size_of is part of std::prelude as of Rust 1.80 (with size_of_val,
align_of, align_of_val), and the workspace MSRV is 1.89, so qualifying
it (mem::size_of, std::mem::size_of, core::mem::size_of) is unnecessary.
Convert every qualified size_of call-site to the bare prelude form and
drop the now-redundant `use std::mem::size_of;` imports, keeping
`use std::mem;` where it still serves non-prelude items (transmute,
swap, replace, take, zeroed, MaybeUninit, offset_of). size_of is the
only one of the four currently used in the tree.
Pure refactor, no behavioural change. Follow-up to the
clippy::absolute_paths cleanup (#7670), as discussed in #8444.
Signed-off-by: Henry Hrvoje Tonkovac <htonkovac@gmail.com>
Assisted-by: Claude:Opus-4.8
Import the modules used in the crate instead of spelling the full paths
at every use site, and drop the now-unnecessary crate-level
generated msr_index.rs was trimmed separately.
Signed-off-by: Henry Hrvoje Tonkovac <htonkovac@gmail.com>
Assisted-by: Claude:Opus-4.8
Currently, Cloud Hypervisor round-trips CNTVCT_EL0 through
KVM_GET_REG_LIST/SET_ONE_REG, which leaves a cold-restored or migrated
guest behind real UTC by the downtime. Same-host pause/resume
self-corrects (the physical counter keeps running across the pause), so
only restore and migration cases required the clock to catch up to wall
clock time.
Since ARM has no kernel helper, compute the difference in wall clock
time and compute the ticks so that it can advance the CNTVCT correctly.
It is set via vcpu0 only as it affects a single VM wide value after
Linux 6.4. For older kernels, it was a truly vcpu value which needs to
be invoked for every vcpu.
Gated on all(target_arch = "aarch64", feature = "kvm"); x86 is
unchanged.
Basic manual test case (aarch64 + KVM) verified both in intra host and
inter host snapshot save/restore:
1. Boot a Linux guest; in the guest, `date -u` tracks the host's UTC.
2. Pause and snapshot the VM (ch-remote pause; ch-remote snapshot
file:///<dir>).
3. Leave it down for several minutes (the off-host interval).
4. Restore and resume into a fresh VMM (ch-remote restore
source_url=file:///<dir>,resume=true).
5. In the guest, run `date -u` again and compare to the host: the guest
now tracks current UTC, having advanced by ~the time it spent down.
Before this change the restored guest reads behind real UTC by the
downtime; after it, the guest clock is back in sync (to within the
snapshot-to-restore sampling slop).
Signed-off-by: Atish Patra <atishp@meta.com>
Unlike x86, ARM64 has no kvmclock support to sync guest time upon
required. However, the guest reads the architected virtual timer
(CNTVCT_EL0) directly which can be modified by the VMM to update the
time after snapshot restore. Since the CNTVCT is in ticks, we also need
to read CNTFRQ (via mrs due to lack of ONEREG interface) to compute the
ticks from wall clock difference.
Because the counter is a vCPU register, the capture must run with the
vCPUs quiesced, so the VMM now captures the clock just after
cpu_manager.pause() through the boot vCPU. This is behaviorally
identical for x86, whose clock is VM-wide. There is no restore/advance
yet, so aarch64 guests still resume behind real time until the following
commit.
Signed-off-by: Atish Patra <atishp@meta.com>
Preserving the guest clock across pause/resume and snapshot/restore is
currently open-coded in the VMM against the x86-only
get_clock/set_clock. aarch64 needs the same correction but via a
different mechanism (i.e. the architected counter, CNTVCT). Having a
common backend-agnostic interface that VMM can drive uniformly allows us
to keep the architecture details behind the Hypervisor abstraction.
This commit only introduces the abstraction while the future commits
will actually move the implementation to use it.
Use this opportunity to fix the full path to get SystemTime as well.
