From: Brijesh Singh <brijesh.singh@amd.com>
To: linux-kernel@vger.kernel.org, x86@kernel.org,
        linux-efi@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
        kvm@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
        "H . Peter Anvin" <hpa@zytor.com>, Borislav Petkov <bp@suse.de>,
        Andy Lutomirski <luto@kernel.org>, Tony Luck <tony.luck@intel.com>,
        Piotr Luc <piotr.luc@intel.com>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        Fenghua Yu <fenghua.yu@intel.com>, Lu Baolu <baolu.lu@linux.intel.com>,
        Reza Arbab <arbab@linux.vnet.ibm.com>,
        David Howells <dhowells@redhat.com>,
        Matt Fleming <matt@codeblueprint.co.uk>,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Laura Abbott <labbott@redhat.com>,
        Ard Biesheuvel <ard.biesheuvel@linaro.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Eric Biederman <ebiederm@xmission.com>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
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        Kees Cook <keescook@chromium.org>, Paolo Bonzini <pbonzini@redhat.com>,
        =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= <rkrcmar@redhat.com>,
        Arnd Bergmann <arnd@arndb.de>, Tejun Heo <tj@kernel.org>,
        Christoph Lameter <cl@linux.com>,
        Brijesh Singh <brijesh.singh@amd.com>
Subject: [RFC Part1 PATCH v3 03/17] x86/mm: Secure Encrypted Virtualization (SEV) support
Date: Mon, 24 Jul 2017 14:07:43 -0500
Message-Id: <20170724190757.11278-4-brijesh.singh@amd.com>
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From: Tom Lendacky <thomas.lendacky@amd.com>

Provide support for Secure Encyrpted Virtualization (SEV). This initial
support defines a flag that is used by the kernel to determine if it is
running with SEV active.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
 arch/x86/include/asm/mem_encrypt.h | 2 ++
 arch/x86/mm/mem_encrypt.c          | 3 +++
 include/linux/mem_encrypt.h        | 8 +++++++-
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h
index 8e618fc..9274ec7 100644
--- a/arch/x86/include/asm/mem_encrypt.h
+++ b/arch/x86/include/asm/mem_encrypt.h
@@ -22,6 +22,7 @@
 #ifdef CONFIG_AMD_MEM_ENCRYPT
 
 extern unsigned long sme_me_mask;
+extern unsigned int sev_enabled;
 
 void sme_encrypt_execute(unsigned long encrypted_kernel_vaddr,
 			 unsigned long decrypted_kernel_vaddr,
@@ -50,6 +51,7 @@ void swiotlb_set_mem_attributes(void *vaddr, unsigned long size);
 #else	/* !CONFIG_AMD_MEM_ENCRYPT */
 
 #define sme_me_mask	0UL
+#define sev_enabled	0
 
 static inline void __init sme_early_encrypt(resource_size_t paddr,
 					    unsigned long size) { }
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index 0fbd092..1e4643e 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -40,6 +40,9 @@ static char sme_cmdline_off[] __initdata = "off";
 unsigned long sme_me_mask __section(.data) = 0;
 EXPORT_SYMBOL_GPL(sme_me_mask);
 
+unsigned int sev_enabled __section(.data) = 0;
+EXPORT_SYMBOL_GPL(sev_enabled);
+
 /* Buffer used for early in-place encryption by BSP, no locking needed */
 static char sme_early_buffer[PAGE_SIZE] __aligned(PAGE_SIZE);
 
diff --git a/include/linux/mem_encrypt.h b/include/linux/mem_encrypt.h
index 1255f09..ea0831a 100644
--- a/include/linux/mem_encrypt.h
+++ b/include/linux/mem_encrypt.h
@@ -22,12 +22,18 @@
 #else	/* !CONFIG_ARCH_HAS_MEM_ENCRYPT */
 
 #define sme_me_mask	0UL
+#define sev_enabled	0
 
 #endif	/* CONFIG_ARCH_HAS_MEM_ENCRYPT */
 
 static inline bool sme_active(void)
 {
-	return !!sme_me_mask;
+	return (sme_me_mask && !sev_enabled);
+}
+
+static inline bool sev_active(void)
+{
+	return (sme_me_mask && sev_enabled);
 }
 
 static inline unsigned long sme_get_me_mask(void)
-- 
2.9.4