Implementing RAMFB migration is quite straightforward. One caveat is to
treat the whole RAMFBCfg as a blob, since that's what is exposed to the
guest directly. This avoid having to fiddle with endianness issues if we
were to migrate fields individually as integers.
The devices using RAMFB will have to include ramfb_vmstate in their
migration description.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
No functional changes.
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
Move all the code really dependent on the legacy VFIO container/group
into a separate file: container.c. What does remain in common.c is
the code related to VFIOAddressSpace, MemoryListeners, migration and
all other general operations.
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
Some functions iterate over all the VFIODevices. This is currently
achieved by iterating over all groups/devices. Let's
introduce a global list of VFIODevices simplifying that scan.
This will also be useful while migrating to IOMMUFD by hiding the
group specificity.
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
let's store the parent contaienr within the VFIODevice.
This simplifies the logic in vfio_viommu_preset() and
brings the benefice to hide the group specificity which
is useful for IOMMUFD migration.
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
Several functions need to iterate over the VFIO devices attached to
a given container. This is currently achieved by iterating over the
groups attached to the container and then over the devices in the group.
Let's introduce a per container device list that simplifies this
search.
Per container list is used in below functions:
vfio_devices_all_dirty_tracking
vfio_devices_all_device_dirty_tracking
vfio_devices_all_running_and_mig_active
vfio_devices_dma_logging_stop
vfio_devices_dma_logging_start
vfio_devices_query_dirty_bitmap
This will also ease the migration of IOMMUFD by hiding the group
specificity.
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
Let the vfio-ccw device use vfio_attach_device() and
vfio_detach_device(), hence hiding the details of the used
IOMMU backend.
Note that the migration reduces the following trace
"vfio: subchannel %s has already been attached" (featuring
cssid.ssid.devid) into "device is already attached"
Also now all the devices have been migrated to use the new
vfio_attach_device/vfio_detach_device API, let's turn the
legacy functions into static functions, local to container.c.
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
We want the VFIO devices to be able to use two different
IOMMU backends, the legacy VFIO one and the new iommufd one.
Introduce vfio_[attach/detach]_device which aim at hiding the
underlying IOMMU backend (IOCTLs, datatypes, ...).
Once vfio_attach_device completes, the device is attached
to a security context and its fd can be used. Conversely
When vfio_detach_device completes, the device has been
detached from the security context.
At the moment only the implementation based on the legacy
container/group exists. Let's use it from the vfio-pci device.
Subsequent patches will handle other devices.
We also take benefit of this patch to properly free
vbasedev->name on failure.
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
Introduce two new helpers, vfio_kvm_device_[add/del]_fd
which take as input a file descriptor which can be either a group fd or
a cdev fd. This uses the new KVM_DEV_VFIO_FILE VFIO KVM device group,
which aliases to the legacy KVM_DEV_VFIO_GROUP.
vfio_kvm_device_[add/del]_group then call those new helpers.
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
Move low-level iommu agnostic helpers to a separate helpers.c
file. They relate to regions, interrupts, device/region
capabilities and etc.
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
This is intended to be a semantic revert of commit 9b09503752
("migration: run setup callbacks out of big lock"). There have been so
many changes since that commit (e.g. a new setup callback
dirty_bitmap_save_setup() that also needs to be adapted now), it's
easier to do the revert manually.
For snapshots, the bdrv_writev_vmstate() function is used during setup
(in QIOChannelBlock backing the QEMUFile), but not holding the BQL
while calling it could lead to an assertion failure. To understand
how, first note the following:
1. Generated coroutine wrappers for block layer functions spawn the
coroutine and use AIO_WAIT_WHILE()/aio_poll() to wait for it.
2. If the host OS switches threads at an inconvenient time, it can
happen that a bottom half scheduled for the main thread's AioContext
is executed as part of a vCPU thread's aio_poll().
An example leading to the assertion failure is as follows:
main thread:
1. A snapshot-save QMP command gets issued.
2. snapshot_save_job_bh() is scheduled.
vCPU thread:
3. aio_poll() for the main thread's AioContext is called (e.g. when
the guest writes to a pflash device, as part of blk_pwrite which is a
generated coroutine wrapper).
