryRegion *mr = section->mr;
if (memory_region_is_ram(mr) && !memory_region_is_rom(mr)) {
uint8_t dirty_mask = memory_region_get_dirty_log_mask(mr);
uint8_t handled_dirty;
/*
* Kernel based vhost doesn't handle any block which is doing
* dirty-tracking other than migration for which it has
* specific logging support. However for TCG the kernel never
* gets involved anyway so we can also ignore it's
* self-modiying code detection flags. However a vhost-user
* client could still confuse a TCG guest if it re-writes
* executable memory that has already been translated.
*/
handled_dirty = (1 << DIRTY_MEMORY_MIGRATION) |
(1 << DIRTY_MEMORY_CODE);
if (dirty_mask & ~handled_dirty) {
trace_vhost_reject_section(mr->name, 1);
return false;
}
if (dev->vhost_ops->vhost_backend_mem_section_filter &&
!dev->vhost_ops->vhost_backend_mem_section_filter(dev, section)) {
trace_vhost_reject_section(mr->name, 2);
return false;
}
trace_vhost_section(mr->name);
return true;
} else {
trace_vhost_reject_section(mr->name, 3);
return false;
}
}
static void vhost_begin(MemoryListener *listener)
{
struct vhost_dev *dev = container_of(listener, struct vhost_dev,
memory_listener);
dev->tmp_sections = NULL;
dev->n_tmp_sections = 0;
}
static void vhost_commit(MemoryListener *listener)
{
struct vhost_dev *dev = container_of(listener, struct vhost_dev,
memory_listener);
MemoryRegionSection *old_sections;
int n_old_sections;
uint64_t log_size;
size_t regions_size;
int r;
int i;
bool changed = false;
/* Note we can be called before the device is started, but then
* starting the device calls set_mem_table, so we need to have
* built the data structures.
*/
old_sections = dev->mem_sections;
n_old_sections = dev->n_mem_sections;
dev->mem_sections = dev->tmp_sections;
dev->n_mem_sections = dev->n_tmp_sections;
if (dev->n_mem_sections != n_old_sections) {
changed = true;
} else {
/* Same size, lets check the contents */
for (int i = 0; i < n_old_sections; i++) {
if (!MemoryRegionSection_eq(&old_sections[i],
&dev->mem_sections[i])) {
changed = true;
break;
}
}
}
trace_vhost_commit(dev->started, changed);
if (!changed) {
goto out;
}
/* Rebuild the regions list from the new sections list */
regions_size = offsetof(struct vhost_memory, regions) +
dev->n_mem_sections * sizeof dev->mem->regions[0];
dev->mem = g_realloc(dev->mem, regions_size);
dev->mem->nregions = dev->n_mem_sections;
used_memslots = dev->mem->nregions;
for (i = 0; i < dev->n_mem_sections; i++) {
struct vhost_memory_region *cur_vmr = dev->mem->regions + i;
struct MemoryRegionSection *mrs = dev->mem_sections + i;
cur_vmr->guest_phys_addr = mrs->offset_within_address_space;
cur_vmr->memory_size = int128_get64(mrs->size);
cur_vmr->userspace_addr =
(uintptr_t)memory_region_get_ram_ptr(mrs->mr) +
mrs->offset_within_region;
cur_vmr->flags_padding = 0;
}
if (!dev->started) {
goto out;
}
for (i = 0; i < dev->mem->nregions; i++) {
if (vhost_verify_ring_mappings(dev,
(void *)(uintptr_t)dev->mem->regions[i].userspace_addr,
dev->mem->regions[i].guest_phys_addr,
dev->mem->regions[i].memory_size)) {
error_report("Verify ring failure on region %d", i);
abort();
}
}
if (!dev->log_enabled) {
r = dev->vhost_ops->vhost_set_mem_table(dev, dev->mem);
if (r < 0) {
VHOST_OPS_DEBUG("vhost_set_mem_table failed");
}
goto out;
}
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);
if (r < 0) {
VHOST_OPS_DEBUG("vhost_set_mem_table failed");
}
/* 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);
}
out:
/* Deref the old list of sections, this must happen _after_ the
* vhost_set_mem_table to ensure the client isn't still using the
* section we're about to unref.
