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Migration pull 2021-02-08

Browse Source 
v2
   Dropped vmstate: Fix memory leak in vmstate_handle_alloc
     Broke on Power
   Added migration: only check page size match if RAM postcopy is enabled
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Merge remote-tracking branch 'remotes/dgilbert/tags/pull-migration-20210208a' into staging

Migration pull 2021-02-08

v2
  Dropped vmstate: Fix memory leak in vmstate_handle_alloc
    Broke on Power
  Added migration: only check page size match if RAM postcopy is enabled

# gpg: Signature made Mon 08 Feb 2021 11:28:14 GMT
# gpg:                using RSA key 45F5C71B4A0CB7FB977A9FA90516331EBC5BFDE7
# gpg: Good signature from "Dr. David Alan Gilbert (RH2) <dgilbert@redhat.com>" [full]
# Primary key fingerprint: 45F5 C71B 4A0C B7FB 977A  9FA9 0516 331E BC5B FDE7

* remotes/dgilbert/tags/pull-migration-20210208a: (27 commits)
  migration: only check page size match if RAM postcopy is enabled
  migration: introduce snapshot-{save, load, delete} QMP commands
  iotests: fix loading of common.config from tests/ subdir
  iotests: add support for capturing and matching QMP events
  migration: introduce a delete_snapshot wrapper
  migration: wire up support for snapshot device selection
  migration: control whether snapshots are ovewritten
  block: rename and alter bdrv_all_find_snapshot semantics
  block: allow specifying name of block device for vmstate storage
  block: add ability to specify list of blockdevs during snapshot
  migration: stop returning errno from load_snapshot()
  migration: Make save_snapshot() return bool, not 0/-1
  block: push error reporting into bdrv_all_*_snapshot functions
  migration: Display the migration blockers
  migration: Add blocker information
  migration: Fix a few absurdly defective error messages
  migration: Fix cache_init()'s "Failed to allocate" error messages
  migration: Clean up signed vs. unsigned XBZRLE cache-size
  migration: Fix migrate-set-parameters argument validation
  migration: introduce 'userfaultfd-wrlat.py' script
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Peter Maydell 2021-02-08 18:23:47 +00:00
commit 2436651b26
30 changed files with 2153 additions and 234 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
block/monitor/block-hmp-cmds.c
View File

@ -900,10 +900,11 @@ void hmp_info_snapshots(Monitor *mon, const QDict *qdict)
ImageEntry *image_entry, *next_ie;
SnapshotEntry *snapshot_entry;
Error *err = NULL;
bs = bdrv_all_find_vmstate_bs();
bs = bdrv_all_find_vmstate_bs(NULL, false, NULL, &err);
if (!bs) {
monitor_printf(mon, "No available block device supports snapshots\n");
error_report_err(err);
return;
}
aio_context = bdrv_get_aio_context(bs);
@ -953,7 +954,7 @@ void hmp_info_snapshots(Monitor *mon, const QDict *qdict)
total = 0;
for (i = 0; i < nb_sns; i++) {
SnapshotEntry *next_sn;
if (bdrv_all_find_snapshot(sn_tab[i].name, &bs1) == 0) {
if (bdrv_all_has_snapshot(sn_tab[i].name, false, NULL, NULL) == 1) {
global_snapshots[total] = i;
total++;
QTAILQ_FOREACH(image_entry, &image_list, next) {

270
block/snapshot.c
View File

@ -447,6 +447,41 @@ int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs,
return ret;
}
static int bdrv_all_get_snapshot_devices(bool has_devices, strList *devices,
GList **all_bdrvs,
Error **errp)
{
g_autoptr(GList) bdrvs = NULL;
if (has_devices) {
if (!devices) {
error_setg(errp, "At least one device is required for snapshot");
return -1;
}
while (devices) {
BlockDriverState *bs = bdrv_find_node(devices->value);
if (!bs) {
error_setg(errp, "No block device node '%s'", devices->value);
return -1;
}
bdrvs = g_list_append(bdrvs, bs);
devices = devices->next;
}
} else {
BlockDriverState *bs;
BdrvNextIterator it;
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
bdrvs = g_list_append(bdrvs, bs);
}
}
*all_bdrvs = g_steal_pointer(&bdrvs);
return 0;
}
static bool bdrv_all_snapshots_includes_bs(BlockDriverState *bs)
{
if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
@ -462,44 +497,59 @@ static bool bdrv_all_snapshots_includes_bs(BlockDriverState *bs)
* These functions will properly handle dataplane (take aio_context_acquire
* when appropriate for appropriate block drivers) */
bool bdrv_all_can_snapshot(BlockDriverState **first_bad_bs)
bool bdrv_all_can_snapshot(bool has_devices, strList *devices,
Error **errp)
{
bool ok = true;
BlockDriverState *bs;
BdrvNextIterator it;
g_autoptr(GList) bdrvs = NULL;
GList *iterbdrvs;
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0) {
return false;
}
iterbdrvs = bdrvs;
while (iterbdrvs) {
BlockDriverState *bs = iterbdrvs->data;
AioContext *ctx = bdrv_get_aio_context(bs);
bool ok = true;
aio_context_acquire(ctx);
if (bdrv_all_snapshots_includes_bs(bs)) {
if (devices || bdrv_all_snapshots_includes_bs(bs)) {
ok = bdrv_can_snapshot(bs);
}
aio_context_release(ctx);
if (!ok) {
bdrv_next_cleanup(&it);
goto fail;
error_setg(errp, "Device '%s' is writable but does not support "
"snapshots", bdrv_get_device_or_node_name(bs));
return false;
}
iterbdrvs = iterbdrvs->next;
}
fail:
*first_bad_bs = bs;
return ok;
return true;
}
int bdrv_all_delete_snapshot(const char *name, BlockDriverState **first_bad_bs,
int bdrv_all_delete_snapshot(const char *name,
bool has_devices, strList *devices,
Error **errp)
{
int ret = 0;
BlockDriverState *bs;
BdrvNextIterator it;
QEMUSnapshotInfo sn1, *snapshot = &sn1;
g_autoptr(GList) bdrvs = NULL;
GList *iterbdrvs;
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0) {
return -1;
}
iterbdrvs = bdrvs;
while (iterbdrvs) {
BlockDriverState *bs = iterbdrvs->data;
AioContext *ctx = bdrv_get_aio_context(bs);
QEMUSnapshotInfo sn1, *snapshot = &sn1;
int ret = 0;
aio_context_acquire(ctx);
if (bdrv_all_snapshots_includes_bs(bs) &&
if ((devices || bdrv_all_snapshots_includes_bs(bs)) &&
bdrv_snapshot_find(bs, snapshot, name) >= 0)
{
ret = bdrv_snapshot_delete(bs, snapshot->id_str,
@ -507,118 +557,180 @@ int bdrv_all_delete_snapshot(const char *name, BlockDriverState **first_bad_bs,
}
aio_context_release(ctx);
if (ret < 0) {
bdrv_next_cleanup(&it);
goto fail;
error_prepend(errp, "Could not delete snapshot '%s' on '%s': ",
name, bdrv_get_device_or_node_name(bs));
return -1;
}
iterbdrvs = iterbdrvs->next;
}
fail:
*first_bad_bs = bs;
return ret;
return 0;
}
int bdrv_all_goto_snapshot(const char *name, BlockDriverState **first_bad_bs,
int bdrv_all_goto_snapshot(const char *name,
bool has_devices, strList *devices,
Error **errp)
{
int ret = 0;
BlockDriverState *bs;
BdrvNextIterator it;
g_autoptr(GList) bdrvs = NULL;
GList *iterbdrvs;
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0) {
return -1;
}
iterbdrvs = bdrvs;
while (iterbdrvs) {
BlockDriverState *bs = iterbdrvs->data;
AioContext *ctx = bdrv_get_aio_context(bs);
int ret = 0;
aio_context_acquire(ctx);
if (bdrv_all_snapshots_includes_bs(bs)) {
if (devices || bdrv_all_snapshots_includes_bs(bs)) {
ret = bdrv_snapshot_goto(bs, name, errp);
}
aio_context_release(ctx);
if (ret < 0) {
bdrv_next_cleanup(&it);
goto fail;
error_prepend(errp, "Could not load snapshot '%s' on '%s': ",
name, bdrv_get_device_or_node_name(bs));
return -1;
}
iterbdrvs = iterbdrvs->next;
}
fail:
*first_bad_bs = bs;
return ret;
return 0;
}
int bdrv_all_find_snapshot(const char *name, BlockDriverState **first_bad_bs)
int bdrv_all_has_snapshot(const char *name,
bool has_devices, strList *devices,
Error **errp)
{
QEMUSnapshotInfo sn;
int err = 0;
BlockDriverState *bs;
BdrvNextIterator it;
g_autoptr(GList) bdrvs = NULL;
GList *iterbdrvs;
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
AioContext *ctx = bdrv_get_aio_context(bs);
aio_context_acquire(ctx);
if (bdrv_all_snapshots_includes_bs(bs)) {
err = bdrv_snapshot_find(bs, &sn, name);
}
aio_context_release(ctx);
if (err < 0) {
bdrv_next_cleanup(&it);
goto fail;
}
if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0) {
return -1;
}
fail:
*first_bad_bs = bs;
return err;
iterbdrvs = bdrvs;
while (iterbdrvs) {
BlockDriverState *bs = iterbdrvs->data;
AioContext *ctx = bdrv_get_aio_context(bs);
QEMUSnapshotInfo sn;
int ret = 0;
aio_context_acquire(ctx);
if (devices || bdrv_all_snapshots_includes_bs(bs)) {
ret = bdrv_snapshot_find(bs, &sn, name);
}
aio_context_release(ctx);
if (ret < 0) {
if (ret == -ENOENT) {
return 0;
} else {
error_setg_errno(errp, errno,
"Could not check snapshot '%s' on '%s'",
name, bdrv_get_device_or_node_name(bs));
return -1;
}
}
iterbdrvs = iterbdrvs->next;
}
return 1;
}
int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn,
BlockDriverState *vm_state_bs,
uint64_t vm_state_size,
BlockDriverState **first_bad_bs)
bool has_devices, strList *devices,
Error **errp)
{
int err = 0;
BlockDriverState *bs;
BdrvNextIterator it;
g_autoptr(GList) bdrvs = NULL;
GList *iterbdrvs;
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0) {
return -1;
}
iterbdrvs = bdrvs;
while (iterbdrvs) {
BlockDriverState *bs = iterbdrvs->data;
AioContext *ctx = bdrv_get_aio_context(bs);
int ret = 0;
aio_context_acquire(ctx);
if (bs == vm_state_bs) {
sn->vm_state_size = vm_state_size;
err = bdrv_snapshot_create(bs, sn);
} else if (bdrv_all_snapshots_includes_bs(bs)) {
ret = bdrv_snapshot_create(bs, sn);
} else if (devices || bdrv_all_snapshots_includes_bs(bs)) {
sn->vm_state_size = 0;
err = bdrv_snapshot_create(bs, sn);
ret = bdrv_snapshot_create(bs, sn);
}
aio_context_release(ctx);
if (err < 0) {
bdrv_next_cleanup(&it);
goto fail;
if (ret < 0) {
error_setg(errp, "Could not create snapshot '%s' on '%s'",
sn->name, bdrv_get_device_or_node_name(bs));
return -1;
}
iterbdrvs = iterbdrvs->next;
}
fail:
*first_bad_bs = bs;
return err;
return 0;
}
BlockDriverState *bdrv_all_find_vmstate_bs(void)
{
BlockDriverState *bs;
BdrvNextIterator it;
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
BlockDriverState *bdrv_all_find_vmstate_bs(const char *vmstate_bs,
bool has_devices, strList *devices,
Error **errp)
{
g_autoptr(GList) bdrvs = NULL;
GList *iterbdrvs;
if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0) {
return NULL;
}
iterbdrvs = bdrvs;
while (iterbdrvs) {
BlockDriverState *bs = iterbdrvs->data;
AioContext *ctx = bdrv_get_aio_context(bs);
bool found;
bool found = false;
aio_context_acquire(ctx);
found = bdrv_all_snapshots_includes_bs(bs) && bdrv_can_snapshot(bs);
found = (devices || bdrv_all_snapshots_includes_bs(bs)) &&
bdrv_can_snapshot(bs);
aio_context_release(ctx);
if (found) {
bdrv_next_cleanup(&it);
break;
if (vmstate_bs) {
if (g_str_equal(vmstate_bs,
bdrv_get_node_name(bs))) {
if (found) {
return bs;
} else {
error_setg(errp,
"vmstate block device '%s' does not support snapshots",
vmstate_bs);
return NULL;
}
}
} else if (found) {
return bs;
}
iterbdrvs = iterbdrvs->next;
}
return bs;
if (vmstate_bs) {
error_setg(errp,
"vmstate block device '%s' does not exist", vmstate_bs);
} else {
error_setg(errp,
"no block device can store vmstate for snapshot");
}
return NULL;
}

11
hw/ppc/spapr_pci.c
View File

@ -2173,6 +2173,16 @@ static int spapr_pci_pre_save(void *opaque)
return 0;
}
static int spapr_pci_post_save(void *opaque)
{
SpaprPhbState *sphb = opaque;
g_free(sphb->msi_devs);
sphb->msi_devs = NULL;
sphb->msi_devs_num = 0;
return 0;
}
static int spapr_pci_post_load(void *opaque, int version_id)
{
SpaprPhbState *sphb = opaque;
@ -2205,6 +2215,7 @@ static const VMStateDescription vmstate_spapr_pci = {
.version_id = 2,
.minimum_version_id = 2,
.pre_save = spapr_pci_pre_save,
.post_save = spapr_pci_post_save,
.post_load = spapr_pci_post_load,
.fields = (VMStateField[]) {
VMSTATE_UINT64_EQUAL(buid, SpaprPhbState, NULL),