Suggested-by: Sebastien Boeuf <sboeuf@meta.com>
Signed-off-by: Atish Patra <atishp@meta.com>
Removal of absolute paths is currently in progress. To avoid regressing
those changes add a clippy deny at the workspace level and at the crate
level override with #[expect(clippy::absolute_paths)]
See: #7670
Signed-off-by: Rob Bradford <rbradford@meta.com>
If `KVM_GET_CLOCK` already filled out the `realtime` field, it sets the
`KVM_CLOCK_REALTIME` flag, but if we instead preserve this flag, the
kernel will automatically adjust the kvmclock clock when calling
`KVM_SET_CLOCK` based on the elapsed wall-clock time between pause and
resume. This just requires removing the `reset_flags()` function, which
allows the `KVM_CLOCK_REALTIME` flag to persist in the serialized clock
state.
However, the kernel does not always fill the `realtime` field, depending
on clock source; in this case, fill `realtime` during pause based on the
system time. This is not as precise as the automatic `KVM_GET_CLOCK`
version, since we query the time slightly after the vCPU was paused, but
it allows the clock to be resumed mostly in sync instead of being wildly
off. In this case, we also set the `KVM_CLOCK_REALTIME` flag in the
saved `struct kvmclock` so `KVM_SET_CLOCK` will adjust the clock on
resume.
Basic test case:
1. Run a VM with a Linux guest.
2. Pause the guest via `vm.pause` API.
3. Wait several minutes.
4. Resume the guest via `vm.resume` API.
5. Verify the guest time (e.g. via `date` command) is valid.
6. Verify guest is still using `kvm-clock` timesource:
cat /sys/devices/system/clocksource/clocksource0/current_clocksource
Before applying the patch, the guest clock would be off by the delta
time between pause and resume; after the patch, the clock is (more or
less) in sync with the correct wall-clock time.
Old snapshots will not have the `KVM_CLOCK_REALTIME` flag populated, so
they will not be affected by the new behavior.
Signed-off-by: Daniel Verkamp <drv@meta.com>
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>
Introduce the SevFd abstraction that wraps /dev/sev and implements the
KVM_SEV_INIT2 and KVM_SEV_SNP_LAUNCH_START ioctls for SEV-SNP VM
initialization on KVM.
Key changes:
- Add sev.rs with KvmSevInit and KvmSevSnpLaunchStart ioctl structs
matching the kernel layout (linux/arch/x86/include/uapi/asm/kvm.h)
- Implement KVM_SEV_INIT2 and KVM_SEV_SNP_LAUNCH_START ioctls
- Set KVM_MEMORY_ATTRIBUTE_PRIVATE on newly created memory regions
when guest_memfd is supported
- Widen SevSnpPageAccessProxy cfg gates from mshv-only to all
sev_snp-enabled builds
- Make sev_snp_init a required trait method (remove default impl)
- Include KVM_SEV_SNP_LAUNCH_START in the seccomp allowlist
- Parse VMSA SEV features from IGVM and include them in the
KVM_SEV_INIT2 ioctl
Co-authored-by: Keith Adler <kadler@cloudflare.com>
Signed-off-by: Keith Adler <kadler@cloudflare.com>
Co-authored-by: Alex Orozco <aorozco@google.com>
Signed-off-by: Alex Orozco <aorozco@google.com>
Co-authored-by: Rob Bradford <rbradford@meta.com>
Signed-off-by: Rob Bradford <rbradford@meta.com>
Signed-off-by: Ruben Hakobyan <hruben@meta.com>
Add support for guest_memfd (available in Linux kernel v6.8+), which
enables private memory for confidential VMs.
