From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brijesh Singh Subject: [RFC PATCH v1 11/28] x86: Don't decrypt trampoline area if SEV is active Date: Mon, 22 Aug 2016 19:25:51 -0400 Message-ID: <147190835102.9523.9786544054464015663.stgit__42481.2495163225$1471910452$gmane$org@brijesh-build-machine> References: <147190820782.9523.4967724730957229273.stgit@brijesh-build-machine> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Received: from mail-by2nam01on0044.outbound.protection.outlook.com ([104.47.34.44]:60832 "EHLO NAM01-BY2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755358AbcHVX7w (ORCPT ); Mon, 22 Aug 2016 19:59:52 -0400 In-Reply-To: <147190820782.9523.4967724730957229273.stgit@brijesh-build-machine> Sender: linux-crypto-owner@vger.kernel.org List-ID: From: Tom Lendacky When Secure Encrypted Virtualization is active instruction fetches are always interpreted as being from encrypted memory so the trampoline area must remain encrypted when SEV is active. Signed-off-by: Tom Lendacky --- arch/x86/realmode/init.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c index c3edb49..f3207e5 100644 --- a/arch/x86/realmode/init.c +++ b/arch/x86/realmode/init.c @@ -138,10 +138,13 @@ static void __init set_real_mode_permissions(void) /* * If memory encryption is active, the trampoline area will need to * be in non-encrypted memory in order to bring up other processors - * successfully. + * successfully. This only applies to SME, SEV requires the trampoline + * to be encrypted. */ - sme_early_mem_dec(__pa(base), size); - sme_set_mem_dec(base, size); + if (!sev_active) { + sme_early_mem_dec(__pa(base), size); + sme_set_mem_dec(base, size); + } set_memory_nx((unsigned long) base, size >> PAGE_SHIFT); set_memory_ro((unsigned long) base, ro_size >> PAGE_SHIFT);