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Subject: Re: [PATCH v2 01/11] xen/manage: keep track of the on-going suspend
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To:     Anchal Agarwal <anchalag@amazon.com>
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From:   Boris Ostrovsky <boris.ostrovsky@oracle.com>
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Date:   Wed, 15 Jul 2020 17:18:08 -0400
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On 7/15/20 4:49 PM, Anchal Agarwal wrote:
> On Mon, Jul 13, 2020 at 11:52:01AM -0400, Boris Ostrovsky wrote:
>> CAUTION: This email originated from outside of the organization. Do no=
t click links or open attachments unless you can confirm the sender and k=
now the content is safe.
>>
>>
>>
>> On 7/2/20 2:21 PM, Anchal Agarwal wrote:
>>> +
>>> +bool xen_is_xen_suspend(void)
>>
>> Weren't you going to call this pv suspend? (And also --- is this suspe=
nd
>> or hibernation? Your commit messages and cover letter talk about fixin=
g
>> hibernation).
>>
>>
> This is for hibernation is for pvhvm/hvm/pv-on-hvm guests as you may ca=
ll it.
> The method is just there to check if "xen suspend" is in progress.
> I do not see "xen_suspend" differentiating between pv or hvm
> domain until later in the code hence, I abstracted it to xen_is_xen_sus=
pend.


I meant "pv suspend" in the sense that this is paravirtual suspend, not
suspend for paravirtual guests. Just like pv drivers are for both pv and
hvm guests.


And then --- should it be pv suspend or pv hibernation?


>>> +{
>>> +     return suspend_mode =3D=3D XEN_SUSPEND;
>>> +}
>>> +
>>
>> +static int xen_setup_pm_notifier(void)
>> +{
>> +     if (!xen_hvm_domain())
>> +             return -ENODEV;
>>
>> I forgot --- what did we decide about non-x86 (i.e. ARM)?
> It would be great to support that however, its  out of
> scope for this patch set.
> I=E2=80=99ll be happy to discuss it separately.


I wasn't implying that this *should* work on ARM but rather whether this
will break ARM somehow (because xen_hvm_domain() is true there).


>>
>> And PVH dom0.
> That's another good use case to make it work with however, I still
> think that should be tested/worked upon separately as the feature itsel=
f
> (PVH Dom0) is very new.


Same question here --- will this break PVH dom0?


-boris