Key changes:
- Introduce UserMemoryRegion abstraction with guest_memfd fields
- Add From impls between kvm_userspace_memory_region2 and UserMemoryRegion
- Convert all KVM memory region operations from kvm_userspace_memory_region
to kvm_userspace_memory_region2, with automatic fallback to v1 when
guest_memfd is not supported
- Add set_user_memory_region() wrapper that dispatches to v1/v2 based on
kvm_guest_memfd_supported capability
- Create guest_memfd via KVM_CREATE_GUEST_MEMFD ioctl when supported
- Extend KvmDirtyLogSlot to preserve region2 fields across dirty log
start/stop cycles
This is prerequisite infrastructure for KVM-based confidential computing
that requires private guest memory backed by guest_memfd.
Co-authored-by: Alex Orozco <aorozco@google.com>
Signed-off-by: Keith Adler <kadler@cloudflare.com>
Signed-off-by: Ruben Hakobyan <hruben@meta.com>
Set HV_PARTITION_CREATION_FLAG_SMT_ENABLED_GUEST when the guest
topology has more than one thread per core. This allows the
hypervisor to schedule guest VPs correctly on SMT-enabled hosts.
Without this flag, the hypervisor schedules guest VPs incorrectly,
causing SMT unusable.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
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>
For MSHV customers don't want to make everything
default during partition creation. For example
nested support, some synthetic features could be
controlled from CLI through platform argument.
Create_vm API getting messy after adding more flags.
This patch introduces common data struct to be passed
from vmm crate to hypervisor crate during partition creation.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
KVM supports GICv3-ITS emulation and the current GicState is modelled
around the KVM implementation. We should refactor this to accomodate
other hypervisor requirements. For example, MSHV only support GICv2M
emulation for guests for delivering MSI interrupts instead of GICv3-ITS.
Signed-off-by: Jinank Jain <jinankjain@microsoft.com>
Use the definitions from the rust-vmm/mshv crate for various
datastructures such as StandardRegisters, RegList, VcpuInit etc.
Signed-off-by: Jinank Jain <jinankjain@microsoft.com>
Currently we are just storing the StandardRegisters in the Vcpu state
which would be required for saving and restoring the ARM64 guest on
MSHV.
Signed-off-by: Jinank Jain <jinankjain@microsoft.com>
This will become useful when we build the fuzzing target for the
instruction emulator, because there is no need to pull in the rest of
the hypervisor crate in that situation.
Signed-off-by: Wei Liu <liuwe@microsoft.com>
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>
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>
And modify to code to use the updated interfaces.
Arguments for map_guest_memory, get_dirty_bitmap, vp.run(),
import_isolated_pages, modify_gpa_host_access have changed.
Update these to use the new interfaces, including new MSHV_*
definitions, and remove some redundant arguments.
Update seccomp IOCTLs to reflect interface changes.
Fix irq-related definitions naming.
Bump vfio-ioctls to support mshv v0.3.0.
Signed-off-by: Nuno Das Neves <nudasnev@microsoft.com>
This change is along the lines of x86 platform which defined similar
convinence macros to access the StandardRegisters.
Signed-off-by: Jinank Jain <jinankjain@microsoft.com>
Currently we are redefining StandardRegisters instead of using the ones
coming from bindings. With this we can remove the unnecessary
construction of global structure which contains fields from different
hypervisor dependent structs.
Signed-off-by: Jinank Jain <jinankjain@microsoft.com>
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>
When doctests are built, the crate is built with itself as a
dependency via --extern. This causes a compiler error if using a
module with the name same as the crate, because it's ambiguous whether
it's referring to the module, or the extern version of the crate, so
it's necessary to disambiguate when using the hypervisor module here.
Fixes running cargo test --doc --workspace.
Signed-off-by: Alyssa Ross <hi@alyssa.is>
There was an unnecessary change in previous PR #5077.
This is the follow-up clean up patch.
Right now there is no use case of the drive of
Eq and PartialEq.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
MSHV does not require to ensure MMIO/PIO exits complete
before pausing. This patch makes sure the above requirement
by checking the hypervisor type run-time.
Fixes#5037
Signed-off-by: Muminul Islam <muislam@microsoft.com>
