KVM initializes RISC-V vCPUs with sstateen0 cleared. When AIA is
exposed to the guest, Linux touches supervisor AIA CSRs while bringing
up the IMSIC path, and those accesses fail if the stateen bits remain
disabled.
Program sstateen0 for newly created vCPUs so the guest can use the
supervisor interrupt state needed by AIA.
Assisted-by: OpenAI-Codex:GPT-5
Signed-off-by: wangyf0611 <wangyufeng@iscas.ac.cn>
Each VM reboot re-entered the VFIO/virtio-net add paths and re-appended
the same originating fds, leaving duplicates in preserved_fds and a
double-close hazard at final teardown. Switching to HashSet makes
add_preserved_fds idempotent.
Signed-off-by: Bo Chen <bchen@crusoe.ai>
Assisted-by: Claude:Opus-4.7
When SVE is enabled, KVM replaces the FPSIMD V-registers with wider
SVE Z-registers. Attempting to access the old FPSIMD offsets returns
EINVAL.
Fix by classifying each register from KVM_GET_REG_LIST as core, system,
or extended. Extended registers (currently SVE only) are saved as
generic `ExtendedReg` entries split into `pre_finalize_regs` (registers
like SVE VLS that must be written before `vcpu_finalize`) and
`extended_regs`. FPSIMD registers are only accessed when SVE is absent.
Unrecognized register families error immediately so future extensions
like SME fail clearly rather than silently losing state.
The snapshot is deserialized before vCPU init to make pre-finalize
register state available for the init -> VLS -> finalize ordering
required by KVM.
Signed-off-by: Ruben Hakobyan <hruben@meta.com>
Split the SVE detection and finalization logic out of `init()` into a
dedicated `finalize_sve()` method. This separates the concerns of vCPU
initialization (preferred target, processor features, KVM init) from SVE
finalization, and enables a subsequent commit to insert SVE VLS register
in the restore path without needing to add a restore state in `init()`.
Signed-off-by: Ruben Hakobyan <hruben@meta.com>
Move the inline FPSIMD register read/write code from `get_regs()` and
`set_regs()` into dedicated `get_fpsimd_regs()` and `set_fpsimd_regs()`
methods on `KvmVcpu`.
This helps keep the larger `{get,set}_regs()` easier to understand and
prepares them for a subsequent commit that needs to conditionally
skip FPSIMD access when SVE registers are used instead.
Signed-off-by: Ruben Hakobyan <hruben@meta.com>
QCOW2 compressed L2 entries encode their extent layout in bits that
overlap with the flags used by standard L2 entries. In particular,
bit 0 can be part of the compressed entry layout, so it must not be
interpreted as ZERO_FLAG until the entry has first been ruled out as
compressed.
Keep compressed deallocation ahead of zero-flag handling in both the
shared QcowMetadata path and the legacy QcowFile path. This ensures
WRITE_ZEROES deallocates compressed clusters instead of treating a
compressed entry with bit 0 set as an existing logical-zero marker.
Add regression coverage that forces bit 0 on a compressed L2 entry
and verifies WRITE_ZEROES still clears the entry through the
compressed-cluster path.
Assisted-by: Codex:GPT-5
Signed-off-by: Ian Klemm <hi@ianklemm.de>
QCOW2 empty L2 entries in an overlay mean that reads fall
through to the backing file. Reusing the punch_hole path for
WRITE_ZEROES therefore turns a full-cluster zero operation on an
unallocated overlay cluster into backing data exposure.
Keep discard/punch_hole behavior unchanged, but let WRITE_ZEROES
request a logical-zero marker when the image has a backing file.
ZERO_FLAG entries now read as zeros in both the legacy QcowFile
path and the shared runtime metadata path. Partial writes after
such entries seed new clusters from zeros instead of backing data.
Treat ZERO_FLAG entries as logical holes for SEEK_HOLE/SEEK_DATA.
Empty overlay entries with a backing file still report data because
the data exists in the backing file.
