[SRU][H][F][PATCH 1/2] s390/uv: add prot virt guest/host indication files

[frank.heimes at canonical.com]

From: Janosch Frank <frankja at linux.ibm.com>

BugLink: https://bugs.launchpad.net/bugs/1933173

Let's export the prot_virt_guest and prot_virt_host variables into the
UV sysfs firmware interface to make them easily consumable by
administrators.

prot_virt_host being 1 indicates that we did the UV
initialization (opt-in)

prot_virt_guest being 1 indicates that the UV indicates the share and
unshare ultravisor calls which is an indication that we are running as
a protected guest.

Signed-off-by: Janosch Frank <frankja at linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger at de.ibm.com>
Signed-off-by: Heiko Carstens <hca at linux.ibm.com>
(cherry picked from commit 37564ed834aca26993b77b9b2a0119ec1ba6e00c)
Signed-off-by: Frank Heimes <frank.heimes at canonical.com>
---
 arch/s390/kernel/uv.c | 37 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index c86d654351d1..1db237b6a4b7 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -382,6 +382,35 @@ static struct attribute_group uv_query_attr_group = {
 	.attrs = uv_query_attrs,
 };
 
+static ssize_t uv_is_prot_virt_guest(struct kobject *kobj,
+				     struct kobj_attribute *attr, char *page)
+{
+	int val = 0;
+
+#ifdef CONFIG_PROTECTED_VIRTUALIZATION_GUEST
+	val = prot_virt_guest;
+#endif
+	return scnprintf(page, PAGE_SIZE, "%d\n", val);
+}
+
+static ssize_t uv_is_prot_virt_host(struct kobject *kobj,
+				    struct kobj_attribute *attr, char *page)
+{
+	return scnprintf(page, PAGE_SIZE, "%d\n", prot_virt_host);
+}
+
+static struct kobj_attribute uv_prot_virt_guest =
+	__ATTR(prot_virt_guest, 0444, uv_is_prot_virt_guest, NULL);
+
+static struct kobj_attribute uv_prot_virt_host =
+	__ATTR(prot_virt_host, 0444, uv_is_prot_virt_host, NULL);
+
+static const struct attribute *uv_prot_virt_attrs[] = {
+	&uv_prot_virt_guest.attr,
+	&uv_prot_virt_host.attr,
+	NULL,
+};
+
 static struct kset *uv_query_kset;
 static struct kobject *uv_kobj;
 
@@ -396,15 +425,21 @@ static int __init uv_info_init(void)
 	if (!uv_kobj)
 		return -ENOMEM;
 
+	rc = sysfs_create_files(uv_kobj, uv_prot_virt_attrs);
+	if (rc)
+		goto out_kobj;
+
 	uv_query_kset = kset_create_and_add("query", NULL, uv_kobj);
 	if (!uv_query_kset)
-		goto out_kobj;
+		goto out_ind_files;
 
 	rc = sysfs_create_group(&uv_query_kset->kobj, &uv_query_attr_group);
 	if (!rc)
 		return 0;
 
 	kset_unregister(uv_query_kset);
+out_ind_files:
+	sysfs_remove_files(uv_kobj, uv_prot_virt_attrs);
 out_kobj:
 	kobject_del(uv_kobj);
 	kobject_put(uv_kobj);
-- 
2.25.1