[v3] x86: Convert x86_platform_ops to timespec64

Message ID 20180427201435.3194219-1-arnd@arndb.de
State New
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Series
  • [v3] x86: Convert x86_platform_ops to timespec64
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Commit Message

Arnd Bergmann April 27, 2018, 8:13 p.m.
The x86 platform operations are fairly isolated, so we can
change them from using timespec to timespec64. I checked that
All the users and callers are safe, and there is only one
critical function that is broken beyond 2106:

pvclock_read_wallclock() uses a 32-bit number of seconds since
the epoch to communicate the boot time between host and guest
in a virtual environment. This will work until 2106, but we
should ideally find a replacement anyway. I've added a comment
about it there.

Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

---
v2 changes:
- move comment block (Boris)
- remove unnecessary type cast (Boris)
- fix format string (0day bot)
- fix include order (0day bot)

v3 changes:
- add jailhouse specific change
- avoid include file header by relying on another
  patch ("timekeeping: Remove timespec64 hack")

Not sure how we want to merge this (assuming the last modification
worked, this has seen little testing). The "timekeeping: Remove
timespec64 hack" patch should go through the timekeeping branch
in tip, while this one is for x86. I assume the linux-tip maintainers
can come up with a plan.
---
 arch/x86/include/asm/intel_mid_vrtc.h        |  4 ++--
 arch/x86/include/asm/mc146818rtc.h           |  4 ++--
 arch/x86/include/asm/pvclock.h               |  2 +-
 arch/x86/include/asm/x86_init.h              |  6 +++---
 arch/x86/kernel/jailhouse.c                  |  2 +-
 arch/x86/kernel/kvmclock.c                   |  4 ++--
 arch/x86/kernel/pvclock.c                    | 15 +++++++++++----
 arch/x86/kernel/rtc.c                        | 10 +++++-----
 arch/x86/platform/intel-mid/intel_mid_vrtc.c | 12 ++++++------
 arch/x86/xen/time.c                          | 10 +++++-----
 10 files changed, 38 insertions(+), 31 deletions(-)

-- 
2.9.0

Comments

Radim Krčmář April 27, 2018, 8:56 p.m. | #1
2018-04-27 22:13+0200, Arnd Bergmann:
> The x86 platform operations are fairly isolated, so we can

> change them from using timespec to timespec64. I checked that

> All the users and callers are safe, and there is only one

> critical function that is broken beyond 2106:

> 

> pvclock_read_wallclock() uses a 32-bit number of seconds since

> the epoch to communicate the boot time between host and guest

> in a virtual environment. This will work until 2106, but we

> should ideally find a replacement anyway. I've added a comment

> about it there.

> 

> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

> ---

> v2 changes:

> - move comment block (Boris)

> - remove unnecessary type cast (Boris)

> - fix format string (0day bot)

> - fix include order (0day bot)

> 

> v3 changes:

> - add jailhouse specific change

> - avoid include file header by relying on another

>   patch ("timekeeping: Remove timespec64 hack")

> 

> Not sure how we want to merge this (assuming the last modification

> worked, this has seen little testing). The "timekeeping: Remove

> timespec64 hack" patch should go through the timekeeping branch

> in tip, while this one is for x86. I assume the linux-tip maintainers

> can come up with a plan.

> ---

> diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h

> @@ -12,7 +12,7 @@ void pvclock_set_flags(u8 flags);

>  unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src);

>  void pvclock_read_wallclock(struct pvclock_wall_clock *wall,

>  			    struct pvclock_vcpu_time_info *vcpu,

> -			    struct timespec *ts);

> +			    struct timespec64 *ts);

>  void pvclock_resume(void);

>  

>  void pvclock_touch_watchdogs(void);

> diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c

> @@ -53,7 +53,7 @@ static struct pvclock_wall_clock *wall_clock;

>   * have elapsed since the hypervisor wrote the data. So we try to account for

>   * that with system time

>   */

> -static void kvm_get_wallclock(struct timespec *now)

> +static void kvm_get_wallclock(struct timespec64 *now)

>  {

>  	struct pvclock_vcpu_time_info *vcpu_time;

>  	int low, high;

> @@ -72,7 +72,7 @@ static void kvm_get_wallclock(struct timespec *now)

>  	put_cpu();

>  }

>  

> -static int kvm_set_wallclock(const struct timespec *now)

> +static int kvm_set_wallclock(const struct timespec64 *now)

>  {

>  	return -ENODEV;

>  }

> diff --git 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.