Avoid cluster-sized userspace zero buffers when materializing
zero-flagged clusters by zeroing the allocated host range directly.
This keeps recycled clusters safe without making partial writes
allocate large zero-filled Vecs.
Add regression coverage for legacy QcowFile, QcowSync, direct I/O,
QcowAsync/io_uring overlay paths, and a large-cluster partial-write
case.
Assisted-by: Codex:GPT-5
Signed-off-by: Ian Klemm <hi@ianklemm.de>
Add support for formatting logs following the popular glog crate style.
In particular this can use local or UTC time along with a single
character level.
As an implementation detail of that implement finegrained date time log
outputs including both local and UTC variants.
Signed-off-by: Rob Bradford <rbradford@meta.com>
Assisted-by: Claude:Opus-4.6
Extend the TCP live-migration test with a hotplugged block device using
a stable ID before migration. After migration, verify that the disk
still exists on the restored destination VM.
Then hot-remove the disk and add it again with the same ID. This covers
the stale restore snapshot case because the disk ID exists in the
migration snapshot, but the live device tree no longer contains it after
hot-remove.
Assisted-by: Codex:GPT-5.5
On-behalf-of: SAP philipp.schuster@sap.com
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
Storing the snapshot causes issues when needing to do a subsequent
hotplug instead just pass it through on all the methods that need it
making the lifecycle cleaner.
Assisted-by: Claude:Opus-4.6
Signed-off-by: Rob Bradford <rbradford@meta.com>
Agents are totally capable of setting up the host and run dev_cli.sh.
The removed text discouraged them to do that even when asked to.
Signed-off-by: Wei Liu <liuwe@microsoft.com>
The serial-manager thread was the only VMM-managed thread without a
seccomp filter. Add a Thread::SerialManager variant and whitelist the
31 syscalls needed for its epoll-based I/O loop (read, write, socket
ops, signal handling, memory allocation, glibc internals).
The filter is computed in start_thread() and applied before the epoll
loop, matching the pattern used by other VMM threads.
Signed-off-by: Wei Liu <liuwe@microsoft.com>
Assisted-by: Pi-agent:Claude-Opus-4.7
Only Thread::Vmm and Thread::Vcpu need to know the hypervisor type.
Make the type optional, and then simplify the users.
Assisted-by: Pi-agent:Claude-Opus-4.7
Signed-off-by: Wei Liu <liuwe@microsoft.com>
QCOW2 backing file paths stored in image headers may be
relative. These paths should be interpreted relative to the image
that references them, but the block backend opened them relative to
the process working directory.
Resolve the current image path inside parse_qcow() from the open
file descriptor and use its parent directory for relative backing
paths. Recursive backing chains work the same way because each layer
is parsed from its own file descriptor.
Signed-off-by: Rowen-Ye <rowenye1@gmail.com>
Userfaultfd is a great mechanism for providing fast restore to Cloud
Hypervisor VMs. But that means the price to pay for bringing pages in
happens at runtime, which might slow down the guest when it's touching
pages which haven't been brought in yet.
By prefaulting the pages in the background, we're trying to get the best
of both worlds. That means we still get a very fast restore with the
uffd handler, but within a few seconds (depending on VM's RAM size), we
also get the pages fully faulted and we can stop the uffd handler thread
at that point.
Signed-off-by: Sebastien Boeuf <sboeuf@meta.com>
Assisted-by: Claude:claude-opus-4-7
Centralize test configuration (filters, retries, fail-fast,
sequential/parallel scheduling) into nextest profiles, replacing
scattered flags across shell scripts. This simplifies the scripts
and provides a single source of truth for test behavior.
Enable JUnit XML output per profile, giving CI systems structured
test results for better reporting.
Not all test invocations are converted to profiles yet. Just the
ones that are repeated across scripts.
Signed-off-by: Anirudh Rayabharam <anrayabh@microsoft.com>
Update the container image tag to trigger a rebuild. The new image
pins cargo-nextest to version 0.9.128, which supports profile
inheritance, needed for the following nextest configuration changes.
