[PATCH v3 35/37] s390: protvirt: Add sysfs firmware interface for Ultravisor information

Christian Borntraeger
2020-02-20T10:40:30Z

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

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>
---
arch/s390/kernel/uv.c | 86 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 86 insertions(+)

diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index 4539003dac9d..550e9617c459 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -323,5 +323,91 @@ int arch_make_page_accessible(struct page *page)
return rc;
}
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;
+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
--
2.25.0