Re: [PATCH] xen/x86: Do not call xen_init_time_ops() until shared_info is initialized

From: Juergen Gross
Date: Thu May 04 2017 - 02:37:42 EST


On 03/05/17 22:20, Boris Ostrovsky wrote:
> Routines that are set by xen_init_time_ops() use shared_info's
> pvclock_vcpu_time_info area. This area is not properly available until
> shared_info is mapped in xen_setup_shared_info().
>
> This became especially problematic due to commit dd759d93f4dd ("x86/timers:
> Add simple udelay calibration") where we end up reading tsc_to_system_mul
> from xen_dummy_shared_info (i.e. getting zero value) and then trying
> to divide by it in pvclock_tsc_khz().
>
> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>

Reviewed-by: Juergen Gross <jgross@xxxxxxxx>


Thanks,

Juergen