Re: [Xen-devel] [PATCH] xen: Make VPMU init message look less scary

From: Konrad Rzeszutek Wilk
Date: Mon Aug 01 2016 - 10:12:05 EST


On Mon, Aug 01, 2016 at 01:41:20PM +0200, Juergen Gross wrote:
> 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@xxxxxxxx>
> ---
> arch/x86/xen/pmu.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/xen/pmu.c b/arch/x86/xen/pmu.c
> index 32bdc2c..e9d66fa 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 usage disabled due to Xen settings\n");

How about 'VPMU disabled by hypevisor.'

> + else
> + pr_info_once("Could not initialize VPMU for cpu %d, error %d\n",
> + cpu, err);
> free_pages((unsigned long)xenpmu_data, 0);
> }
>
> --
> 2.6.6
>
>
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