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Date:   Mon, 20 Jul 2020 11:37:05 +0200
From:   Roger Pau =?utf-8?B?TW9ubsOp?= <roger.pau@citrix.com>
To:     Boris Ostrovsky <boris.ostrovsky@oracle.com>
CC:     Anchal Agarwal <anchalag@amazon.com>, <tglx@linutronix.de>,
        <mingo@redhat.com>, <bp@alien8.de>, <hpa@zytor.com>,
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        <linux-mm@kvack.org>, <kamatam@amazon.com>,
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Subject: Re: [PATCH v2 01/11] xen/manage: keep track of the on-going suspend
 mode
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On Sat, Jul 18, 2020 at 09:47:04PM -0400, Boris Ostrovsky wrote:
> (Roger, question for you at the very end)
> 
> On 7/17/20 3:10 PM, Anchal Agarwal wrote:
> > On Wed, Jul 15, 2020 at 05:18:08PM -0400, Boris Ostrovsky wrote:
> >> CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you can confirm the sender and know the content is safe.
> >>
> >>
> >>
> >> 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 not click links or open attachments unless you can confirm the sender and know the content is safe.
> >>>>
> >>>>
> >>>>
> >>>> On 7/2/20 2:21 PM, Anchal Agarwal wrote:
> >>>> 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 itself
> >>> (PVH Dom0) is very new.
> >>
> >> Same question here --- will this break PVH dom0?
> >>
> > I haven't tested it as a part of this series. Is that a blocker here?
> 
> 
> I suspect dom0 will not do well now as far as hibernation goes, in which
> case you are not breaking anything.
> 
> 
> Roger?

I sadly don't have any box ATM that supports hibernation where I
could test it. We have hibernation support for PV dom0, so while I
haven't done anything specific to support or test hibernation on PVH
dom0 I would at least aim to not make this any worse, and hence the
check should at least also fail for a PVH dom0?

if (!xen_hvm_domain() || xen_initial_domain())
    return -ENODEV;

Ie: none of this should be applied to a PVH dom0, as it doesn't have
PV devices and hence should follow the bare metal device suspend.

Also I would contact the QubesOS guys, they rely heavily on the
suspend feature for dom0, and that's something not currently tested by
osstest so any breakages there go unnoticed.

Thanks, Roger.