> +		 */


(Modern TSC extensions stripped pvclock of all advantages, so we'll
 likely abandon pvclock by then.)

>  		now.tv_sec  = wall_clock->sec;

>  		now.tv_nsec = wall_clock->nsec;

>  		rmb();		/* fetch time before checking version */

>  	} while ((wall_clock->version & 1) || (version != wall_clock->version));

>  

>  	delta = pvclock_clocksource_read(vcpu_time);	/* time since system boot */

> -	delta += now.tv_sec * (u64)NSEC_PER_SEC + now.tv_nsec;

> +	delta += now.tv_sec * NSEC_PER_SEC + now.tv_nsec;

>  

>  	now.tv_nsec = do_div(delta, NSEC_PER_SEC);

>  	now.tv_sec = delta;

>  

> -	set_normalized_timespec(ts, now.tv_sec, now.tv_nsec);

> +	set_normalized_timespec64(ts, now.tv_sec, now.tv_nsec);

>  }

>  

>  void pvclock_set_pvti_cpu0_va(struct pvclock_vsyscall_time_info *pvti)


kvmclock and pvclock changes

Acked-by: Radim Krčmář <rkrcmar@redhat.com>
Joao Martins April 27, 2018, 10:21 p.m. | #2
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
Jan Kiszka April 28, 2018, 7:25 a.m. | #3
On 2018-04-27 22:13, Arnd Bergmann wrote:
> The x86 platform operations are fairly isolated, so we can

> change them from using timespec to timespec64. I checked that

> All the users and callers are safe, and there is only one

> critical function that is broken beyond 2106:

> 

> pvclock_read_wallclock() uses a 32-bit number of seconds since

> the epoch to communicate the boot time between host and guest

> in a virtual environment. This will work until 2106, but we

> should ideally find a replacement anyway. I've added a comment

> about it there.

> 

> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

> ---

> v2 changes:

> - move comment block (Boris)

> - remove unnecessary type cast (Boris)

> - fix format string (0day bot)

> - fix include order (0day bot)

> 

> v3 changes:

> - add jailhouse specific change

> - avoid include file header by relying on another

>   patch ("timekeeping: Remove timespec64 hack")

> 

> Not sure how we want to merge this (assuming the last modification

> worked, this has seen little testing). The "timekeeping: Remove

> timespec64 hack" patch should go through the timekeeping branch

> in tip, while this one is for x86. I assume the linux-tip maintainers

> can come up with a plan.

> ---

>  arch/x86/include/asm/intel_mid_vrtc.h        |  4 ++--

>  arch/x86/include/asm/mc146818rtc.h           |  4 ++--

>  arch/x86/include/asm/pvclock.h               |  2 +-

>  arch/x86/include/asm/x86_init.h              |  6 +++---

>  arch/x86/kernel/jailhouse.c                  |  2 +-

>  arch/x86/kernel/kvmclock.c                   |  4 ++--

>  arch/x86/kernel/pvclock.c                    | 15 +++++++++++----

>  arch/x86/kernel/rtc.c                        | 10 +++++-----

>  arch/x86/platform/intel-mid/intel_mid_vrtc.c | 12 ++++++------

>  arch/x86/xen/time.c                          | 10 +++++-----

>  10 files changed, 38 insertions(+), 31 deletions(-)

> 

> diff --git a/arch/x86/include/asm/intel_mid_vrtc.h b/arch/x86/include/asm/intel_mid_vrtc.h

> index 35555016b1be..0b44b1abe4d9 100644

> --- a/arch/x86/include/asm/intel_mid_vrtc.h

> +++ b/arch/x86/include/asm/intel_mid_vrtc.h

> @@ -4,7 +4,7 @@

>  

>  extern unsigned char vrtc_cmos_read(unsigned char reg);