25
include/block/snapshot.h
View File

@ -25,7 +25,7 @@
#ifndef SNAPSHOT_H
#define SNAPSHOT_H
#include "qapi/qapi-builtin-types.h"
#define SNAPSHOT_OPT_BASE "snapshot."
#define SNAPSHOT_OPT_ID "snapshot.id"
@ -77,17 +77,26 @@ int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs,
* These functions will properly handle dataplane (take aio_context_acquire
* when appropriate for appropriate block drivers */
bool bdrv_all_can_snapshot(BlockDriverState **first_bad_bs);
int bdrv_all_delete_snapshot(const char *name, BlockDriverState **first_bsd_bs,
Error **errp);
int bdrv_all_goto_snapshot(const char *name, BlockDriverState **first_bad_bs,
bool bdrv_all_can_snapshot(bool has_devices, strList *devices,
Error **errp);
int bdrv_all_find_snapshot(const char *name, BlockDriverState **first_bad_bs);
int bdrv_all_delete_snapshot(const char *name,
bool has_devices, strList *devices,
Error **errp);
int bdrv_all_goto_snapshot(const char *name,
bool has_devices, strList *devices,
Error **errp);
int bdrv_all_has_snapshot(const char *name,
bool has_devices, strList *devices,
Error **errp);
int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn,
BlockDriverState *vm_state_bs,
uint64_t vm_state_size,
BlockDriverState **first_bad_bs);
bool has_devices,
strList *devices,
Error **errp);
BlockDriverState *bdrv_all_find_vmstate_bs(void);
BlockDriverState *bdrv_all_find_vmstate_bs(const char *vmstate_bs,
bool has_devices, strList *devices,
Error **errp);
#endif

8
include/exec/memory.h
View File

@ -149,6 +149,14 @@ typedef struct IOMMUTLBEvent {
/* RAM is a persistent kind memory */
#define RAM_PMEM (1 << 5)
/*
* UFFDIO_WRITEPROTECT is used on this RAMBlock to
* support 'write-tracking' migration type.
* Implies ram_state->ram_wt_enabled.
*/
#define RAM_UF_WRITEPROTECT (1 << 6)
static inline void iommu_notifier_init(IOMMUNotifier *n, IOMMUNotify fn,
IOMMUNotifierFlag flags,
hwaddr start, hwaddr end,

47
include/migration/snapshot.h
View File

@ -15,7 +15,50 @@
#ifndef QEMU_MIGRATION_SNAPSHOT_H
#define QEMU_MIGRATION_SNAPSHOT_H
int save_snapshot(const char *name, Error **errp);
int load_snapshot(const char *name, Error **errp);
#include "qapi/qapi-builtin-types.h"
/**
* save_snapshot: Save an internal snapshot.
* @name: name of internal snapshot
* @overwrite: replace existing snapshot with @name
* @vmstate: blockdev node name to store VM state in
* @has_devices: whether to use explicit device list
* @devices: explicit device list to snapshot
* @errp: pointer to error object
* On success, return %true.
* On failure, store an error through @errp and return %false.
*/
bool save_snapshot(const char *name, bool overwrite,
const char *vmstate,
bool has_devices, strList *devices,
Error **errp);
/**
* load_snapshot: Load an internal snapshot.
* @name: name of internal snapshot
* @vmstate: blockdev node name to load VM state from
* @has_devices: whether to use explicit device list
* @devices: explicit device list to snapshot
* @errp: pointer to error object
* On success, return %true.
* On failure, store an error through @errp and return %false.
*/
bool load_snapshot(const char *name,
const char *vmstate,
bool has_devices, strList *devices,
Error **errp);
/**
* delete_snapshot: Delete a snapshot.
* @name: path to snapshot
* @has_devices: whether to use explicit device list
* @devices: explicit device list to snapshot
* @errp: pointer to error object
* On success, return %true.
* On failure, store an error through @errp and return %false.
*/
bool delete_snapshot(const char *name,
bool has_devices, strList *devices,
Error **errp);
#endif

35
include/qemu/userfaultfd.h Normal file
View File

@ -0,0 +1,35 @@
/*
* Linux UFFD-WP support
*
* Copyright Virtuozzo GmbH, 2020
*
* Authors:
* Andrey Gruzdev <andrey.gruzdev@virtuozzo.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or
* later. See the COPYING file in the top-level directory.
*/
#ifndef USERFAULTFD_H
#define USERFAULTFD_H
#include "qemu/osdep.h"
#include "exec/hwaddr.h"
#include <linux/userfaultfd.h>
int uffd_query_features(uint64_t *features);
int uffd_create_fd(uint64_t features, bool non_blocking);
void uffd_close_fd(int uffd_fd);
int uffd_register_memory(int uffd_fd, void *addr, uint64_t length,
uint64_t mode, uint64_t *ioctls);
int uffd_unregister_memory(int uffd_fd, void *addr, uint64_t length);
int uffd_change_protection(int uffd_fd, void *addr, uint64_t length,
bool wp, bool dont_wake);
int uffd_copy_page(int uffd_fd, void *dst_addr, void *src_addr,
uint64_t length, bool dont_wake);
int uffd_zero_page(int uffd_fd, void *addr, uint64_t length, bool dont_wake);
int uffd_wakeup(int uffd_fd, void *addr, uint64_t length);
int uffd_read_events(int uffd_fd, struct uffd_msg *msgs, int count);
bool uffd_poll_events(int uffd_fd, int tmo);
#endif /* USERFAULTFD_H */

