lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20120229100550.GF24600@redhat.com>
Date:	Wed, 29 Feb 2012 12:05:50 +0200
From:	Gleb Natapov <gleb@...hat.com>
To:	Avi Kivity <avi@...hat.com>
Cc:	Wen Congyang <wency@...fujitsu.com>,
	kvm list <kvm@...r.kernel.org>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	"Daniel P. Berrange" <berrange@...hat.com>,
	linux-kernel@...r.kernel.org, qemu-devel <qemu-devel@...gnu.org>
Subject: Re: [PATCH] kvm: notify host when guest paniced

On Wed, Feb 29, 2012 at 12:00:41PM +0200, Avi Kivity wrote:
> On 02/29/2012 11:55 AM, Gleb Natapov wrote:
> > > >
> > > 
> > > How about using a virtio-serial channel for this?  You can transfer any
> > > amount of information (including the dump itself).
> > > 
> > Isn't it unreliable after the guest panicked? 
> 
> So is calling hypercalls, or dumping, or writing to the screen.  Of
> course calling a hypercall is simpler and so is more reliable.
> 
Yes, crash can be so severe that it is not even detected by a kernel
itself, so not OOPS message even printed. But in most cases if kernel is
functional enough to print OOPS it is functional enough to call single
hypercall instruction.

> > Having special kdump
> > kernel that transfers dump to a host via virtio-serial channel though
> > sounds interesting. May be that's what you mean.
> 
> Yes.  The "panic, starting dump" signal should be initiated by the
> panicking kernel though, in case the dump fails.
> 
Then panic hypercall sounds like a reasonable solution.

--
			Gleb.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