From: "Marek Marczykowski-Górecki" <marmarek@invisiblethingslab.com>
To: James Dingwall <james@dingwall.me.uk>
Cc: xen-devel@lists.xen.org,
"Andrew Cooper" <andrew.cooper3@citrix.com>,
"Jan Beulich" <jbeulich@suse.com>,
"Roger Pau Monné" <roger.pau@citrix.com>,
"security@xenproject.org" <security@xenproject.org>
Subject: Re: stable-4.18: reliably crash network driver domain by squeezing free_memory
Date: Mon, 2 Dec 2024 20:08:27 +0100 [thread overview]
Message-ID: <Z04Fq1dXfIim_A8u@mail-itl> (raw)
In-Reply-To: <Z03YL1KHwE1fO98g@dingwall.me.uk>
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On Mon, Dec 02, 2024 at 03:54:23PM +0000, James Dingwall wrote:
> So there is some undefined range for (free_memory - m) to (free_memory - n)
> where it is possible to crash the driver domain depending on the guest
> startup ordering. My (perhaps naive) reasoning would be that
> free_memory is the resource available to safely assign without having to
> allow for some unknown overhead and if I do ask for too much then I
> get a 'safe' failure.
FWIW Qubes OS tries to always keep at least 50MB free for Xen. So, our
formula is (free_memory - 50MB).
--
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab
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next prev parent reply other threads:[~2024-12-02 19:08 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-28 15:31 stable-4.18: reliably crash network driver domain by squeezing free_memory James Dingwall
2024-11-28 15:39 ` Andrew Cooper
2024-12-02 15:54 ` James Dingwall
2024-12-02 19:08 ` Marek Marczykowski-Górecki [this message]
2024-12-03 8:20 ` Jan Beulich
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