>  extern void vrtc_cmos_write(unsigned char val, unsigned char reg);

> -extern void vrtc_get_time(struct timespec *now);

> -extern int vrtc_set_mmss(const struct timespec *now);

> +extern void vrtc_get_time(struct timespec64 *now);

> +extern int vrtc_set_mmss(const struct timespec64 *now);

>  

>  #endif

> diff --git a/arch/x86/include/asm/mc146818rtc.h b/arch/x86/include/asm/mc146818rtc.h

> index 1775a32f7ea6..97198001e567 100644

> --- a/arch/x86/include/asm/mc146818rtc.h

> +++ b/arch/x86/include/asm/mc146818rtc.h

> @@ -95,8 +95,8 @@ static inline unsigned char current_lock_cmos_reg(void)

>  unsigned char rtc_cmos_read(unsigned char addr);

>  void rtc_cmos_write(unsigned char val, unsigned char addr);

>  

> -extern int mach_set_rtc_mmss(const struct timespec *now);

> -extern void mach_get_cmos_time(struct timespec *now);

> +extern int mach_set_rtc_mmss(const struct timespec64 *now);

> +extern void mach_get_cmos_time(struct timespec64 *now);

>  

>  #define RTC_IRQ 8

>  

> diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h

> index a7471dcd2205..b6033680d458 100644

> --- a/arch/x86/include/asm/pvclock.h

> +++ b/arch/x86/include/asm/pvclock.h

> @@ -12,7 +12,7 @@ void pvclock_set_flags(u8 flags);

>  unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src);

>  void pvclock_read_wallclock(struct pvclock_wall_clock *wall,

>  			    struct pvclock_vcpu_time_info *vcpu,

> -			    struct timespec *ts);

> +			    struct timespec64 *ts);

>  void pvclock_resume(void);

>  

>  void pvclock_touch_watchdogs(void);

> diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h

> index ce8b4da07e35..2d27236c16a3 100644

> --- a/arch/x86/include/asm/x86_init.h

> +++ b/arch/x86/include/asm/x86_init.h

> @@ -170,7 +170,7 @@ struct x86_cpuinit_ops {

>  	void (*fixup_cpu_id)(struct cpuinfo_x86 *c, int node);

>  };

>  

> -struct timespec;

> +struct timespec64;

>  

>  /**

>   * struct x86_legacy_devices - legacy x86 devices

> @@ -264,8 +264,8 @@ struct x86_hyper_runtime {

>  struct x86_platform_ops {

>  	unsigned long (*calibrate_cpu)(void);

>  	unsigned long (*calibrate_tsc)(void);

> -	void (*get_wallclock)(struct timespec *ts);

> -	int (*set_wallclock)(const struct timespec *ts);

> +	void (*get_wallclock)(struct timespec64 *ts);

> +	int (*set_wallclock)(const struct timespec64 *ts);

>  	void (*iommu_shutdown)(void);

>  	bool (*is_untracked_pat_range)(u64 start, u64 end);

>  	void (*nmi_init)(void);

> diff --git a/arch/x86/kernel/jailhouse.c b/arch/x86/kernel/jailhouse.c

> index fa183a131edc..a0b05bf185ac 100644

> --- a/arch/x86/kernel/jailhouse.c

> +++ b/arch/x86/kernel/jailhouse.c

> @@ -37,7 +37,7 @@ static uint32_t __init jailhouse_detect(void)

>  	return jailhouse_cpuid_base();

>  }

>  

> -static void jailhouse_get_wallclock(struct timespec *now)

> +static void jailhouse_get_wallclock(struct timespec64 *now)

>  {

>  	memset(now, 0, sizeof(*now));

>  }

> diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c

> index 8b26c9e01cc4..bf8d1eb7fca3 100644

> --- a/arch/x86/kernel/kvmclock.c

> +++ b/arch/x86/kernel/kvmclock.c

> @@ -53,7 +53,7 @@ static struct pvclock_wall_clock *wall_clock;

>   * have elapsed since the hypervisor wrote the data. So we try to account for

>   * that with system time

>   */

> -static void kvm_get_wallclock(struct timespec *now)

