From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [Part1 PATCH v4 15/17] percpu: introduce DEFINE_PER_CPU_UNENCRYPTED Date: Mon, 18 Sep 2017 20:13:44 -0700 Message-ID: <20170919031344.GL378890@devbig577.frc2.facebook.com> References: <20170916123418.37807-1-brijesh.singh@amd.com> <20170916123418.37807-16-brijesh.singh@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org, Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Borislav Petkov , Andy Lutomirski , Tom Lendacky , Arnd Bergmann , Christoph Lameter , linux-arch@vger.kernel.org To: Brijesh Singh Return-path: Content-Disposition: inline In-Reply-To: <20170916123418.37807-16-brijesh.singh@amd.com> Sender: linux-arch-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Sat, Sep 16, 2017 at 07:34:16AM -0500, Brijesh Singh wrote: > When SEV is active, memory is encrypted with guest-specific key, and if > guest OS wants to share the memory region with hypervisor then it must > clear the C-bit (i.e set unencrypted) before sharing it. > > DEFINE_PER_CPU_UNENCRYPTED can be used to define the per-cpu variables > which will be shared between guest and hypervisor. Currently, KVM defines > three variables (steal-time, apf_reason, and avic_eio) which are shared > with hypervisor. > > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: "H. Peter Anvin" > Cc: Borislav Petkov > Cc: Arnd Bergmann > Cc: Tejun Heo > Cc: Christoph Lameter > Cc: linux-arch@vger.kernel.org > Cc: x86@kernel.org > Cc: linux-kernel@vger.kernel.org > Cc: Tom Lendacky > Signed-off-by: Brijesh Singh Acked-by: Tejun Heo Thanks. -- tejun