From mboxrd@z Thu Jan 1 00:00:00 1970 From: Theodore Ts'o Subject: Re: Standardizing an MSR or other hypercall to get an RNG seed? Date: Fri, 19 Sep 2014 19:35:02 -0400 Message-ID: <20140919233502.GV26995@thunk.org> References: <541C5C8A.6030304@zytor.com> <20140919220537.GR26995@thunk.org> <20140919225727.GT26995@thunk.org> <541CBC71.6050707@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Mathew John , kvm list , Gleb Natapov , Niels Ferguson , Andy Lutomirski , David Hepkin , Jake Oshins , Paolo Bonzini , Linux Virtualization , John Starks To: "H. Peter Anvin" Return-path: Content-Disposition: inline In-Reply-To: <541CBC71.6050707@zytor.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org List-Id: kvm.vger.kernel.org On Fri, Sep 19, 2014 at 04:29:53PM -0700, H. Peter Anvin wrote: > > Actually, a much bigger reason is because it lets rogue guest *user > space*, even will a well-behaved guest OS, do something potentially > harmful to the host. Right, but if the host kernel is dependent on the guest OS for security, the game is over. The Guest Kernel must NEVER been able to do anything harmful to the host. If it can, it is a severe security bug in KVM that must be fixed ASAP. - Ted