> +static void kvm_get_wallclock(struct timespec64 *now)

>  {

>  	struct pvclock_vcpu_time_info *vcpu_time;

>  	int low, high;

> @@ -72,7 +72,7 @@ static void kvm_get_wallclock(struct timespec *now)

>  	put_cpu();

>  }

>  

> -static int kvm_set_wallclock(const struct timespec *now)

> +static int kvm_set_wallclock(const struct timespec64 *now)

>  {

>  	return -ENODEV;

>  }

> 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;

>  		now.tv_nsec = wall_clock->nsec;

>  		rmb();		/* fetch time before checking version */

>  	} while ((wall_clock->version & 1) || (version != wall_clock->version));

>  

>  	delta = pvclock_clocksource_read(vcpu_time);	/* time since system boot */

> -	delta += now.tv_sec * (u64)NSEC_PER_SEC + now.tv_nsec;

> +	delta += now.tv_sec * NSEC_PER_SEC + now.tv_nsec;

>  

>  	now.tv_nsec = do_div(delta, NSEC_PER_SEC);

>  	now.tv_sec = delta;

>  

> -	set_normalized_timespec(ts, now.tv_sec, now.tv_nsec);

> +	set_normalized_timespec64(ts, now.tv_sec, now.tv_nsec);

>  }

>  

>  void pvclock_set_pvti_cpu0_va(struct pvclock_vsyscall_time_info *pvti)

> diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c

> index f7b82ed7b5b5..586f718b8e95 100644

> --- a/arch/x86/kernel/rtc.c

> +++ b/arch/x86/kernel/rtc.c

> @@ -39,7 +39,7 @@ EXPORT_SYMBOL(rtc_lock);

>   * jump to the next second precisely 500 ms later. Check the Motorola

>   * MC146818A or Dallas DS12887 data sheet for details.

>   */

> -int mach_set_rtc_mmss(const struct timespec *now)

> +int mach_set_rtc_mmss(const struct timespec64 *now)

>  {

>  	unsigned long long nowtime = now->tv_sec;

>  	struct rtc_time tm;

> @@ -60,7 +60,7 @@ int mach_set_rtc_mmss(const struct timespec *now)

>  	return retval;

>  }

>  

> -void mach_get_cmos_time(struct timespec *now)

> +void mach_get_cmos_time(struct timespec64 *now)

>  {

>  	unsigned int status, year, mon, day, hour, min, sec, century = 0;

>  	unsigned long flags;

> @@ -118,7 +118,7 @@ void mach_get_cmos_time(struct timespec *now)

>  	} else

>  		year += CMOS_YEARS_OFFS;

>  

> -	now->tv_sec = mktime(year, mon, day, hour, min, sec);

> +	now->tv_sec = mktime64(year, mon, day, hour, min, sec);

>  	now->tv_nsec = 0;

>  }

>  

> @@ -145,13 +145,13 @@ void rtc_cmos_write(unsigned char val, unsigned char addr)

>  }

>  EXPORT_SYMBOL(rtc_cmos_write);

>  

> -int update_persistent_clock(struct timespec now)

> +int update_persistent_clock64(struct timespec64 now)

>  {

>  	return x86_platform.set_wallclock(&now);

>  }

>  

>  /* not static: needed by APM */

> -void read_persistent_clock(struct timespec *ts)

> +void read_persistent_clock64(struct timespec64 *ts)

>  {

>  	x86_platform.get_wallclock(ts);

>  }

> diff --git a/arch/x86/platform/intel-mid/intel_mid_vrtc.c b/arch/x86/platform/intel-mid/intel_mid_vrtc.c

> index 58024862a7eb..a52914aa3b6c 100644

> --- a/arch/x86/platform/intel-mid/intel_mid_vrtc.c

> +++ b/arch/x86/platform/intel-mid/intel_mid_vrtc.c

> @@ -57,7 +57,7 @@ void vrtc_cmos_write(unsigned char val, unsigned char reg)

>  }

>  EXPORT_SYMBOL_GPL(vrtc_cmos_write);

>  

> -void vrtc_get_time(struct timespec *now)

