From: Mykola Kvach <mykola_kvach@epam.com>

Add a new entry under the "Virtual Hardware, QEMU" section documenting
support for the optional PSCI SYSTEM_SUSPEND function exposed to guests.

This function is available via the virtual PSCI (vPSCI) interface and
allows guest domains (domUs) to initiate system suspend operations.

The feature is currently marked as Experimental.

Signed-off-by: Mykola Kvach <mykola_kvach@epam.com>
---
Changes in v6:
- Dropped the generic guest PSCI support entry (merged in a separate patch)
- This patch now documents only the SYSTEM_SUSPEND optional function
- Reworded commit message to match the final form after rebase

Changes in v5:
- Dropped ARM/PSCI entry: this refers to internal use of PSCI SMC calls,
  which is not relevant for SUPPORT.md
- Added a dedicated entry for PSCI SYSTEM_SUSPEND instead of generic guest
  PSCI info; guest PSCI support was documented in a separate patch
---
 SUPPORT.md | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/SUPPORT.md b/SUPPORT.md
index 6a82a92189..b5ab049b52 100644
--- a/SUPPORT.md
+++ b/SUPPORT.md
@@ -962,8 +962,9 @@ Emulated PSCI interface exposed to guests. We support all mandatory
 functions of PSCI 1.1. See below for the list of optional PSCI call
 implemented and their status.
 
-   Status, Mandatory: Supported
-   Status, MIGRATE_INFO_TYPE: Supported
+    Status, Mandatory: Supported
+    Status, MIGRATE_INFO_TYPE: Supported
+    Status, SYSTEM_SUSPEND: Experimental
 
 ## Virtual Hardware, QEMU
 
-- 
2.48.1

Hi Mykola,

On 18/08/2025 09:49, Mykola Kvach wrote:
> From: Mykola Kvach <mykola_kvach@epam.com>
> 
> Add a new entry under the "Virtual Hardware, QEMU" section documenting
> support for the optional PSCI SYSTEM_SUSPEND function exposed to guests.
> 
> This function is available via the virtual PSCI (vPSCI) interface and
> allows guest domains (domUs) to initiate system suspend operations.
> 
> The feature is currently marked as Experimental.
> 
> Signed-off-by: Mykola Kvach <mykola_kvach@epam.com>
> ---
> Changes in v6:
> - Dropped the generic guest PSCI support entry (merged in a separate patch)
> - This patch now documents only the SYSTEM_SUSPEND optional function
> - Reworded commit message to match the final form after rebase
> 
> Changes in v5:
> - Dropped ARM/PSCI entry: this refers to internal use of PSCI SMC calls,
>    which is not relevant for SUPPORT.md
> - Added a dedicated entry for PSCI SYSTEM_SUSPEND instead of generic guest
>    PSCI info; guest PSCI support was documented in a separate patch
> ---
>   SUPPORT.md | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/SUPPORT.md b/SUPPORT.md
> index 6a82a92189..b5ab049b52 100644
> --- a/SUPPORT.md
> +++ b/SUPPORT.md
> @@ -962,8 +962,9 @@ Emulated PSCI interface exposed to guests. We support all mandatory
>   functions of PSCI 1.1. See below for the list of optional PSCI call
>   implemented and their status.
>   
> -   Status, Mandatory: Supported
> -   Status, MIGRATE_INFO_TYPE: Supported
> +    Status, Mandatory: Supported
> +    Status, MIGRATE_INFO_TYPE: Supported
> +    Status, SYSTEM_SUSPEND: Experimental

Experimental implies the feature is not complete. But it is unclear to 
me what is missing (or I probably forgotten). Can this be clarified in 
the commit message?

If there is nothing, then I think it can be a tech preview.

Cheers,

-- 
Julien Grall

Hi Julien,

On Sun, Aug 24, 2025 at 12:31 AM Julien Grall <julien@xen.org> wrote:
>
> Hi Mykola,
>
> On 18/08/2025 09:49, Mykola Kvach wrote:
> > From: Mykola Kvach <mykola_kvach@epam.com>
> >
> > Add a new entry under the "Virtual Hardware, QEMU" section documenting
> > support for the optional PSCI SYSTEM_SUSPEND function exposed to guests.
> >
> > This function is available via the virtual PSCI (vPSCI) interface and
> > allows guest domains (domUs) to initiate system suspend operations.
> >
> > The feature is currently marked as Experimental.
> >
> > Signed-off-by: Mykola Kvach <mykola_kvach@epam.com>
> > ---
> > Changes in v6:
> > - Dropped the generic guest PSCI support entry (merged in a separate patch)
> > - This patch now documents only the SYSTEM_SUSPEND optional function
> > - Reworded commit message to match the final form after rebase
> >
> > Changes in v5:
> > - Dropped ARM/PSCI entry: this refers to internal use of PSCI SMC calls,
> >    which is not relevant for SUPPORT.md
> > - Added a dedicated entry for PSCI SYSTEM_SUSPEND instead of generic guest
> >    PSCI info; guest PSCI support was documented in a separate patch
> > ---
> >   SUPPORT.md | 5 +++--
> >   1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/SUPPORT.md b/SUPPORT.md
> > index 6a82a92189..b5ab049b52 100644
> > --- a/SUPPORT.md
> > +++ b/SUPPORT.md
> > @@ -962,8 +962,9 @@ Emulated PSCI interface exposed to guests. We support all mandatory
> >   functions of PSCI 1.1. See below for the list of optional PSCI call
> >   implemented and their status.
> >
> > -   Status, Mandatory: Supported
> > -   Status, MIGRATE_INFO_TYPE: Supported
> > +    Status, Mandatory: Supported
> > +    Status, MIGRATE_INFO_TYPE: Supported
> > +    Status, SYSTEM_SUSPEND: Experimental
>
> Experimental implies the feature is not complete. But it is unclear to
> me what is missing (or I probably forgotten). Can this be clarified in
> the commit message?
>
> If there is nothing, then I think it can be a tech preview.

I initially thought that we would need to add a "xl suspend" command
in order to allow suspending another domain via the control/hardware
domain. However, after your question I reconsidered it and realized
that this functionality is not directly related to vPSCI, but rather
to Xen system suspend support.

So, I will change it to "Tech Preview" as you proposed. Thank you!

>
> Cheers,
>
> --
> Julien Grall
>

Best regards,
Mykola