*/
while (n_old_sections--) {
memory_region_unref(old_sections[n_old_sections].mr);
}
g_free(old_sections);
return;
}
/* Adds the section data to the tmp_section structure.
* It relies on the listener calling us in memory address order
* and for each region (via the _add and _nop methods) to
* join neighbours.
*/
static void vhost_region_add_section(struct vhost_dev *dev,
MemoryRegionSection *section)
{
bool need_add = true;
uint64_t mrs_size = int128_get64(section->size);
uint64_t mrs_gpa = section->offset_within_address_space;
uintptr_t mrs_host = (uintptr_t)memory_region_get_ram_ptr(section->mr) +
section->offset_within_region;
RAMBlock *mrs_rb = section->mr->ram_block;
trace_vhost_region_add_section(section->mr->name, mrs_gpa, mrs_size,
mrs_host);
if (dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER) {
/* Round the section to it's page size */
/* First align the start down to a page boundary */
size_t mrs_page = qemu_ram_pagesize(mrs_rb);
uint64_t alignage = mrs_host & (mrs_page - 1);
if (alignage) {
mrs_host -= alignage;
mrs_size += alignage;
mrs_gpa -= alignage;
}
/* Now align the size up to a page boundary */
alignage = mrs_size & (mrs_page - 1);
if (alignage) {
mrs_size += mrs_page - alignage;
}
trace_vhost_region_add_section_aligned(section->mr->name, mrs_gpa,
mrs_size, mrs_host);
}
if (dev->n_tmp_sections) {
/* Since we already have at least one section, lets see if
* this extends it; since we're scanning in order, we only
* have to look at the last one, and the FlatView that calls
* us shouldn't have overlaps.
*/
MemoryRegionSection *prev_sec = dev->tmp_sections +
(dev->n_tmp_sections - 1);
uint64_t prev_gpa_start = prev_sec->offset_within_address_space;
uint64_t prev_size = int128_get64(prev_sec->size);
uint64_t prev_gpa_end = range_get_last(prev_gpa_start, prev_size);
uint64_t prev_host_start =
(uintptr_t)memory_region_get_ram_ptr(prev_sec->mr) +
prev_sec->offset_within_region;
uint64_t prev_host_end = range_get_last(prev_host_start, prev_size);
if (mrs_gpa <= (prev_gpa_end + 1)) {
/* OK, looks like overlapping/intersecting - it's possible that
* the rounding to page sizes has made them overlap, but they should
* match up in the same RAMBlock if they do.
*/
if (mrs_gpa < prev_gpa_start) {
error_report("%s:Section '%s' rounded to %"PRIx64
" prior to previous '%s' %"PRIx64,
__func__, section->mr->name, mrs_gpa,
prev_sec->mr->name, prev_gpa_start);
/* A way to cleanly fail here would be better */
return;
}
/* Offset from the start of the previous GPA to this GPA */
size_t offset = mrs_gpa - prev_gpa_start;
if (prev_host_start + offset == mrs_host &&
section->mr == prev_sec->mr &&
(!dev->vhost_ops->vhost_backend_can_merge ||
dev->vhost_ops->vhost_backend_can_merge(dev,
mrs_host, mrs_size,
prev_host_start, prev_size))) {
uint64_t max_end = MAX(prev_host_end, mrs_host + mrs_size);
need_add = false;
prev_sec->offset_within_address_space =
MIN(prev_gpa_start, mrs_gpa);
prev_sec->offset_within_region =
MIN(prev_host_start, mrs_host) -
(uintptr_t)memory_region_get_ram_ptr(prev_sec->mr);
prev_sec->size = int128_make64(max_end - MIN(prev_host_start,
mrs_host));
trace_vhost_region_add_section_merge(section->mr->name,
int128_get64(prev_sec->size),
prev_sec->offset_within_address_space,
prev_sec->offset_within_region);
} else {
/* adjoining regions are fine, but overlapping ones with
* different blocks/offsets shouldn't happen
*/
if (mrs_gpa != prev_gpa_end + 1) {
error_report("%s: Overlapping but not coherent sections "
"at %"PRIx64,
__func__, mrs_gpa);
return;
}
}
}
}
if (need_add) {
++dev->n_tmp_sections;
dev->tmp_sections = g_renew(MemoryRegionSection, dev->tmp_sections,
dev->n_tmp_sections);
dev->tmp_sections[dev->n_tmp_sections - 1] = *section;
/* The flatview isn't stable and we don't use it, making it NULL
* means we can memcmp the list.