> +void vrtc_get_time(struct timespec64 *now)

>  {

>  	u8 sec, min, hour, mday, mon;

>  	unsigned long flags;

> @@ -83,18 +83,18 @@ void vrtc_get_time(struct timespec *now)

>  	pr_info("vRTC: sec: %d min: %d hour: %d day: %d "

>  		"mon: %d year: %d\n", sec, min, hour, mday, mon, year);

>  

> -	now->tv_sec = mktime(year, mon, mday, hour, min, sec);

> +	now->tv_sec = mktime64(year, mon, mday, hour, min, sec);

>  	now->tv_nsec = 0;

>  }

>  

> -int vrtc_set_mmss(const struct timespec *now)

> +int vrtc_set_mmss(const struct timespec64 *now)

>  {

>  	unsigned long flags;

>  	struct rtc_time tm;

>  	int year;

>  	int retval = 0;

>  

> -	rtc_time_to_tm(now->tv_sec, &tm);

> +	rtc_time64_to_tm(now->tv_sec, &tm);

>  	if (!rtc_valid_tm(&tm) && tm.tm_year >= 72) {

>  		/*

>  		 * tm.year is the number of years since 1900, and the

> @@ -110,8 +110,8 @@ int vrtc_set_mmss(const struct timespec *now)

>  		vrtc_cmos_write(tm.tm_sec, RTC_SECONDS);

>  		spin_unlock_irqrestore(&rtc_lock, flags);

>  	} else {

> -		pr_err("%s: Invalid vRTC value: write of %lx to vRTC failed\n",

> -			__func__, now->tv_sec);

> +		pr_err("%s: Invalid vRTC value: write of %llx to vRTC failed\n",

> +			__func__, (s64)now->tv_sec);

>  		retval = -EINVAL;

>  	}

>  	return retval;

> diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c

> index 29163c43ebbd..e0f1bcf01d63 100644

> --- a/arch/x86/xen/time.c

> +++ b/arch/x86/xen/time.c

> @@ -57,7 +57,7 @@ static u64 xen_clocksource_get_cycles(struct clocksource *cs)

>  	return xen_clocksource_read();

>  }

>  

> -static void xen_read_wallclock(struct timespec *ts)

> +static void xen_read_wallclock(struct timespec64 *ts)

>  {

>  	struct shared_info *s = HYPERVISOR_shared_info;

>  	struct pvclock_wall_clock *wall_clock = &(s->wc);

> @@ -68,12 +68,12 @@ static void xen_read_wallclock(struct timespec *ts)

>  	put_cpu_var(xen_vcpu);

>  }

>  

> -static void xen_get_wallclock(struct timespec *now)

> +static void xen_get_wallclock(struct timespec64 *now)

>  {

>  	xen_read_wallclock(now);

>  }

>  

> -static int xen_set_wallclock(const struct timespec *now)

> +static int xen_set_wallclock(const struct timespec64 *now)

>  {

>  	return -ENODEV;

>  }

> @@ -461,7 +461,7 @@ static void __init xen_time_init(void)

>  {

>  	struct pvclock_vcpu_time_info *pvti;

>  	int cpu = smp_processor_id();

> -	struct timespec tp;

> +	struct timespec64 tp;

>  

>  	/* As Dom0 is never moved, no penalty on using TSC there */

>  	if (xen_initial_domain())

> @@ -479,7 +479,7 @@ static void __init xen_time_init(void)

>  

>  	/* Set initial system time with full resolution */

>  	xen_read_wallclock(&tp);

> -	do_settimeofday(&tp);

> +	do_settimeofday64(&tp);

>  

>  	setup_force_cpu_cap(X86_FEATURE_TSC);

>  

> 


For the few Jailhouse bits.

Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Arnd Bergmann April 28, 2018, 10:09 a.m. | #4
On Sat, Apr 28, 2018 at 12:21 AM, Joao Martins
<joao.m.martins@oracle.com> wrote:
> 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


Ah, good. How portable is that? Will it do the right thing (i.e.
guarantee to have
zeroes on the upper half, or the epoch if supported) on all versions of both KVM
and Xen, or do we need an additional check in there?