Assisted-by: Copilot-CLI:Claude-Opus-4.7
Signed-off-by: Anirudh Rayabharam <anrayabh@microsoft.com>
The JSON parser expects the field to be named
`iommu_address_width_bits`, but the code declared it as
`iommu_address_width`. This mismatch caused the field to be
unrecognized when deserializing configuration from JSON.
Rename the field to `iommu_address_width_bits` to match the
expected schema.
Signed-off-by: tchaton <thomas.chaton.ai@gmail.com>
Windows 11 PnP rebalance rewrites peer BARs into the same range CH
packed the initial layout at, causing move_bar() failures and boot
deadlock. Pack Mmio64 BARs at 8 MiB stride. Mmio32 isn't wide enough
for the same stride, but its BARs don't participate in guest BAR
rebalancing.
On restore, pin the BAR to the snapshot address (alignment=None) so a
guest-relocated BAR with smaller alignment is accepted.
Signed-off-by: CMGS <ilskdw@gmail.com>
IommuEpollHandler::request_queue() can fail because the guest put in a
bad request or because of a fatal error. Handle those cases differently,
letting the guest continue, but see the error if it can.
This makes debugging from the guest easier as one mistake doesn't cause
a VM reset if it's avoidable.
Signed-off-by: Dylan Reid <dgreid@fb.com>
VfioUserDmaMapping::map panicked when find_region returned an anonymous
mmap region. Change this so a user gets an error instead of a panic.
When the VMM hotplugs a region into a guest that also has a vfio-user
device, all region's handlers are called. With the anonymous memory
backing (no file=, shared=on, or hugepages), region.file_offset()
returns None and the .unwrap() panics the VMM. Replace the unwrap with
an explicit error and use checked_add for the offset combine.
Signed-off-by: Dylan Reid <dgreid@fb.com>
Assert VirtioPciNotifyCap and VirtioPciCap64 size cap_len from
their own type. Catches a future regression of the same shape as
the VirtioPciCfgCap one in any of the sibling capabilities.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Assert the emitted VirtioPciCfgCap carries cfg_type 5, the value
assigned to PciCapabilityType::Pci by virtio 1.2 section 4.1.4.1.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Regression test for the cap_len fix. The emitted VirtioPciCfgCap
must report cap_len 20, covering the trailing pci_cfg_data window
per virtio 1.2 section 4.1.4.9.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
VirtioPciCfgCap::new built its inner header via VirtioPciCap::new,
which sized cap_len from the bare virtio_pci_cap layout, yielding
16. The emitted capability is VirtioPciCfgCap, which appends a four
byte pci_cfg_data window, so the correct value is 20.
The virtio 1.2 specification defines this cap as virtio_pci_cap
followed by pci_cfg_data[4] and requires cap_len to
cover the whole structure. Build the header inline so cap_len
reflects the actual emitted size, matching VirtioPciNotifyCap and
VirtioPciCap64.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
This reverts commit ced3762a67.
This change lead to a serious memory regression when not using hugepages
or shared=on.
`MAP_PRIVATE` creates an anonymous memory allocation for every page
written when the backing store is a file. This CoW behaviour is useful
but leads to double allocations when the backing store is an empty file
created by `memfd_create()`. When the page is written to, the CoW
semantics require a real page to be created in the memory for the memfd
(previously before the page was touched they would all point to the zero
page). This real page is filled with zeroes because in theory this page
would be accessible via read/write syscalls on the FD even though in our
implementation it is only ever `mmap()`ed.
The intention of the commit was to enable `fallocate()` to be used to
punch holes but that would only affect the inaccessible backing page and
the page in the CoW anonymous memory would be unaffected. Leading it
likely not to have the desired effect.
