xen: Make VPMU init message look less scary

The default for the Xen hypervisor is to not enable VPMU in order to
avoid security issues. In this case the Linux kernel will issue the
message "Could not initialize VPMU for cpu 0, error -95" which looks
more like an error than a normal state.

Change the message to something less scary in case the hypervisor
returns EOPNOTSUPP or ENOSYS when trying to activate VPMU.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Orabug: 25873416

(cherry picked from commit 0252937a87e1d46a8261da85cbd99dffe612a2d3)
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Dhaval Giani <dhaval.giani@gmail.com>

diff --git a/arch/x86/xen/pmu.c b/arch/x86/xen/pmu.c
index 04c2551c08015c112c16fd5647c53265ec0ca6a3..3896a7fe9c433c14ac979562ae1f2cd00f319507 100644 (file)
--- a/arch/x86/xen/pmu.c
+++ b/arch/x86/xen/pmu.c
@@ -547,8 +547,11 @@ void xen_pmu_init(int cpu)
        return;
 
 fail:
-       pr_info_once("Could not initialize VPMU for cpu %d, error %d\n",
-               cpu, err);
+       if (err == -EOPNOTSUPP || err == -ENOSYS)
+               pr_info_once("VPMU disabled by hypervisor.\n");
+       else
+               pr_info_once("Could not initialize VPMU for cpu %d, error %d\n",
+                       cpu, err);
        free_pages((unsigned long)xenpmu_data, 0);
 }