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From:   Martin Fernandez <martin.fernandez@eclypsium.com>
To:     linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org,
        platform-driver-x86@vger.kernel.org, linux-mm@kvack.org
Cc:     tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
        dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com,
        ardb@kernel.org, dvhart@infradead.org, andy@infradead.org,
        gregkh@linuxfoundation.org, rafael@kernel.org, rppt@kernel.org,
        akpm@linux-foundation.org, daniel.gutson@eclypsium.com,
        hughsient@gmail.com, alex.bazhaniuk@eclypsium.com,
        alison.schofield@intel.com, keescook@chromium.org,
        Martin Fernandez <martin.fernandez@eclypsium.com>
Subject: [PATCH v8 8/8] drivers/node: Show in sysfs node's crypto capabilities
Date:   Fri, 29 Apr 2022 17:17:17 -0300
Message-Id: <20220429201717.1946178-9-martin.fernandez@eclypsium.com>
In-Reply-To: <20220429201717.1946178-1-martin.fernandez@eclypsium.com>
References: <20220429201717.1946178-1-martin.fernandez@eclypsium.com>
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Show in each node in sysfs if its memory is able to do be encrypted by
the CPU; on EFI systems: if all its memory is marked with
EFI_MEMORY_CPU_CRYPTO in the EFI memory map.

Signed-off-by: Martin Fernandez <martin.fernandez@eclypsium.com>
---
 Documentation/ABI/testing/sysfs-devices-node | 10 ++++++++++
 drivers/base/node.c                          | 10 ++++++++++
 2 files changed, 20 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-devices-node

diff --git a/Documentation/ABI/testing/sysfs-devices-node b/Documentation/ABI/testing/sysfs-devices-node
new file mode 100644
index 000000000000..0e95420bd7c5
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-node
@@ -0,0 +1,10 @@
+What:		/sys/devices/system/node/nodeX/crypto_capable
+Date:		April 2022
+Contact:	Martin Fernandez <martin.fernandez@eclypsium.com>
+Users:		fwupd (https://fwupd.org)
+Description:
+		This value is 1 if all system memory in this node is
+		capable of being protected with the CPU's memory
+		cryptographic capabilities.  It is 0 otherwise.
+		On EFI systems the node will be marked with
+		EFI_MEMORY_CPU_CRYPTO.
\ No newline at end of file
diff --git a/drivers/base/node.c b/drivers/base/node.c
index ec8bb24a5a22..1df15ea03c27 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -560,11 +560,21 @@ static ssize_t node_read_distance(struct device *dev,
 }
 static DEVICE_ATTR(distance, 0444, node_read_distance, NULL);
 
+static ssize_t crypto_capable_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct pglist_data *pgdat = NODE_DATA(dev->id);
+
+	return sysfs_emit(buf, "%d\n", pgdat->crypto_capable);
+}
+static DEVICE_ATTR_RO(crypto_capable);
+
 static struct attribute *node_dev_attrs[] = {
 	&dev_attr_meminfo.attr,
 	&dev_attr_numastat.attr,
 	&dev_attr_distance.attr,
 	&dev_attr_vmstat.attr,
+	&dev_attr_crypto_capable.attr,
 	NULL
 };
 
-- 
2.30.2