Now that v2 protocol implementation has been added, remove the
deprecated v1 implementation.
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Link: https://lore.kernel.org/r/20230216143630.25610-10-avihaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Implement the basic mandatory part of VFIO migration protocol v2.
This includes all functionality that is necessary to support
VFIO_MIGRATION_STOP_COPY part of the v2 protocol.
The two protocols, v1 and v2, will co-exist and in the following patches
v1 protocol code will be removed.
There are several main differences between v1 and v2 protocols:
- VFIO device state is now represented as a finite state machine instead
of a bitmap.
- Migration interface with kernel is now done using VFIO_DEVICE_FEATURE
ioctl and normal read() and write() instead of the migration region.
- Pre-copy is made optional in v2 protocol. Support for pre-copy will be
added later on.
Detailed information about VFIO migration protocol v2 and its difference
compared to v1 protocol can be found here [1].
[1]
https://lore.kernel.org/all/20220224142024.147653-10-yishaih@nvidia.com/
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>.
Link: https://lore.kernel.org/r/20230216143630.25610-9-avihaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
To avoid name collisions, rename functions and structs related to VFIO
migration protocol v1. This will allow the two protocols to co-exist
when v2 protocol is added, until v1 is removed. No functional changes
intended.
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Link: https://lore.kernel.org/r/20230216143630.25610-8-avihaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Move vfio_dev_get_region_info() logic from vfio_migration_probe() to
vfio_migration_init(). This logic is specific to v1 protocol and moving
it will make it easier to add the v2 protocol implementation later.
No functional changes intended.
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Link: https://lore.kernel.org/r/20230216143630.25610-7-avihaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Currently VFIO migration doesn't implement some kind of intermediate
quiescent state in which P2P DMAs are quiesced before stopping or
running the device. This can cause problems in multi-device migration
where the devices are doing P2P DMAs, since the devices are not stopped
together at the same time.
Until such support is added, block migration of multiple devices.
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Link: https://lore.kernel.org/r/20230216143630.25610-6-avihaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Currently, if IOMMU of a VFIO container doesn't support dirty page
tracking, migration is blocked. This is because a DMA-able VFIO device
can dirty RAM pages without updating QEMU about it, thus breaking the
migration.
However, this doesn't mean that migration can't be done at all.
In such case, allow migration and let QEMU VFIO code mark all pages
dirty.
This guarantees that all pages that might have gotten dirty are reported
back, and thus guarantees a valid migration even without VFIO IOMMU
dirty tracking support.
The motivation for this patch is the introduction of iommufd [1].
iommufd can directly implement the /dev/vfio/vfio container IOCTLs by
mapping them into its internal ops, allowing the usage of these IOCTLs
over iommufd. However, VFIO IOMMU dirty tracking is not supported by
this VFIO compatibility API.
This patch will allow migration by hosts that use the VFIO compatibility
API and prevent migration regressions caused by the lack of VFIO IOMMU
dirty tracking support.
[1]
https://lore.kernel.org/kvm/0-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com/
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Link: https://lore.kernel.org/r/20230216143630.25610-4-avihaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
As part of its error flow, vfio_vmstate_change() accesses
MigrationState->to_dst_file without any checks. This can cause a NULL
pointer dereference if the error flow is taken and
MigrationState->to_dst_file is not set.
For example, this can happen if VM is started or stopped not during
migration and vfio_vmstate_change() error flow is taken, as
MigrationState->to_dst_file is not set at that time.
Fix it by checking that MigrationState->to_dst_file is set before using
it.
Fixes: 02a7e71b1e ("vfio: Add VM state change handler to know state of VM")
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Link: https://lore.kernel.org/r/20230216143630.25610-3-avihaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Once that res_compatible is removed, they don't make sense anymore.
We remove the _only preffix. And to make things clearer we rename
them to must_precopy and can_postcopy.
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Nothing assigns to it after previous commit.
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Until previous commit, save_live_pending() was used for ram. Now with
the split into state_pending_estimate() and state_pending_exact() it
is not needed anymore, so remove them.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
We split the function into to:
- state_pending_estimate: We estimate the remaining state size without
stopping the machine.
- state pending_exact: We calculate the exact amount of remaining
state.
The only "device" that implements different functions for _estimate()
and _exact() is ram.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
vfio_migration_init() initializes VFIOMigration->device_state using enum
of VFIO migration protocol v2. Current implemented protocol is v1 so v1
enum should be used. Fix it.
