Re: [Qemu-devel] [RFC] sanitize memory on system reset

2013-06-17 Thread Peter Lieven
Am 14.06.2013 15:43, schrieb Paolo Bonzini: Il 14/06/2013 05:44, Alexander Graf ha scritto: Legacy 286 protected mode to real mode switching also happens through the CPU reset PIN, so there certainly is a need to distinguish. That's a separate thing because devices aren't reset at all---not

Re: [Qemu-devel] [RFC] sanitize memory on system reset

2013-06-14 Thread Christian Borntraeger
On 13/06/13 13:56, Anthony Liguori wrote: Markus Armbruster arm...@redhat.com writes: Peter Lieven p...@kamp.de writes: On 13.06.2013 10:40, Stefan Hajnoczi wrote: On Thu, Jun 13, 2013 at 08:09:09AM +0200, Peter Lieven wrote: I was thinking if it would be a good idea to zeroize all memory

Re: [Qemu-devel] [RFC] sanitize memory on system reset

2013-06-14 Thread Alexander Graf
Am 14.06.2013 um 08:56 schrieb Christian Borntraeger borntrae...@de.ibm.com: On 13/06/13 13:56, Anthony Liguori wrote: Markus Armbruster arm...@redhat.com writes: Peter Lieven p...@kamp.de writes: On 13.06.2013 10:40, Stefan Hajnoczi wrote: On Thu, Jun 13, 2013 at 08:09:09AM +0200,

Re: [Qemu-devel] [RFC] sanitize memory on system reset

2013-06-14 Thread Stefan Hajnoczi
On Thu, Jun 13, 2013 at 10:46:39AM +0200, Peter Lieven wrote: On 13.06.2013 10:40, Stefan Hajnoczi wrote: On Thu, Jun 13, 2013 at 08:09:09AM +0200, Peter Lieven wrote: I was thinking if it would be a good idea to zeroize all memory resources on system reset and madvise dontneed them

Re: [Qemu-devel] [RFC] sanitize memory on system reset

2013-06-14 Thread Paolo Bonzini
Il 14/06/2013 05:44, Alexander Graf ha scritto: Legacy 286 protected mode to real mode switching also happens through the CPU reset PIN, so there certainly is a need to distinguish. That's a separate thing because devices aren't reset at all---not just memory. I have pending patches for that,

Re: [Qemu-devel] [RFC] sanitize memory on system reset

2013-06-14 Thread H. Peter Anvin
Only on a real 286. At least since 486 the legacy switch has been INIT, not RESET. Alexander Graf ag...@suse.de wrote: Am 14.06.2013 um 08:56 schrieb Christian Borntraeger borntrae...@de.ibm.com: On 13/06/13 13:56, Anthony Liguori wrote: Markus Armbruster arm...@redhat.com writes:

[Qemu-devel] [RFC] sanitize memory on system reset

2013-06-13 Thread Peter Lieven
Hi, I was thinking if it would be a good idea to zeroize all memory resources on system reset and madvise dontneed them afterwards. This would avoid system reset attacks in case the attacker has only access to the console of a vServer but not on the physical host and it would shrink RSS size

Re: [Qemu-devel] [RFC] sanitize memory on system reset

2013-06-13 Thread Stefan Hajnoczi
On Thu, Jun 13, 2013 at 08:09:09AM +0200, Peter Lieven wrote: I was thinking if it would be a good idea to zeroize all memory resources on system reset and madvise dontneed them afterwards. This would avoid system reset attacks in case the attacker has only access to the console of a

Re: [Qemu-devel] [RFC] sanitize memory on system reset

2013-06-13 Thread Peter Lieven
On 13.06.2013 10:40, Stefan Hajnoczi wrote: On Thu, Jun 13, 2013 at 08:09:09AM +0200, Peter Lieven wrote: I was thinking if it would be a good idea to zeroize all memory resources on system reset and madvise dontneed them afterwards. This would avoid system reset attacks in case the attacker