4. snapshot_save_job_bh() is executed as part of aio_poll().
3. qemu_savevm_state() is called.
4. qemu_mutex_unlock_iothread() is called. Now
qemu_get_current_aio_context() returns 0x0.
5. bdrv_writev_vmstate() is executed during the usual savevm setup
via qemu_fflush(). But this function is a generated coroutine wrapper,
so it uses AIO_WAIT_WHILE. There, the assertion
assert(qemu_get_current_aio_context() == qemu_get_aio_context());
will fail.
To fix it, ensure that the BQL is held during setup. While it would
only be needed for snapshots, adapting migration too avoids additional
logic for conditional locking/unlocking in the setup callbacks.
Writing the header could (in theory) also trigger qemu_fflush() and
thus bdrv_writev_vmstate(), so the locked section also covers the
qemu_savevm_state_header() call, even for migration for consistency.
The section around multifd_send_sync_main() needs to be unlocked to
avoid a deadlock. In particular, the multifd_save_setup() function calls
socket_send_channel_create() using multifd_new_send_channel_async() as a
callback and then waits for the callback to signal via the
channels_ready semaphore. The connection happens via
qio_task_run_in_thread(), but the callback is only executed via
qio_task_thread_result() which is scheduled for the main event loop.
Without unlocking the section, the main thread would never get to
process the task result and the callback meaning there would be no
signal via the channels_ready semaphore.
The comment in ram_init_bitmaps() was introduced by 4987783400
("migration: fix incorrect memory_global_dirty_log_start outside BQL")
and is removed, because it referred to the qemu_mutex_lock_iothread()
call.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231013105839.415989-1-f.ebner@proxmox.com>
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Merge tag 'pull-loongarch-20231013' of https://gitlab.com/gaosong/qemu into staging
pull-loongarch-20231013
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# -----END PGP SIGNATURE-----
# gpg: Signature made Thu 12 Oct 2023 22:06:45 EDT
# gpg: using RSA key B8FF1DA0D2FDCB2DA09C6C2C40A2FFF239263EDF
# gpg: Good signature from "Song Gao <m17746591750@163.com>" [unknown]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg: There is no indication that the signature belongs to the owner.
# Primary key fingerprint: B8FF 1DA0 D2FD CB2D A09C 6C2C 40A2 FFF2 3926 3EDF
* tag 'pull-loongarch-20231013' of https://gitlab.com/gaosong/qemu:
LoongArch: step down as general arch maintainer
hw/loongarch/virt: Remove unused 'loongarch_virt_pm' region
hw/loongarch/virt: Remove unused ISA Bus
hw/loongarch/virt: Remove unused ISA UART
hw/loongarch: remove global loaderparams variable
target/loongarch: Add preldx instruction
target/loongarch: fix ASXE flag conflict
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
- Clean up coroutine versions of bdrv_{is_allocated,block_status}*
- Graph locking part 5 (protect children/parent links)
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Merge tag 'for-upstream' of https://repo.or.cz/qemu/kevin into staging
Block layer patches
- Clean up coroutine versions of bdrv_{is_allocated,block_status}*
- Graph locking part 5 (protect children/parent links)
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# gpg: Signature made Thu 12 Oct 2023 12:20:15 EDT
# gpg: using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg: issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74 56FE 7F09 B272 C88F 2FD6
* tag 'for-upstream' of https://repo.or.cz/qemu/kevin: (26 commits)
block: Add assertion for bdrv_graph_wrlock()
block: Protect bs->children with graph_lock
block: Protect bs->parents with graph_lock
block: Mark bdrv_get_specific_info() and callers GRAPH_RDLOCK
block: Mark bdrv_apply_auto_read_only() and callers GRAPH_RDLOCK
block: Mark bdrv_op_is_blocked() and callers GRAPH_RDLOCK
qcow2: Mark check_constraints_on_bitmap() GRAPH_RDLOCK
qcow2: Mark qcow2_inactivate() and callers GRAPH_RDLOCK
qcow2: Mark qcow2_signal_corruption() and callers GRAPH_RDLOCK
block: Mark bdrv_amend_options() and callers GRAPH_RDLOCK
block: Mark bdrv_get_parent_name() and callers GRAPH_RDLOCK
block: Mark bdrv_primary_child() and callers GRAPH_RDLOCK
block: Mark bdrv_refresh_filename() and callers GRAPH_RDLOCK
block: Mark bdrv_get_xdbg_block_graph() and callers GRAPH_RDLOCK
block: Take graph rdlock in parts of reopen
block: Mark bdrv_snapshot_fallback() and callers GRAPH_RDLOCK
block: Mark bdrv_parent_cb_resize() and callers GRAPH_RDLOCK
block: Mark drain related functions GRAPH_RDLOCK
block: Mark bdrv_first_blk() and bdrv_is_root_node() GRAPH_RDLOCK
block: Take graph rdlock in bdrv_inactivate_all()
...
