[PATCH 2/3] x86/sev: Create /sys/devices/system/cpu/sev/ for all SEV guests

[Jörg Rödel]

From: Joerg Roedel <joerg.roedel@xxxxxxx>

The SYSFS directory for SEV is only created for SEV-SNP guests right
now. Change it to create it for SEV and SEV-ES guests as well so
attributes available on all versions of SEV have a place.

Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
---
 .../ABI/testing/sysfs-devices-system-cpu      |  5 ++--
 arch/x86/coco/sev/core.c                      | 29 ++++++++++++-------
 2 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
index 82d10d556cc8..63586e299aa8 100644
--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -694,10 +694,11 @@ Date:		May 2024
 Contact:	Linux kernel mailing list <linux-kernel@xxxxxxxxxxxxxxx>
 Description:	Secure Encrypted Virtualization (SEV) information
 
-		This directory is only present when running as an SEV-SNP guest.
+		This directory is only present when running as an SEV guest.
 
 		vmpl: Reports the Virtual Machine Privilege Level (VMPL) at which
-		      the SEV-SNP guest is running.
+		      the SEV-SNP guest is running. This file is only present
+		      when running as an SEV-SNP guest.
 
 
 What:		/sys/devices/system/cpu/svm
diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c
index ecd77d3217f3..5770b99feb9b 100644
--- a/arch/x86/coco/sev/core.c
+++ b/arch/x86/coco/sev/core.c
@@ -1433,14 +1433,7 @@ static ssize_t vmpl_show(struct kobject *kobj,
 
 static struct kobj_attribute vmpl_attr = __ATTR_RO(vmpl);
 
-static struct attribute *vmpl_attrs[] = {
-	&vmpl_attr.attr,
-	NULL
-};
-
-static struct attribute_group sev_attr_group = {
-	.attrs = vmpl_attrs,
-};
+static struct attribute_group sev_attr_group = {};
 
 static int __init sev_sysfs_init(void)
 {
@@ -1448,7 +1441,7 @@ static int __init sev_sysfs_init(void)
 	struct device *dev_root;
 	int ret;
 
-	if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
+	if (!cc_platform_has(CC_ATTR_GUEST_SEV))
 		return -ENODEV;
 
 	dev_root = bus_get_dev_root(&cpu_subsys);
@@ -1463,9 +1456,25 @@ static int __init sev_sysfs_init(void)
 
 	ret = sysfs_create_group(sev_kobj, &sev_attr_group);
 	if (ret)
-		kobject_put(sev_kobj);
+		goto drop_kobj;
+
+	/* Add SEV-SNP specific attributes */
+	if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) {
+		/* VMPL */
+		ret = sysfs_add_file_to_group(sev_kobj, &vmpl_attr.attr, NULL);
+		if (ret)
+			goto drop_sysfs;
+	}
+
+	return 0;
+
+drop_sysfs:
+	sysfs_remove_group(sev_kobj, &sev_attr_group);
+drop_kobj:
+	kobject_put(sev_kobj);
 
 	return ret;
+
 }
 arch_initcall(sev_sysfs_init);
 #endif // CONFIG_SYSFS
-- 
2.53.0