I'd suggest leaving the implementation of that to a follow-up patch that you
can add once my patch is merged.

        Arnd
Joao Martins May 2, 2018, 4:44 p.m. | #5
On 04/28/2018 11:09 AM, Arnd Bergmann wrote:
> On Sat, Apr 28, 2018 at 12:21 AM, Joao Martins

> <joao.m.martins@oracle.com> wrote:

>> 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

> 

> Ah, good. How portable is that? Will it do the right thing (i.e.

> guarantee to have

> zeroes on the upper half, or the epoch if supported) on all versions of both KVM

> and Xen, or do we need an additional check in there?

>

The whole shared info page is zeroed out by Xen when allocated, so on
unsupported platforms that includes the upper half. But I don't know if this is
considered ABI or not. FWIW, the oldest release (2.0) has that behavior.

But this is Xen that I'm speaking about; KVM doesn't support this IIUC.

On KVM, there's HC_CLOCK_PAIRING hypercall or else *maybe* host could just write
wc_sec_hi at the end of the wall_clock struct (with the current MSR) and given
that it's (PAGE_SIZE aligned) guest memory, guest could always keep it zeroed
out for unsupported platforms (that won't write more than 12bytes).

> I'd suggest leaving the implementation of that to a follow-up patch that you

> can add once my patch is merged.


/nods

	Joao

Patch

diff --git a/arch/x86/include/asm/intel_mid_vrtc.h b/arch/x86/include/asm/intel_mid_vrtc.h
index 35555016b1be..0b44b1abe4d9 100644
--- a/arch/x86/include/asm/intel_mid_vrtc.h
+++ b/arch/x86/include/asm/intel_mid_vrtc.h
@@ -4,7 +4,7 @@ 
 
 extern unsigned char vrtc_cmos_read(unsigned char reg);
 extern void vrtc_cmos_write(unsigned char val, unsigned char reg);
-extern void vrtc_get_time(struct timespec *now);
-extern int vrtc_set_mmss(const struct timespec *now);
+extern void vrtc_get_time(struct timespec64 *now);
+extern int vrtc_set_mmss(const struct timespec64 *now);
 
 #endif
diff --git a/arch/x86/include/asm/mc146818rtc.h b/arch/x86/include/asm/mc146818rtc.h
index 1775a32f7ea6..97198001e567 100644
--- a/arch/x86/include/asm/mc146818rtc.h
+++ b/arch/x86/include/asm/mc146818rtc.h
@@ -95,8 +95,8 @@  static inline unsigned char current_lock_cmos_reg(void)
 unsigned char rtc_cmos_read(unsigned char addr);
 void rtc_cmos_write(unsigned char val, unsigned char addr);
 
-extern int mach_set_rtc_mmss(const struct timespec *now);
-extern void mach_get_cmos_time(struct timespec *now);
+extern int mach_set_rtc_mmss(const struct timespec64 *now);
+extern void mach_get_cmos_time(struct timespec64 *now);
 
 #define RTC_IRQ 8
 
diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h
index a7471dcd2205..b6033680d458 100644
--- a/arch/x86/include/asm/pvclock.h
+++ b/arch/x86/include/asm/pvclock.h
@@ -12,7 +12,7 @@  void pvclock_set_flags(u8 flags);
 unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src);
 void pvclock_read_wallclock(struct pvclock_wall_clock *wall,
 			    struct pvclock_vcpu_time_info *vcpu,
-			    struct timespec *ts);
+			    struct timespec64 *ts);
 void pvclock_resume(void);
 
 void pvclock_touch_watchdogs(void);
diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index ce8b4da07e35..2d27236c16a3 100644
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -170,7 +170,7 @@  struct x86_cpuinit_ops {
 	void (*fixup_cpu_id)(struct cpuinfo_x86 *c, int node);
 };
 
-struct timespec;
+struct timespec64;
 
