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From: "Colm MacCárthaigh" <colmmacc@amazon.com>
To: Jann Horn <jannh@google.com>
Cc: "Catangiu, Adrian Costin" <acatan@amazon.com>,
	<linux-mm@kvack.org>, <linux-pm@vger.kernel.org>,
	<virtualization@lists.linux-foundation.org>,
	<linux-api@vger.kernel.org>, <akpm@linux-foundation.org>,
	<rjw@rjwysocki.net>, <len.brown@intel.com>, <pavel@ucw.cz>,
	<mhocko@kernel.org>, <fweimer@redhat.com>,
	<keescook@chromium.org>, <luto@amacapital.net>,
	<wad@chromium.org>, <mingo@kernel.org>, <bonzini@gnu.org>,
	"Graf (AWS), Alexander" <graf@amazon.de>,
	"Singh, Balbir" <sblbir@amazon.com>,
	"Sandu, Andrei" <sandreim@amazon.com>,
	"Brooker, Marc" <mbrooker@amazon.com>,
	"Weiss, Radu" <raduweis@amazon.com>,
	"Manwaring, Derek" <derekmn@amazon.com>
Subject: Re: [RFC]: mm,power: introduce MADV_WIPEONSUSPEND
Date: Fri, 3 Jul 2020 18:33:05 -0700	[thread overview]
Message-ID: <5E780027-A6A7-4ED3-AA76-16C2036FF8D4@amazon.com> (raw)
In-Reply-To: <CAG48ez2CpHX9i3YgkNyMHPz63ohjkaSZscMtwSHOFYN4VQow3Q@mail.gmail.com>



On 3 Jul 2020, at 4:04, Jann Horn wrote:

>>  - Provides a simple mechanism to avoid RAM exfiltration during
>>    traditional sleep/hibernate on a laptop or desktop when memory,
>>    and thus secrets, are vulnerable to offline tampering or 
>> inspection.
>
> For the first usecase, I wonder which way around this would work
> better - do the wiping when a VM is saved, or do it when the VM is
> restored? I guess that at least in some scenarios, doing it on restore
> would be nicer because that way the hypervisor can always instantly
> save a VM without having to wait for the guest to say "alright, I'm
> ready" - especially if someone e.g. wants to take a snapshot of a
> running VM while keeping it running? Or do hypervisors inject such
> ACPI transitions every time they snapshot/save/restore a VM anyway?


Just to answer this - I’d expect wipe-after-save rather than 
wipe-on-restore to be common for some. That provides the most defense 
against secrets ending up on disk or some other durable medium when the 
VM images are being saved.

-
Colm

  reply	other threads:[~2020-07-04  1:33 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-03 10:34 [RFC]: mm,power: introduce MADV_WIPEONSUSPEND Catangiu, Adrian Costin
2020-07-03 11:04 ` Jann Horn
2020-07-04  1:33   ` Colm MacCárthaigh [this message]
2020-07-06 12:09   ` Alexander Graf
2020-07-03 11:30 ` Michal Hocko
2020-07-03 12:17   ` Rafael J. Wysocki
2020-07-03 22:39     ` Pavel Machek
2020-07-03 13:29   ` Jann Horn
2020-07-03 22:34     ` Pavel Machek
2020-07-03 22:53       ` Jann Horn
2020-07-07  7:38     ` Michal Hocko
2020-07-07  8:07       ` Pavel Machek
2020-07-07  8:58         ` Michal Hocko
2020-07-07 16:37           ` Pavel Machek
     [not found]             ` <E6B41570-E206-4458-921B-465B9EF74949@amazon.com>
2020-07-12  7:22               ` Pavel Machek
2020-07-13  8:02                 ` Michal Hocko
2020-07-04  1:45   ` Colm MacCárthaigh
2020-07-07  7:40     ` Michal Hocko
2020-07-03 22:44 ` Pavel Machek
2020-07-03 22:56   ` Jann Horn
2020-07-04 11:48     ` Pavel Machek
2020-07-06 12:26       ` Alexander Graf
2020-07-06 12:52         ` Jann Horn
2020-07-06 13:14           ` Alexander Graf
2020-07-07  7:44           ` Michal Hocko
2020-07-07  8:01             ` Alexander Graf
2020-07-07  9:14               ` Michal Hocko

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