xen: report hypervisor version

Various versions of the hypervisor have differences in what ABIs and
features they support.  Print some details into the boot log to help
with remote debugging.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index bb50845..5328e46 100644 (file)
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -167,10 +167,14 @@ void xen_vcpu_restore(void)
 
 static void __init xen_banner(void)
 {
+       unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL);
+       struct xen_extraversion extra;
+       HYPERVISOR_xen_version(XENVER_extraversion, &extra);
+
        printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
               pv_info.name);
-       printk(KERN_INFO "Hypervisor signature: %s%s\n",
-              xen_start_info->magic,
+       printk(KERN_INFO "Xen version: %d.%d%s%s\n",
+              version >> 16, version & 0xffff, extra.extraversion,
               xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
 }