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
"Host Memory Backends" and "Memory devices" queue ("mem"):
- Support memory devices with multiple memslots
- Support memory devices that dynamically consume memslots
- Support memory devices that can automatically decide on the number of
memslots to use
- virtio-mem support for exposing memory dynamically via multiple
memslots
- Some required cleanups/refactorings
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Merge tag 'mem-2023-10-12' of https://github.com/davidhildenbrand/qemu into staging
Hi,
"Host Memory Backends" and "Memory devices" queue ("mem"):
- Support memory devices with multiple memslots
- Support memory devices that dynamically consume memslots
- Support memory devices that can automatically decide on the number of
memslots to use
- virtio-mem support for exposing memory dynamically via multiple
memslots
- Some required cleanups/refactorings
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# -----END PGP SIGNATURE-----
# gpg: Signature made Thu 12 Oct 2023 09:49:39 EDT
# gpg: using RSA key 1BD9CAAD735C4C3A460DFCCA4DDE10F700FF835A
# gpg: issuer "david@redhat.com"
# gpg: Good signature from "David Hildenbrand <david@redhat.com>" [unknown]
# gpg: aka "David Hildenbrand <davidhildenbrand@gmail.com>" [full]
# gpg: aka "David Hildenbrand <hildenbr@in.tum.de>" [unknown]
# gpg: WARNING: The key's User ID is not certified with a trusted signature!
# gpg: There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 1BD9 CAAD 735C 4C3A 460D FCCA 4DDE 10F7 00FF 835A
* tag 'mem-2023-10-12' of https://github.com/davidhildenbrand/qemu:
virtio-mem: Mark memslot alias memory regions unmergeable
memory,vhost: Allow for marking memory device memory regions unmergeable
virtio-mem: Expose device memory dynamically via multiple memslots if enabled
virtio-mem: Update state to match bitmap as soon as it's been migrated
virtio-mem: Pass non-const VirtIOMEM via virtio_mem_range_cb
memory: Clarify mapping requirements for RamDiscardManager
memory-device,vhost: Support automatic decision on the number of memslots
vhost: Add vhost_get_max_memslots()
kvm: Add stub for kvm_get_max_memslots()
memory-device,vhost: Support memory devices that dynamically consume memslots
memory-device: Track required and actually used memslots in DeviceMemoryState
stubs: Rename qmp_memory_device.c to memory_device.c
memory-device: Support memory devices with multiple memslots
vhost: Return number of free memslots
kvm: Return number of free memslots
softmmu/physmem: Fixup qemu_ram_block_from_host() documentation
vhost: Remove vhost_backend_can_merge() callback
vhost: Rework memslot filtering and fix "used_memslot" tracking
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This modifies the common virtio-gpu.h file have the fields and
defintions needed by gfxstream/rutabaga, by VirtioGpuRutabaga.
Signed-off-by: Gurchetan Singh <gurchetansingh@chromium.org>
Tested-by: Alyssa Ross <hi@alyssa.is>
Tested-by: Emmanouil Pitsidianakis <manos.pitsidianakis@linaro.org>
Tested-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Emmanouil Pitsidianakis <manos.pitsidianakis@linaro.org>
Reviewed-by: Antonio Caggiano <quic_acaggian@quicinc.com>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Use VIRTIO_GPU_SHM_ID_HOST_VISIBLE as id for virtio-gpu.
