From 734560ac39aeb2516419c5878856df011f794a74 Mon Sep 17 00:00:00 2001
From: Ryan Grimm <grimm@linux.vnet.ibm.com>
Date: Mon, 19 Aug 2019 23:13:21 -0300
Subject: powerpc/pseries/svm: Export guest SVM status to user space via sysfs

User space might want to know it's running in a secure VM.  It can't do
a mfmsr because mfmsr is a privileged instruction.

The solution here is to create a cpu attribute:

/sys/devices/system/cpu/svm

which will read 0 or 1 based on the S bit of the current CPU.

Signed-off-by: Ryan Grimm <grimm@linux.vnet.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190820021326.6884-12-bauerman@linux.ibm.com
---
 Documentation/ABI/testing/sysfs-devices-system-cpu | 10 ++++++++++
 1 file changed, 10 insertions(+)

(limited to 'Documentation/ABI')

diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
index 5f7d7b14fa44..06d0931119cc 100644
--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -562,3 +562,13 @@ Description:	Umwait control
 			  or C0.2 state. The time is an unsigned 32-bit number.
 			  Note that a value of zero means there is no limit.
 			  Low order two bits must be zero.
+
+What:		/sys/devices/system/cpu/svm
+Date:		August 2019
+Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
+		Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
+Description:	Secure Virtual Machine
+
+		If 1, it means the system is using the Protected Execution
+		Facility in POWER9 and newer processors. i.e., it is a Secure
+		Virtual Machine.
-- 
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