*/
dev->tmp_sections[dev->n_tmp_sections - 1].fv = NULL;
memory_region_ref(section->mr);
}
}
/* Used for both add and nop callbacks */
static void vhost_region_addnop(MemoryListener *listener,
MemoryRegionSection *section)
{
struct vhost_dev *dev = container_of(listener, struct vhost_dev,
memory_listener);
if (!vhost_section(dev, section)) {
return;
}
vhost_region_add_section(dev, section);
}
static void vhost_iommu_unmap_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
{
struct vhost_iommu *iommu = container_of(n, struct vhost_iommu, n);
struct vhost_dev *hdev = iommu->hdev;
hwaddr iova = iotlb->iova + iommu->iommu_offset;
if (vhost_backend_invalidate_device_iotlb(hdev, iova,
iotlb->addr_mask + 1)) {
error_report("Fail to invalidate device iotlb");
}
}
static void vhost_iommu_region_add(MemoryListener *listener,
MemoryRegionSection *section)
{
struct vhost_dev *dev = container_of(listener, struct vhost_dev,
iommu_listener);
struct vhost_iommu *iommu;
Int128 end;
int iommu_idx;
IOMMUMemoryRegion *iommu_mr;
if (!memory_region_is_iommu(section->mr)) {
return;
}
iommu_mr = IOMMU_MEMORY_REGION(section->mr);
iommu = g_malloc0(sizeof(*iommu));
end = int128_add(int128_make64(section->offset_within_region),
section->size);
end = int128_sub(end, int128_one());
iommu_idx = memory_region_iommu_attrs_to_index(iommu_mr,
MEMTXATTRS_UNSPECIFIED);
iommu_notifier_init(&iommu->n, vhost_iommu_unmap_notify,
IOMMU_NOTIFIER_DEVIOTLB_UNMAP,
section->offset_within_region,
int128_get64(end),
iommu_idx);
iommu->mr = section->mr;
iommu->iommu_offset = section->offset_within_address_space -
section->offset_within_region;
iommu->hdev = dev;
memory_region_register_iommu_notifier(section->mr, &iommu->n,
&error_fatal);
QLIST_INSERT_HEAD(&dev->iommu_list, iommu, iommu_next);
/* TODO: can replay help performance here? */
}
static void vhost_iommu_region_del(MemoryListener *listener,
MemoryRegionSection *section)
{
struct vhost_dev *dev = container_of(listener, struct vhost_dev,
iommu_listener);
struct vhost_iommu *iommu;
if (!memory_region_is_iommu(section->mr)) {
return;
}
QLIST_FOREACH(iommu, &dev->iommu_list, iommu_next) {
if (iommu->mr == section->mr &&
iommu->n.start == section->offset_within_region) {
memory_region_unregister_iommu_notifier(iommu->mr,
&iommu->n);
QLIST_REMOVE(iommu, iommu_next);
g_free(iommu);
break;
}
}
}
static int vhost_virtqueue_set_addr(struct vhost_dev *dev,
struct vhost_virtqueue *vq,
unsigned idx, bool enable_log)
{
struct vhost_vring_addr addr;
int r;
memset(&addr, 0, sizeof(struct vhost_vring_addr));
if (dev->vhost_ops->vhost_vq_get_addr) {
r = dev->vhost_ops->vhost_vq_get_addr(dev, &addr, vq);
if (r < 0) {
VHOST_OPS_DEBUG("vhost_vq_get_addr failed");
return -errno;
}
} else {
addr.desc_user_addr = (uint64_t)(unsigned long)vq->desc;
addr.avail_user_addr = (uint64_t)(unsigned long)vq->avail;
addr.used_user_addr = (uint64_t)(unsigned long)vq->used;
