[v4,34/36] s390: protvirt: Add sysfs firmware interface for Ultravisor information

Commit Message

Christian Borntraeger Feb. 24, 2020, 11:41 a.m. UTC

From: Janosch Frank <[e-mail]>

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 <[e-mail]>
Reviewed-by: David Hildenbrand <[e-mail]>
Signed-off-by: Christian Borntraeger <[e-mail]>
---
 arch/s390/kernel/uv.c | 86 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)

Comments

Cornelia Huck Feb. 25, 2020, 1:30 p.m. UTC | #1

On Mon, 24 Feb 2020 06:41:05 -0500
Christian Borntraeger <[e-mail]> wrote:

> From: Janosch Frank <[e-mail]>
> 
> 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 <[e-mail]>
> Reviewed-by: David Hildenbrand <[e-mail]>
> Signed-off-by: Christian Borntraeger <[e-mail]>
> ---
>  arch/s390/kernel/uv.c | 86 +++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 86 insertions(+)

Reviewed-by: Cornelia Huck <[e-mail]>

Cornelia Huck Feb. 25, 2020, 1:37 p.m. UTC | #2

On Mon, 24 Feb 2020 06:41:05 -0500
Christian Borntraeger <[e-mail]> wrote:

> From: Janosch Frank <[e-mail]>
> 
> 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 <[e-mail]>
> Reviewed-by: David Hildenbrand <[e-mail]>
> Signed-off-by: Christian Borntraeger <[e-mail]>
> ---
>  arch/s390/kernel/uv.c | 86 +++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 86 insertions(+)

...oh, and maybe document the new interfaces under Documentation/ABI/
as well?

(No objection if you do that in a follow-up patch.)

Patch

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