Re: [Qemu-devel] [RFC] sanitize memory on system reset

2013-06-13 Thread Peter Lieven
On 13.06.2013 10:40, Stefan Hajnoczi wrote: On Thu, Jun 13, 2013 at 08:09:09AM +0200, Peter Lieven wrote: I was thinking if it would be a good idea to zeroize all memory resources on system reset and madvise dontneed them afterwards. This would avoid system reset attacks in case the attacker

Re: [Qemu-devel] [RFC] sanitize memory on system reset

2013-06-13 Thread Andreas Färber
Hi, Am 13.06.2013 08:09, schrieb Peter Lieven: I was thinking if it would be a good idea to zeroize all memory resources on system reset and madvise dontneed them afterwards. The current way of not zeroing memory has led to discovery of some firmware bugs that we wouldn't have found if QEMU

Re: [Qemu-devel] [RFC] sanitize memory on system reset

2013-06-13 Thread Peter Lieven
On 13.06.2013 11:22, Andreas Färber wrote: Hi, Am 13.06.2013 08:09, schrieb Peter Lieven: I was thinking if it would be a good idea to zeroize all memory resources on system reset and madvise dontneed them afterwards. The current way of not zeroing memory has led to discovery of some firmware

Re: [Qemu-devel] [RFC] sanitize memory on system reset

2013-06-13 Thread Markus Armbruster
Peter Lieven p...@kamp.de writes: On 13.06.2013 10:40, Stefan Hajnoczi wrote: On Thu, Jun 13, 2013 at 08:09:09AM +0200, Peter Lieven wrote: I was thinking if it would be a good idea to zeroize all memory resources on system reset and madvise dontneed them afterwards. This would avoid system

Re: [Qemu-devel] [RFC] sanitize memory on system reset

2013-06-13 Thread Anthony Liguori
Markus Armbruster arm...@redhat.com writes: Peter Lieven p...@kamp.de writes: On 13.06.2013 10:40, Stefan Hajnoczi wrote: On Thu, Jun 13, 2013 at 08:09:09AM +0200, Peter Lieven wrote: I was thinking if it would be a good idea to zeroize all memory resources on system reset and madvise

Re: [Qemu-devel] [RFC] sanitize memory on system reset

2013-06-13 Thread Paolo Bonzini
Il 13/06/2013 07:56, Anthony Liguori ha scritto: Markus Armbruster arm...@redhat.com writes: Peter Lieven p...@kamp.de writes: On 13.06.2013 10:40, Stefan Hajnoczi wrote: On Thu, Jun 13, 2013 at 08:09:09AM +0200, Peter Lieven wrote: I was thinking if it would be a good idea to zeroize all

Re: [Qemu-devel] [RFC] sanitize memory on system reset

2013-06-13 Thread Peter Lieven
On 13.06.2013 12:55, Markus Armbruster wrote: Peter Lieven p...@kamp.de writes: On 13.06.2013 10:40, Stefan Hajnoczi wrote: On Thu, Jun 13, 2013 at 08:09:09AM +0200, Peter Lieven wrote: I was thinking if it would be a good idea to zeroize all memory resources on system reset and madvise

Re: [Qemu-devel] [RFC] sanitize memory on system reset

2013-06-13 Thread Markus Armbruster
Peter Lieven p...@kamp.de writes: On 13.06.2013 12:55, Markus Armbruster wrote: Peter Lieven p...@kamp.de writes: On 13.06.2013 10:40, Stefan Hajnoczi wrote: On Thu, Jun 13, 2013 at 08:09:09AM +0200, Peter Lieven wrote: I was thinking if it would be a good idea to zeroize all memory

Re: [Qemu-devel] [RFC] sanitize memory on system reset

2013-06-13 Thread Peter Lieven
Am 13.06.2013 um 17:51 schrieb Markus Armbruster arm...@redhat.com: Peter Lieven p...@kamp.de writes: On 13.06.2013 12:55, Markus Armbruster wrote: Peter Lieven p...@kamp.de writes: On 13.06.2013 10:40, Stefan Hajnoczi wrote: On Thu, Jun 13, 2013 at 08:09:09AM +0200, Peter Lieven wrote: