Live migration should be terminated if the vhost-user backend crashes
before the migration completes.
Specifically, since the vhost device will be stopped when VM is stopped
before the end of the live migration, in current implementation if the
backend crashes, vhost-user device set_status() won't return failure,
live migration won't perceive the disconnection between QEMU and the
backend.
When the VM is migrated to the destination, the inflight IO will be
resubmitted, and if the IO was completed out of order before, it will
cause IO error.
To fix this issue:
1. Add the return value to set_status() for VirtioDeviceClass.
a. For the vhost-user device, return failure when the backend crashes.
b. For other virtio devices, always return 0.
2. Return failure if vhost_dev_stop() failed for vhost-user device.
If QEMU loses connection with the vhost-user backend, virtio set_status()
can return failure to the upper layer, migration_completion() can handle
the error, terminate the live migration, and restore the VM, so that
inflight IO can be completed normally.
Signed-off-by: Haoqian He <haoqian.he@smartx.com>
Message-Id: <20250416024729.3289157-4-haoqian.he@smartx.com>
Tested-by: Lei Yang <leiyang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
If the backend crashes and restarts, the device is broken.
This patch adds reconnect for vhost-user-scsi.
This patch also improves the error messages, and reports some silent errors.
Tested with spdk backend.
Signed-off-by: Li Feng <fengli@smartx.com>
Message-Id: <20231009044735.941655-4-fengli@smartx.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Qemu will send GET_INFLIGHT_FD and SET_INFLIGH_FD to backend, and
the backend setup the inflight memory to track the io.
Change-Id: I805d6189996f7a1b44c65f0b12ef7473b1789510
Signed-off-by: Li Feng <fengli@smartx.com>
Message-Id: <20200909122021.1055174-1-fengli@smartx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Some typedefs and macros are defined after the type check macros.
This makes it difficult to automatically replace their
definitions with OBJECT_DECLARE_TYPE.
Patch generated using:
$ ./scripts/codeconverter/converter.py -i \
--pattern=QOMStructTypedefSplit $(git grep -l '' -- '*.[ch]')
which will split "typdef struct { ... } TypedefName"
declarations.
Followed by:
$ ./scripts/codeconverter/converter.py -i --pattern=MoveSymbols \
$(git grep -l '' -- '*.[ch]')
which will:
- move the typedefs and #defines above the type check macros
- add missing #include "qom/object.h" lines if necessary
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20200831210740.126168-9-ehabkost@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20200831210740.126168-10-ehabkost@redhat.com>
Message-Id: <20200831210740.126168-11-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
In my "build everything" tree, changing hw/qdev-properties.h triggers
a recompile of some 2700 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).
Many places including hw/qdev-properties.h (directly or via hw/qdev.h)
actually need only hw/qdev-core.h. Include hw/qdev-core.h there
instead.
hw/qdev.h is actually pointless: all it does is include hw/qdev-core.h
and hw/qdev-properties.h, which in turn includes hw/qdev-core.h.
Replace the remaining uses of hw/qdev.h by hw/qdev-properties.h.
While there, delete a few superfluous inclusions of hw/qdev-core.h.
Touching hw/qdev-properties.h now recompiles some 1200 objects.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Daniel P. Berrangé" <berrange@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20190812052359.30071-22-armbru@redhat.com>
No header includes qemu-common.h after this commit, as prescribed by
qemu-common.h's file comment.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-5-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c
block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c
target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h
target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h
target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h
target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and
net/tap-bsd.c fixed up]
In order to perform a valid migration of a vhost-scsi device,
the following requirements must be met:
(1) The virtio-scsi device state needs to be saved & loaded.
(2) The vhost backend must be stopped before virtio-scsi device state
is saved:
(2.1) Sync vhost backend state to virtio-scsi device state.
(2.2) No further I/O requests are made by vhost backend to target
SCSI device.
(2.3) No further guest memory access takes place after VM is stopped.
(3) Requests in-flight to target SCSI device are completed before
migration handover.
(4) Target SCSI device state needs to be saved & loaded into the
destination host target SCSI device.
Previous commit ("vhost-scsi: Add VMState descriptor")
add support to save & load the device state using VMState.
This meets requirement (1).
When VM is stopped by migration thread (On Pre-Copy complete), the
following code path is executed:
migration_completion() -> vm_stop_force_state() -> vm_stop() ->
do_vm_stop().
do_vm_stop() calls first pause_all_vcpus() which pause all guest
vCPUs and then call vm_state_notify().
In case of vhost-scsi device, this will lead to the following code path
to be executed:
vm_state_notify() -> virtio_vmstate_change() ->
virtio_set_status() -> vhost_scsi_set_status() -> vhost_scsi_stop().
vhost_scsi_stop() then calls vhost_scsi_clear_endpoint() and
vhost_scsi_common_stop().
vhost_scsi_clear_endpoint() sends VHOST_SCSI_CLEAR_ENDPOINT ioctl to
vhost backend which will reach kernel's vhost_scsi_clear_endpoint()
which process all pending I/O requests and wait for them to complete
(vhost_scsi_flush()). This meets requirement (3).
vhost_scsi_common_stop() will stop the vhost backend.
As part of this stop, dirty-bitmap is synced and vhost backend state is
synced with virtio-scsi device state. As at this point guest vCPUs are
already paused, this meets requirement (2).
At this point we are left with requirement (4) which is target SCSI
device specific and therefore cannot be done by QEMU. Which is the main
reason why vhost-scsi adds a migration blocker.
However, as this can be handled either by an external orchestrator or
by using shared-storage (i.e. iSCSI), there is no reason to limit the
orchestrator from being able to explictly specify it wish to enable
migration even when VM have a vhost-scsi device.
Considering all the above, this commit allows orchestrator to explictly
specify that it is responsbile for taking care of requirement (4) and
therefore vhost-scsi should not add a migration blocker.
Reviewed-by: Nir Weiner <nir.weiner@oracle.com>
Reviewed-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Message-Id: <20190416125912.44001-4-liran.alon@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
In preparation for having vhost-scsi also make use of host_features,
move it from struct VHostUserSCSI into struct VHostSCSICommon.
Signed-off-by: Greg Edwards <gedwards@ddn.com>
Message-Id: <20180808195235.5843-2-gedwards@ddn.com>
Reviewed-by: Felipe Franciosi <felipe@nutanix.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In order to introduce a new vhost-user-scsi host device type, it makes
sense to abstract part of vhost-scsi into a common parent class. This
commit does exactly that.
Signed-off-by: Felipe Franciosi <felipe@nutanix.com>
Message-Id: <1488479153-21203-3-git-send-email-felipe@nutanix.com>
