From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sean Christopherson Subject: Re: SEV guest regression in 4.18 Date: Wed, 22 Aug 2018 08:00:34 -0700 Message-ID: <20180822150033.GA14200@linux.intel.com> References: <20ad6cd5-394c-d3ae-d99c-b656d7ef8293@amd.com> <20180821083911.GF24940@nazgul.tnic> <3d46f44c-dd78-8fa9-02ac-8206676ffde9@amd.com> <20180821151938.GA31212@nazgul.tnic> <92e2b80c-0dcc-94be-8d3a-5e11e5cf2370@amd.com> <20180822081417.GB4069@nazgul.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Cc: Brijesh Singh , Paolo Bonzini , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , "Lendacky, Thomas" , Thomas Gleixner To: Borislav Petkov Return-path: Content-Disposition: inline In-Reply-To: <20180822081417.GB4069@nazgul.tnic> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Wed, Aug 22, 2018 at 10:14:17AM +0200, Borislav Petkov wrote: > Dropping Pavel as it bounces. > > On Tue, Aug 21, 2018 at 11:07:38AM -0500, Brijesh Singh wrote: > > The tsc_early_init() is called before setup_arch() -> init_mem_mapping. > > Ok, I see it, thanks for explaining. > > So back to your original ideas - I'm wondering whether we should define > a chunk of memory which the hypervisor and guest can share and thus > communicate over... Something ala SEV-ES also with strictly defined > layout and put all those variables there. And then the guest can map > decrypted. What about creating a data section specifically for shared memory? The section would be PMD aligned and sized so that it could be mapped appropriately without having to fracture the page. Then define a macro to easily declare data in the new section, a la __read_mostly. > There might be something similar though, I dunno. > > Maybe Paolo has a better idea... > > -- > Regards/Gruss, > Boris. > > SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) > --