Signed-off-by: Antonio Caggiano <antonio.caggiano@collabora.com>
Tested-by: Alyssa Ross <hi@alyssa.is>
Tested-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Tested-by: Huang Rui <ray.huang@amd.com>
Acked-by: Huang Rui <ray.huang@amd.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Define a new capability type 'VIRTIO_PCI_CAP_SHARED_MEMORY_CFG' to allow
defining shared memory regions with sizes and offsets of 2^32 and more.
Multiple instances of the capability are allowed and distinguished
by a device-specific 'id'.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Antonio Caggiano <antonio.caggiano@collabora.com>
Signed-off-by: Gurchetan Singh <gurchetansingh@chromium.org>
Tested-by: Alyssa Ross <hi@alyssa.is>
Tested-by: Huang Rui <ray.huang@amd.com>
Tested-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
This patch fixes invalid ufs register fields.
This fixes an issue reported by Bin Meng that
caused ufs to fail over riscv.
Fixes: bc4e68d362 ("hw/ufs: Initial commit for emulated Universal-Flash-Storage")
Signed-off-by: Jeuk Kim <jeuk20.kim@samsung.com>
Reported-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Bin Meng <bmeng@tinylab.org>
Tested-by: Bin Meng <bmeng@tinylab.org>
The LoongArch 'virt' machine doesn't use its ISA I/O region.
If a ISA device were to be mapped there, there is no support
for ISA IRQ. Unlikely useful. Simply remove.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Song Gao <gaosong@loongson.cn>
Message-Id: <20231010135342.40219-3-philmd@linaro.org>
Signed-off-by: Song Gao <gaosong@loongson.cn>
bdrv_graph_wrlock() can't run in a coroutine (because it polls) and
requires holding the BQL. We already have GLOBAL_STATE_CODE() to assert
the latter. Assert the former as well and add a no_coroutine_fn marker.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-23-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Almost all functions that access the child links already take the graph
lock now. Add locking to the remaining users and finally annotate the
struct field itself as protected by the graph lock.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-22-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Almost all functions that access the parent link already take the graph
lock now. Add locking to the remaining user in a test case and finally
annotate the struct field itself as protected by the graph lock.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-21-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_get_specific_info() need to hold a reader lock for the graph.
This removes an assume_graph_lock() call in vmdk's implementation.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-20-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_apply_auto_read_only() need to hold a reader lock for the graph
because it calls bdrv_can_set_read_only(), which indirectly accesses the
parents list of a node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-19-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_op_is_blocked() need to hold a reader lock for the graph
because it calls bdrv_get_device_or_node_name(), which accesses the
parents list of a node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-18-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
qcow2_signal_corruption() need to hold a reader lock for the graph
because it calls bdrv_get_node_name(), which accesses the parents list
of a node.
For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-15-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_amend_options() need to hold a reader lock for the graph. This
removes an assume_graph_lock() call in crypto's implementation.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-14-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_get_parent_name() need to hold a reader lock for the graph
because it accesses the parents list of a node.
For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-13-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_primary_child() need to hold a reader lock for the graph
because it accesses the children list of a node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-12-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_refresh_filename() need to hold a reader lock for the graph
because it accesses the children list of a node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-11-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_get_xdbg_block_graph() need to hold a reader lock for the graph
because it accesses the children list of a node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-10-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reopen isn't easy with respect to locking because many of its functions
need to iterate the graph, some change it, and then you get some drains
in the middle where you can't hold any locks.
Therefore just documents most of the functions to be unlocked, and take
locks internally before accessing the graph.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-9-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_snapshot_fallback() need to hold a reader lock for the graph
because it accesses the children list of a node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-8-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Draining recursively traverses the graph, therefore we need to make sure
that also such accesses to the graph are protected by the graph rdlock.
There are 3 different drain callers to consider:
1. drain in the main loop: no issue at all, rdlock is nop.
