xen: add sysfs node for hypervisor build id (84b76257) · Commits · 戴 / test

Documentation/ABI/testing/sysfs-hypervisor-xen

+10 −1

Original line number	Diff line number	Diff line
		What: /sys/hypervisor/guest_type
		Date: May 2017
		Date: June 2017
		KernelVersion: 4.13
		Contact: xen-devel@lists.xenproject.org
		Description: If running under Xen:
		@@ -32,3 +32,12 @@ Description: If running under Xen:
		Describes Xen PMU features (as an integer). A set bit indicates
		that the corresponding feature is enabled. See
		include/xen/interface/xenpmu.h for available features

		What: /sys/hypervisor/properties/buildid
		Date: June 2017
		KernelVersion: 4.13
		Contact: xen-devel@lists.xenproject.org
		Description: If running under Xen:
		Build id of the hypervisor, needed for hypervisor live patching.
		Might return "<denied>" in case of special security settings
		in the hypervisor.

+28 −0

Original line number	Diff line number	Diff line
		@@ -356,12 +356,40 @@ static ssize_t features_show(struct hyp_sysfs_attr attr, char buffer)

		HYPERVISOR_ATTR_RO(features);

		static ssize_t buildid_show(struct hyp_sysfs_attr attr, char buffer)
		{
		ssize_t ret;
		struct xen_build_id *buildid;

		ret = HYPERVISOR_xen_version(XENVER_build_id, NULL);
		if (ret < 0) {
		if (ret == -EPERM)
		ret = sprintf(buffer, "<denied>");
		return ret;
		}

		buildid = kmalloc(sizeof(*buildid) + ret, GFP_KERNEL);
		if (!buildid)
		return -ENOMEM;

		buildid->len = ret;
		ret = HYPERVISOR_xen_version(XENVER_build_id, buildid);
		if (ret > 0)
		ret = sprintf(buffer, "%s", buildid->buf);
		kfree(buildid);

		return ret;
		}

		HYPERVISOR_ATTR_RO(buildid);

		static struct attribute *xen_properties_attrs[] = {
		&capabilities_attr.attr,
		&changeset_attr.attr,
		&virtual_start_attr.attr,
		&pagesize_attr.attr,
		&features_attr.attr,
		&buildid_attr.attr,
		NULL
		};