Commit Graph

287 Commits

Author SHA1 Message Date
Rob Bradford
e05065f509 build: Bump rust-vmm dependencies
Bump to the released versions that are compatible wherever possible but
for the vhost and vfio crates they are git hashes as no releases with
compatible versions have yet been made.

Signed-off-by: Rob Bradford <rbradford@meta.com>
2026-03-23 10:04:07 +00:00
Shayon Mukherjee
c417924a29 vmm: memory_manager: add on-demand snapshot restore via userfaultfd
When memory_restore_mode=ondemand is specified on the restore command,
the memory manager creates a userfaultfd descriptor, registers each
guest RAM range for missing-page fault interception, and spawns a
handler thread that serves page faults from the snapshot file using
UFFDIO_COPY. This avoids reading the entire memory-ranges file into
guest RAM before restore completes.

The handler uses epoll to multiplex the userfaultfd and a stop eventfd
for clean shutdown. Concurrent faults from multiple vCPUs are handled
by treating EEXIST as a benign race and waking blocked threads with
UFFDIO_WAKE. Once all pages have been served the handler exits
automatically. If the handler thread panics the VMM is signalled to
exit since the VM cannot continue without page fault service.

MemoryZone gains a backing_page_size field so the handler resolves
fault granularity from the zone rather than the top-level config.

Errors from the UFFD setup path use a structured UffdError enum
and a new MigratableError::OnDemandRestore variant, with a From
impl to keep call sites concise.

The seccomp filter is updated to allow the userfaultfd syscall and
the four uffd ioctls (UFFDIO_API, UFFDIO_COPY, UFFDIO_REGISTER,
UFFDIO_WAKE) under the VMM thread profile.

Signed-off-by: Shayon Mukherjee <shayonj@gmail.com>
2026-03-13 21:17:21 +00:00
Philipp Schuster
d4b5502472 vmm: reduce verbosity of dirty logging output
Lower several informational messages in the dirty logging path to
debug level.

These messages are noisy in practice and provide little value since
dirty logging is known to work reliably. More useful migration metrics
(e.g., dirty size per iteration) is logged per iteration in subsequent
commits.

Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
2026-03-13 13:18:07 +00:00
Champ-Goblem
1e0eba60af vmm: always try THP for VM RAM
The kernel allows madvise on shared memory if
/sys/kernel/mm/transparent_hugepage/shmem_enabled is set.
Always try and configure THP via madvise when
the user requests THP be enabled.
If this fails, only a warning log is emitted and THP won't be enabled.

Signed-off-by: Champ-Goblem <cameron@northflank.com>
2026-02-06 18:40:26 +00:00
Rowen-Ye
2c2f5d2431 vmm: open backing file read-only when not shared
When restoring from snapshot with shared=false, write access to the
backing file is not required. Opening it read-only allows restore to
succeed on read-only media and overlay lower layers while preserving
MAP_PRIVATE semantics.

Signed-off-by: Rowen-Ye <rowenye1@gmail.com>
2026-02-06 16:06:48 +00:00
Oliver Anderson
8de24b5f08 vmm: Fix clippy lints
This PR fixes some clippy lints in the vmm crate.

Signed-off-by: Oliver Anderson <oliver.anderson@cyberus-technology.de>
On-behalf-of: SAP oliver.anderson@sap.com
2025-12-09 16:14:44 +00:00
Julian Stecklina
1861bc49e7 vmm: simplify receiving memory fds
... and nuke some Option<> while I was there. Given that HashMap has a
usable default and we end up passing an empty HashMap anyway, just get
rid of the Option.

On-behalf-of: SAP julian.stecklina@sap.com
Signed-off-by: Julian Stecklina <julian.stecklina@cyberus-technology.de>
2025-11-28 08:41:47 +00:00
Philipp Schuster
c53781bf5f misc: clippy: add needless_pass_by_value
This is a follow-up of [0].

# Advantages

- This saves dozens of unneeded clone()s across the whole code base
- Makes it much easier to reason about how parameters are used
  (often we passed owned Arc/Rc versions without actually needing
  ownership)

# Exceptions

For certain code paths, the alternatives would require awkward or overly
complex code, and in some cases the functions are the logical owners of
the values they take. In those cases, I've added
#[allow(clippy::needless_pass_by_value)].

This does not mean that one should not improve this in the future.

