xen/sysfs: Use XENVER_guest_handle to query UUID

This hypercall has been present since Xen 3.1, and is the preferred
method for a domain to obtain its UUID. Fall back to the xenstore method
if using an older version of Xen (which returns -ENOSYS).

Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Daniel De Graaf 2012-08-16 16:40:26 -04:00 committed by Konrad Rzeszutek Wilk
parent b8b0f559c7
commit 5c13f80677
2 changed files with 15 additions and 1 deletions

View file

@ -114,7 +114,7 @@ static void xen_sysfs_version_destroy(void)
/* UUID */
static ssize_t uuid_show(struct hyp_sysfs_attr *attr, char *buffer)
static ssize_t uuid_show_fallback(struct hyp_sysfs_attr *attr, char *buffer)
{
char *vm, *val;
int ret;
@ -135,6 +135,17 @@ static ssize_t uuid_show(struct hyp_sysfs_attr *attr, char *buffer)
return ret;
}
static ssize_t uuid_show(struct hyp_sysfs_attr *attr, char *buffer)
{
xen_domain_handle_t uuid;
int ret;
ret = HYPERVISOR_xen_version(XENVER_guest_handle, uuid);
if (ret)
return uuid_show_fallback(attr, buffer);
ret = sprintf(buffer, "%pU\n", uuid);
return ret;
}
HYPERVISOR_ATTR_RO(uuid);
static int __init xen_sysfs_uuid_init(void)

View file

@ -60,4 +60,7 @@ struct xen_feature_info {
/* arg == NULL; returns host memory page size. */
#define XENVER_pagesize 7
/* arg == xen_domain_handle_t. */
#define XENVER_guest_handle 8
#endif /* __XEN_PUBLIC_VERSION_H__ */