Daniel Henrique Barboza <danie...@linux.ibm.com> writes: > On 05/15/2018 12:35 PM, Markus Armbruster wrote: >> Daniel Henrique Barboza <danie...@linux.ibm.com> writes: >> >>> This patch updates the descriptions of 'guest-suspend-ram' and >>> 'guest-suspend-hybrid' to mention that both commands relies now >>> on the existence of 'system_wakeup' and also on the proper support >>> for wake up from suspend, retrieved by the 'wakeup-suspend-support' >>> attribute of the 'query-target' QMP command. >>> >>> Reported-by: Balamuruhan S <bal...@linux.vnet.ibm.com> >>> Signed-off-by: Daniel Henrique Barboza <danie...@linux.ibm.com> >>> Reviewed-by: Michael Roth <mdr...@linux.vnet.ibm.com> >>> --- >>> qga/qapi-schema.json | 14 ++++++++++---- >>> 1 file changed, 10 insertions(+), 4 deletions(-) >>> >>> diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json >>> index 17884c7c70..e3fb8adfce 100644 >>> --- a/qga/qapi-schema.json >>> +++ b/qga/qapi-schema.json >>> @@ -566,8 +566,11 @@ >>> # package installed in the guest. >>> # >>> # IMPORTANT: guest-suspend-ram requires QEMU to support the >>> 'system_wakeup' >>> -# command. Thus, it's *required* to query QEMU for the presence of the >>> -# 'system_wakeup' command before issuing guest-suspend-ram. >>> +# command and the guest to support wake up from suspend. Thus, it's >>> +# *required* to query QEMU for the presence of the 'system_wakeup' command >>> +# and to verify that wake up from suspend is enabled by checking the >>> +# 'wakeup-suspend-support' flag of 'query-target' QMP command, before >>> issuing >>> +# guest-suspend-ram. >> Isn't checking for presence of system_wakeup redundant? >> >> When query-target tells us "system_wakeup works" by returning >> wakeup-suspend-support: true, we surely have system_wakeup (or else >> query-target would be lying to us). >> >> When it returns wakeup-suspend-support: false, it doesn't matter whether >> we have system_wakeup. >> >> Unless I'm wrong, we can simplify this to something like >> >> # IMPORTANT: guest-suspend-ram requires working wakeup support in >> # QEMU. You *must* check QMP command query-target returns >> # wakeup-suspend-support: true before issuing this command. > > It is worth noticing that this API isn't checking for the existence of > system_wakeup. It is checking whether there are notifiers added in > the wakeup_notifiers QLIST. > > However, I think we can simplify the text as you suggested because that > part seems outdated anyway. Is there any relevant scenario where > system_wakeup will not be present?
I doubt it: we have system_wakeup since 1.1, and we've even backported it to RHEL-6. But even if there *was* a relevant scenario involving a QEMU that doesn't provide system_wakeup, that QEMU will also not provide member wakeup-suspend-support, let alone tell us wakeup-suspend-support: true, unless somebody set out to break things on purpose. That somebody would get to keep the pieces then.
