| Message ID | 1470120213-16683-1-git-send-email-jgross@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
>>> On 02.08.16 at 08:43, <JGross@suse.com> wrote: > --- 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) > + pr_info_once("VPMU disabled by hypervisor.\n"); > + else > + pr_info_once("Could not initialize VPMU for cpu %d, error %d\n", > + cpu, err); I'm sorry for not already having thought about this for v1, but what about older hypervisors, where the hypercall would return -ENOSYS? Jan
On 02/08/16 09:10, Jan Beulich wrote: >>>> On 02.08.16 at 08:43, <JGross@suse.com> wrote: >> --- 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) >> + pr_info_once("VPMU disabled by hypervisor.\n"); >> + else >> + pr_info_once("Could not initialize VPMU for cpu %d, error %d\n", >> + cpu, err); > > I'm sorry for not already having thought about this for v1, but > what about older hypervisors, where the hypercall would return > -ENOSYS? I wasn't aware of that possibility. It should be covered, of course! V3 will be sent soon... Thanks for noticing now, Juergen
diff --git a/arch/x86/xen/pmu.c b/arch/x86/xen/pmu.c index 32bdc2c..bfe8880 100644 --- 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) + 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); }
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 when trying to activate VPMU. Signed-off-by: Juergen Gross <jgross@suse.com> --- V2: modify error message as suggested by Konrad Wilk --- arch/x86/xen/pmu.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)