2. drain in an iothread: rdlock only works in main loop or coroutines,
so disallow it.
3. drain in a coroutine (regardless of AioContext): the drain mechanism
takes care of scheduling a BH in the bs->aio_context that will
then take care of perform the actual draining. This is wrong,
because as pointed in (2) if bs->aio_context is an iothread then
rdlock won't work. Therefore change bdrv_co_yield_to_drain to
schedule the BH in the main loop.
Caller (2) also implies that we need to modify test-bdrv-drain.c to
disallow draining in the iothreads.
For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-6-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_first_blk() and bdrv_is_root_node() need to hold a reader lock
for the graph. These functions are the only functions in block-backend.c
that access the parent list of a node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-5-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add a new wrapper type for GRAPH_RDLOCK functions that should be called
from coroutine context.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-3-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20230904100306.156197-4-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Include both coroutine and non-coroutine versions, the latter being
co_wrapper_mixed_bdrv_rdlock of the former.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20230904100306.156197-3-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* Add support for the max CPU
* Detect user choice in TCG
* Clear CSR values at reset and sync MPSTATE with host
* Fix the typo of inverted order of pmpaddr13 and pmpaddr14
* Split TCG/KVM accelerators from cpu.c
* Add extension properties for all cpus
* Replace GDB exit calls with proper shutdown
* Support KVM_GET_REG_LIST
* Remove RVG warning
* Use env_archcpu for better performance
* Deprecate capital 'Z' CPU properties
* Fix vfwmaccbf16.vf
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Merge tag 'pull-riscv-to-apply-20231012-1' of https://github.com/alistair23/qemu into staging
Second RISC-V PR for 8.2
* Add support for the max CPU
* Detect user choice in TCG
* Clear CSR values at reset and sync MPSTATE with host
* Fix the typo of inverted order of pmpaddr13 and pmpaddr14
* Split TCG/KVM accelerators from cpu.c
* Add extension properties for all cpus
* Replace GDB exit calls with proper shutdown
* Support KVM_GET_REG_LIST
* Remove RVG warning
* Use env_archcpu for better performance
* Deprecate capital 'Z' CPU properties
* Fix vfwmaccbf16.vf
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# gpg: Signature made Thu 12 Oct 2023 00:09:36 EDT
# gpg: using RSA key 6AE902B6A7CA877D6D659296AF7C95130C538013
# gpg: Good signature from "Alistair Francis <alistair@alistair23.me>" [unknown]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg: There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 6AE9 02B6 A7CA 877D 6D65 9296 AF7C 9513 0C53 8013
* tag 'pull-riscv-to-apply-20231012-1' of https://github.com/alistair23/qemu: (54 commits)
target/riscv: Fix vfwmaccbf16.vf
target/riscv: deprecate capital 'Z' CPU properties
target/riscv: Use env_archcpu for better performance
target/riscv/tcg: remove RVG warning
target/riscv/kvm: support KVM_GET_REG_LIST
target/riscv/kvm: improve 'init_multiext_cfg' error msg
gdbstub: replace exit calls with proper shutdown for softmmu
hw/char: riscv_htif: replace exit calls with proper shutdown
hw/misc/sifive_test.c: replace exit calls with proper shutdown
softmmu: pass the main loop status to gdb "Wxx" packet
softmmu: add means to pass an exit code when requesting a shutdown
target/riscv/tcg-cpu.c: add extension properties for all cpus
target/riscv: add riscv_cpu_get_name()
target/riscv/cpu: move priv spec functions to tcg-cpu.c
target/riscv/cpu.c: export isa_edata_arr[]
target/riscv/tcg: move riscv_cpu_add_misa_properties() to tcg-cpu.c
target/riscv/cpu.c: make misa_ext_cfgs[] 'const'
target/riscv/tcg: introduce tcg_cpu_instance_init()
target/riscv/cpu.c: export set_misa()
target/riscv/kvm: do not use riscv_cpu_add_misa_properties()
...
