From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brijesh Singh Subject: [Part1 PATCH v4 15/17] percpu: introduce DEFINE_PER_CPU_UNENCRYPTED Date: Sat, 16 Sep 2017 07:34:16 -0500 Message-ID: <20170916123418.37807-16-brijesh.singh@amd.com> References: <20170916123418.37807-1-brijesh.singh@amd.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <20170916123418.37807-1-brijesh.singh@amd.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Borislav Petkov , Andy Lutomirski , Tom Lendacky , Brijesh Singh , Arnd Bergmann , Tejun Heo , Christoph Lameter , linux-arch@vger.kernel.org List-Id: linux-arch.vger.kernel.org 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 --- include/asm-generic/vmlinux.lds.h | 11 +++++++++++ include/linux/percpu-defs.h | 15 +++++++++++++++ 2 files changed, 26 insertions(+) diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 8acfc1e099e1..363858f43cbc 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -777,6 +777,16 @@ #define INIT_RAM_FS #endif +#ifdef CONFIG_AMD_MEM_ENCRYPT +#define PERCPU_UNENCRYPTED_SECTION \ + . = ALIGN(PAGE_SIZE); \ + *(.data..percpu..unencrypted) \ + . = ALIGN(PAGE_SIZE); +#else +#define PERCPU_UNENCRYPTED_SECTION +#endif + + /* * Default discarded sections. * @@ -815,6 +825,7 @@ . = ALIGN(cacheline); \ *(.data..percpu) \ *(.data..percpu..shared_aligned) \ + PERCPU_UNENCRYPTED_SECTION \ VMLINUX_SYMBOL(__per_cpu_end) = .; /** diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h index 8f16299ca068..b2b99ad4b31d 100644 --- a/include/linux/percpu-defs.h +++ b/include/linux/percpu-defs.h @@ -173,6 +173,21 @@ DEFINE_PER_CPU_SECTION(type, name, "..read_mostly") /* + * Declaration/definition used for per-CPU variables that should be accessed + * as unencrypted when memory encryption is enabled in the guest. + */ +#if defined(CONFIG_VIRTUALIZATION) && defined(CONFIG_AMD_MEM_ENCRYPT) + +#define DECLARE_PER_CPU_UNENCRYPTED(type, name) \ + DECLARE_PER_CPU_SECTION(type, name, "..unencrypted") + +#define DEFINE_PER_CPU_UNENCRYPTED(type, name) \ + DEFINE_PER_CPU_SECTION(type, name, "..unencrypted") +#else +#define DEFINE_PER_CPU_UNENCRYPTED(type, name) DEFINE_PER_CPU(type, name) +#endif + +/* * Intermodule exports for per-CPU variables. sparse forgets about * address space across EXPORT_SYMBOL(), change EXPORT_SYMBOL() to * noop if __CHECKER__. -- 2.9.5 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-dm3nam03on0064.outbound.protection.outlook.com ([104.47.41.64]:54405 "EHLO NAM03-DM3-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751587AbdIPMfN (ORCPT ); Sat, 16 Sep 2017 08:35:13 -0400 From: Brijesh Singh Subject: [Part1 PATCH v4 15/17] percpu: introduce DEFINE_PER_CPU_UNENCRYPTED Date: Sat, 16 Sep 2017 07:34:16 -0500 Message-ID: <20170916123418.37807-16-brijesh.singh@amd.com> In-Reply-To: <20170916123418.37807-1-brijesh.singh@amd.com> References: <20170916123418.37807-1-brijesh.singh@amd.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Borislav Petkov , Andy Lutomirski , Tom Lendacky , Brijesh Singh , Arnd Bergmann , Tejun Heo , Christoph Lameter , linux-arch@vger.kernel.org Message-ID: <20170916123416.ITTYgd0df9U4CANNCgdiOu5j0p2g1yzmKKy4HXnzl-o@z> 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 --- include/asm-generic/vmlinux.lds.h | 11 +++++++++++ include/linux/percpu-defs.h | 15 +++++++++++++++ 2 files changed, 26 insertions(+) diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 8acfc1e099e1..363858f43cbc 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -777,6 +777,16 @@ #define INIT_RAM_FS #endif +#ifdef CONFIG_AMD_MEM_ENCRYPT +#define PERCPU_UNENCRYPTED_SECTION \ + . = ALIGN(PAGE_SIZE); \ + *(.data..percpu..unencrypted) \ + . = ALIGN(PAGE_SIZE); +#else +#define PERCPU_UNENCRYPTED_SECTION +#endif + + /* * Default discarded sections. * @@ -815,6 +825,7 @@ . = ALIGN(cacheline); \ *(.data..percpu) \ *(.data..percpu..shared_aligned) \ + PERCPU_UNENCRYPTED_SECTION \ VMLINUX_SYMBOL(__per_cpu_end) = .; /** diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h index 8f16299ca068..b2b99ad4b31d 100644 --- a/include/linux/percpu-defs.h +++ b/include/linux/percpu-defs.h @@ -173,6 +173,21 @@ DEFINE_PER_CPU_SECTION(type, name, "..read_mostly") /* + * Declaration/definition used for per-CPU variables that should be accessed + * as unencrypted when memory encryption is enabled in the guest. + */ +#if defined(CONFIG_VIRTUALIZATION) && defined(CONFIG_AMD_MEM_ENCRYPT) + +#define DECLARE_PER_CPU_UNENCRYPTED(type, name) \ + DECLARE_PER_CPU_SECTION(type, name, "..unencrypted") + +#define DEFINE_PER_CPU_UNENCRYPTED(type, name) \ + DEFINE_PER_CPU_SECTION(type, name, "..unencrypted") +#else +#define DEFINE_PER_CPU_UNENCRYPTED(type, name) DEFINE_PER_CPU(type, name) +#endif + +/* * Intermodule exports for per-CPU variables. sparse forgets about * address space across EXPORT_SYMBOL(), change EXPORT_SYMBOL() to * noop if __CHECKER__. -- 2.9.5