From: Markus Armbruster <armbru@redhat.com>
To: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>, avi@redhat.com, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH] memory: add -dont-dump-guest option to reduce core dump size
Date: Fri, 06 Jul 2012 07:11:04 +0200 [thread overview]
Message-ID: <m3ipe1tqxj.fsf@blackfin.pond.sub.org> (raw)
In-Reply-To: <20120706000418.GB7150@amt.cnet> (Marcelo Tosatti's message of "Thu, 5 Jul 2012 21:04:18 -0300")
Marcelo Tosatti <mtosatti@redhat.com> writes:
> On Mon, May 21, 2012 at 01:53:36PM -0400, Jason Baron wrote:
>> On Fri, May 04, 2012 at 05:23:51PM -0400, Jason Baron wrote:
>> > Add a command line parameter to not dump guest memory in the core dump, the
>> > command line is: -dont-dump-guest. This brought the core dump down from
>> > 383MB to 13 MB on a 1GB guest.
>> >
>> > Signed-off-by: Jason Baron <jbaron@redhat.com>
>> > ---
>> > exec.c | 13 +++++++++++++
>> > osdep.h | 7 +++++++
>> > qemu-options.hx | 5 +++++
>> > sysemu.h | 1 +
>> > vl.c | 4 ++++
>> > 5 files changed, 30 insertions(+), 0 deletions(-)
>> >
>>
>> Any thoughts on this? Is the guest memory often helpful in debugging
>> when the qemu process segfaults?
>
> For most development related usage, no (with large guests, its
> troublesome).
>
> Please add documentation for the command (patch looks fine otherwise).
>
>> This feature also seems useful if somebody is running a sensitive
>> workload, such that the non-sensitive qemu state can be dumped
>> independently of the guest state. In that case, perhaps there should
I wouldn't make claims related to guest data confidentiality, because
sensitive stuff could conceivably leak from guest RAM (not dumped) into
device model state (dumped).
>> also be an option that allows the guest to be dumped on a segfault, now
>> separately?
>
> Isnt what this option does? (well, disabling it).
It seems there could be more knobs to control than just "dump guest
state yes/no". Therefore, extensible command line syntax like
"--core-dump guest-ram=off" seems to be advisable. We have too many
-dont-do-FOO options already.
next prev parent reply other threads:[~2012-07-06 5:11 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-04 21:23 [Qemu-devel] [PATCH] memory: add -dont-dump-guest option to reduce core dump size Jason Baron
2012-05-21 17:53 ` Jason Baron
2012-07-06 0:04 ` Marcelo Tosatti
2012-07-06 5:11 ` Markus Armbruster [this message]
2012-07-11 14:14 ` Avi Kivity
2012-07-06 20:26 ` Jason Baron
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