Fixes: 429c728006 ("vfio/migration: Fix incorrect initialization value for parameters in VFIOMigration")
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Zhang Chen <chen.zhang@intel.com>
Link: https://lore.kernel.org/r/20221016085752.32740-1-avihaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The structure VFIOMigration of a VFIODevice is allocated and initialized
in vfio_migration_init(). "device_state" and "vm_running" are initialized
to 0, indicating that VFIO device is_STOP and VM is not-running. The
initialization value is incorrect. According to the agreement, default
state of VFIO device is _RUNNING. And if a VFIO device is hot-plugged
while the VM is running, "vm_running" should be 1. This patch fixes it.
Fixes: 02a7e71b1e ("vfio: Add VM state change handler to know state of VM")
Signed-off-by: Kunkun Jiang <jiangkunkun@huawei.com>
Link: https://lore.kernel.org/r/20220711014651.1327-1-jiangkunkun@huawei.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Update to c5eb0a61238d ("Linux 5.18-rc6"). Mechanical search and
replace of vfio defines with white space massaging.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
When migrate_add_blocker(blocker, &err) is followed by
error_propagate(errp, err), we can often just as well do
migrate_add_blocker(..., errp). This is the case in
vfio_migration_probe().
Prior art: commit 386f6c07d2 "error: Avoid error_propagate() after
migrate_add_blocker()".
Cc: Kirti Wankhede <kwankhede@nvidia.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20210720125408.387910-8-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed by: Kirti Wankhede <kwankhede@nvidia.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Set _SAVING flag for device state from vmstate change handler when it
gets called from savevm.
Currently State transition savevm/suspend is seen as:
_RUNNING -> _STOP -> Stop-and-copy -> _STOP
State transition savevm/suspend should be:
_RUNNING -> Stop-and-copy -> _STOP
State transition from _RUNNING to _STOP occurs from
vfio_vmstate_change() where when vmstate changes from running to
!running, _RUNNING flag is reset but at the same time when
vfio_vmstate_change() is called for RUN_STATE_SAVE_VM, _SAVING bit
should be set.
Reported by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Message-Id: <1623177441-27496-1-git-send-email-kwankhede@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
In the vfio_migration_init(), the SaveVMHandler is registered for
VFIO device. But it lacks the operation of 'unregister'. It will
lead to 'Segmentation fault (core dumped)' in
qemu_savevm_state_setup(), if performing live migration after a
VFIO device is hot deleted.
Fixes: 7c2f5f75f9 (vfio: Register SaveVMHandlers for VFIO device)
Reported-by: Qixin Gan <ganqixin@huawei.com>
Signed-off-by: Kunkun Jiang <jiangkunkun@huawei.com>
Message-Id: <20210527123101.289-1-jiangkunkun@huawei.com>
Reviewed by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Stop including cpu.h in files that don't need it.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210416171314.2074665-4-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
For now the switch of vfio dirty page tracking is integrated into
@vfio_save_handler. The reason is that some PCI vendor driver may
start to track dirty base on _SAVING state of device, so if dirty
tracking is started before setting device state, vfio will report
full-dirty to QEMU.
However, the dirty bmap of all ramblocks are fully set when setup
ram saving, so it's not matter whether the device is in _SAVING
state when start vfio dirty tracking.
Moreover, this logic causes some problems [1]. The object of dirty
tracking is guest memory, but the object of @vfio_save_handler is
device state, which produces unnecessary coupling and conflicts:
1. Coupling: Their saving granule is different (perVM vs perDevice).
vfio will enable dirty_page_tracking for each devices, actually
once is enough.
2. Conflicts: The ram_save_setup() traverses all memory_listeners
to execute their log_start() and log_sync() hooks to get the
first round dirty bitmap, which is used by the bulk stage of
ram saving. However, as vfio dirty tracking is not yet started,
it can't get dirty bitmap from vfio. Then we give up the chance
to handle vfio dirty page at bulk stage.
Move the switch of vfio dirty_page_tracking into vfio_memory_listener
can solve above problems. Besides, Do not require devices in SAVING
state for vfio_sync_dirty_bitmap().
[1] https://www.spinics.net/lists/kvm/msg229967.html
Reported-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210309031913.11508-1-zhukeqian1@huawei.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
In the VFIO VM state change handler when stopping the VM, the _RUNNING
bit in device_state is cleared which makes the VFIO device stop, including
no longer generating interrupts. Then we can save the pending states of
all interrupts in the GIC VM state change handler (on ARM).
So we have to set the priority of the VFIO VM state change handler
explicitly (like virtio devices) to ensure it is called before the
GIC's in saving.
Signed-off-by: Shenming Lu <lushenming@huawei.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20210310030233.1133-3-lushenming@huawei.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
On ARM64 the VFIO SET_IRQS ioctl is dependent on the VM interrupt
setup, if the restoring of the VFIO PCI device config space is
before the VGIC, an error might occur in the kernel.