[0] 6a86c157af

Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
2025-11-27 17:11:14 +00:00
Philipp Schuster
6a86c157af misc: clippy: add needless_pass_by_value (partially)
This helps to uncover expensive and needless clones in the code base.
For example, I prevented extensive clones in the snapshot path where
(nested) BTreeMap's have been cloned over and over again. Further,
the lint helps devs to much better reason about the ownership of
parameters.

All of these changes have been done manually with the necessary
caution. A few structs that are cheap to clone are now `copy` so that
this lint won't trigger for them.

I didn't enable the lint so far as it is a massive rabbit hole and
needs much more fixes. Nevertheless, it is very useful.

Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
2025-11-25 16:05:46 +00:00
Philipp Schuster
0a07c96d17 misc: clippy: add if_not_else
This removes cognitive load when reading if statements.
All changes were applied by clippy via `--fix`.

Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
2025-11-25 16:05:46 +00:00
Philipp Schuster
67fc9d990e misc: vmm: drop extern crate, use modern rust
This commit is part of a series of similar commits.

Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
2025-11-24 22:36:46 +00:00
Demi Marie Obenour
42522a88c0 misc: do not use u64 to represent host pointers
To ensure that struct sizes are the same on 32-bit and 64-bit, various
kernel APIs use __u64 (Rust u64) to represent userspace pointers.
Userspace is expected to cast pointers to __u64 before passing them to
the kernel, and cast kernel-provided __u64 to a pointer before using
them.  However, various safe APIs in Cloud Hypervisor took
caller-provided u64 values and passed them to syscalls that interpret
them as userspace addresses.  Therefore, passing bad u64 values would
cause memory disclosure or corruption.

Fix the bug by using usize and pointer types as appropriate.  To make
soundness of the code easier to reason about, the PCI code gains a new
MmapRegion abstraction that ensures the validity of pointers.  The rest
of the code already has an MmapRegion abstraction it can use.  To avoid
having to reason about whether something is keeping the MmapRegion
alive, reference counting is added.  MmapRegion cannot hold references
to other objects, so the reference counting cannot introduce cycles.

Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
2025-11-22 10:24:13 +00:00
Demi Marie Obenour
fdc19ad85e misc: Mark memory region APIs as unsafe
To ensure that struct sizes are the same on 32-bit and 64-bit, various
kernel APIs use __u64 (Rust u64) to represent userspace pointers.
Userspace is expected to cast pointers to __u64 before passing them to
the kernel, and cast kernel-provided __u64 to a pointer before using
them.  However, various safe APIs in Cloud Hypervisor took
caller-provided u64 values and passed them to syscalls that treat them
as userspace addresses.  Therefore, passing bad u64 values would cause
memory disclosure or corruption.  The memory region APIs are one example
of this, so mark them as unsafe.

Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
2025-11-22 10:24:13 +00:00
Philipp Schuster
b4c62bf159 misc: clippy: add semicolon_if_nothing_returned
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
2025-11-21 09:32:11 +00:00
Philipp Schuster
ea4f07d3bf misc: clippy: add uninlined_format_args
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
2025-11-21 09:32:11 +00:00
Philipp Schuster
7cb73e9e56 misc: clippy: add unnecessary_semicolon
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
2025-11-21 09:32:11 +00:00
Philipp Schuster
a7fa3a0c86 vm-migration: better naming + unittests
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
2025-11-17 14:34:54 +00:00
Julian Stecklina
b6c266c880 vmm: avoid creating large temporary vector during migration
... by just passing the iterator along. For large VMs this bitmap is
gigantic. A 12TB VM has 384MB of dirty bitmap.

With all these optimizations from the previous commits in place, we
see quite the improvement when it comes to scanning the dirty bitmap.

For a bitmap with 1% bits (randomly) set, dirty_log() takes:

Original code: 2166ms (100.0%)
New code:       382ms ( 17.6%)

on my system. The sparser the dirty bitmap the faster. Scanning an
empty bitmap is 100x faster. For a 5% populated bitmap we are still 3x
faster.

