On 04/27/2018 09:13 PM, Arnd Bergmann wrote:
> diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c
> index 761f6af6efa5..637982efecd8 100644
> --- a/arch/x86/kernel/pvclock.c
> +++ b/arch/x86/kernel/pvclock.c
> @@ -123,28 +123,35 @@ u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src)
>
> void pvclock_read_wallclock(struct pvclock_wall_clock *wall_clock,
> struct pvclock_vcpu_time_info *vcpu_time,
> - struct timespec *ts)
> + struct timespec64 *ts)
> {
> u32 version;
> u64 delta;
> - struct timespec now;
> + struct timespec64 now;
>
> /* get wallclock at system boot */
> do {
> version = wall_clock->version;
> rmb(); /* fetch version before time */
> + /*
> + * Note: wall_clock->sec is a u32 value, so it can
> + * only store dates between 1970 and 2106. To allow
> + * times beyond that, we need to create a new hypercall
> + * interface with an extended pvclock_wall_clock structure
> + * like ARM has.
> + */
> now.tv_sec = wall_clock->sec;
IIUC the interface you're probably speaking about is common to both ARM and x86
on Xen[*] (since Xen 4.6) i.e.
now.tv_sec = ((uint64_t)s->wc_sec_hi << 32) | s->wc_sec;
s representing struct shared_info like on ARM (there's a 32-bit hole where
wc_sec_hi is placed on x86_64/ARM). Except on x86 32-bit guests wc_sec_hi is
located elsewhere.
Joao
[*]
https://xenbits.xen.org/docs/4.6-testing/hypercall/x86_64/include,public,xen.h.html#incontents_startofday_shared
