David Woodhouse
97413cea1c
The PSCI v1.3 specification adds support for a SYSTEM_OFF2 function which is analogous to ACPI S4 state. This will allow hosting environments to determine that a guest is hibernated rather than just powered off, and ensure that they preserve the virtual environment appropriately to allow the guest to resume safely (or bump the hardware_signature in the FACS to trigger a clean reboot instead). This feature is safe to enable unconditionally (in a subsequent commit) because it is exposed to userspace through the existing KVM_SYSTEM_EVENT_SHUTDOWN event, just with an additional flag which userspace can use to know that the instance intended hibernation instead of a plain power-off. As with SYSTEM_RESET2, there is only one type available (in this case HIBERNATE_OFF), and it is not explicitly reported to userspace through the event; userspace can get it from the registers if it cares). Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Miguel Luis <miguel.luis@oracle.com> Link: https://lore.kernel.org/r/20241019172459.2241939-3-dwmw2@infradead.org [oliver: slight cleanup of comments] Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.