From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
To: Andrew Cooper <andrew.cooper3@citrix.com>,
David Vrabel <david.vrabel@citrix.com>,
konrad.wilk@oracle.com
Cc: xen-devel@lists.xenproject.org, mcgrof@kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [Xen-devel] [PATCH] xen/x86: Zero out .bss for PV guests
Date: Wed, 24 Feb 2016 09:52:11 -0500 [thread overview]
Message-ID: <56CDC39B.3060004@oracle.com> (raw)
In-Reply-To: <56CDBB0F.9000203@citrix.com>
On 02/24/2016 09:15 AM, Andrew Cooper wrote:
> On 24/02/16 14:12, David Vrabel wrote:
>> On 22/02/16 22:06, Boris Ostrovsky wrote:
>>> Baremetal kernels clear .bss early in the boot. Since Xen PV guests don't
>>> excecute that early code they should do it too.
>>>
>>> (Since we introduce macros for specifying 32- and 64-bit registers we
>>> can get rid of ifdefs in startup_xen())
>> .bss must have been cleared for PV guests otherwise they would be
>> horribly broken. What was the method and why is it no longer sufficient?
I couldn't find this being done anywhere, hence this patch.
> The domain builder hands out zeroed pages. I don't believe we guarantee
> that the guests RAM is clean, but it is in practice.
OK, that's what I suspected but didn't actually look.
I, in fact, wonder whether this should go to stable trees as well.
-boris
next prev parent reply other threads:[~2016-02-24 14:52 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-22 22:06 [PATCH] xen/x86: Zero out .bss for PV guests Boris Ostrovsky
2016-02-24 14:12 ` [Xen-devel] " David Vrabel
2016-02-24 14:15 ` Andrew Cooper
2016-02-24 14:52 ` Boris Ostrovsky [this message]
2016-02-24 14:58 ` David Vrabel
2016-02-24 16:22 ` Luis R. Rodriguez
2016-02-24 16:46 ` Boris Ostrovsky
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