| Message ID | 1493842851-10859-1-git-send-email-boris.ostrovsky@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Thanks, Juergen
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@oracle.com> Pushed to xen/tip for-linus-4.12b Thanks, Juergen
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index a732bc2..6f80a01 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -988,6 +988,13 @@ void xen_setup_shared_info(void) #endif xen_setup_mfn_list_list(); + + /* + * Now that shared info is set up we can start using routines that + * point to pvclock area. + */ + if (system_state == SYSTEM_BOOTING) + xen_init_time_ops(); } /* This is called once we have the cpu_possible_mask */ @@ -1286,8 +1293,6 @@ asmlinkage __visible void __init xen_start_kernel(void) x86_init.oem.arch_setup = xen_arch_setup; x86_init.oem.banner = xen_banner; - xen_init_time_ops(); - /* * Set up some pagetable state before starting to set any ptes. */ diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index 090c7eb..a1895a8 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -406,7 +406,7 @@ static void __init xen_time_init(void) pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier); } -void __init xen_init_time_ops(void) +void __ref xen_init_time_ops(void) { pv_time_ops = xen_time_ops;
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@oracle.com> --- arch/x86/xen/enlighten_pv.c | 9 +++++++-- arch/x86/xen/time.c | 2 +- 2 files changed, 8 insertions(+), 3 deletions(-)