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Let's allow for marking memory regions unmergeable, to teach
flatview code and vhost to not merge adjacent aliases to the same memory
region into a larger memory section; instead, we want separate aliases to
stay separate such that we can atomically map/unmap aliases without
affecting other aliases.
This is desired for virtio-mem mapping device memory located on a RAM
memory region via multiple aliases into a memory region container,
resulting in separate memslots that can get (un)mapped atomically.
As an example with virtio-mem, the layout would look something like this:
[...]
0000000240000000-00000020bfffffff (prio 0, i/o): device-memory
0000000240000000-000000043fffffff (prio 0, i/o): virtio-mem
0000000240000000-000000027fffffff (prio 0, ram): alias memslot-0 @mem2 0000000000000000-000000003fffffff
0000000280000000-00000002bfffffff (prio 0, ram): alias memslot-1 @mem2 0000000040000000-000000007fffffff
00000002c0000000-00000002ffffffff (prio 0, ram): alias memslot-2 @mem2 0000000080000000-00000000bfffffff
[...]
Without unmergable memory regions, all three memslots would get merged into
a single memory section. For example, when mapping another alias (e.g.,
virtio-mem-memslot-3) or when unmapping any of the mapped aliases,
memory listeners will first get notified about the removal of the big
memory section to then get notified about re-adding of the new
(differently merged) memory section(s).
In an ideal world, memory listeners would be able to deal with that
atomically, like KVM nowadays does. However, (a) supporting this for other
memory listeners (vhost-user, vfio) is fairly hard: temporary removal
can result in all kinds of issues on concurrent access to guest memory;
and (b) this handling is undesired, because temporarily removing+readding
can consume quite some time on bigger memslots and is not efficient
(e.g., vfio unpinning and repinning pages ...).
Let's allow for marking a memory region unmergeable, such that we
can atomically (un)map aliases to the same memory region, similar to
(un)mapping individual DIMMs.
Similarly, teach vhost code to not redo what flatview core stopped doing:
don't merge such sections. Merging in vhost code is really only relevant
for handling random holes in boot memory where; without this merging,
the vhost-user backend wouldn't be able to mmap() some boot memory
backed on hugetlb.
We'll use this for virtio-mem next.
Message-ID: <20230926185738.277351-18-david@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Having large virtio-mem devices that only expose little memory to a VM
is currently a problem: we map the whole sparse memory region into the
guest using a single memslot, resulting in one gigantic memslot in KVM.
KVM allocates metadata for the whole memslot, which can result in quite
some memory waste.
Assuming we have a 1 TiB virtio-mem device and only expose little (e.g.,
1 GiB) memory, we would create a single 1 TiB memslot and KVM has to
allocate metadata for that 1 TiB memslot: on x86, this implies allocating
a significant amount of memory for metadata:
(1) RMAP: 8 bytes per 4 KiB, 8 bytes per 2 MiB, 8 bytes per 1 GiB
-> For 1 TiB: 2147483648 + 4194304 + 8192 = ~ 2 GiB (0.2 %)
With the TDP MMU (cat /sys/module/kvm/parameters/tdp_mmu) this gets
allocated lazily when required for nested VMs
(2) gfn_track: 2 bytes per 4 KiB
-> For 1 TiB: 536870912 = ~512 MiB (0.05 %)
(3) lpage_info: 4 bytes per 2 MiB, 4 bytes per 1 GiB
-> For 1 TiB: 2097152 + 4096 = ~2 MiB (0.0002 %)
(4) 2x dirty bitmaps for tracking: 2x 1 bit per 4 KiB page
-> For 1 TiB: 536870912 = 64 MiB (0.006 %)
So we primarily care about (1) and (2). The bad thing is, that the
memory consumption *doubles* once SMM is enabled, because we create the
memslot once for !SMM and once for SMM.
Having a 1 TiB memslot without the TDP MMU consumes around:
* With SMM: 5 GiB
* Without SMM: 2.5 GiB
Having a 1 TiB memslot with the TDP MMU consumes around:
* With SMM: 1 GiB
* Without SMM: 512 MiB
... and that's really something we want to optimize, to be able to just
start a VM with small boot memory (e.g., 4 GiB) and a virtio-mem device
that can grow very large (e.g., 1 TiB).
