Hi Alexandr
According to my test result, this series of patches introduce issues,
it prints the following error messages when compiling the process
after applying your patch.
The test based on this commit:
commit 3a2d5612a7422732b648b46d4b934e2e54622fd6 (origin/master, origin/HEAD)
Author: Peter Maydell <[email protected]>
Date: Fri Oct 17 14:31:56 2025 +0100
Error messages:
[1849/2964] Compiling C object
libqemu-x86_64-softmmu.a.p/hw_block_vhost-user-blk.c.o
FAILED: libqemu-x86_64-softmmu.a.p/hw_block_vhost-user-blk.c.o
cc -m64 -Ilibqemu-x86_64-softmmu.a.p -I. -I.. -Itarget/i386
-I../target/i386 -Isubprojects/dtc/libfdt -I../subprojects/dtc/libfdt
-Isubprojects/libvduse -I../subprojects/libvduse -Iqapi -Itrace -Iui
-Iui/shader -I/usr/include/pixman-1 -I/usr/include/glib-2.0
-I/usr/lib64/glib-2.0/include -I/usr/include/libmount
-I/usr/include/blkid -I/usr/include/sysprof-6
-I/usr/include/gio-unix-2.0 -I/usr/include/slirp
-fdiagnostics-color=auto -Wall -Winvalid-pch -Werror -std=gnu11 -O0 -g
-fstack-protector-strong -Wempty-body -Wendif-labels
-Wexpansion-to-defined -Wformat-security -Wformat-y2k
-Wignored-qualifiers -Wimplicit-fallthrough=2 -Winit-self
-Wmissing-format-attribute -Wmissing-prototypes -Wnested-externs
-Wold-style-declaration -Wold-style-definition -Wredundant-decls
-Wshadow=local -Wstrict-prototypes -Wtype-limits -Wundef -Wvla
-Wwrite-strings -Wno-missing-include-dirs -Wno-psabi
-Wno-shift-negative-value -isystem
/mnt/tests/distribution/command/qemu/linux-headers -isystem
linux-headers -iquote . -iquote /mnt/tests/distribution/command/qemu
-iquote /mnt/tests/distribution/command/qemu/include -iquote
/mnt/tests/distribution/command/qemu/host/include/x86_64 -iquote
/mnt/tests/distribution/command/qemu/host/include/generic -iquote
/mnt/tests/distribution/command/qemu/tcg/i386 -pthread -mcx16 -msse2
-D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE
-fno-strict-aliasing -fno-common -fwrapv -ftrivial-auto-var-init=zero
-fzero-call-used-regs=used-gpr -fPIE -DWITH_GZFILEOP
-isystem../linux-headers -isystemlinux-headers -DCOMPILING_PER_TARGET
'-DCONFIG_TARGET="x86_64-softmmu-config-target.h"'
'-DCONFIG_DEVICES="x86_64-softmmu-config-devices.h"' -MD -MQ
libqemu-x86_64-softmmu.a.p/hw_block_vhost-user-blk.c.o -MF
libqemu-x86_64-softmmu.a.p/hw_block_vhost-user-blk.c.o.d -o
libqemu-x86_64-softmmu.a.p/hw_block_vhost-user-blk.c.o -c
../hw/block/vhost-user-blk.c
In file included from
/mnt/tests/distribution/command/qemu/migration/options.h:19,
from ../hw/block/vhost-user-blk.c:34:
/mnt/tests/distribution/command/qemu/include/migration/client-options.h:26:1:
error: unknown type name ‘MigMode’
26 | MigMode migrate_mode(void);
| ^~~~~~~
/mnt/tests/distribution/command/qemu/migration/options.h:66:7: error:
unknown type name ‘BitmapMigrationNodeAliasList’
66 | const BitmapMigrationNodeAliasList *migrate_block_bitmap_mapping(void);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/mnt/tests/distribution/command/qemu/migration/options.h:80:1: error:
unknown type name ‘MultiFDCompression’
80 | MultiFDCompression migrate_multifd_compression(void);
| ^~~~~~~~~~~~~~~~~~
/mnt/tests/distribution/command/qemu/migration/options.h:89:1: error:
unknown type name ‘ZeroPageDetection’
89 | ZeroPageDetection migrate_zero_page_detection(void);
| ^~~~~~~~~~~~~~~~~
/mnt/tests/distribution/command/qemu/migration/options.h:93:27: error:
unknown type name ‘MigrationParameters’; did you mean
‘MigrationState’?
93 | bool migrate_params_check(MigrationParameters *params, Error **errp);
| ^~~~~~~~~~~~~~~~~~~
| MigrationState
/mnt/tests/distribution/command/qemu/migration/options.h:94:26: error:
unknown type name ‘MigrationParameters’; did you mean
‘MigrationState’?
94 | void migrate_params_init(MigrationParameters *params);
| ^~~~~~~~~~~~~~~~~~~
| MigrationState
ninja: build stopped: subcommand failed.
make[1]: *** [Makefile:168: run-ninja] Error 1
Thanks
Lei
On Mon, Oct 20, 2025 at 1:47 PM Alexandr Moshkov
<[email protected]> wrote:
>
> In vhost_user_blk_stop() on incoming migration make force_stop = true,
> so GET_VRING_BASE will not be executed.
