On Tue, 2024-03-12 at 08:47 -0700, Oliver Upton wrote: > Hi, > > On Tue, Mar 12, 2024 at 01:51:28PM +0000, David Woodhouse wrote: > > From: David Woodhouse <dwmw@xxxxxxxxxxxx> > > > > The PSCI v1.3 specification (alpha) 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). > > > > The beta version will be changed to say that PSCI_FEATURES returns a bit > > mask of the supported hibernate types, which is implemented here. > > Have you considered doing the PSCI implementation in userspace? The > SMCCC filter [*] was added for this exact purpose. > For the purpose of deprecating the in-KVM PSCI implementation and reimplementing it in VMMs? So we're never going to add new features and versions to the kernel PSCI? If that's the case then I suppose I can send the patch to clearly document the in-KVM PSCI as deprecated, and do it that way. But to answer your question directly, no I hadn't considered that. I was just following the existing precedent of adding new optional PSCI features like SYSTEM_RESET2. I didn't think that the addition of SYSTEM_OFF2 in precisely the same fashion would be the straw that broke the camel's back, and pushed us to reimplement it in userspace instead.
Attachment:
smime.p7s
Description: S/MIME cryptographic signature