409
migration/migration.c
View File

@ -58,6 +58,7 @@
#include "qemu/queue.h"
#include "multifd.h"
#include "qemu/yank.h"
#include "sysemu/cpus.h"
#ifdef CONFIG_VFIO
#include "hw/vfio/vfio-common.h"
@ -134,6 +135,38 @@ enum mig_rp_message_type {
MIG_RP_MSG_MAX
};
/* Migration capabilities set */
struct MigrateCapsSet {
int size; /* Capability set size */
MigrationCapability caps[]; /* Variadic array of capabilities */
};
typedef struct MigrateCapsSet MigrateCapsSet;
/* Define and initialize MigrateCapsSet */
#define INITIALIZE_MIGRATE_CAPS_SET(_name, ...) \
MigrateCapsSet _name = { \
.size = sizeof((int []) { __VA_ARGS__ }) / sizeof(int), \
.caps = { __VA_ARGS__ } \
}
/* Background-snapshot compatibility check list */
static const
INITIALIZE_MIGRATE_CAPS_SET(check_caps_background_snapshot,
MIGRATION_CAPABILITY_POSTCOPY_RAM,
MIGRATION_CAPABILITY_DIRTY_BITMAPS,
MIGRATION_CAPABILITY_POSTCOPY_BLOCKTIME,
MIGRATION_CAPABILITY_LATE_BLOCK_ACTIVATE,
MIGRATION_CAPABILITY_RETURN_PATH,
MIGRATION_CAPABILITY_MULTIFD,
MIGRATION_CAPABILITY_PAUSE_BEFORE_SWITCHOVER,
MIGRATION_CAPABILITY_AUTO_CONVERGE,
MIGRATION_CAPABILITY_RELEASE_RAM,
MIGRATION_CAPABILITY_RDMA_PIN_ALL,
MIGRATION_CAPABILITY_COMPRESS,
MIGRATION_CAPABILITY_XBZRLE,
MIGRATION_CAPABILITY_X_COLO,
MIGRATION_CAPABILITY_VALIDATE_UUID);
/* When we add fault tolerance, we could have several
migrations at once. For now we don't need to add
dynamic creation of migration */
@ -141,6 +174,8 @@ enum mig_rp_message_type {
static MigrationState *current_migration;
static MigrationIncomingState *current_incoming;
static GSList *migration_blockers;
static bool migration_object_check(MigrationState *ms, Error **errp);
static int migration_maybe_pause(MigrationState *s,
int *current_active_state,
@ -1041,6 +1076,27 @@ static void fill_source_migration_info(MigrationInfo *info)
{
MigrationState *s = migrate_get_current();
info->blocked = migration_is_blocked(NULL);
info->has_blocked_reasons = info->blocked;
info->blocked_reasons = NULL;
if (info->blocked) {
GSList *cur_blocker = migration_blockers;
/*
* There are two types of reasons a migration might be blocked;
* a) devices marked in VMState as non-migratable, and
* b) Explicit migration blockers
* We need to add both of them here.
*/
qemu_savevm_non_migratable_list(&info->blocked_reasons);
while (cur_blocker) {
QAPI_LIST_PREPEND(info->blocked_reasons,
g_strdup(error_get_pretty(cur_blocker->data)));
cur_blocker = g_slist_next(cur_blocker);
}
}
switch (s->state) {
case MIGRATION_STATUS_NONE:
/* no migration has happened ever */
@ -1089,6 +1145,31 @@ static void fill_source_migration_info(MigrationInfo *info)
info->status = s->state;
}
typedef enum WriteTrackingSupport {
WT_SUPPORT_UNKNOWN = 0,
WT_SUPPORT_ABSENT,
WT_SUPPORT_AVAILABLE,
WT_SUPPORT_COMPATIBLE
} WriteTrackingSupport;
static
WriteTrackingSupport migrate_query_write_tracking(void)
{
/* Check if kernel supports required UFFD features */
if (!ram_write_tracking_available()) {
return WT_SUPPORT_ABSENT;
}
/*
* Check if current memory configuration is
* compatible with required UFFD features.
*/
if (!ram_write_tracking_compatible()) {
return WT_SUPPORT_AVAILABLE;
}
return WT_SUPPORT_COMPATIBLE;
}
/**
* @migration_caps_check - check capability validity
*
@ -1150,6 +1231,39 @@ static bool migrate_caps_check(bool *cap_list,
}
}
if (cap_list[MIGRATION_CAPABILITY_BACKGROUND_SNAPSHOT]) {
WriteTrackingSupport wt_support;
int idx;
/*
* Check if 'background-snapshot' capability is supported by
* host kernel and compatible with guest memory configuration.
*/
wt_support = migrate_query_write_tracking();
if (wt_support < WT_SUPPORT_AVAILABLE) {
error_setg(errp, "Background-snapshot is not supported by host kernel");
return false;
}
if (wt_support < WT_SUPPORT_COMPATIBLE) {
error_setg(errp, "Background-snapshot is not compatible "
"with guest memory configuration");
return false;
}
/*
* Check if there are any migration capabilities
* incompatible with 'background-snapshot'.
*/
for (idx = 0; idx < check_caps_background_snapshot.size; idx++) {
int incomp_cap = check_caps_background_snapshot.caps[idx];
if (cap_list[incomp_cap]) {
error_setg(errp,
"Background-snapshot is not compatible with %s",
MigrationCapability_str(incomp_cap));
return false;
}
}
}
return true;
}
@ -1226,21 +1340,21 @@ static bool migrate_params_check(MigrationParameters *params, Error **errp)
if (params->has_compress_level &&
(params->compress_level > 9)) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "compress_level",
"is invalid, it should be in the range of 0 to 9");
"a value between 0 and 9");
return false;
}
if (params->has_compress_threads && (params->compress_threads < 1)) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
"compress_threads",
"is invalid, it should be in the range of 1 to 255");
"a value between 1 and 255");
return false;
}
if (params->has_decompress_threads && (params->decompress_threads < 1)) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
"decompress_threads",
"is invalid, it should be in the range of 1 to 255");
"a value between 1 and 255");
return false;
}
@ -1293,21 +1407,21 @@ static bool migrate_params_check(MigrationParameters *params, Error **errp)
if (params->has_multifd_channels && (params->multifd_channels < 1)) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
"multifd_channels",
"is invalid, it should be in the range of 1 to 255");
"a value between 1 and 255");
return false;
}
if (params->has_multifd_zlib_level &&
(params->multifd_zlib_level > 9)) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "multifd_zlib_level",
"is invalid, it should be in the range of 0 to 9");
"a value between 0 and 9");
return false;
}
if (params->has_multifd_zstd_level &&
(params->multifd_zstd_level > 20)) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "multifd_zstd_level",
"is invalid, it should be in the range of 0 to 20");
"a value between 0 and 20");
return false;
}
@ -1316,8 +1430,7 @@ static bool migrate_params_check(MigrationParameters *params, Error **errp)
!is_power_of_2(params->xbzrle_cache_size))) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
"xbzrle_cache_size",
"is invalid, it should be bigger than target page size"
" and a power of 2");
"a power of two no less than the target page size");
return false;
}
@ -1334,21 +1447,21 @@ static bool migrate_params_check(MigrationParameters *params, Error **errp)
params->announce_initial > 100000) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
"announce_initial",
"is invalid, it must be less than 100000 ms");
"a value between 0 and 100000");
return false;
}
if (params->has_announce_max &&
params->announce_max > 100000) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
"announce_max",
"is invalid, it must be less than 100000 ms");
"a value between 0 and 100000");
return false;
}
if (params->has_announce_rounds &&
params->announce_rounds > 1000) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
"announce_rounds",
"is invalid, it must be in the range of 0 to 1000");
"a value between 0 and 1000");
return false;
}
if (params->has_announce_step &&
@ -1356,7 +1469,7 @@ static bool migrate_params_check(MigrationParameters *params, Error **errp)
params->announce_step > 10000)) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
"announce_step",
"is invalid, it must be in the range of 1 to 10000 ms");
"a value between 0 and 10000");
return false;
}
@ -1909,6 +2022,7 @@ void migrate_init(MigrationState *s)
* locks.
*/
s->cleanup_bh = 0;
s->vm_start_bh = 0;
s->to_dst_file = NULL;
s->state = MIGRATION_STATUS_NONE;
s->rp_state.from_dst_file = NULL;
@ -1934,8 +2048,6 @@ void migrate_init(MigrationState *s)
s->threshold_size = 0;
}
static GSList *migration_blockers;
int migrate_add_blocker(Error *reason, Error **errp)
{
if (only_migratable) {
@ -2216,7 +2328,7 @@ void qmp_migrate_set_cache_size(int64_t value, Error **errp)
qmp_migrate_set_parameters(&p, errp);
}
int64_t qmp_query_migrate_cache_size(Error **errp)
uint64_t qmp_query_migrate_cache_size(Error **errp)
{
return migrate_xbzrle_cache_size();
}
@ -2446,7 +2558,7 @@ int migrate_use_xbzrle(void)
return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE];
}
int64_t migrate_xbzrle_cache_size(void)
uint64_t migrate_xbzrle_cache_size(void)
{
MigrationState *s;
@ -2491,6 +2603,15 @@ bool migrate_use_block_incremental(void)
return s->parameters.block_incremental;
}
bool migrate_background_snapshot(void)
{
MigrationState *s;
s = migrate_get_current();
return s->enabled_capabilities[MIGRATION_CAPABILITY_BACKGROUND_SNAPSHOT];
}
/* migration thread support */
/*
* Something bad happened to the RP stream, mark an error
@ -3117,6 +3238,50 @@ fail:
MIGRATION_STATUS_FAILED);
}
/**
* bg_migration_completion: Used by bg_migration_thread when after all the
* RAM has been saved. The caller 'breaks' the loop when this returns.
*
* @s: Current migration state
*/
static void bg_migration_completion(MigrationState *s)
{
int current_active_state = s->state;
/*
* Stop tracking RAM writes - un-protect memory, un-register UFFD
* memory ranges, flush kernel wait queues and wake up threads
* waiting for write fault to be resolved.
*/
ram_write_tracking_stop();
if (s->state == MIGRATION_STATUS_ACTIVE) {
/*
* By this moment we have RAM content saved into the migration stream.
* The next step is to flush the non-RAM content (device state)
* right after the ram content. The device state has been stored into
* the temporary buffer before RAM saving started.
*/
qemu_put_buffer(s->to_dst_file, s->bioc->data, s->bioc->usage);
qemu_fflush(s->to_dst_file);
} else if (s->state == MIGRATION_STATUS_CANCELLING) {
goto fail;
}
if (qemu_file_get_error(s->to_dst_file)) {
trace_migration_completion_file_err();
goto fail;
}
migrate_set_state(&s->state, current_active_state,
MIGRATION_STATUS_COMPLETED);
return;
fail:
migrate_set_state(&s->state, current_active_state,
MIGRATION_STATUS_FAILED);
}
bool migrate_colo_enabled(void)
{
MigrationState *s = migrate_get_current();
@ -3457,6 +3622,47 @@ static void migration_iteration_finish(MigrationState *s)
qemu_mutex_unlock_iothread();
}
static void bg_migration_iteration_finish(MigrationState *s)
{
qemu_mutex_lock_iothread();
switch (s->state) {
case MIGRATION_STATUS_COMPLETED:
migration_calculate_complete(s);
break;
case MIGRATION_STATUS_ACTIVE:
case MIGRATION_STATUS_FAILED:
case MIGRATION_STATUS_CANCELLED:
case MIGRATION_STATUS_CANCELLING:
break;
default:
/* Should not reach here, but if so, forgive the VM. */
error_report("%s: Unknown ending state %d", __func__, s->state);
break;
}
migrate_fd_cleanup_schedule(s);
qemu_mutex_unlock_iothread();
}
/*
* Return true if continue to the next iteration directly, false
* otherwise.
*/
static MigIterateState bg_migration_iteration_run(MigrationState *s)
{
int res;
res = qemu_savevm_state_iterate(s->to_dst_file, false);
if (res > 0) {
bg_migration_completion(s);
return MIG_ITERATE_BREAK;
}
return MIG_ITERATE_RESUME;
}
void migration_make_urgent_request(void)
{
qemu_sem_post(&migrate_get_current()->rate_limit_sem);
@ -3604,6 +3810,165 @@ static void *migration_thread(void *opaque)
return NULL;
}
static void bg_migration_vm_start_bh(void *opaque)
{
MigrationState *s = opaque;
qemu_bh_delete(s->vm_start_bh);
s->vm_start_bh = NULL;
vm_start();
s->downtime = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - s->downtime_start;
}
/**
* Background snapshot thread, based on live migration code.
* This is an alternative implementation of live migration mechanism
* introduced specifically to support background snapshots.
*
* It takes advantage of userfault_fd write protection mechanism introduced
* in v5.7 kernel. Compared to existing dirty page logging migration much
* lesser stream traffic is produced resulting in smaller snapshot images,
* simply cause of no page duplicates can get into the stream.
*
* Another key point is that generated vmstate stream reflects machine state
* 'frozen' at the beginning of snapshot creation compared to dirty page logging
* mechanism, which effectively results in that saved snapshot is the state of VM
* at the end of the process.
*/
static void *bg_migration_thread(void *opaque)
{
MigrationState *s = opaque;
int64_t setup_start;
MigThrError thr_error;
QEMUFile *fb;
bool early_fail = true;
rcu_register_thread();
object_ref(OBJECT(s));
qemu_file_set_rate_limit(s->to_dst_file, INT64_MAX);
setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
/*
* We want to save vmstate for the moment when migration has been
* initiated but also we want to save RAM content while VM is running.
* The RAM content should appear first in the vmstate. So, we first
* stash the non-RAM part of the vmstate to the temporary buffer,
* then write RAM part of the vmstate to the migration stream
* with vCPUs running and, finally, write stashed non-RAM part of
* the vmstate from the buffer to the migration stream.
*/
s->bioc = qio_channel_buffer_new(128 * 1024);
qio_channel_set_name(QIO_CHANNEL(s->bioc), "vmstate-buffer");
fb = qemu_fopen_channel_output(QIO_CHANNEL(s->bioc));
object_unref(OBJECT(s->bioc));
update_iteration_initial_status(s);
qemu_savevm_state_header(s->to_dst_file);
qemu_savevm_state_setup(s->to_dst_file);
if (qemu_savevm_state_guest_unplug_pending()) {
migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
MIGRATION_STATUS_WAIT_UNPLUG);
while (s->state == MIGRATION_STATUS_WAIT_UNPLUG &&
qemu_savevm_state_guest_unplug_pending()) {
qemu_sem_timedwait(&s->wait_unplug_sem, 250);
}
migrate_set_state(&s->state, MIGRATION_STATUS_WAIT_UNPLUG,
MIGRATION_STATUS_ACTIVE);
} else {
migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
MIGRATION_STATUS_ACTIVE);
}
s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
trace_migration_thread_setup_complete();
s->downtime_start = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
qemu_mutex_lock_iothread();
/*
* If VM is currently in suspended state, then, to make a valid runstate
* transition in vm_stop_force_state() we need to wakeup it up.
*/
qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, NULL);
s->vm_was_running = runstate_is_running();
if (global_state_store()) {
goto fail;
}
/* Forcibly stop VM before saving state of vCPUs and devices */
if (vm_stop_force_state(RUN_STATE_PAUSED)) {
goto fail;
}
/*
* Put vCPUs in sync with shadow context structures, then
* save their state to channel-buffer along with devices.
*/
cpu_synchronize_all_states();
if (qemu_savevm_state_complete_precopy_non_iterable(fb, false, false)) {
goto fail;
}
/* Now initialize UFFD context and start tracking RAM writes */
if (ram_write_tracking_start()) {
goto fail;
}
early_fail = false;
/*
* Start VM from BH handler to avoid write-fault lock here.
* UFFD-WP protection for the whole RAM is already enabled so
* calling VM state change notifiers from vm_start() would initiate
* writes to virtio VQs memory which is in write-protected region.
*/
s->vm_start_bh = qemu_bh_new(bg_migration_vm_start_bh, s);
qemu_bh_schedule(s->vm_start_bh);
qemu_mutex_unlock_iothread();
while (migration_is_active(s)) {
MigIterateState iter_state = bg_migration_iteration_run(s);
if (iter_state == MIG_ITERATE_SKIP) {
continue;
} else if (iter_state == MIG_ITERATE_BREAK) {
break;
}
/*
* Try to detect any kind of failures, and see whether we
* should stop the migration now.
*/
thr_error = migration_detect_error(s);
if (thr_error == MIG_THR_ERR_FATAL) {
/* Stop migration */
break;
}
migration_update_counters(s, qemu_clock_get_ms(QEMU_CLOCK_REALTIME));
}
trace_migration_thread_after_loop();
fail:
if (early_fail) {
migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE,
MIGRATION_STATUS_FAILED);
qemu_mutex_unlock_iothread();
}
bg_migration_iteration_finish(s);
qemu_fclose(fb);
object_unref(OBJECT(s));
rcu_unregister_thread();
return NULL;
}
void migrate_fd_connect(MigrationState *s, Error *error_in)
{
Error *local_err = NULL;
@ -3667,8 +4032,14 @@ void migrate_fd_connect(MigrationState *s, Error *error_in)
migrate_fd_cleanup(s);
return;
}
qemu_thread_create(&s->thread, "live_migration", migration_thread, s,
QEMU_THREAD_JOINABLE);
if (migrate_background_snapshot()) {
qemu_thread_create(&s->thread, "bg_snapshot",
bg_migration_thread, s, QEMU_THREAD_JOINABLE);
} else {
qemu_thread_create(&s->thread, "live_migration",
migration_thread, s, QEMU_THREAD_JOINABLE);
}
s->migration_thread_running = true;
}
@ -3784,6 +4155,8 @@ static Property migration_properties[] = {
DEFINE_PROP_MIG_CAP("x-block", MIGRATION_CAPABILITY_BLOCK),
DEFINE_PROP_MIG_CAP("x-return-path", MIGRATION_CAPABILITY_RETURN_PATH),
DEFINE_PROP_MIG_CAP("x-multifd", MIGRATION_CAPABILITY_MULTIFD),
DEFINE_PROP_MIG_CAP("x-background-snapshot",
MIGRATION_CAPABILITY_BACKGROUND_SNAPSHOT),
DEFINE_PROP_END_OF_LIST(),
};

6
migration/migration.h
View File

@ -20,6 +20,7 @@
#include "qemu/thread.h"
#include "qemu/coroutine_int.h"
#include "io/channel.h"
#include "io/channel-buffer.h"
#include "net/announce.h"
#include "qom/object.h"
@ -147,8 +148,10 @@ struct MigrationState {
/*< public >*/
QemuThread thread;
QEMUBH *vm_start_bh;
QEMUBH *cleanup_bh;
QEMUFile *to_dst_file;
QIOChannelBuffer *bioc;
/*
* Protects to_dst_file pointer. We need to make sure we won't
* yield or hang during the critical section, since this lock will
@ -324,7 +327,7 @@ int migrate_multifd_zlib_level(void);
int migrate_multifd_zstd_level(void);
int migrate_use_xbzrle(void);
int64_t migrate_xbzrle_cache_size(void);
uint64_t migrate_xbzrle_cache_size(void);
bool migrate_colo_enabled(void);
bool migrate_use_block(void);
@ -341,6 +344,7 @@ int migrate_compress_wait_thread(void);
int migrate_decompress_threads(void);
bool migrate_use_events(void);
bool migrate_postcopy_blocktime(void);
bool migrate_background_snapshot(void);
/* Sending on the return path - generic and then for each message type */
void migrate_send_rp_shut(MigrationIncomingState *mis,

8
migration/page_cache.c
View File

@ -38,7 +38,7 @@ struct PageCache {
size_t num_items;
};
PageCache *cache_init(int64_t new_size, size_t page_size, Error **errp)
PageCache *cache_init(uint64_t new_size, size_t page_size, Error **errp)
{
int64_t i;
size_t num_pages = new_size / page_size;
@ -60,8 +60,7 @@ PageCache *cache_init(int64_t new_size, size_t page_size, Error **errp)
/* We prefer not to abort if there is no memory */
cache = g_try_malloc(sizeof(*cache));
if (!cache) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
"Failed to allocate cache");
error_setg(errp, "Failed to allocate cache");
return NULL;
}
cache->page_size = page_size;
@ -74,8 +73,7 @@ PageCache *cache_init(int64_t new_size, size_t page_size, Error **errp)
cache->page_cache = g_try_malloc((cache->max_num_items) *
sizeof(*cache->page_cache));
if (!cache->page_cache) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
"Failed to allocate page cache");
error_setg(errp, "Failed to allocate page cache");
g_free(cache);
return NULL;
}

2
migration/page_cache.h
View File

@ -28,7 +28,7 @@ typedef struct PageCache PageCache;
* @page_size: cache page size
* @errp: set *errp if the check failed, with reason
*/
PageCache *cache_init(int64_t cache_size, size_t page_size, Error **errp);
PageCache *cache_init(uint64_t cache_size, size_t page_size, Error **errp);
/**
* cache_fini: free all cache resources
* @cache pointer to the PageCache struct

2
migration/qemu-file.c
View File

@ -595,7 +595,7 @@ size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size)
{
if (size < IO_BUF_SIZE) {
size_t res;
uint8_t *src;
uint8_t *src = NULL;
res = qemu_peek_buffer(f, &src, size, 0);

