Explain how operators can exclude selected VFIO BARs from mmap
when they know their workloads do not require MMIO access to those
regions.
Documenting the option separately keeps the new device argument
discoverable and calls out the valid BAR index range.
Signed-off-by: Damian Barabonkov <dbctl@pm.me>
Assisted-by: OpenCode:gpt-5.5
Remove CI workflow description section as the yaml
files change often and the docs become stale quickly.
Assisted-by: Claude:Opus-4.6
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Add docs/testing.md covering the dev_cli.sh interface, all
test types (unit, integration, VFIO, Windows, live migration,
rate limiter, CVM), custom kernel/firmware overrides via
environment variables, performance metrics, code coverage,
and the CI workflow matrix.
Assisted-by: GitHub Copilot:Claude-Opus-4.6
Signed-off-by: Muminul Islam <muislam@microsoft.com>
QEMU supports passing inline string values to the guest via fw_cfg
(-fw_cfg name=...,string=...). Cloud Hypervisor previously only
supported file-backed fw_cfg items. This adds the 'string' option
so users can pass values like OVMF's X-PciMmio64Mb without creating
a temporary file on the host.
Each fw_cfg item now accepts exactly one of 'file' or 'string'.
The FwCfgInvalidItem invariant is validated in PayloadConfig::validate()
(via FwCfgConfig::validate()), covering both CLI and JSON API paths.
The populate_fw_cfg match arm uses unreachable!() since validation
guarantees the invariant holds at that point.
CLI syntax:
--fw-cfg-config items=[name=opt/ovmf/X-PciMmio64Mb,string=262144]
Signed-off-by: Keith Adler <kadler@cloudflare.com>
Some of the documentation references PCI segment ID. For those documents
add a mention of the new PCI device ID.
Signed-off-by: Rob Bradford <rbradford@meta.com>
Add a `mergeable` field to `MemoryZoneConfig` so that KSM page merging
can be enabled selectively per memory zone rather than globally for all
guest RAM.
Previously, `MADV_MERGEABLE` was only controllable via the top-level
`--memory mergeable=on` flag, which applied uniformly to all regions.
With this change, users can leave boot memory unmerged while enabling
KSM only on hotplug zones:
--memory size=0,hotplug_method=virtio-mem
--memory-zone id=boot,size=512M,shared=on,mergeable=off
--memory-zone id=hotplug,size=256M,hotplug_size=1G,shared=off,mergeable=on
The `MemoryZone` runtime struct now carries the `mergeable` flag so
that both `allocate_address_space` and `add_ram_region` can apply
per-zone `MADV_MERGEABLE` instead of the global `self.mergeable`.
The top-level `--memory mergeable=on` path continues to work unchanged:
the default zone is synthesised from `MemoryConfig` and inherits its
`mergeable` value.
AI/LLM disclosure: this patch was co-authored with
GitHub Copilot and Claude Code (Opus 4.6).
Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Add an option that can be used when restoring to resume the VM. This is
particularly useful when restoring the VM via the direct VMM command
line, when you might not want/have an API socket configured.
Signed-off-by: Rob Bradford <rbradford@meta.com>
Add a MemoryRestoreMode enum (Copy | OnDemand) to RestoreConfig so
the restore path can be selected at restore time. Copy preserves the
existing eager read-copy behavior. OnDemand enables userfaultfd-based
demand paging and fails restore if the kernel does not support it.
Validate that prefault=on is not combined with OnDemand mode.
Update the OpenAPI spec with the new enum field.
Signed-off-by: Shayon Mukherjee <shayonj@gmail.com>
Add docs/disk_locking.md explaining advisory OFD locking, the
lock_granularity parameter, byte-range vs whole-file semantics,
and fallback behavior.
Signed-off-by: Victor Vieux <vieux@repl.it>
Add a core_scheduling option to --cpus with three modes of operation.
This feature takes advantage of a kernel feature that restricts
scheduling of processes on the SMT threads on the same core. This is
useful for mitigating certain classes of side-channel attacks and has
better performance that disabling SMT on the CPU.
- vm (default): All vCPU threads share one core scheduling cookie.
They may be co-scheduled on SMT siblings while host threads are
excluded - this has minimal performance impact and can even
potentially improve performance from co-location.
- vcpu: Each vCPU gets a unique cookie preventing any two vCPUs from
sharing SMT siblings. This has the strongest isolation but at some
compromise of performance.
- off: No core scheduling applied (old behaviour).
This isolation is done by the kernel maintaining a "cookie" - threads
with the same cookie can share the same core.
In vCPU mode each vCPU thread the cookie is created when the thread
starts and each gets a unique cookie. For VM mode the first vCPU thread
(the leader) will create the cookie. All other vCPU threads started (via
hotplug or during boot) will have that cookie shared to it.
EINVAL/ENODEV from prctl is silently ignored so this works transparently
on kernels older than 5.14 that lack PR_SCHED_CORE or when SMT disabled.
Full details of this kernel feature can be found at:
https://docs.kernel.org/admin-guide/hw-vuln/core-scheduling.html
This implementation was inspired by crosvm's implementation - in
particular the enable_core_scheduling() function.
This is challenging to test via integration testing but the logging of
the received cookie shows it working:
VM case:
cloud-hypervisor: 0.243102s: <vcpu1> INFO:vmm/src/cpu.rs:1247 -- vCPU 1: core scheduling cookie = 0x33e4c167
cloud-hypervisor: 0.243102s: <vcpu0> INFO:vmm/src/cpu.rs:1247 -- vCPU 0: core scheduling cookie = 0x33e4c167
vCPU case:
cloud-hypervisor: 0.089356s: <vcpu0> INFO:vmm/src/cpu.rs:1247 -- vCPU 0: core scheduling cookie = 0x13993ad6
cloud-hypervisor: 0.089380s: <vcpu1> INFO:vmm/src/cpu.rs:1247 -- vCPU 1: core scheduling cookie = 0xd48e86e
Signed-off-by: Rob Bradford <rbradford@meta.com>
Document device_id parameter in NumaConfig, automatic
guest_numa_id assignment, default NUMA distances and
restrictions on Generoc Initiator NUMA nodes
Add numa configuration examples with GPU device and distance
relationships.
Signed-off-by: Saravanan D <saravanand@crusoe.ai>
build_edk2() module in scripts/common-aarch64.sh
does not produce the UEFI firmware for aarch64 as
the commits used to assemble sources for acpica,
edk2-platforms and edk2 do not compile after GCC
version upgraded from 11.4.0 to 13.3.0 in the
developer container (ubuntu 22.04 to 24.04)
Apply minimum upgrade to EDK2_REPO and ACPICA_REPO
required to compile with GCC 13.3.0
while still assuring guest VM boot for all
integration tests
BaseTools: Brotli compression submodule that was
previously failing has been fixed following commit
bump
Developers can now produce UEFI firmware for
aarch64 using the following commands
```
./scripts/dev_cli.sh shell
source scripts/test-util.sh
source scripts/common-aarch64.sh
build_edk2
```
Update docs/uefi.md
Fixes#7608
Signed-off-by: Saravanan D <saravanand@crusoe.ai>
Minor modifications were made to make the sentences sound more natural.
Also fixed some parameter usage issues in bash code block.
Signed-off-by: Yi Wang <foxywang@tencent.com>
There are some syntax and format issues in tdx/sev documents.
Make some modification to make the description more natural.
And the link of SEV-SNP is invalid, fix it.
Signed-off-by: Yi Wang <foxywang@tencent.com>
There are some minor syntax and command issues in debug-port document.
As commit 5febdec81a (vmm: Enable `gdbstub` on AArch64) supported
aarch64, the docs should keep consistent.
Signed-off-by: Yi Wang <foxywang@tencent.com>
Fix some minor syntax issues in api/building document to make
the sentences more fluent and easy to read.
