linux-kernel - Re: [PATCH 3/3] KVM: PPC: Book3S: Add support for hwrng found on some powernv systems

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]

Date:	Thu, 03 Oct 2013 08:07:22 +1000
From:	Benjamin Herrenschmidt <benh@...nel.crashing.org>
To:	Gleb Natapov <gleb@...hat.com>
Cc:	Alexander Graf <agraf@...e.de>,
	Paolo Bonzini <pbonzini@...hat.com>,
	Paul Mackerras <paulus@...ba.org>,
	Michael Ellerman <michael@...erman.id.au>,
	linux-kernel@...r.kernel.org, mpm@...enic.com,
	herbert@...dor.hengli.com.au, linuxppc-dev@...abs.org,
	kvm@...r.kernel.org, kvm-ppc@...r.kernel.org, tytso@....edu
Subject: Re: [PATCH 3/3] KVM: PPC: Book3S: Add support for hwrng found on
 some powernv systems

On Wed, 2013-10-02 at 13:02 +0300, Gleb Natapov wrote:

> Yes, I alluded to it in my email to Paul and Paolo asked also. How this
> interface is disabled? Also hwrnd is MMIO in a host why guest needs to
> use hypercall instead of emulating the device (in kernel or somewhere
> else?). Another things is that on a host hwrnd is protected from
> direct userspace access by virtue of been a device, but guest code (event
> kernel mode) is userspace as far as hosts security model goes, so by
> implementing this hypercall in a way that directly access hwrnd you
> expose hwrnd to a userspace unconditionally. Why is this a good idea? 

BTW. Is this always going to be like this ?

Every *single* architectural or design decision we make for our
architecture has to be justified 30 times over, every piece of code bike
shedded to oblivion for month, etc... ?

Do we always have to finally get to some kind of agreement on design, go
to the 6 month bike-shedding phase, just to have somebody else come up
and start re-questioning the whole original design (without any
understanding of our specific constraints of course) ?

You guys are the most horrendous community I have ever got to work with.
It's simply impossible to get anything done in any reasonable time
frame .

At this stage, it would have taken us an order of magnitude less time to
simply rewrite an entire hypervisor from scratch.

This is sad.

Ben.

--
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/