307
migration/ram.c
View File

@ -56,6 +56,11 @@
#include "savevm.h"
#include "qemu/iov.h"
#include "multifd.h"
#include "sysemu/runstate.h"
#if defined(__linux__)
#include "qemu/userfaultfd.h"
#endif /* defined(__linux__) */
/***********************************************************/
/* ram save/restore */
@ -126,7 +131,7 @@ static void XBZRLE_cache_unlock(void)
* @new_size: new cache size
* @errp: set *errp if the check failed, with reason
*/
int xbzrle_cache_resize(int64_t new_size, Error **errp)
int xbzrle_cache_resize(uint64_t new_size, Error **errp)
{
PageCache *new_cache;
int64_t ret = 0;
@ -298,6 +303,8 @@ struct RAMSrcPageRequest {
struct RAMState {
/* QEMUFile used for this migration */
QEMUFile *f;
/* UFFD file descriptor, used in 'write-tracking' migration */
int uffdio_fd;
/* Last block that we have visited searching for dirty pages */
RAMBlock *last_seen_block;
/* Last block from where we have sent data */
@ -1434,6 +1441,269 @@ static RAMBlock *unqueue_page(RAMState *rs, ram_addr_t *offset)
return block;
}
#if defined(__linux__)
/**
* poll_fault_page: try to get next UFFD write fault page and, if pending fault
* is found, return RAM block pointer and page offset
*
* Returns pointer to the RAMBlock containing faulting page,
* NULL if no write faults are pending
*
* @rs: current RAM state
* @offset: page offset from the beginning of the block
*/
static RAMBlock *poll_fault_page(RAMState *rs, ram_addr_t *offset)
{
struct uffd_msg uffd_msg;
void *page_address;
RAMBlock *bs;
int res;
if (!migrate_background_snapshot()) {
return NULL;
}
res = uffd_read_events(rs->uffdio_fd, &uffd_msg, 1);
if (res <= 0) {
return NULL;
}
page_address = (void *)(uintptr_t) uffd_msg.arg.pagefault.address;
bs = qemu_ram_block_from_host(page_address, false, offset);
assert(bs && (bs->flags & RAM_UF_WRITEPROTECT) != 0);
return bs;
}
/**
* ram_save_release_protection: release UFFD write protection after
* a range of pages has been saved
*
* @rs: current RAM state
* @pss: page-search-status structure
* @start_page: index of the first page in the range relative to pss->block
*
* Returns 0 on success, negative value in case of an error
*/
static int ram_save_release_protection(RAMState *rs, PageSearchStatus *pss,
unsigned long start_page)
{
int res = 0;
/* Check if page is from UFFD-managed region. */
if (pss->block->flags & RAM_UF_WRITEPROTECT) {
void *page_address = pss->block->host + (start_page << TARGET_PAGE_BITS);
uint64_t run_length = (pss->page - start_page + 1) << TARGET_PAGE_BITS;
/* Flush async buffers before un-protect. */
qemu_fflush(rs->f);
/* Un-protect memory range. */
res = uffd_change_protection(rs->uffdio_fd, page_address, run_length,
false, false);
}
return res;
}
/* ram_write_tracking_available: check if kernel supports required UFFD features
*
* Returns true if supports, false otherwise
*/
bool ram_write_tracking_available(void)
{
uint64_t uffd_features;
int res;
res = uffd_query_features(&uffd_features);
return (res == 0 &&
(uffd_features & UFFD_FEATURE_PAGEFAULT_FLAG_WP) != 0);
}
/* ram_write_tracking_compatible: check if guest configuration is
* compatible with 'write-tracking'
*
* Returns true if compatible, false otherwise
*/
bool ram_write_tracking_compatible(void)
{
const uint64_t uffd_ioctls_mask = BIT(_UFFDIO_WRITEPROTECT);
int uffd_fd;
RAMBlock *bs;
bool ret = false;
/* Open UFFD file descriptor */
uffd_fd = uffd_create_fd(UFFD_FEATURE_PAGEFAULT_FLAG_WP, false);
if (uffd_fd < 0) {
return false;
}
RCU_READ_LOCK_GUARD();
RAMBLOCK_FOREACH_NOT_IGNORED(bs) {
uint64_t uffd_ioctls;
/* Nothing to do with read-only and MMIO-writable regions */
if (bs->mr->readonly || bs->mr->rom_device) {
continue;
}
/* Try to register block memory via UFFD-IO to track writes */
if (uffd_register_memory(uffd_fd, bs->host, bs->max_length,
UFFDIO_REGISTER_MODE_WP, &uffd_ioctls)) {
goto out;
}
if ((uffd_ioctls & uffd_ioctls_mask) != uffd_ioctls_mask) {
goto out;
}
}
ret = true;
out:
uffd_close_fd(uffd_fd);
return ret;
}
/*
* ram_write_tracking_start: start UFFD-WP memory tracking
*
* Returns 0 for success or negative value in case of error
*/
int ram_write_tracking_start(void)
{
int uffd_fd;
RAMState *rs = ram_state;
RAMBlock *bs;
/* Open UFFD file descriptor */
uffd_fd = uffd_create_fd(UFFD_FEATURE_PAGEFAULT_FLAG_WP, true);
if (uffd_fd < 0) {
return uffd_fd;
}
rs->uffdio_fd = uffd_fd;
RCU_READ_LOCK_GUARD();
RAMBLOCK_FOREACH_NOT_IGNORED(bs) {
/* Nothing to do with read-only and MMIO-writable regions */
if (bs->mr->readonly || bs->mr->rom_device) {
continue;
}
/* Register block memory with UFFD to track writes */
if (uffd_register_memory(rs->uffdio_fd, bs->host,
bs->max_length, UFFDIO_REGISTER_MODE_WP, NULL)) {
goto fail;
}
/* Apply UFFD write protection to the block memory range */
if (uffd_change_protection(rs->uffdio_fd, bs->host,
bs->max_length, true, false)) {
goto fail;
}
bs->flags |= RAM_UF_WRITEPROTECT;
memory_region_ref(bs->mr);
trace_ram_write_tracking_ramblock_start(bs->idstr, bs->page_size,
bs->host, bs->max_length);
}
return 0;
fail:
error_report("ram_write_tracking_start() failed: restoring initial memory state");
RAMBLOCK_FOREACH_NOT_IGNORED(bs) {
if ((bs->flags & RAM_UF_WRITEPROTECT) == 0) {
continue;
}
/*
* In case some memory block failed to be write-protected
* remove protection and unregister all succeeded RAM blocks
*/
uffd_change_protection(rs->uffdio_fd, bs->host, bs->max_length, false, false);
uffd_unregister_memory(rs->uffdio_fd, bs->host, bs->max_length);
/* Cleanup flags and remove reference */
bs->flags &= ~RAM_UF_WRITEPROTECT;
memory_region_unref(bs->mr);
}
uffd_close_fd(uffd_fd);
rs->uffdio_fd = -1;
return -1;
}
/**
* ram_write_tracking_stop: stop UFFD-WP memory tracking and remove protection
*/
void ram_write_tracking_stop(void)
{
RAMState *rs = ram_state;
RAMBlock *bs;
RCU_READ_LOCK_GUARD();
RAMBLOCK_FOREACH_NOT_IGNORED(bs) {
if ((bs->flags & RAM_UF_WRITEPROTECT) == 0) {
continue;
}
/* Remove protection and unregister all affected RAM blocks */
uffd_change_protection(rs->uffdio_fd, bs->host, bs->max_length, false, false);
uffd_unregister_memory(rs->uffdio_fd, bs->host, bs->max_length);
trace_ram_write_tracking_ramblock_stop(bs->idstr, bs->page_size,
bs->host, bs->max_length);
/* Cleanup flags and remove reference */
bs->flags &= ~RAM_UF_WRITEPROTECT;
memory_region_unref(bs->mr);
}
/* Finally close UFFD file descriptor */
uffd_close_fd(rs->uffdio_fd);
rs->uffdio_fd = -1;
}
#else
/* No target OS support, stubs just fail or ignore */
static RAMBlock *poll_fault_page(RAMState *rs, ram_addr_t *offset)
{
(void) rs;
(void) offset;
return NULL;
}
static int ram_save_release_protection(RAMState *rs, PageSearchStatus *pss,
unsigned long start_page)
{
(void) rs;
(void) pss;
(void) start_page;
return 0;
}
bool ram_write_tracking_available(void)
{
return false;
}
bool ram_write_tracking_compatible(void)
{
assert(0);
return false;
}
int ram_write_tracking_start(void)
{
assert(0);
return -1;
}
void ram_write_tracking_stop(void)
{
assert(0);
}
#endif /* defined(__linux__) */
/**
* get_queued_page: unqueue a page from the postcopy requests
*
@ -1473,6 +1743,14 @@ static bool get_queued_page(RAMState *rs, PageSearchStatus *pss)
} while (block && !dirty);
if (!block) {
/*
* Poll write faults too if background snapshot is enabled; that's
* when we have vcpus got blocked by the write protected pages.
*/
block = poll_fault_page(rs, &offset);
}
if (block) {
/*
* As soon as we start servicing pages out of order, then we have
@ -1715,6 +1993,8 @@ static int ram_save_host_page(RAMState *rs, PageSearchStatus *pss,
int tmppages, pages = 0;
size_t pagesize_bits =
qemu_ram_pagesize(pss->block) >> TARGET_PAGE_BITS;
unsigned long start_page = pss->page;
int res;
if (ramblock_is_ignored(pss->block)) {
error_report("block %s should not be migrated !", pss->block->idstr);
@ -1740,10 +2020,11 @@ static int ram_save_host_page(RAMState *rs, PageSearchStatus *pss,
} while ((pss->page & (pagesize_bits - 1)) &&
offset_in_ramblock(pss->block,
((ram_addr_t)pss->page) << TARGET_PAGE_BITS));
/* The offset we leave with is the last one we looked at */
pss->page--;
return pages;
res = ram_save_release_protection(rs, pss, start_page);
return (res < 0 ? res : pages);
}
/**
@ -1880,10 +2161,13 @@ static void ram_save_cleanup(void *opaque)
RAMState **rsp = opaque;
RAMBlock *block;
/* caller have hold iothread lock or is in a bh, so there is
* no writing race against the migration bitmap
*/
memory_global_dirty_log_stop();
/* We don't use dirty log with background snapshots */
if (!migrate_background_snapshot()) {
/* caller have hold iothread lock or is in a bh, so there is
* no writing race against the migration bitmap
*/
memory_global_dirty_log_stop();
}
RAMBLOCK_FOREACH_NOT_IGNORED(block) {
g_free(block->clear_bmap);
@ -2343,8 +2627,11 @@ static void ram_init_bitmaps(RAMState *rs)
WITH_RCU_READ_LOCK_GUARD() {
ram_list_init_bitmaps();
memory_global_dirty_log_start();
migration_bitmap_sync_precopy(rs);
/* We don't use dirty log with background snapshots */
if (!migrate_background_snapshot()) {
memory_global_dirty_log_start();
migration_bitmap_sync_precopy(rs);
}
}
qemu_mutex_unlock_ramlist();
qemu_mutex_unlock_iothread();
@ -3521,7 +3808,7 @@ static int ram_load_precopy(QEMUFile *f)
}
}
/* For postcopy we need to check hugepage sizes match */
if (postcopy_advised &&
if (postcopy_advised && migrate_postcopy_ram() &&
block->page_size != qemu_host_page_size) {
uint64_t remote_page_size = qemu_get_be64(f);
if (remote_page_size != block->page_size) {

8
migration/ram.h
View File

@ -47,7 +47,7 @@ bool ramblock_is_ignored(RAMBlock *block);
INTERNAL_RAMBLOCK_FOREACH(block) \
if (!qemu_ram_is_migratable(block)) {} else
int xbzrle_cache_resize(int64_t new_size, Error **errp);
int xbzrle_cache_resize(uint64_t new_size, Error **errp);
uint64_t ram_bytes_remaining(void);
uint64_t ram_bytes_total(void);
@ -79,4 +79,10 @@ void colo_flush_ram_cache(void);
void colo_release_ram_cache(void);
void colo_incoming_start_dirty_log(void);
/* Background snapshot */
bool ram_write_tracking_available(void);
bool ram_write_tracking_compatible(void);
int ram_write_tracking_start(void);
void ram_write_tracking_stop(void);
#endif

341
migration/savevm.c
View File

@ -43,6 +43,8 @@
#include "qapi/error.h"
#include "qapi/qapi-commands-migration.h"
#include "qapi/qmp/json-writer.h"
#include "qapi/clone-visitor.h"
#include "qapi/qapi-builtin-visit.h"
#include "qapi/qmp/qerror.h"
#include "qemu/error-report.h"
#include "sysemu/cpus.h"
@ -315,6 +317,16 @@ static int configuration_pre_save(void *opaque)
return 0;
}
static int configuration_post_save(void *opaque)
{
SaveState *state = opaque;
g_free(state->capabilities);
state->capabilities = NULL;
state->caps_count = 0;
return 0;
}
static int configuration_pre_load(void *opaque)
{
SaveState *state = opaque;
@ -365,24 +377,36 @@ static int configuration_post_load(void *opaque, int version_id)
{
SaveState *state = opaque;
const char *current_name = MACHINE_GET_CLASS(current_machine)->name;
int ret = 0;
if (strncmp(state->name, current_name, state->len) != 0) {
error_report("Machine type received is '%.*s' and local is '%s'",
(int) state->len, state->name, current_name);
return -EINVAL;
ret = -EINVAL;
goto out;
}
if (state->target_page_bits != qemu_target_page_bits()) {
error_report("Received TARGET_PAGE_BITS is %d but local is %d",
state->target_page_bits, qemu_target_page_bits());
return -EINVAL;
ret = -EINVAL;
goto out;
}
if (!configuration_validate_capabilities(state)) {
return -EINVAL;
ret = -EINVAL;
goto out;
}
return 0;
out:
g_free((void *)state->name);
state->name = NULL;
state->len = 0;
g_free(state->capabilities);
state->capabilities = NULL;
state->caps_count = 0;
return ret;
}
static int get_capability(QEMUFile *f, void *pv, size_t size,
@ -516,6 +540,7 @@ static const VMStateDescription vmstate_configuration = {
.pre_load = configuration_pre_load,
.post_load = configuration_post_load,
.pre_save = configuration_pre_save,
.post_save = configuration_post_save,
.fields = (VMStateField[]) {
VMSTATE_UINT32(len, SaveState),
VMSTATE_VBUFFER_ALLOC_UINT32(name, SaveState, 0, NULL, len),
@ -1131,6 +1156,19 @@ bool qemu_savevm_state_blocked(Error **errp)
return false;
}
void qemu_savevm_non_migratable_list(strList **reasons)
{
SaveStateEntry *se;
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
if (se->vmsd && se->vmsd->unmigratable) {
QAPI_LIST_PREPEND(*reasons,
g_strdup_printf("non-migratable device: %s",
se->idstr));
}
}
}
void qemu_savevm_state_header(QEMUFile *f)
{
trace_savevm_state_header();
@ -1355,7 +1393,6 @@ int qemu_savevm_state_complete_precopy_iterable(QEMUFile *f, bool in_postcopy)
return 0;
}
static
int qemu_savevm_state_complete_precopy_non_iterable(QEMUFile *f,
bool in_postcopy,
bool inactivate_disks)
@ -2729,9 +2766,10 @@ int qemu_load_device_state(QEMUFile *f)
return 0;
}
int save_snapshot(const char *name, Error **errp)
bool save_snapshot(const char *name, bool overwrite, const char *vmstate,
bool has_devices, strList *devices, Error **errp)
{
BlockDriverState *bs, *bs1;
BlockDriverState *bs;
QEMUSnapshotInfo sn1, *sn = &sn1;
int ret = -1, ret2;
QEMUFile *f;
@ -2742,35 +2780,43 @@ int save_snapshot(const char *name, Error **errp)
AioContext *aio_context;
if (migration_is_blocked(errp)) {
return ret;
return false;
}
if (!replay_can_snapshot()) {
error_setg(errp, "Record/replay does not allow making snapshot "
"right now. Try once more later.");
return ret;
return false;
}
if (!bdrv_all_can_snapshot(&bs)) {
error_setg(errp, "Device '%s' is writable but does not support "
"snapshots", bdrv_get_device_or_node_name(bs));
return ret;
if (!bdrv_all_can_snapshot(has_devices, devices, errp)) {
return false;
}
/* Delete old snapshots of the same name */
if (name) {
ret = bdrv_all_delete_snapshot(name, &bs1, errp);
if (ret < 0) {
error_prepend(errp, "Error while deleting snapshot on device "
"'%s': ", bdrv_get_device_or_node_name(bs1));
return ret;
if (overwrite) {
if (bdrv_all_delete_snapshot(name, has_devices,
devices, errp) < 0) {
return false;
}
} else {
ret2 = bdrv_all_has_snapshot(name, has_devices, devices, errp);
if (ret2 < 0) {
return false;
}
if (ret2 == 1) {
error_setg(errp,
"Snapshot '%s' already exists in one or more devices",
name);
return false;
}
}
}
bs = bdrv_all_find_vmstate_bs();
bs = bdrv_all_find_vmstate_bs(vmstate, has_devices, devices, errp);
if (bs == NULL) {
error_setg(errp, "No block device can accept snapshots");
return ret;
return false;
}
aio_context = bdrv_get_aio_context(bs);
@ -2779,7 +2825,7 @@ int save_snapshot(const char *name, Error **errp)
ret = global_state_store();
if (ret) {
error_setg(errp, "Error saving global state");
return ret;
return false;
}
vm_stop(RUN_STATE_SAVE_VM);
@ -2833,11 +2879,10 @@ int save_snapshot(const char *name, Error **errp)
aio_context_release(aio_context);
aio_context = NULL;
ret = bdrv_all_create_snapshot(sn, bs, vm_state_size, &bs);
ret = bdrv_all_create_snapshot(sn, bs, vm_state_size,
has_devices, devices, errp);
if (ret < 0) {
error_setg(errp, "Error while creating snapshot on '%s'",
bdrv_get_device_or_node_name(bs));
bdrv_all_delete_snapshot(sn->name, &bs, NULL);
bdrv_all_delete_snapshot(sn->name, has_devices, devices, NULL);
goto the_end;
}
@ -2853,7 +2898,7 @@ int save_snapshot(const char *name, Error **errp)
if (saved_vm_running) {
vm_start();
}
return ret;
return ret == 0;
}
void qmp_xen_save_devices_state(const char *filename, bool has_live, bool live,
@ -2938,33 +2983,32 @@ void qmp_xen_load_devices_state(const char *filename, Error **errp)
migration_incoming_state_destroy();
}
int load_snapshot(const char *name, Error **errp)
bool load_snapshot(const char *name, const char *vmstate,
bool has_devices, strList *devices, Error **errp)
{
BlockDriverState *bs, *bs_vm_state;
BlockDriverState *bs_vm_state;
QEMUSnapshotInfo sn;
QEMUFile *f;
int ret;
AioContext *aio_context;
MigrationIncomingState *mis = migration_incoming_get_current();
if (!bdrv_all_can_snapshot(&bs)) {
error_setg(errp,
"Device '%s' is writable but does not support snapshots",
bdrv_get_device_or_node_name(bs));
return -ENOTSUP;
if (!bdrv_all_can_snapshot(has_devices, devices, errp)) {
return false;
}
ret = bdrv_all_find_snapshot(name, &bs);
ret = bdrv_all_has_snapshot(name, has_devices, devices, errp);
if (ret < 0) {
error_setg(errp,
"Device '%s' does not have the requested snapshot '%s'",
bdrv_get_device_or_node_name(bs), name);
return ret;
return false;
}
if (ret == 0) {
error_setg(errp, "Snapshot '%s' does not exist in one or more devices",
name);
return false;
}
bs_vm_state = bdrv_all_find_vmstate_bs();
bs_vm_state = bdrv_all_find_vmstate_bs(vmstate, has_devices, devices, errp);
if (!bs_vm_state) {
error_setg(errp, "No block device supports snapshots");
return -ENOTSUP;
return false;
}
aio_context = bdrv_get_aio_context(bs_vm_state);
@ -2973,11 +3017,11 @@ int load_snapshot(const char *name, Error **errp)
ret = bdrv_snapshot_find(bs_vm_state, &sn, name);
aio_context_release(aio_context);
if (ret < 0) {
return ret;
return false;
} else if (sn.vm_state_size == 0) {
error_setg(errp, "This is a disk-only snapshot. Revert to it "
" offline using qemu-img");
return -EINVAL;
return false;
}
/*
@ -2989,10 +3033,8 @@ int load_snapshot(const char *name, Error **errp)
/* Flush all IO requests so they don't interfere with the new state. */
bdrv_drain_all_begin();
ret = bdrv_all_goto_snapshot(name, &bs, errp);
ret = bdrv_all_goto_snapshot(name, has_devices, devices, errp);
if (ret < 0) {
error_prepend(errp, "Could not load snapshot '%s' on '%s': ",
name, bdrv_get_device_or_node_name(bs));
goto err_drain;
}
@ -3000,7 +3042,6 @@ int load_snapshot(const char *name, Error **errp)
f = qemu_fopen_bdrv(bs_vm_state, 0);
if (!f) {
error_setg(errp, "Could not open VM state file");
ret = -EINVAL;
goto err_drain;
}
@ -3020,14 +3061,28 @@ int load_snapshot(const char *name, Error **errp)
if (ret < 0) {
error_setg(errp, "Error %d while loading VM state", ret);
return ret;
return false;
}
return 0;
return true;
err_drain:
bdrv_drain_all_end();
return ret;
return false;
}
bool delete_snapshot(const char *name, bool has_devices,
strList *devices, Error **errp)
{
if (!bdrv_all_can_snapshot(has_devices, devices, errp)) {
return false;
}
if (bdrv_all_delete_snapshot(name, has_devices, devices, errp) < 0) {
return false;
}
return true;
}
void vmstate_register_ram(MemoryRegion *mr, DeviceState *dev)
@ -3057,3 +3112,187 @@ bool vmstate_check_only_migratable(const VMStateDescription *vmsd)
return !(vmsd && vmsd->unmigratable);
}
typedef struct SnapshotJob {
Job common;
char *tag;
char *vmstate;
strList *devices;
Coroutine *co;
Error **errp;
bool ret;
} SnapshotJob;
static void qmp_snapshot_job_free(SnapshotJob *s)
{
g_free(s->tag);
g_free(s->vmstate);
qapi_free_strList(s->devices);
}
static void snapshot_load_job_bh(void *opaque)
{
Job *job = opaque;
SnapshotJob *s = container_of(job, SnapshotJob, common);
int orig_vm_running;
job_progress_set_remaining(&s->common, 1);
orig_vm_running = runstate_is_running();
vm_stop(RUN_STATE_RESTORE_VM);
s->ret = load_snapshot(s->tag, s->vmstate, true, s->devices, s->errp);
if (s->ret && orig_vm_running) {
vm_start();
}
job_progress_update(&s->common, 1);
qmp_snapshot_job_free(s);
aio_co_wake(s->co);
}
static void snapshot_save_job_bh(void *opaque)
{
Job *job = opaque;
SnapshotJob *s = container_of(job, SnapshotJob, common);
job_progress_set_remaining(&s->common, 1);
s->ret = save_snapshot(s->tag, false, s->vmstate,
true, s->devices, s->errp);
job_progress_update(&s->common, 1);
qmp_snapshot_job_free(s);
aio_co_wake(s->co);
}
static void snapshot_delete_job_bh(void *opaque)
{
Job *job = opaque;
SnapshotJob *s = container_of(job, SnapshotJob, common);
job_progress_set_remaining(&s->common, 1);
s->ret = delete_snapshot(s->tag, true, s->devices, s->errp);
job_progress_update(&s->common, 1);
qmp_snapshot_job_free(s);
aio_co_wake(s->co);
}
static int coroutine_fn snapshot_save_job_run(Job *job, Error **errp)
{
SnapshotJob *s = container_of(job, SnapshotJob, common);
s->errp = errp;
s->co = qemu_coroutine_self();
aio_bh_schedule_oneshot(qemu_get_aio_context(),
snapshot_save_job_bh, job);
qemu_coroutine_yield();
return s->ret ? 0 : -1;
}
static int coroutine_fn snapshot_load_job_run(Job *job, Error **errp)
{
SnapshotJob *s = container_of(job, SnapshotJob, common);
s->errp = errp;
s->co = qemu_coroutine_self();
aio_bh_schedule_oneshot(qemu_get_aio_context(),
snapshot_load_job_bh, job);
qemu_coroutine_yield();
return s->ret ? 0 : -1;
}
static int coroutine_fn snapshot_delete_job_run(Job *job, Error **errp)
{
SnapshotJob *s = container_of(job, SnapshotJob, common);
s->errp = errp;
s->co = qemu_coroutine_self();
aio_bh_schedule_oneshot(qemu_get_aio_context(),
snapshot_delete_job_bh, job);
qemu_coroutine_yield();
return s->ret ? 0 : -1;
}
static const JobDriver snapshot_load_job_driver = {
.instance_size = sizeof(SnapshotJob),
.job_type = JOB_TYPE_SNAPSHOT_LOAD,
.run = snapshot_load_job_run,
};
static const JobDriver snapshot_save_job_driver = {
.instance_size = sizeof(SnapshotJob),
.job_type = JOB_TYPE_SNAPSHOT_SAVE,
.run = snapshot_save_job_run,
};
static const JobDriver snapshot_delete_job_driver = {
.instance_size = sizeof(SnapshotJob),
.job_type = JOB_TYPE_SNAPSHOT_DELETE,
.run = snapshot_delete_job_run,
};
void qmp_snapshot_save(const char *job_id,
const char *tag,
const char *vmstate,
strList *devices,
Error **errp)
{
SnapshotJob *s;
s = job_create(job_id, &snapshot_save_job_driver, NULL,
qemu_get_aio_context(), JOB_MANUAL_DISMISS,
NULL, NULL, errp);
if (!s) {
return;
}
s->tag = g_strdup(tag);
s->vmstate = g_strdup(vmstate);
s->devices = QAPI_CLONE(strList, devices);
job_start(&s->common);
}
void qmp_snapshot_load(const char *job_id,
const char *tag,
const char *vmstate,
strList *devices,
Error **errp)
{
SnapshotJob *s;
s = job_create(job_id, &snapshot_load_job_driver, NULL,
qemu_get_aio_context(), JOB_MANUAL_DISMISS,
NULL, NULL, errp);
if (!s) {
return;
}
s->tag = g_strdup(tag);
s->vmstate = g_strdup(vmstate);
s->devices = QAPI_CLONE(strList, devices);
job_start(&s->common);
}
void qmp_snapshot_delete(const char *job_id,
const char *tag,
strList *devices,
Error **errp)
{
SnapshotJob *s;
s = job_create(job_id, &snapshot_delete_job_driver, NULL,
qemu_get_aio_context(), JOB_MANUAL_DISMISS,
NULL, NULL, errp);
if (!s) {
return;
}
s->tag = g_strdup(tag);
s->devices = QAPI_CLONE(strList, devices);
job_start(&s->common);
}

3
migration/savevm.h
View File

@ -30,6 +30,7 @@
#define QEMU_VM_SECTION_FOOTER 0x7e
bool qemu_savevm_state_blocked(Error **errp);
void qemu_savevm_non_migratable_list(strList **reasons);
void qemu_savevm_state_setup(QEMUFile *f);
bool qemu_savevm_state_guest_unplug_pending(void);
int qemu_savevm_state_resume_prepare(MigrationState *s);
@ -64,5 +65,7 @@ int qemu_loadvm_state(QEMUFile *f);
void qemu_loadvm_state_cleanup(void);
int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis);
int qemu_load_device_state(QEMUFile *f);
int qemu_savevm_state_complete_precopy_non_iterable(QEMUFile *f,
bool in_postcopy, bool inactivate_disks);
#endif

2
migration/trace-events
View File

@ -111,6 +111,8 @@ save_xbzrle_page_skipping(void) ""
save_xbzrle_page_overflow(void) ""
ram_save_iterate_big_wait(uint64_t milliconds, int iterations) "big wait: %" PRIu64 " milliseconds, %d iterations"
ram_load_complete(int ret, uint64_t seq_iter) "exit_code %d seq iteration %" PRIu64
ram_write_tracking_ramblock_start(const char *block_id, size_t page_size, void *addr, size_t length) "%s: page_size: %zu addr: %p length: %zu"
ram_write_tracking_ramblock_stop(const char *block_id, size_t page_size, void *addr, size_t length) "%s: page_size: %zu addr: %p length: %zu"
# multifd.c
multifd_new_send_channel_async(uint8_t id) "channel %d"

45
monitor/hmp-cmds.c
View File

@ -224,6 +224,15 @@ void hmp_info_migrate(Monitor *mon, const QDict *qdict)
migration_global_dump(mon);
if (info->blocked) {
strList *reasons = info->blocked_reasons;
monitor_printf(mon, "Outgoing migration blocked:\n");
while (reasons) {
monitor_printf(mon, " %s\n", reasons->value);
reasons = reasons->next;
}
}
if (info->has_status) {
monitor_printf(mon, "Migration status: %s",
MigrationStatus_str(info->status));
@ -1130,7 +1139,7 @@ void hmp_loadvm(Monitor *mon, const QDict *qdict)
vm_stop(RUN_STATE_RESTORE_VM);
if (load_snapshot(name, &err) == 0 && saved_vm_running) {
if (!load_snapshot(name, NULL, false, NULL, &err) && saved_vm_running) {
vm_start();
}
hmp_handle_error(mon, err);
@ -1140,21 +1149,17 @@ void hmp_savevm(Monitor *mon, const QDict *qdict)
{
Error *err = NULL;
save_snapshot(qdict_get_try_str(qdict, "name"), &err);
save_snapshot(qdict_get_try_str(qdict, "name"),
true, NULL, false, NULL, &err);
hmp_handle_error(mon, err);
}
void hmp_delvm(Monitor *mon, const QDict *qdict)
{
BlockDriverState *bs;
Error *err = NULL;
const char *name = qdict_get_str(qdict, "name");
if (bdrv_all_delete_snapshot(name, &bs, &err) < 0) {
error_prepend(&err,
"deleting snapshot on device '%s': ",
bdrv_get_device_name(bs));
}
delete_snapshot(name, false, NULL, &err);
hmp_handle_error(mon, err);
}
@ -1294,11 +1299,11 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
switch (val) {
case MIGRATION_PARAMETER_COMPRESS_LEVEL:
p->has_compress_level = true;
visit_type_int(v, param, &p->compress_level, &err);
visit_type_uint8(v, param, &p->compress_level, &err);
break;
case MIGRATION_PARAMETER_COMPRESS_THREADS:
p->has_compress_threads = true;
visit_type_int(v, param, &p->compress_threads, &err);
visit_type_uint8(v, param, &p->compress_threads, &err);
break;
case MIGRATION_PARAMETER_COMPRESS_WAIT_THREAD:
p->has_compress_wait_thread = true;
@ -1306,19 +1311,19 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
break;
case MIGRATION_PARAMETER_DECOMPRESS_THREADS:
p->has_decompress_threads = true;
visit_type_int(v, param, &p->decompress_threads, &err);
visit_type_uint8(v, param, &p->decompress_threads, &err);
break;
case MIGRATION_PARAMETER_THROTTLE_TRIGGER_THRESHOLD:
p->has_throttle_trigger_threshold = true;
visit_type_int(v, param, &p->throttle_trigger_threshold, &err);
visit_type_uint8(v, param, &p->throttle_trigger_threshold, &err);
break;
case MIGRATION_PARAMETER_CPU_THROTTLE_INITIAL:
p->has_cpu_throttle_initial = true;
visit_type_int(v, param, &p->cpu_throttle_initial, &err);
visit_type_uint8(v, param, &p->cpu_throttle_initial, &err);
break;
case MIGRATION_PARAMETER_CPU_THROTTLE_INCREMENT:
p->has_cpu_throttle_increment = true;
visit_type_int(v, param, &p->cpu_throttle_increment, &err);
visit_type_uint8(v, param, &p->cpu_throttle_increment, &err);
break;
case MIGRATION_PARAMETER_CPU_THROTTLE_TAILSLOW:
p->has_cpu_throttle_tailslow = true;
@ -1326,7 +1331,7 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
break;
case MIGRATION_PARAMETER_MAX_CPU_THROTTLE:
p->has_max_cpu_throttle = true;
visit_type_int(v, param, &p->max_cpu_throttle, &err);
visit_type_uint8(v, param, &p->max_cpu_throttle, &err);
break;
case MIGRATION_PARAMETER_TLS_CREDS:
p->has_tls_creds = true;
@ -1362,11 +1367,11 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
break;
case MIGRATION_PARAMETER_DOWNTIME_LIMIT:
p->has_downtime_limit = true;
visit_type_int(v, param, &p->downtime_limit, &err);
visit_type_size(v, param, &p->downtime_limit, &err);
break;
case MIGRATION_PARAMETER_X_CHECKPOINT_DELAY:
p->has_x_checkpoint_delay = true;
visit_type_int(v, param, &p->x_checkpoint_delay, &err);
visit_type_uint32(v, param, &p->x_checkpoint_delay, &err);
break;
case MIGRATION_PARAMETER_BLOCK_INCREMENTAL:
p->has_block_incremental = true;
@ -1374,7 +1379,7 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
break;
case MIGRATION_PARAMETER_MULTIFD_CHANNELS:
p->has_multifd_channels = true;
visit_type_int(v, param, &p->multifd_channels, &err);
visit_type_uint8(v, param, &p->multifd_channels, &err);
break;
case MIGRATION_PARAMETER_MULTIFD_COMPRESSION:
p->has_multifd_compression = true;
@ -1383,11 +1388,11 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
break;
case MIGRATION_PARAMETER_MULTIFD_ZLIB_LEVEL:
p->has_multifd_zlib_level = true;
visit_type_int(v, param, &p->multifd_zlib_level, &err);
visit_type_uint8(v, param, &p->multifd_zlib_level, &err);
break;
case MIGRATION_PARAMETER_MULTIFD_ZSTD_LEVEL:
p->has_multifd_zstd_level = true;
visit_type_int(v, param, &p->multifd_zstd_level, &err);
visit_type_uint8(v, param, &p->multifd_zstd_level, &err);
break;
case MIGRATION_PARAMETER_XBZRLE_CACHE_SIZE:
p->has_xbzrle_cache_size = true;

9
qapi/job.json
View File

@ -22,10 +22,17 @@
#
# @amend: image options amend job type, see "x-blockdev-amend" (since 5.1)
#
# @snapshot-load: snapshot load job type, see "snapshot-load" (since 6.0)
#
# @snapshot-save: snapshot save job type, see "snapshot-save" (since 6.0)
#
# @snapshot-delete: snapshot delete job type, see "snapshot-delete" (since 6.0)
#
# Since: 1.7
##
{ 'enum': 'JobType',
'data': ['commit', 'stream', 'mirror', 'backup', 'create', 'amend'] }
'data': ['commit', 'stream', 'mirror', 'backup', 'create', 'amend',
'snapshot-load', 'snapshot-save', 'snapshot-delete'] }
##
# @JobStatus:

218
qapi/migration.json
View File

@ -78,7 +78,7 @@
# Since: 1.2
##
{ 'struct': 'XBZRLECacheStats',
'data': {'cache-size': 'int', 'bytes': 'int', 'pages': 'int',
'data': {'cache-size': 'size', 'bytes': 'int', 'pages': 'int',
'cache-miss': 'int', 'cache-miss-rate': 'number',
'encoding-rate': 'number', 'overflow': 'int' } }
@ -224,6 +224,10 @@
# only returned if VFIO device is present, migration is supported by all
# VFIO devices and status is 'active' or 'completed' (since 5.2)
#
# @blocked: True if outgoing migration is blocked (since 6.0)
#
# @blocked-reasons: A list of reasons an outgoing migration is blocked (since 6.0)
#
# Since: 0.14
##
{ 'struct': 'MigrationInfo',
@ -237,6 +241,8 @@
'*setup-time': 'int',
'*cpu-throttle-percentage': 'int',
'*error-desc': 'str',
'blocked': 'bool',
'*blocked-reasons': ['str'],
'*postcopy-blocktime' : 'uint32',
'*postcopy-vcpu-blocktime': ['uint32'],
'*compression': 'CompressionStats',
@ -442,6 +448,11 @@
# @validate-uuid: Send the UUID of the source to allow the destination
# to ensure it is the same. (since 4.2)
#
# @background-snapshot: If enabled, the migration stream will be a snapshot
# of the VM exactly at the point when the migration
# procedure starts. The VM RAM is saved with running VM.
# (since 6.0)
#
# Since: 1.2
##
{ 'enum': 'MigrationCapability',
@ -449,7 +460,7 @@
'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram',
'block', 'return-path', 'pause-before-switchover', 'multifd',
'dirty-bitmaps', 'postcopy-blocktime', 'late-block-activate',
'x-ignore-shared', 'validate-uuid' ] }
'x-ignore-shared', 'validate-uuid', 'background-snapshot'] }
##
# @MigrationCapabilityStatus:
@ -885,28 +896,28 @@
'*announce-max': 'size',
'*announce-rounds': 'size',
'*announce-step': 'size',
'*compress-level': 'int',
'*compress-threads': 'int',
'*compress-level': 'uint8',
'*compress-threads': 'uint8',
'*compress-wait-thread': 'bool',
'*decompress-threads': 'int',
'*throttle-trigger-threshold': 'int',
'*cpu-throttle-initial': 'int',
'*cpu-throttle-increment': 'int',
'*decompress-threads': 'uint8',
'*throttle-trigger-threshold': 'uint8',
'*cpu-throttle-initial': 'uint8',
'*cpu-throttle-increment': 'uint8',
'*cpu-throttle-tailslow': 'bool',
'*tls-creds': 'StrOrNull',
'*tls-hostname': 'StrOrNull',
'*tls-authz': 'StrOrNull',
'*max-bandwidth': 'int',
'*downtime-limit': 'int',
'*x-checkpoint-delay': 'int',
'*max-bandwidth': 'size',
'*downtime-limit': 'uint64',
'*x-checkpoint-delay': 'uint32',
'*block-incremental': 'bool',
'*multifd-channels': 'int',
'*multifd-channels': 'uint8',
'*xbzrle-cache-size': 'size',
'*max-postcopy-bandwidth': 'size',
'*max-cpu-throttle': 'int',
'*max-cpu-throttle': 'uint8',
'*multifd-compression': 'MultiFDCompression',
'*multifd-zlib-level': 'int',
'*multifd-zstd-level': 'int',
'*multifd-zlib-level': 'uint8',
'*multifd-zstd-level': 'uint8',
'*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ] } }
##
@ -1093,7 +1104,7 @@
'*max-bandwidth': 'size',
'*downtime-limit': 'uint64',
'*x-checkpoint-delay': 'uint32',
'*block-incremental': 'bool' ,
'*block-incremental': 'bool',
'*multifd-channels': 'uint8',
'*xbzrle-cache-size': 'size',
'*max-postcopy-bandwidth': 'size',
@ -1465,7 +1476,7 @@
# <- { "return": 67108864 }
#
##
{ 'command': 'query-migrate-cache-size', 'returns': 'int',
{ 'command': 'query-migrate-cache-size', 'returns': 'size',
'features': [ 'deprecated' ] }
##
@ -1843,3 +1854,176 @@
# Since: 5.2
##
{ 'command': 'query-dirty-rate', 'returns': 'DirtyRateInfo' }
##
# @snapshot-save:
#
# Save a VM snapshot
#
# @job-id: identifier for the newly created job
# @tag: name of the snapshot to create
# @vmstate: block device node name to save vmstate to
# @devices: list of block device node names to save a snapshot to
#
# Applications should not assume that the snapshot save is complete
# when this command returns. The job commands / events must be used
# to determine completion and to fetch details of any errors that arise.
#
# Note that execution of the guest CPUs may be stopped during the
# time it takes to save the snapshot. A future version of QEMU
# may ensure CPUs are executing continuously.
#
# It is strongly recommended that @devices contain all writable
# block device nodes if a consistent snapshot is required.
#
# If @tag already exists, an error will be reported
#
# Returns: nothing
#
# Example:
#
# -> { "execute": "snapshot-save",
# "data": {
# "job-id": "snapsave0",
# "tag": "my-snap",
# "vmstate": "disk0",
# "devices": ["disk0", "disk1"]
# }
# }
# <- { "return": { } }
# <- {"event": "JOB_STATUS_CHANGE",
# "data": {"status": "created", "id": "snapsave0"}}
# <- {"event": "JOB_STATUS_CHANGE",
# "data": {"status": "running", "id": "snapsave0"}}
# <- {"event": "STOP"}
# <- {"event": "RESUME"}
# <- {"event": "JOB_STATUS_CHANGE",
# "data": {"status": "waiting", "id": "snapsave0"}}
# <- {"event": "JOB_STATUS_CHANGE",
# "data": {"status": "pending", "id": "snapsave0"}}
# <- {"event": "JOB_STATUS_CHANGE",
# "data": {"status": "concluded", "id": "snapsave0"}}
# -> {"execute": "query-jobs"}
# <- {"return": [{"current-progress": 1,
# "status": "concluded",
# "total-progress": 1,
# "type": "snapshot-save",
# "id": "snapsave0"}]}
#
# Since: 6.0
##
{ 'command': 'snapshot-save',
'data': { 'job-id': 'str',
'tag': 'str',
'vmstate': 'str',
'devices': ['str'] } }
##
# @snapshot-load:
#
# Load a VM snapshot
#
# @job-id: identifier for the newly created job
# @tag: name of the snapshot to load.
# @vmstate: block device node name to load vmstate from
# @devices: list of block device node names to load a snapshot from
#
# Applications should not assume that the snapshot load is complete
# when this command returns. The job commands / events must be used
# to determine completion and to fetch details of any errors that arise.
#
# Note that execution of the guest CPUs will be stopped during the
# time it takes to load the snapshot.
#
# It is strongly recommended that @devices contain all writable
# block device nodes that can have changed since the original
# @snapshot-save command execution.
#
# Returns: nothing
#
# Example:
#
# -> { "execute": "snapshot-load",
# "data": {
# "job-id": "snapload0",
# "tag": "my-snap",
# "vmstate": "disk0",
# "devices": ["disk0", "disk1"]
# }
# }
# <- { "return": { } }
# <- {"event": "JOB_STATUS_CHANGE",
# "data": {"status": "created", "id": "snapload0"}}
# <- {"event": "JOB_STATUS_CHANGE",
# "data": {"status": "running", "id": "snapload0"}}
# <- {"event": "STOP"}
# <- {"event": "RESUME"}
# <- {"event": "JOB_STATUS_CHANGE",
# "data": {"status": "waiting", "id": "snapload0"}}
# <- {"event": "JOB_STATUS_CHANGE",
# "data": {"status": "pending", "id": "snapload0"}}
# <- {"event": "JOB_STATUS_CHANGE",
# "data": {"status": "concluded", "id": "snapload0"}}
# -> {"execute": "query-jobs"}
# <- {"return": [{"current-progress": 1,
# "status": "concluded",
# "total-progress": 1,
# "type": "snapshot-load",
# "id": "snapload0"}]}
#
# Since: 6.0
##
{ 'command': 'snapshot-load',
'data': { 'job-id': 'str',
'tag': 'str',
'vmstate': 'str',
'devices': ['str'] } }
##
# @snapshot-delete:
#
# Delete a VM snapshot
#
# @job-id: identifier for the newly created job
# @tag: name of the snapshot to delete.
# @devices: list of block device node names to delete a snapshot from
#
# Applications should not assume that the snapshot delete is complete
# when this command returns. The job commands / events must be used
# to determine completion and to fetch details of any errors that arise.
#
# Returns: nothing
#
# Example:
#
# -> { "execute": "snapshot-delete",
# "data": {
# "job-id": "snapdelete0",
# "tag": "my-snap",
# "devices": ["disk0", "disk1"]
# }
# }
# <- { "return": { } }
# <- {"event": "JOB_STATUS_CHANGE",
# "data": {"status": "created", "id": "snapdelete0"}}
# <- {"event": "JOB_STATUS_CHANGE",
# "data": {"status": "running", "id": "snapdelete0"}}
# <- {"event": "JOB_STATUS_CHANGE",
# "data": {"status": "waiting", "id": "snapdelete0"}}
# <- {"event": "JOB_STATUS_CHANGE",
# "data": {"status": "pending", "id": "snapdelete0"}}
# <- {"event": "JOB_STATUS_CHANGE",
# "data": {"status": "concluded", "id": "snapdelete0"}}
# -> {"execute": "query-jobs"}
# <- {"return": [{"current-progress": 1,
# "status": "concluded",
# "total-progress": 1,
# "type": "snapshot-delete",
# "id": "snapdelete0"}]}
#
# Since: 6.0
##
{ 'command': 'snapshot-delete',
'data': { 'job-id': 'str',
'tag': 'str',
'devices': ['str'] } }