Signed-off-by: Yi Wang <foxywang@tencent.com>
Some description in the device document were inconsistent with the
source code. Also fix some syntax issues to make the sentences more
fluent.
Signed-off-by: Yi Wang <foxywang@tencent.com>
This patch updates the documentation to reflect the newly added
nested CPU feature option in the CLI.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
The API documentation tells users to expect a message when Cloud
Hypervisor is launched, this message was removed in commit 13724db
This change updates the documentation to reflect how the program
actually functions, which is to say no message.
Signed-off-by: Ariel Chenet <achenet@fastmail.com>
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>
Here we add the fw_cfg device as a legacy device to the device manager.
It is guarded behind a fw_cfg flag in vmm at creation of the
DeviceManager. In this cl we implement the fw_cfg device with one
function (signature).
Signed-off-by: Alex Orozco <alexorozco@google.com>
The current documentation only mentions Windows
server support. Since only minimal adjustments
are needed for Windows 11 support, these were
added where applicable.
Also contains whitespace fixes, adds missing `\`
in example code and adds more cross references.
Signed-off-by: Lucas Grosche <lucas.grosche@cyberus-technology.de>
When invoking the script chown shows a warning.
chown: warning: '.' should be ':': ‘1000.1000’
From `info coreutils 'chown invocation'`.
Some older scripts may still use ‘.’ in place of the ‘:’ separator.
POSIX 1003.1-2001 (*note Standards conformance::) does not require
support for that, but for backward compatibility GNU ‘chown’ supports
‘.’ so long as no ambiguity results, although it issues a warning and
support may be removed in future versions. New scripts should avoid the
use of ‘.’ because it is not portable, and because it has undesirable
results if the entire OWNER‘.’GROUP happens to identify a user whose
name contains ‘.’.
Signed-off-by: Wei Liu <liuwe@microsoft.com>
Since there are not a wide availability of RISC-V boards available at
the moment, it is easiest to develop with a QEMU virtual machine. I had
a hard time setting one up, but with the assistance of Ruoqing, I was
able to get one running. These are the steps I took to do so.
Signed-off-by: abm-77 <andrewmiller77@protonmail.com>
Add `riscv.md` to guide developers/users on preparing guest kernel,
image, and direct boot VM on riscv64 platforms; document support status
and known limitations.
Co-authored-by: Bo Chen <bchen@crusoe.ai>
Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>
TDX homepage was moved to elsewhere, and `sgx` support is upstreamed
since v5.11 kernel.
Format `intel_sgx.md` using `mdformat` with GitHub Flavored Markdown
(GFM).
Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>
TDX homepage was moved to elsewhere, and `tdx-tools` repo was removed.
Provide a valid link of TDX homepage and change all reference to
`tdx-tools` to `tdx-linux`.
Format `intel_tdx.md` using `mdformat` with GitHub Flavored Markdown
(GFM).
Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>
There is a link referencing `rate-limiter` module of `firecracker`, but
that module no longer exsits.
Point the link to a commit with the same date in `firecracker` when this
commit was merged to `cloud-hypervisor`.
Format `io_throttling.md` using `mdformat` with GitHub Flavored Markdown
(GFM).
Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>
Previous link `docs/logging` is not valid, replacing `docs/logging` with
`docs/logging.md`.
Format `logging.md` using `mdformat` with GitHub Flavored Markdown
(GFM).
Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>
Updated the live migration documentation to include instructions for
performing cross-host live migrations over TCP connections.
Signed-off-by: Jinrong Liang <cloudliang@tencent.com>
The previous docs were very developer centric and have led several
people to believe that cross-machine migration is not supported at
all.
Signed-off-by: Julian Stecklina <julian.stecklina@cyberus-technology.de>
I've added newlines between paragraphs and code blocks for easier
reading. I've also changed the code blocks to use the correct
highlighting.
Signed-off-by: Julian Stecklina <julian.stecklina@cyberus-technology.de>