If someone wants to play with this, there is a benchmark harness here:
https://github.com/blitz/chv-bitmap-bench

On-behalf-of: SAP julian.stecklina@sap.com
Signed-off-by: Julian Stecklina <julian.stecklina@cyberus-technology.de>
2025-11-17 14:34:54 +00:00
Ruoqing He
f2dfa7f6e0 misc: Use variables directly in format! string
Fix clippy warning `uninlined_format_args` reported by rustc rustc
1.89.0 (29483883e 2025-08-04).

```console
warning: variables can be used directly in the `format!` string
   --> block/src/lib.rs:649:17
    |
649 |                 info!("{} failed to create io_uring instance: {}", error_msg, e);
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
    = note: `#[warn(clippy::uninlined_format_args)]` on by default
help: change this to
    |
649 -                 info!("{} failed to create io_uring instance: {}", error_msg, e);
649 +                 info!("{error_msg} failed to create io_uring instance: {e}");
    |
```

Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>
2025-09-24 02:28:12 +00:00
Philipp Schuster
c995b72384 build: treewide: clippy: collapse nested ifs, use let chains
This bumps the MSRV to 1.88 (also, Rust edition 2024 is mandatory).

Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
2025-09-10 18:35:38 +00:00
Philipp Schuster
363273111a build: treewide: fmt for edition 2024
`cargo +nightly fmt`

Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
2025-09-10 18:35:38 +00:00
Shubham Chakrawar
2d9e243163 misc: Remove SGX support from Cloud Hypervisor
This commit removes the SGX support from cloud hypervisor. SGX support
was deprecated in May as part of #7090.

Signed-off-by: Shubham Chakrawar <schakrawar@crusoe.ai>
2025-09-05 18:08:36 +00:00
Ruoqing He
2e0ec8095c vmm: Enable uefi_flash field for riscv64
uefi_flash field in memory_manager is required for uefi loading and
booting, enable it for riscv64 architecture.

Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>
2025-08-11 10:10:27 +00:00
Songqian Li
cd2c43b489 misc: Fix beta clippy errors
Fix clippy error: "error: manual implementation of `.is_multiple_of()
`" from rustc 1.90.0-beta.1 (788da80fc 2025-08-04).

Signed-off-by: Songqian Li <sionli@tencent.com>
2025-08-07 16:53:59 +00:00
Demi Marie Obenour
24998c1672 vmm: do not treat libc::MAP_FAILED as a pointer
It will likely be safely rejected by the kernel, but it's still wrong.

Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
2025-06-23 09:06:32 +00:00
Philipp Schuster
d7edd9d51f misc: vmm: streamline error Display::fmt()
The changes were mostly automatically applied using the following
Python script:

```python
import os, re

for root, _, files in os.walk("."):
    for f in files:
        if not f.endswith(".rs"):
            continue
        p = os.path.join(root, f)
        with open(p, "r", encoding="utf-8") as file:
            lines = file.readlines()
        changed = False
        for i in range(len(lines) - 1):
            if re.search(r'#\[error\(".*: \{0[^}]*\}"\)\]', lines[i]) and "#[source]" in lines[i + 1].strip():
                lines[i] = re.sub(r': \{0[^}]*\}"\)\]', '")]', lines[i])
                changed = True
        if changed:
            with open(p, "w", encoding="utf-8") as file:
                file.writelines(lines)
            print("Fixed:", p)
```

Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com

# Conflicts:
#	vmm/src/api/http/mod.rs
2025-06-13 19:55:54 +00:00
Paolo Bonzini
0463f4f156 vmm: use MmapRegion::bitmap() directly
For use in QEMU, I would like GuestMemoryRegion to return a BitmapSlice
instead of a &Bitmap.  This adds some flexibility that QEMU needs in
order to support a single global dirty bitmap that is sliced by the
various GuestMemoryRegions.

However, this removes access to the methods of AtomicBitmap, and in
particular reset() and get_and_reset().  Fortunately, cloud-hypervisor
always uses GuestMemoryMmap, and therefore `region` is known to be a
&GuestRegionMmap.  Dereferencing it returns the MmapRegion to which the
bitmap is attached, thus calling MmapRegion::bitmap(); this has the
same effect as `<GuestRegionMmap as GuestRegion>::bitmap()`, and works
both with or without https://github.com/rust-vmm/vm-memory/pull/324.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-05-21 13:00:07 +00:00
Philipp Schuster
78b0f68b21 vmm: Error for MemoryManagerError
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>

On-behalf-of: SAP <philipp.schuster@sap.com>
2025-05-16 11:42:01 +00:00
Jinank Jain
034aa514d7 vmm: Unify address space allocation
It seems like address allocation has been spread into different files
and different location for x86 vs ARM. This makes it hard to follow the
code. Thus, unify it a single location which satisfies all the
requirement.

