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>,
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        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>,
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        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 05/17] x86, realmode: Don't decrypt trampoline area under SEV
Date: Mon, 24 Jul 2017 14:07:45 -0500
Message-Id: <20170724190757.11278-6-brijesh.singh@amd.com>
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From: Tom Lendacky <thomas.lendacky@amd.com>

When SEV is active the trampoline area will need to be in encrypted
memory so only mark the area decrypted if SME is active.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
 arch/x86/realmode/init.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c
index 1f71980..c7eeca7 100644
--- a/arch/x86/realmode/init.c
+++ b/arch/x86/realmode/init.c
@@ -63,9 +63,11 @@ static void __init setup_real_mode(void)
 	/*
 	 * If SME is active, the trampoline area will need to be in
 	 * decrypted memory in order to bring up other processors
-	 * successfully.
+	 * successfully. For SEV the trampoline area needs to be in
+	 * encrypted memory, so only do this for SME.
 	 */
-	set_memory_decrypted((unsigned long)base, size >> PAGE_SHIFT);
+	if (sme_active())
+		set_memory_decrypted((unsigned long)base, size >> PAGE_SHIFT);
 
 	memcpy(base, real_mode_blob, size);
 
-- 
2.9.4