Consequently, using multiple memslots and only mapping the memslots we
really need can significantly reduce memory waste and speed up
memslot-related operations. Let's expose the sparse RAM memory region using
multiple memslots, mapping only the memslots we currently need into our
device memory region container.
The feature can be enabled using "dynamic-memslots=on" and requires
"unplugged-inaccessible=on", which is nowadays the default.
Once enabled, we'll auto-detect the number of memslots to use based on the
memslot limit provided by the core. We'll use at most 1 memslot per
gigabyte. Note that our global limit of memslots accross all memory devices
is currently set to 256: even with multiple large virtio-mem devices,
we'd still have a sane limit on the number of memslots used.
The default is to not dynamically map memslot for now
("dynamic-memslots=off"). The optimization must be enabled manually,
because some vhost setups (e.g., hotplug of vhost-user devices) might be
problematic until we support more memslots especially in vhost-user backends.
Note that "dynamic-memslots=on" is just a hint that multiple memslots
*may* be used for internal optimizations, not that multiple memslots
*must* be used. The actual number of memslots that are used is an
internal detail: for example, once memslot metadata is no longer an
issue, we could simply stop optimizing for that. Migration source and
destination can differ on the setting of "dynamic-memslots".
Message-ID: <20230926185738.277351-17-david@redhat.com>
Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
We really only care about the RAM memory region not being mapped into
an address space yet as long as we're still setting up the
RamDiscardManager. Once mapped into an address space, memory notifiers
would get notified about such a region and any attempts to modify the
RamDiscardManager would be wrong.
While "mapped into an address space" is easy to check for RAM regions that
are mapped directly (following the ->container links), it's harder to
check when such regions are mapped indirectly via aliases. For now, we can
only detect that a region is mapped through an alias (->mapped_via_alias),
but we don't have a handle on these aliases to follow all their ->container
links to test if they are eventually mapped into an address space.
So relax the assertion in memory_region_set_ram_discard_manager(),
remove the check in memory_region_get_ram_discard_manager() and clarify
the doc.
Message-ID: <20230926185738.277351-14-david@redhat.com>
Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
We want to support memory devices that can automatically decide how many
memslots they will use. In the worst case, they have to use a single
memslot.
The target use cases are virtio-mem and the hyper-v balloon.
Let's calculate a reasonable limit such a memory device may use, and
instruct the device to make a decision based on that limit. Use a simple
heuristic that considers:
* A memslot soft-limit for all memory devices of 256; also, to not
consume too many memslots -- which could harm performance.
* Actually still free and unreserved memslots
* The percentage of the remaining device memory region that memory device
will occupy.
Further, while we properly check before plugging a memory device whether
there still is are free memslots, we have other memslot consumers (such as
boot memory, PCI BARs) that don't perform any checks and might dynamically
consume memslots without any prior reservation. So we might succeed in
plugging a memory device, but once we dynamically map a PCI BAR we would
be in trouble. Doing accounting / reservation / checks for all such
users is problematic (e.g., sometimes we might temporarily split boot
memory into two memslots, triggered by the BIOS).
We use the historic magic memslot number of 509 as orientation to when
supporting 256 memory devices -> memslots (leaving 253 for boot memory and
other devices) has been proven to work reliable. We'll fallback to
suggesting a single memslot if we don't have at least 509 total memslots.
Plugging vhost devices with less than 509 memslots available while we
have memory devices plugged that consume multiple memslots due to
automatic decisions can be problematic. Most configurations might just fail
due to "limit < used + reserved", however, it can also happen that these
memory devices would suddenly consume memslots that would actually be
required by other memslot consumers (boot, PCI BARs) later. Note that this
has always been sketchy with vhost devices that support only a small number
of memslots; but we don't want to make it any worse.So let's keep it simple
and simply reject plugging such vhost devices in such a configuration.
Eventually, all vhost devices that want to be fully compatible with such
memory devices should support a decent number of memslots (>= 509).
Message-ID: <20230926185738.277351-13-david@redhat.com>
Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