>
> Signed-off-by: Alexandr Moshkov <[email protected]>
> ---
> hw/block/vhost-user-blk.c | 52 +++++++++++++++++++++++++++++++++++++++
> migration/options.c | 7 ++++++
> migration/options.h | 1 +
> qapi/migration.json | 9 +++++--
> 4 files changed, 67 insertions(+), 2 deletions(-)
>
> diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
> index c0cc5f6942..49f67d0451 100644
> --- a/hw/block/vhost-user-blk.c
> +++ b/hw/block/vhost-user-blk.c
> @@ -31,6 +31,7 @@
> #include "hw/virtio/virtio-access.h"
> #include "system/system.h"
> #include "system/runstate.h"
> +#include "migration/options.h"
>
> static const int user_feature_bits[] = {
> VIRTIO_BLK_F_SIZE_MAX,
> @@ -224,6 +225,11 @@ static int vhost_user_blk_stop(VirtIODevice *vdev)
> force_stop = s->skip_get_vring_base_on_force_shutdown &&
> qemu_force_shutdown_requested();
>
> + if (migrate_inflight_vhost_user_blk() &&
> + runstate_check(RUN_STATE_FINISH_MIGRATE)) {
> + force_stop = true;
> + }
> +
> ret = force_stop ? vhost_dev_force_stop(&s->dev, vdev, true) :
> vhost_dev_stop(&s->dev, vdev, true);
>
> @@ -568,12 +574,58 @@ static struct vhost_dev
> *vhost_user_blk_get_vhost(VirtIODevice *vdev)
> return &s->dev;
> }
>
> +static int vhost_user_blk_save(QEMUFile *f, void *pv, size_t size,
> + const VMStateField *field, JSONWriter *vmdesc)
> +{
> + VirtIODevice *vdev = pv;
> + VHostUserBlk *s = VHOST_USER_BLK(vdev);
> +
> + if (!migrate_inflight_vhost_user_blk()) {
> + return 0;
> + }
> +
> + vhost_dev_save_inflight(s->inflight, f);
> +
> + return 0;
> +}
> +
> +static int vhost_user_blk_load(QEMUFile *f, void *pv, size_t size,
> + const VMStateField *field)
> +{
> + VirtIODevice *vdev = pv;
> + VHostUserBlk *s = VHOST_USER_BLK(vdev);
> + int ret;
> +
> + if (!migrate_inflight_vhost_user_blk()) {
> + return 0;
> + }
> +
> + ret = vhost_dev_load_inflight(s->inflight, f);
> + if (ret < 0) {
> + g_autofree char *path = object_get_canonical_path(OBJECT(vdev));
> + error_report("%s [%s]: can't load in-flight requests",
> + path, TYPE_VHOST_USER_BLK);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> static const VMStateDescription vmstate_vhost_user_blk = {
> .name = "vhost-user-blk",
> .minimum_version_id = 1,
> .version_id = 1,
> .fields = (const VMStateField[]) {
> VMSTATE_VIRTIO_DEVICE,
> + {
> + .name = "backend state",
> + .info = &(const VMStateInfo) {
> + .name = "vhost-user-blk backend state",
> + .get = vhost_user_blk_load,
> + .put = vhost_user_blk_save,
> + },
> + .flags = VMS_SINGLE,
> + },
> VMSTATE_END_OF_LIST()
> },
> };
> diff --git a/migration/options.c b/migration/options.c
> index 5183112775..fcae2b4559 100644
> --- a/migration/options.c
> +++ b/migration/options.c
> @@ -262,6 +262,13 @@ bool migrate_mapped_ram(void)
> return s->capabilities[MIGRATION_CAPABILITY_MAPPED_RAM];
> }
>
> +bool migrate_inflight_vhost_user_blk(void)
> +{
> + MigrationState *s = migrate_get_current();
> +
> + return s->capabilities[MIGRATION_CAPABILITY_INFLIGHT_VHOST_USER_BLK];
> +}
> +
> bool migrate_ignore_shared(void)
> {
> MigrationState *s = migrate_get_current();
> diff --git a/migration/options.h b/migration/options.h
> index 82d839709e..eab1485d1a 100644
> --- a/migration/options.h
> +++ b/migration/options.h
> @@ -30,6 +30,7 @@ bool migrate_colo(void);
> bool migrate_dirty_bitmaps(void);
> bool migrate_events(void);
> bool migrate_mapped_ram(void);
> +bool migrate_inflight_vhost_user_blk(void);
> bool migrate_ignore_shared(void);
> bool migrate_late_block_activate(void);
> bool migrate_multifd(void);
> diff --git a/qapi/migration.json b/qapi/migration.json
> index be0f3fcc12..c9fea59515 100644
> --- a/qapi/migration.json
> +++ b/qapi/migration.json
> @@ -517,9 +517,13 @@
> # each RAM page. Requires a migration URI that supports seeking,
> # such as a file. (since 9.0)
> #
> +# @inflight-vhost-user-blk: If enabled, QEMU will migrate inflight
> +# region for vhost-user-blk. (since 10.2)
> +#
> # Features:
> #
> -# @unstable: Members @x-colo and @x-ignore-shared are experimental.
> +# @unstable: Members @x-colo and @x-ignore-shared,
> +# @inflight-vhost-user-blk are experimental.
> # @deprecated: Member @zero-blocks is deprecated as being part of
> # block migration which was already removed.
> #
> @@ -536,7 +540,8 @@
> { 'name': 'x-ignore-shared', 'features': [ 'unstable' ] },
> 'validate-uuid', 'background-snapshot',
> 'zero-copy-send', 'postcopy-preempt', 'switchover-ack',
> - 'dirty-limit', 'mapped-ram'] }
> + 'dirty-limit', 'mapped-ram',
> + { 'name': 'inflight-vhost-user-blk', 'features': [ 'unstable' ] }
> ] }
>
> ##
> # @MigrationCapabilityStatus:
> --
> 2.34.1
>
>