Signed-off-by: Jinank Jain <jinankjain@microsoft.com>
2025-05-09 16:06:12 +00:00
Ruoqing He
c99660a8f9 vmm: Introduce riscv64 architecture support
Integrate all works done previously to enable booting riscv linux on
riscv platforms, example command:

```console
./target/debug/cloud-hypervisor \
        --kernel path/to/kernel \
        --disk path=path/to/disk \
        --cmdline "console=hvc0 root=/dev/vda rw" \
        --cpus boot=1 \
        --memory size=1024M \
        --seccomp false
```

Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>
2025-03-14 17:00:57 +00:00
Alyssa Ross
50bac1694f vmm: support PCI I/O regions on all architectures
While non-Intel CPU architectures don't have a special concept of IO
address space, support for PCI I/O regions is still needed to be able
to handle PCI devices that use them.

With this change, I'm able to pass through an e1000e device from QEMU
to a cloud-hypervisor VM on aarch64 and use it in the cloud-hypervisor
guest.  Previously, it would hit the unimplemented!().

Signed-off-by: Alyssa Ross <hi@alyssa.is>
2024-12-14 14:12:00 +00:00
Alyssa Ross
dd8a5a7de8 vmm: remove outdated comment
Fixes: def98faf ("vmm, vm-allocator: Introduce an allocator for platform devices")
Signed-off-by: Alyssa Ross <hi@alyssa.is>
2024-12-14 14:12:00 +00:00
Rob Bradford
e3bd5e9b35 vmm: memory_manager: Adapt for new MemorySlotAllocator
Adapt the existing code to transparently the MemorySlotAllocator. The
MemoryManager is the canonical holder of the these values with them
turned into a MemoryAllocator on demand.

Signed-off-by: Rob Bradford <rbradford@rivosinc.com>
2024-11-24 10:45:15 +00:00
Rob Bradford
7a637fe1f4 vmm: memory_manager: Use div_ceil()
--> vmm/src/memory_manager.rs:1972:13
     |
1972 | ...   ((self.start_of_device_area.0 + SGX_PAGE_SIZE - 1) / SGX_PAGE_SIZE) * ...
     |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `self.start_of_device_area.0.div_ceil(SGX_PAGE_SIZE)`
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#manual_div_ceil
     = note: `#[warn(clippy::manual_div_ceil)]` on by default

Signed-off-by: Rob Bradford <rbradford@rivosinc.com>
2024-10-21 15:28:17 +00:00
Ruoqing He
6164aa0885 misc: Replace div_round_up operation with div_ceil
As clippy of rust-toolchain version 1.83.0-beta.1 suggests, replace
manually implemented `div_round_up!` and the like with `div_ceil` from
std.

Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>
2024-10-18 17:46:39 +00:00
Songqian Li
33c15ca273 vmm: remove pub use vm_config in config
This patch removes pub import vm_config in config.rs to eliminate
the ambiguity of vm_comfig reference.

Signed-off-by: Songqian Li <sionli@tencent.com>
2024-09-30 08:18:02 +00:00
Ruoqing He
61e57e1cb1 misc: Further improve imports styling
By introducing `imports_granularity="Module"` format strategy,
effectively groups imports from the same module into one line or block,
improving maintainability and readability.

Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>
2024-09-29 16:13:48 +00:00
Rob Bradford
88a9f79944 misc: Adapt consistent import style formatting
Historically the Cloud Hypervisor coding style has been to ensure that
all imports are ordered and placed in a single group. Unfortunately
cargo fmt has no support for ensuring that all imports are in a single
group so if whitespace lines were added as part of the import statements
then they would only be odered correctly in the group.

By adopting "group_imports="StdExternalCrate" we can enforce a style
where imports are placed in at most three groups for std, external
crates and the crate itself. Choosing a style enforceable by the tooling
reduces the reviewer burden.

Signed-off-by: Rob Bradford <rbradford@rivosinc.com>
2024-09-29 13:08:12 +01:00
Yuhong Zhong
2ad8fac624 vmm: memory_manager: Fix bound checks for memory hotplug
Bound checks for virtio-mem and ACPI memory hotplug are off by
one and two, respectively. This prevents users to fully use the reserved
memory hotplug size.