So we move the saving of the config space to the non-iterable
process, thus it will be called after the VGIC according to
their priorities.
As for the possible dependence of the device specific migration
data on it's config space, we can let the vendor driver to
include any config info it needs in its own data stream.
Signed-off-by: Shenming Lu <lushenming@huawei.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Message-Id: <20210310030233.1133-2-lushenming@huawei.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The 'running' argument from VMChangeStateHandler does not require
other value than 0 / 1. Make it a plain boolean.
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20210111152020.1422021-3-philmd@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Support for migration of vfio devices is still in flux. Developers
are attempting to add support for new devices and new architectures,
but none are yet readily available for validation. We have concerns
whether we're transferring device resources at the right point in the
migration, whether we're guaranteeing that updates during pre-copy are
migrated, and whether we can provide bit-stream compatibility should
any of this change. Even the question of whether devices should
participate in dirty page tracking during pre-copy seems contentious.
In short, migration support has not had enough soak time and it feels
premature to mark it as supported.
Create an experimental option such that we can continue to develop.
[Retaining previous acks/reviews for a previously identical code
change with different specifics in the commit log.]
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Added amount of bytes transferred to the VM at destination by all VFIO
devices
Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Call VFIO_IOMMU_DIRTY_PAGES ioctl to start and stop dirty pages tracking
for VFIO devices.
Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Added helper functions to get IOMMU info capability chain.
Added function to get migration capability information from that
capability chain for IOMMU container.
Similar change was proposed earlier:
https://lists.gnu.org/archive/html/qemu-devel/2018-05/msg03759.html
Disable migration for devices if IOMMU module doesn't support migration
capability.
Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Cc: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Cc: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Sequence during _RESUMING device state:
While data for this device is available, repeat below steps:
a. read data_offset from where user application should write data.
b. write data of data_size to migration region from data_offset.
c. write data_size which indicates vendor driver that data is written in
staging buffer.
For user, data is opaque. User should write data in the same order as
received.
Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Added .save_live_pending, .save_live_iterate and .save_live_complete_precopy
functions. These functions handles pre-copy and stop-and-copy phase.
In _SAVING|_RUNNING device state or pre-copy phase:
- read pending_bytes. If pending_bytes > 0, go through below steps.
- read data_offset - indicates kernel driver to write data to staging
buffer.
- read data_size - amount of data in bytes written by vendor driver in
migration region.
- read data_size bytes of data from data_offset in the migration region.
- Write data packet to file stream as below:
{VFIO_MIG_FLAG_DEV_DATA_STATE, data_size, actual data,
VFIO_MIG_FLAG_END_OF_STATE }
In _SAVING device state or stop-and-copy phase
a. read config space of device and save to migration file stream. This
doesn't need to be from vendor driver. Any other special config state
from driver can be saved as data in following iteration.
b. read pending_bytes. If pending_bytes > 0, go through below steps.
c. read data_offset - indicates kernel driver to write data to staging
buffer.
d. read data_size - amount of data in bytes written by vendor driver in
migration region.
e. read data_size bytes of data from data_offset in the migration region.
f. Write data packet as below:
{VFIO_MIG_FLAG_DEV_DATA_STATE, data_size, actual data}
g. iterate through steps b to f while (pending_bytes > 0)
h. Write {VFIO_MIG_FLAG_END_OF_STATE}
When data region is mapped, its user's responsibility to read data from
data_offset of data_size before moving to next steps.
Added fix suggested by Artem Polyakov to reset pending_bytes in
vfio_save_iterate().
Added fix suggested by Zhi Wang to add 0 as data size in migration stream and
add END_OF_STATE delimiter to indicate phase complete.
Suggested-by: Artem Polyakov <artemp@nvidia.com>
Suggested-by: Zhi Wang <zhi.wang.linux@gmail.com>
Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Define flags to be used as delimiter in migration stream for VFIO devices.
Added .save_setup and .save_cleanup functions. Map & unmap migration
region from these functions at source during saving or pre-copy phase.
Set VFIO device state depending on VM's state. During live migration, VM is
running when .save_setup is called, _SAVING | _RUNNING state is set for VFIO
device. During save-restore, VM is paused, _SAVING state is set for VFIO device.
Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Added migration state change notifier to get notification on migration state
change. These states are translated to VFIO device state and conveyed to
vendor driver.
Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
VM state change handler is called on change in VM's state. Based on
VM state, VFIO device state should be changed.
Added read/write helper functions for migration region.
Added function to set device_state.
Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
[aw: lx -> HWADDR_PRIx, remove redundant parens]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Whether the VFIO device supports migration or not is decided based of
migration region query. If migration region query is successful and migration
region initialization is successful then migration is supported else
migration is blocked.
Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Neo Jia <cjia@nvidia.com>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
