From: Janosch Frank <frankja@linux.ibm.com>
Date: Thu, 13 Feb 2020 04:15:25 -0500
Subject: s390/protvirt: Add sysfs firmware interface for Ultravisor information
Git-commit: a0f60f8431999bf57cf53c3b27c47ef156b4fa17
Patch-mainline: v5.7-rc1
References: jsc#SLE-7512 bsc#1165545

That information, e.g. the maximum number of guests or installed
Ultravisor facilities, is interesting for QEMU, Libvirt and
administrators.

Let's provide an easily parsable API to get that information.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 arch/s390/kernel/uv.c |   87 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)

--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -325,3 +325,90 @@ int arch_make_page_accessible(struct pag
 EXPORT_SYMBOL_GPL(arch_make_page_accessible);
 
 #endif
+
+#if defined(CONFIG_PROTECTED_VIRTUALIZATION_GUEST) || IS_ENABLED(CONFIG_KVM)
+static ssize_t uv_query_facilities(struct kobject *kobj,
+				   struct kobj_attribute *attr, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%lx\n%lx\n%lx\n%lx\n",
+			uv_info.inst_calls_list[0],
+			uv_info.inst_calls_list[1],
+			uv_info.inst_calls_list[2],
+			uv_info.inst_calls_list[3]);
+}
+
+static struct kobj_attribute uv_query_facilities_attr =
+	__ATTR(facilities, 0444, uv_query_facilities, NULL);
+
+static ssize_t uv_query_max_guest_cpus(struct kobject *kobj,
+				       struct kobj_attribute *attr, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%d\n",
+			uv_info.max_guest_cpus);
+}
+
+static struct kobj_attribute uv_query_max_guest_cpus_attr =
+	__ATTR(max_cpus, 0444, uv_query_max_guest_cpus, NULL);
+
+static ssize_t uv_query_max_guest_vms(struct kobject *kobj,
+				      struct kobj_attribute *attr, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%d\n",
+			uv_info.max_num_sec_conf);
+}
+
+static struct kobj_attribute uv_query_max_guest_vms_attr =
+	__ATTR(max_guests, 0444, uv_query_max_guest_vms, NULL);
+
+static ssize_t uv_query_max_guest_addr(struct kobject *kobj,
+				       struct kobj_attribute *attr, char *page)
+{
+	return snprintf(page, PAGE_SIZE, "%lx\n",
+			uv_info.max_sec_stor_addr);
+}
+
+static struct kobj_attribute uv_query_max_guest_addr_attr =
+	__ATTR(max_address, 0444, uv_query_max_guest_addr, NULL);
+
+static struct attribute *uv_query_attrs[] = {
+	&uv_query_facilities_attr.attr,
+	&uv_query_max_guest_cpus_attr.attr,
+	&uv_query_max_guest_vms_attr.attr,
+	&uv_query_max_guest_addr_attr.attr,
+	NULL,
+};
+
+static struct attribute_group uv_query_attr_group = {
+	.attrs = uv_query_attrs,
+};
+
+static struct kset *uv_query_kset;
+static struct kobject *uv_kobj;
+
+static int __init uv_info_init(void)
+{
+	int rc = -ENOMEM;
+
+	if (!test_facility(158))
+		return 0;
+
+	uv_kobj = kobject_create_and_add("uv", firmware_kobj);
+	if (!uv_kobj)
+		return -ENOMEM;
+
+	uv_query_kset = kset_create_and_add("query", NULL, uv_kobj);
+	if (!uv_query_kset)
+		goto out_kobj;
+
+	rc = sysfs_create_group(&uv_query_kset->kobj, &uv_query_attr_group);
+	if (!rc)
+		return 0;
+
+	kset_unregister(uv_query_kset);
+out_kobj:
+	kobject_del(uv_kobj);
+	kobject_put(uv_kobj);
+	return rc;
+}
+device_initcall(uv_info_init);
+#endif