}
addr.index = idx;
addr.log_guest_addr = vq->used_phys;
addr.flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0;
r = dev->vhost_ops->vhost_set_vring_addr(dev, &addr);
if (r < 0) {
VHOST_OPS_DEBUG("vhost_set_vring_addr failed");
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;
}
if (!vhost_dev_has_iommu(dev)) {
features &= ~(0x1ULL << VIRTIO_F_IOMMU_PLATFORM);
}
if (dev->vhost_ops->vhost_force_iommu) {
if (dev->vhost_ops->vhost_force_iommu(dev) == true) {
features |= 0x1ULL << VIRTIO_F_IOMMU_PLATFORM;
}
}
r = dev->vhost_ops->vhost_set_features(dev, features);
if (r < 0) {
VHOST_OPS_DEBUG("vhost_set_features failed");
goto out;
}
if (dev->vhost_ops->vhost_set_backend_cap) {
r = dev->vhost_ops->vhost_set_backend_cap(dev);
if (r < 0) {
VHOST_OPS_DEBUG("vhost_set_backend_cap failed");
goto out;
}
}
out:
return r < 0 ? -errno : 0;
}
static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log)
{
int r, i, idx;
hwaddr addr;
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);
addr = virtio_queue_get_desc_addr(dev->vdev, idx);
if (!addr) {
/*
* The queue might not be ready for start. If this
* is the case there is no reason to continue the process.
* The similar logic is used by the vhost_virtqueue_start()
* routine.
*/
continue;
}
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);
vhost_virtqueue_set_addr(dev, dev->vqs + i, idx,
dev->log_enabled);
}
vhost_dev_set_features(dev, dev->log_enabled);
err_features:
return r;
}
static int vhost_migration_log(MemoryListener *listener, bool 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;
}
r = 0;
if (!enable) {
r = vhost_dev_set_log(dev, false);
if (r < 0) {
goto check_dev_state;
}
vhost_log_put(dev, false);
} else {
vhost_dev_log_resize(dev, vhost_get_log_size(dev));
r = vhost_dev_set_log(dev, true);
if (r < 0) {
goto check_dev_state;
}
}
check_dev_state:
dev->log_enabled = enable;
/*
* vhost-user-* devices could change their state during log
* initialization due to disconnect. So check dev state after
* vhost communication.
*/
if (!dev->started) {
/*
* Since device is in the stopped state, it is okay for
* migration. Return success.
*/
r = 0;
}
if (r) {
/* An error is occured. */
dev->log_enabled = false;
}
return r;
}
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;
}
VHOST_OPS_DEBUG("vhost_set_vring_endian failed");
if (errno == ENOTTY) {
error_report("vhost does not support cross-endian");
return -ENOSYS;
}
return -errno;
}
static int vhost_memory_region_lookup(struct vhost_dev *hdev,
uint64_t gpa, uint64_t *uaddr,
uint64_t *len)
{
int i;
for (i = 0; i < hdev->mem->nregions; i++) {
struct vhost_memory_region *reg = hdev->mem->regions + i;
if (gpa >= reg->guest_phys_addr &&
reg->guest_phys_addr + reg->memory_size > gpa) {
*uaddr = reg->userspace_addr + gpa - reg->guest_phys_addr;
*len = reg->guest_phys_addr + reg->memory_size - gpa;
return 0;
}
}
return -EFAULT;