Fixes: #8211
Signed-off-by: Rob Bradford <rbradford@meta.com>
When reading from an unregistered PIO address, pio_read() wasn't
initialising the buffer, so guests were reading stale bytes from the
previous PIO transaction rather than all 0xff bytes like master abort
on real hardware.
Fill data with 0xff on invalid reads.
Correct 'read to unregistered address' info message to 'read from
unregistered address' while we're touching this block.
Signed-off-by: Chris Webb <chris@arachsys.com>
When reading from an unregistered MMIO address, mmio_read() wasn't
initialising the buffer, so guests were reading stale bytes from the
previous MMIO transaction rather than all 0xff bytes like master abort
on real hardware.
Fill data with 0xff on invalid reads.
Correct 'read to unregistered address' info message to 'read from
unregistered address' while we're touching this block.
Signed-off-by: Chris Webb <chris@arachsys.com>
The post-migration check used a fixed `thread::sleep(3s)` followed by
`try_wait()` to verify the source VM had exited cleanly. That window
is too tight when the source process is the release binary used by
`test_live_upgrade_*` (i.e. `~/workloads/cloud-hypervisor-static`,
pinned to `migratable_version`).
The released binary is older than the locally-built destination and
its virtio-device teardown (resume-paused-thread -> kill -> join
across pmem, block, net, console, rng workers) regularly takes
longer than 3s on contended hosts, causing the test to report:
thread 'common_parallel::test_live_upgrade_basic' panicked:
Test failed: source VM was not terminated successfully.
even though the source process eventually exits with status 0.
Replace the fixed sleep with a `wait_until(Duration::from_secs(30),
...)` poll that returns as soon as `try_wait()` reports a reaped
child, then keep the existing `success()` check on the exit status.
This makes the assertion robust against the slower release-binary
shutdown path while still failing fast on a genuine error.
The same pattern was duplicated across eight migration helpers plus
the virtio-fs migration variant; convert all nine call sites for
consistency.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Reordering commands or adding commands in-between is breaking the
migration protocol. By using explicit numbers, we can increase the
attention required when touching this code.
On-behalf-of: SAP philipp.schuster@sap.com
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
I started by looking at all `Option<Vec<T>>` values in config.rs and
vm_config.rs, and replaced them with `Option<Box<[T]>>`. This has the
advantage that one now can see at a glance if this field will ever
resize during operation or not, reducing cognitive load and increasing
maintainability. All fields that need the properties of a Ver or where
this change was not trivial are kept intact.
On-behalf-of: SAP philipp.schuster@sap.com
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
Some block devices (ZFS volume) may require BLKDISCARD and BLKZEROOUT
ioctls for discard and write_zeroes operations respectively.
There is no good way to probe whether fallocate is supported on a block
device. Arguably, punch_hole and write_zeroes are rare. Instead of
having a complex scheme for the IO uring backend, we force it to always
use ioctls. The code can be changed if the synchronized ioctls become a
performance issue.
Changes:
- Detect block devices at construction time
- Use BLKDISCARD ioctl for punch_hole (discard) on block devices
- Use BLKZEROOUT ioctl for write_zeroes on block devices
- Add BLKDISCARD/BLKZEROOUT to VirtioBlock seccomp whitelist
- Keep fallocate() path for regular files (no behavior change)
- Consolidate some helper functions to the new sparse module
Signed-off-by: Wei Liu <liuwe@microsoft.com>
probe_sparse_support() and DiskTopology::is_block_device() each carry
their own copy of the same fstat()+S_IFMT dance to ask "is this fd a
block device?". Hoist a single pub helper
pub(crate) fn is_block_device(fd: RawFd) -> bool
into block::lib and route both call sites through it. Drop the
MaybeUninit gymnastics in favour of mem::zeroed() since libc::stat is
POD.
Drop DiskTopology::is_block_device since it is now just a one line
wrapper around the new helper function.
Pure refactor in preparation for the BLKDISCARD/BLKZEROOUT support,
which needs the same probe in three more backends.
Signed-off-by: Wei Liu <liuwe@microsoft.com>