For ACPI, if we specific `--memory size=2G,hotplug_size=4G` and run
`ch-remote resize --memory 6G`, cloud-hypervisor will report the
following error because of the incorrect bound check:

`<vmm> ERROR:vmm/src/lib.rs:1631 -- Error when resizing VM:
MemoryManager(InsufficientHotplugRam)`

Similarly, for virtio-mem, cloud-hypervisor will fail the incorrect
bound check and abort the resize. The VM will see the following error
in dmesg:

`virtio_mem virtio3: unknown error, marking device broken: -22`

This patch has fixed both bound checks and ensure that users can
hot add memory up to the reserved hotplug size.

Signed-off-by: Yuhong Zhong <yz@cs.columbia.edu>
2024-09-19 18:02:20 +00:00
Wei Liu
254db7b96a vmm: fix documentation formatting
Signed-off-by: Wei Liu <liuwe@microsoft.com>
2024-06-12 16:59:20 +00:00
Josh Soref
42e9632c53 misc: Fix spelling issues
Misspellings were identified by:
  https://github.com/marketplace/actions/check-spelling

* Initial corrections based on forbidden patterns from the action
* Additional corrections by Google Chrome auto-suggest
* Some manual corrections
* Adding markdown bullets to readme credits section

Signed-off-by: Josh Soref <2119212+jsoref@users.noreply.github.com>
2024-06-08 16:31:30 +00:00
Rob Bradford
10ab87d6a3 misc: Migrate away from versionize
Replace with serde instead.

Fixes: #6370

Signed-off-by: Rob Bradford <rbradford@rivosinc.com>
2024-04-22 17:10:55 +00:00
Alexandru Matei
fbe3e4d642 vmm: memory_manager: don't set backing_file for virtio_mem regions
The memory region that is associated with the hotpluggable part of
a virtio-mem zone isn't backed by the file specified in the
MemoryZoneConfig. The file is used only for the fixed part of the
zone. When you try to restore a snapshot with virtio-mem, the
backing file is used for all its regions. This results in the
following error:

  VmRestore(MemoryManager(GuestMemoryRegion(MappingPastEof)))

This patch sets backing_file only for the fixed part of a virtio-mem
zone.

Fixes: #6337

Signed-off-by: Alexandru Matei <alexandru.matei@uipath.com>
2024-03-29 20:11:20 +00:00
Rob Bradford
adb318f4cd misc: Remove redundant "use" imports
With the nightly toolchain (2024-02-18) cargo check will flag up
redundant imports either because they are pulled in by the prelude on
earlier match.

Remove those redundant imports.

Signed-off-by: Rob Bradford <rbradford@rivosinc.com>
2024-02-19 17:54:30 +00:00
Sean Banko
7633d47293 vmm: prefault memory in parallel to optimize boot time
On guests with large amounts of memory, using the `prefault` option can
lead to a very long boot time. This commit implements the strategy
taken by QEMU to prefault memory in parallel using multiple threads,
decreasing the time to allocate memory for large guests by
an order of magnitude or more.

For example, this commit reduces the time to allocate memory for a
guest configured with 704 GiB of memory on 1 NUMA node using 1 GiB
hugepages from 81.44134669s to just 6.865287881s.

Signed-off-by: Sean Banko <sbanko@crusoeenergy.com>
2024-02-07 08:59:03 -08:00
Thomas Barrett
45b01d592a vmm: assign each pci segment 32-bit mmio allocator
Signed-off-by: Thomas Barrett <tbarrett@crusoeenergy.com>
2023-11-20 15:33:50 -08:00
Bo Chen
d4892f41b3 misc: Stop using deprecated functions from vm-memory crate
See: https://github.com/rust-vmm/vm-memory/pull/247

Signed-off-by: Bo Chen <chen.bo@intel.com>
2023-11-14 09:17:42 +00:00
Philipp Schuster
7bf0cc1ed5 misc: Fix various spelling errors using typos
This fixes all typos found by the typos utility with respect to the config file.

Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
2023-09-09 10:46:21 +01:00
Rob Bradford
4548de194d build: Bump acpi_tables version
Fix newly added deprecation for mispelling of cacheable.

Signed-off-by: Rob Bradford <rbradford@rivosinc.com>
2023-09-07 13:58:33 +01:00
Changyuan Lyu
7f18d0a281 memory_manager: improve memory region creation
Instead of making an owned `zones`, using an iterator is cheaper
since `Vec::remove` may have the performance O(n) [1].

[1]: https://doc.rust-lang.org/std/vec/struct.Vec.html#method.remove

Signed-off-by: Changyuan Lyu <changyuanl@google.com>
2023-07-10 11:54:05 -07:00