linux-kernel - [tip: x86/sev] x86/sev: Detect/setup SEV/SME features earlier in boot

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <164940895248.389.16682272531971510638.tip-bot2@tip-bot2>
Date:   Fri, 08 Apr 2022 09:09:12 -0000
From:   "tip-bot2 for Michael Roth" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Michael Roth <michael.roth@....com>,
        Brijesh Singh <brijesh.singh@....com>,
        Borislav Petkov <bp@...e.de>,
        Venu Busireddy <venu.busireddy@...cle.com>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: x86/sev] x86/sev: Detect/setup SEV/SME features earlier in boot

The following commit has been merged into the x86/sev branch of tip:

Commit-ID:     bcce829083339bf862d66df602cbb111943da8fb
Gitweb:        https://git.kernel.org/tip/bcce829083339bf862d66df602cbb111943da8fb
Author:        Michael Roth <michael.roth@....com>
AuthorDate:    Wed, 09 Feb 2022 12:10:02 -06:00
Committer:     Borislav Petkov <bp@...e.de>
CommitterDate: Wed, 06 Apr 2022 13:02:26 +02:00

x86/sev: Detect/setup SEV/SME features earlier in boot

sme_enable() handles feature detection for both SEV and SME. Future
patches will also use it for SEV-SNP feature detection/setup, which
will need to be done immediately after the first #VC handler is set up.
Move it now in preparation.

Signed-off-by: Michael Roth <michael.roth@....com>
Signed-off-by: Brijesh Singh <brijesh.singh@....com>
Signed-off-by: Borislav Petkov <bp@...e.de>
Reviewed-by: Venu Busireddy <venu.busireddy@...cle.com>
Link: https://lore.kernel.org/r/20220307213356.2797205-9-brijesh.singh@amd.com
---
 arch/x86/kernel/head64.c  |  3 ---
 arch/x86/kernel/head_64.S | 13 +++++++++++++
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 4f5ecbb..cbc285d 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -192,9 +192,6 @@ unsigned long __head __startup_64(unsigned long physaddr,
 	if (load_delta & ~PMD_PAGE_MASK)
 		for (;;);
 
-	/* Activate Secure Memory Encryption (SME) if supported and enabled */
-	sme_enable(bp);
-
 	/* Include the SME encryption mask in the fixup value */
 	load_delta += sme_get_me_mask();
 
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index b8e3019..6bf340c 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -69,6 +69,19 @@ SYM_CODE_START_NOALIGN(startup_64)
 	call	startup_64_setup_env
 	popq	%rsi
 
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+	/*
+	 * Activate SEV/SME memory encryption if supported/enabled. This needs to
+	 * be done now, since this also includes setup of the SEV-SNP CPUID table,
+	 * which needs to be done before any CPUID instructions are executed in
+	 * subsequent code.
+	 */
+	movq	%rsi, %rdi
+	pushq	%rsi
+	call	sme_enable
+	popq	%rsi
+#endif
+
 	/* Now switch to __KERNEL_CS so IRET works reliably */
 	pushq	$__KERNEL_CS
 	leaq	.Lon_kernel_cs(%rip), %rax