12
replay/replay-debugging.c
View File

@ -143,12 +143,13 @@ static char *replay_find_nearest_snapshot(int64_t icount,
QEMUSnapshotInfo *sn_tab;
QEMUSnapshotInfo *nearest = NULL;
char *ret = NULL;
int rv;
int nb_sns, i;
AioContext *aio_context;
*snapshot_icount = -1;
bs = bdrv_all_find_vmstate_bs();
bs = bdrv_all_find_vmstate_bs(NULL, false, NULL, NULL);
if (!bs) {
goto fail;
}
@ -159,7 +160,10 @@ static char *replay_find_nearest_snapshot(int64_t icount,
aio_context_release(aio_context);
for (i = 0; i < nb_sns; i++) {
if (bdrv_all_find_snapshot(sn_tab[i].name, &bs) == 0) {
rv = bdrv_all_has_snapshot(sn_tab[i].name, false, NULL, NULL);
if (rv < 0)
goto fail;
if (rv == 1) {
if (sn_tab[i].icount != -1ULL
&& sn_tab[i].icount <= icount
&& (!nearest || nearest->icount < sn_tab[i].icount)) {
@ -192,7 +196,7 @@ static void replay_seek(int64_t icount, QEMUTimerCB callback, Error **errp)
if (icount < replay_get_current_icount()
|| replay_get_current_icount() < snapshot_icount) {
vm_stop(RUN_STATE_RESTORE_VM);
load_snapshot(snapshot, errp);
load_snapshot(snapshot, NULL, false, NULL, errp);
}
g_free(snapshot);
}
@ -323,7 +327,7 @@ void replay_gdb_attached(void)
*/
if (replay_mode == REPLAY_MODE_PLAY
&& !replay_snapshot) {
if (save_snapshot("start_debugging", NULL) != 0) {
if (!save_snapshot("start_debugging", true, NULL, false, NULL, NULL)) {
/* Can't create the snapshot. Continue conventional debugging. */
}
}

5
replay/replay-snapshot.c
View File

@ -77,13 +77,14 @@ void replay_vmstate_init(void)
if (replay_snapshot) {
if (replay_mode == REPLAY_MODE_RECORD) {
if (save_snapshot(replay_snapshot, &err) != 0) {
if (!save_snapshot(replay_snapshot,
true, NULL, false, NULL, &err)) {
error_report_err(err);
error_report("Could not create snapshot for icount record");
exit(1);
}
} else if (replay_mode == REPLAY_MODE_PLAY) {
if (load_snapshot(replay_snapshot, &err) != 0) {
if (!load_snapshot(replay_snapshot, NULL, false, NULL, &err)) {
error_report_err(err);
error_report("Could not load snapshot for icount replay");
exit(1);

122
scripts/userfaultfd-wrlat.py Executable file
View File

@ -0,0 +1,122 @@
#!/usr/bin/python3
#
# userfaultfd-wrlat Summarize userfaultfd write fault latencies.
# Events are continuously accumulated for the
# run, while latency distribution histogram is
# dumped each 'interval' seconds.
#
# For Linux, uses BCC, eBPF.
#
# USAGE: userfaultfd-lat [interval [count]]
#
# Copyright Virtuozzo GmbH, 2020
#
# Authors:
# Andrey Gruzdev <andrey.gruzdev@virtuozzo.com>
#
# This work is licensed under the terms of the GNU GPL, version 2 or
# later. See the COPYING file in the top-level directory.
from __future__ import print_function
from bcc import BPF
from ctypes import c_ushort, c_int, c_ulonglong
from time import sleep
from sys import argv
def usage():
print("USAGE: %s [interval [count]]" % argv[0])
exit()
# define BPF program
bpf_text = """
#include <uapi/linux/ptrace.h>
#include <linux/mm.h>
BPF_HASH(ev_start, u32, u64);
BPF_HISTOGRAM(ev_delta_hist, u64);
/* Trace UFFD page fault start event. */
static void do_event_start()
{
/* Using "(u32)" to drop group ID which is upper 32 bits */
u32 tid = (u32) bpf_get_current_pid_tgid();
u64 ts = bpf_ktime_get_ns();
ev_start.update(&tid, &ts);
}
/* Trace UFFD page fault end event. */
static void do_event_end()
{
/* Using "(u32)" to drop group ID which is upper 32 bits */
u32 tid = (u32) bpf_get_current_pid_tgid();
u64 ts = bpf_ktime_get_ns();
u64 *tsp;
tsp = ev_start.lookup(&tid);
if (tsp) {
u64 delta = ts - (*tsp);
/* Transform time delta to milliseconds */
ev_delta_hist.increment(bpf_log2l(delta / 1000000));
ev_start.delete(&tid);
}
}
/* KPROBE for handle_userfault(). */
int probe_handle_userfault(struct pt_regs *ctx, struct vm_fault *vmf,
unsigned long reason)
{
/* Trace only UFFD write faults. */
if (reason & VM_UFFD_WP) {
do_event_start();
}
return 0;
}
/* KRETPROBE for handle_userfault(). */
int retprobe_handle_userfault(struct pt_regs *ctx)
{
do_event_end();
return 0;
}
"""
# arguments
interval = 10
count = -1
if len(argv) > 1:
try:
interval = int(argv[1])
if interval == 0:
raise
if len(argv) > 2:
count = int(argv[2])
except: # also catches -h, --help
usage()
# load BPF program
b = BPF(text=bpf_text)
# attach KRPOBEs
b.attach_kprobe(event="handle_userfault", fn_name="probe_handle_userfault")
b.attach_kretprobe(event="handle_userfault", fn_name="retprobe_handle_userfault")
# header
print("Tracing UFFD-WP write fault latency... Hit Ctrl-C to end.")
# output
loop = 0
do_exit = 0
while (1):
if count > 0:
loop += 1
if loop > count:
exit()
try:
sleep(interval)
except KeyboardInterrupt:
pass; do_exit = 1
print()
b["ev_delta_hist"].print_log2_hist("msecs")
if do_exit:
exit()

2
softmmu/vl.c
View File

@ -2545,7 +2545,7 @@ void qmp_x_exit_preconfig(Error **errp)
if (loadvm) {
Error *local_err = NULL;
if (load_snapshot(loadvm, &local_err) < 0) {
if (!load_snapshot(loadvm, NULL, false, NULL, &local_err)) {
error_report_err(local_err);
autostart = 0;
exit(1);

12
tests/qemu-iotests/267.out
View File

@ -6,11 +6,11 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
Testing:
QEMU X.Y.Z monitor - type 'help' for more information
(qemu) savevm snap0
Error: No block device can accept snapshots
Error: no block device can store vmstate for snapshot
(qemu) info snapshots
No available block device supports snapshots
no block device can store vmstate for snapshot
(qemu) loadvm snap0
Error: No block device supports snapshots
Error: no block device can store vmstate for snapshot
(qemu) quit
@ -22,7 +22,7 @@ QEMU X.Y.Z monitor - type 'help' for more information
(qemu) savevm snap0
Error: Device 'none0' is writable but does not support snapshots
(qemu) info snapshots
No available block device supports snapshots
no block device can store vmstate for snapshot
(qemu) loadvm snap0
Error: Device 'none0' is writable but does not support snapshots
(qemu) quit
@ -58,7 +58,7 @@ QEMU X.Y.Z monitor - type 'help' for more information
(qemu) savevm snap0
Error: Device 'virtio0' is writable but does not support snapshots
(qemu) info snapshots
No available block device supports snapshots
no block device can store vmstate for snapshot
(qemu) loadvm snap0
Error: Device 'virtio0' is writable but does not support snapshots
(qemu) quit
@ -83,7 +83,7 @@ QEMU X.Y.Z monitor - type 'help' for more information
(qemu) savevm snap0
Error: Device 'file' is writable but does not support snapshots
(qemu) info snapshots
No available block device supports snapshots
no block device can store vmstate for snapshot
(qemu) loadvm snap0
Error: Device 'file' is writable but does not support snapshots
(qemu) quit

106
tests/qemu-iotests/common.qemu
View File

@ -53,6 +53,15 @@ _in_fd=4
# If $mismatch_only is set, only non-matching responses will
# be echoed.
#
# If $capture_events is non-empty, then any QMP event names it lists
# will not be echoed out, but instead collected in the $QEMU_EVENTS
# variable. The _wait_event function can later be used to receive
# the cached events.
#
# If $only_capture_events is set to anything but an empty string,
# then an error will be raised if a QMP message is seen which is
# not an event listed in $capture_events.
#
# If $success_or_failure is set, the meaning of the arguments is
# changed as follows:
# $2: A string to search for in the response; if found, this indicates
@ -78,6 +87,31 @@ _timed_wait_for()
QEMU_STATUS[$h]=0
while IFS= read -t ${QEMU_COMM_TIMEOUT} resp <&${QEMU_OUT[$h]}
do
if [ -n "$capture_events" ]; then
capture=0
local evname
for evname in $capture_events
do
case ${resp} in
*\"event\":\ \"${evname}\"* ) capture=1 ;;
esac
done
if [ $capture = 1 ];
then
ev=$(echo "${resp}" | tr -d '\r' | tr % .)
QEMU_EVENTS="${QEMU_EVENTS:+${QEMU_EVENTS}%}${ev}"
if [ -n "$only_capture_events" ]; then
return
else
continue
fi
fi
fi
if [ -n "$only_capture_events" ]; then
echo "Only expected $capture_events but got ${resp}"
exit 1
fi
if [ -z "${silent}" ] && [ -z "${mismatch_only}" ]; then
echo "${resp}" | _filter_testdir | _filter_qemu \
| _filter_qemu_io | _filter_qmp | _filter_hmp
@ -172,12 +206,82 @@ _send_qemu_cmd()
let count--;
done
if [ ${QEMU_STATUS[$h]} -ne 0 ] && [ -z "${qemu_error_no_exit}" ]; then
echo "Timeout waiting for ${1} on handle ${h}"
echo "Timeout waiting for command ${1} response on handle ${h}"
exit 1 #Timeout means the test failed
fi
}
# Check event cache for a named QMP event
#
# Input parameters:
# $1: Name of the QMP event to check for
#
# Checks if the named QMP event that was previously captured
# into $QEMU_EVENTS. When matched, the QMP event will be echoed
# and the $matched variable set to 1.
#
# _wait_event is more suitable for test usage in most cases
_check_cached_events()
{
local evname=${1}
local match="\"event\": \"$evname\""
matched=0
if [ -n "$QEMU_EVENTS" ]; then
CURRENT_QEMU_EVENTS=$QEMU_EVENTS
QEMU_EVENTS=
old_IFS=$IFS
IFS="%"
for ev in $CURRENT_QEMU_EVENTS
do
grep -q "$match" < <(echo "${ev}")
if [ $? -eq 0 ] && [ $matched = 0 ]; then
echo "${ev}" | _filter_testdir | _filter_qemu \
| _filter_qemu_io | _filter_qmp | _filter_hmp
matched=1
else
QEMU_EVENTS="${QEMU_EVENTS:+${QEMU_EVENTS}%}${ev}"
fi
done
IFS=$old_IFS
fi
}
# Wait for a named QMP event
#
# Input parameters:
# $1: QEMU handle to use
# $2: Name of the QMP event to wait for
#
# Checks if the named QMP even was previously captured
# into $QEMU_EVENTS. If none are present, then waits for the
# event to arrive on the QMP channel. When matched, the QMP
# event will be echoed
_wait_event()
{
local h=${1}
local evname=${2}
while true
do
_check_cached_events $evname
if [ $matched = 1 ];
then
return
fi
only_capture_events=1 qemu_error_no_exit=1 _timed_wait_for ${h}
if [ ${QEMU_STATUS[$h]} -ne 0 ] ; then
echo "Timeout waiting for event ${evname} on handle ${h}"
exit 1 #Timeout means the test failed
fi
done
}
# Launch a QEMU process.
#
# Input parameters:

10
tests/qemu-iotests/common.rc
View File

@ -109,8 +109,14 @@ peek_file_raw()
dd if="$1" bs=1 skip="$2" count="$3" status=none
}
if ! . ./common.config
config=common.config
test -f $config || config=../common.config
if ! test -f $config
then
echo "$0: failed to find common.config"
exit 1
fi
if ! . $config
then
echo "$0: failed to source common.config"
exit 1

1
util/meson.build
View File

@ -52,6 +52,7 @@ if have_system
util_ss.add(files('crc-ccitt.c'))
util_ss.add(when: 'CONFIG_GIO', if_true: [files('dbus.c'), gio])
util_ss.add(files('yank.c'))
util_ss.add(when: 'CONFIG_LINUX', if_true: files('userfaultfd.c'))
endif
if have_block

9
util/trace-events
View File

@ -91,3 +91,12 @@ qemu_vfio_pci_read_config(void *buf, int ofs, int size, uint64_t region_ofs, uin
qemu_vfio_pci_write_config(void *buf, int ofs, int size, uint64_t region_ofs, uint64_t region_size) "write cfg ptr %p ofs 0x%x size 0x%x (region addr 0x%"PRIx64" size 0x%"PRIx64")"
qemu_vfio_region_info(const char *desc, uint64_t region_ofs, uint64_t region_size, uint32_t cap_offset) "region '%s' addr 0x%"PRIx64" size 0x%"PRIx64" cap_ofs 0x%"PRIx32
qemu_vfio_pci_map_bar(int index, uint64_t region_ofs, uint64_t region_size, int ofs, void *host) "map region bar#%d addr 0x%"PRIx64" size 0x%"PRIx64" ofs 0x%x host %p"
#userfaultfd.c
uffd_query_features_nosys(int err) "errno: %i"
uffd_query_features_api_failed(int err) "errno: %i"
uffd_create_fd_nosys(int err) "errno: %i"
uffd_create_fd_api_failed(int err) "errno: %i"
uffd_create_fd_api_noioctl(uint64_t ioctl_req, uint64_t ioctl_supp) "ioctl_req: 0x%" PRIx64 "ioctl_supp: 0x%" PRIx64
uffd_register_memory_failed(void *addr, uint64_t length, uint64_t mode, int err) "addr: %p length: %" PRIu64 " mode: 0x%" PRIx64 " errno: %i"
uffd_unregister_memory_failed(void *addr, uint64_t length, int err) "addr: %p length: %" PRIu64 " errno: %i"

345
util/userfaultfd.c Normal file
View File

@ -0,0 +1,345 @@
/*
* Linux UFFD-WP support
*
* Copyright Virtuozzo GmbH, 2020
*
* Authors:
* Andrey Gruzdev <andrey.gruzdev@virtuozzo.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or
* later. See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "qemu/bitops.h"
#include "qemu/error-report.h"
#include "qemu/userfaultfd.h"
#include "trace.h"
#include <poll.h>
#include <sys/syscall.h>
#include <sys/ioctl.h>
/**
* uffd_query_features: query UFFD features
*
* Returns: 0 on success, negative value in case of an error
*
* @features: parameter to receive 'uffdio_api.features'
*/
int uffd_query_features(uint64_t *features)
{
int uffd_fd;
struct uffdio_api api_struct = { 0 };
int ret = -1;
uffd_fd = syscall(__NR_userfaultfd, O_CLOEXEC);
if (uffd_fd < 0) {
trace_uffd_query_features_nosys(errno);
return -1;
}
api_struct.api = UFFD_API;
api_struct.features = 0;
if (ioctl(uffd_fd, UFFDIO_API, &api_struct)) {
trace_uffd_query_features_api_failed(errno);
goto out;
}
*features = api_struct.features;
ret = 0;
out:
close(uffd_fd);
return ret;
}
/**
* uffd_create_fd: create UFFD file descriptor
*
* Returns non-negative file descriptor or negative value in case of an error
*
* @features: UFFD features to request
* @non_blocking: create UFFD file descriptor for non-blocking operation
*/
int uffd_create_fd(uint64_t features, bool non_blocking)
{
int uffd_fd;
int flags;
struct uffdio_api api_struct = { 0 };
uint64_t ioctl_mask = BIT(_UFFDIO_REGISTER) | BIT(_UFFDIO_UNREGISTER);
flags = O_CLOEXEC | (non_blocking ? O_NONBLOCK : 0);
uffd_fd = syscall(__NR_userfaultfd, flags);
if (uffd_fd < 0) {
trace_uffd_create_fd_nosys(errno);
return -1;
}
api_struct.api = UFFD_API;
api_struct.features = features;
if (ioctl(uffd_fd, UFFDIO_API, &api_struct)) {
trace_uffd_create_fd_api_failed(errno);
goto fail;
}
if ((api_struct.ioctls & ioctl_mask) != ioctl_mask) {
trace_uffd_create_fd_api_noioctl(ioctl_mask, api_struct.ioctls);
goto fail;
}
return uffd_fd;
fail:
close(uffd_fd);
return -1;
}
/**
* uffd_close_fd: close UFFD file descriptor
*
* @uffd_fd: UFFD file descriptor
*/
void uffd_close_fd(int uffd_fd)
{
assert(uffd_fd >= 0);
close(uffd_fd);
}
/**
* uffd_register_memory: register memory range via UFFD-IO
*
* Returns 0 in case of success, negative value in case of an error
*
* @uffd_fd: UFFD file descriptor
* @addr: base address of memory range
* @length: length of memory range
* @mode: UFFD register mode (UFFDIO_REGISTER_MODE_MISSING, ...)
* @ioctls: optional pointer to receive supported IOCTL mask
*/
int uffd_register_memory(int uffd_fd, void *addr, uint64_t length,
uint64_t mode, uint64_t *ioctls)
{
struct uffdio_register uffd_register;
uffd_register.range.start = (uintptr_t) addr;
uffd_register.range.len = length;
uffd_register.mode = mode;
if (ioctl(uffd_fd, UFFDIO_REGISTER, &uffd_register)) {
trace_uffd_register_memory_failed(addr, length, mode, errno);
return -1;
}
if (ioctls) {
*ioctls = uffd_register.ioctls;
}
return 0;
}
/**
* uffd_unregister_memory: un-register memory range with UFFD-IO
*
* Returns 0 in case of success, negative value in case of an error
*
* @uffd_fd: UFFD file descriptor
* @addr: base address of memory range
* @length: length of memory range
*/
int uffd_unregister_memory(int uffd_fd, void *addr, uint64_t length)
{
struct uffdio_range uffd_range;
uffd_range.start = (uintptr_t) addr;
uffd_range.len = length;
if (ioctl(uffd_fd, UFFDIO_UNREGISTER, &uffd_range)) {
trace_uffd_unregister_memory_failed(addr, length, errno);
return -1;
}
return 0;
}
/**
* uffd_change_protection: protect/un-protect memory range for writes via UFFD-IO
*
* Returns 0 on success, negative value in case of error
*
* @uffd_fd: UFFD file descriptor
* @addr: base address of memory range
* @length: length of memory range
* @wp: write-protect/unprotect
* @dont_wake: do not wake threads waiting on wr-protected page
*/
int uffd_change_protection(int uffd_fd, void *addr, uint64_t length,
bool wp, bool dont_wake)
{
struct uffdio_writeprotect uffd_writeprotect;
uffd_writeprotect.range.start = (uintptr_t) addr;
uffd_writeprotect.range.len = length;
if (!wp && dont_wake) {
/* DONTWAKE is meaningful only on protection release */
uffd_writeprotect.mode = UFFDIO_WRITEPROTECT_MODE_DONTWAKE;
} else {
uffd_writeprotect.mode = (wp ? UFFDIO_WRITEPROTECT_MODE_WP : 0);
}
if (ioctl(uffd_fd, UFFDIO_WRITEPROTECT, &uffd_writeprotect)) {
error_report("uffd_change_protection() failed: addr=%p len=%" PRIu64
" mode=%" PRIx64 " errno=%i", addr, length,
(uint64_t) uffd_writeprotect.mode, errno);
return -1;
}
return 0;
}
/**
* uffd_copy_page: copy range of pages to destination via UFFD-IO
*
* Copy range of source pages to the destination to resolve
* missing page fault somewhere in the destination range.
*
* Returns 0 on success, negative value in case of an error
*
* @uffd_fd: UFFD file descriptor
* @dst_addr: destination base address
* @src_addr: source base address
* @length: length of the range to copy
* @dont_wake: do not wake threads waiting on missing page
*/
int uffd_copy_page(int uffd_fd, void *dst_addr, void *src_addr,
uint64_t length, bool dont_wake)
{
struct uffdio_copy uffd_copy;
uffd_copy.dst = (uintptr_t) dst_addr;
uffd_copy.src = (uintptr_t) src_addr;
uffd_copy.len = length;
uffd_copy.mode = dont_wake ? UFFDIO_COPY_MODE_DONTWAKE : 0;
if (ioctl(uffd_fd, UFFDIO_COPY, &uffd_copy)) {
error_report("uffd_copy_page() failed: dst_addr=%p src_addr=%p length=%" PRIu64
" mode=%" PRIx64 " errno=%i", dst_addr, src_addr,
length, (uint64_t) uffd_copy.mode, errno);
return -1;
}
return 0;
}
/**
* uffd_zero_page: fill range of pages with zeroes via UFFD-IO
*
* Fill range pages with zeroes to resolve missing page fault within the range.
*
* Returns 0 on success, negative value in case of an error
*
* @uffd_fd: UFFD file descriptor
* @addr: base address
* @length: length of the range to fill with zeroes
* @dont_wake: do not wake threads waiting on missing page
*/
int uffd_zero_page(int uffd_fd, void *addr, uint64_t length, bool dont_wake)
{
struct uffdio_zeropage uffd_zeropage;
uffd_zeropage.range.start = (uintptr_t) addr;
uffd_zeropage.range.len = length;
uffd_zeropage.mode = dont_wake ? UFFDIO_ZEROPAGE_MODE_DONTWAKE : 0;
if (ioctl(uffd_fd, UFFDIO_ZEROPAGE, &uffd_zeropage)) {
error_report("uffd_zero_page() failed: addr=%p length=%" PRIu64
" mode=%" PRIx64 " errno=%i", addr, length,
(uint64_t) uffd_zeropage.mode, errno);
return -1;
}
return 0;
}
/**
* uffd_wakeup: wake up threads waiting on page UFFD-managed page fault resolution
*
* Wake up threads waiting on any page/pages from the designated range.
* The main use case is when during some period, page faults are resolved
* via UFFD-IO IOCTLs with MODE_DONTWAKE flag set, then after that all waits
* for the whole memory range are satisfied in a single call to uffd_wakeup().
*
* Returns 0 on success, negative value in case of an error
*
* @uffd_fd: UFFD file descriptor
* @addr: base address
* @length: length of the range
*/
int uffd_wakeup(int uffd_fd, void *addr, uint64_t length)
{
struct uffdio_range uffd_range;
uffd_range.start = (uintptr_t) addr;
uffd_range.len = length;
if (ioctl(uffd_fd, UFFDIO_WAKE, &uffd_range)) {
error_report("uffd_wakeup() failed: addr=%p length=%" PRIu64 " errno=%i",
addr, length, errno);
return -1;
}
return 0;
}
/**
* uffd_read_events: read pending UFFD events
*
* Returns number of fetched messages, 0 if non is available or
* negative value in case of an error
*
* @uffd_fd: UFFD file descriptor
* @msgs: pointer to message buffer
* @count: number of messages that can fit in the buffer
*/
int uffd_read_events(int uffd_fd, struct uffd_msg *msgs, int count)
{
ssize_t res;
do {
res = read(uffd_fd, msgs, count * sizeof(struct uffd_msg));
} while (res < 0 && errno == EINTR);
if ((res < 0 && errno == EAGAIN)) {
return 0;
}
if (res < 0) {
error_report("uffd_read_events() failed: errno=%i", errno);
return -1;
}
return (int) (res / sizeof(struct uffd_msg));
}
/**
* uffd_poll_events: poll UFFD file descriptor for read
*
* Returns true if events are available for read, false otherwise
*
* @uffd_fd: UFFD file descriptor
* @tmo: timeout value
*/
bool uffd_poll_events(int uffd_fd, int tmo)
{
int res;
struct pollfd poll_fd = { .fd = uffd_fd, .events = POLLIN, .revents = 0 };
do {
res = poll(&poll_fd, 1, tmo);
} while (res < 0 && errno == EINTR);
if (res == 0) {
return false;
}
if (res < 0) {
error_report("uffd_poll_events() failed: errno=%i", errno);
return false;
}
return (poll_fd.revents & POLLIN) != 0;
}