 /**
  * struct x86_legacy_devices - legacy x86 devices
@@ -264,8 +264,8 @@  struct x86_hyper_runtime {
 struct x86_platform_ops {
 	unsigned long (*calibrate_cpu)(void);
 	unsigned long (*calibrate_tsc)(void);
-	void (*get_wallclock)(struct timespec *ts);
-	int (*set_wallclock)(const struct timespec *ts);
+	void (*get_wallclock)(struct timespec64 *ts);
+	int (*set_wallclock)(const struct timespec64 *ts);
 	void (*iommu_shutdown)(void);
 	bool (*is_untracked_pat_range)(u64 start, u64 end);
 	void (*nmi_init)(void);
diff --git a/arch/x86/kernel/jailhouse.c b/arch/x86/kernel/jailhouse.c
index fa183a131edc..a0b05bf185ac 100644
--- a/arch/x86/kernel/jailhouse.c
+++ b/arch/x86/kernel/jailhouse.c
@@ -37,7 +37,7 @@  static uint32_t __init jailhouse_detect(void)
 	return jailhouse_cpuid_base();
 }
 
-static void jailhouse_get_wallclock(struct timespec *now)
+static void jailhouse_get_wallclock(struct timespec64 *now)
 {
 	memset(now, 0, sizeof(*now));
 }
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 8b26c9e01cc4..bf8d1eb7fca3 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -53,7 +53,7 @@  static struct pvclock_wall_clock *wall_clock;
  * have elapsed since the hypervisor wrote the data. So we try to account for
  * that with system time
  */
-static void kvm_get_wallclock(struct timespec *now)
+static void kvm_get_wallclock(struct timespec64 *now)
 {
 	struct pvclock_vcpu_time_info *vcpu_time;
 	int low, high;
@@ -72,7 +72,7 @@  static void kvm_get_wallclock(struct timespec *now)
 	put_cpu();
 }
 
-static int kvm_set_wallclock(const struct timespec *now)
+static int kvm_set_wallclock(const struct timespec64 *now)
 {
 	return -ENODEV;
 }
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;
 		now.tv_nsec = wall_clock->nsec;
 		rmb();		/* fetch time before checking version */
 	} while ((wall_clock->version & 1) || (version != wall_clock->version));
 
 	delta = pvclock_clocksource_read(vcpu_time);	/* time since system boot */
-	delta += now.tv_sec * (u64)NSEC_PER_SEC + now.tv_nsec;
+	delta += now.tv_sec * NSEC_PER_SEC + now.tv_nsec;
 
 	now.tv_nsec = do_div(delta, NSEC_PER_SEC);
 	now.tv_sec = delta;
 
-	set_normalized_timespec(ts, now.tv_sec, now.tv_nsec);
+	set_normalized_timespec64(ts, now.tv_sec, now.tv_nsec);
 }
 
 void pvclock_set_pvti_cpu0_va(struct pvclock_vsyscall_time_info *pvti)
diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c
index f7b82ed7b5b5..586f718b8e95 100644
--- a/arch/x86/kernel/rtc.c
+++ b/arch/x86/kernel/rtc.c
@@ -39,7 +39,7 @@  EXPORT_SYMBOL(rtc_lock);
  * jump to the next second precisely 500 ms later. Check the Motorola
  * MC146818A or Dallas DS12887 data sheet for details.
  */
-int mach_set_rtc_mmss(const struct timespec *now)
+int mach_set_rtc_mmss(const struct timespec64 *now)
 {
 	unsigned long long nowtime = now->tv_sec;
 	struct rtc_time tm;
@@ -60,7 +60,7 @@  int mach_set_rtc_mmss(const struct timespec *now)
 	return retval;
 }
 
-void mach_get_cmos_time(struct timespec *now)
+void mach_get_cmos_time(struct timespec64 *now)
 {
 	unsigned int status, year, mon, day, hour, min, sec, century = 0;
 	unsigned long flags;
@@ -118,7 +118,7 @@  void mach_get_cmos_time(struct timespec *now)
 	} else
 		year += CMOS_YEARS_OFFS;
 
-	now->tv_sec = mktime(year, mon, day, hour, min, sec);
+	now->tv_sec = mktime64(year, mon, day, hour, min, sec);
 	now->tv_nsec = 0;
 }
 
@@ -145,13 +145,13 @@  void rtc_cmos_write(unsigned char val, unsigned char addr)
 }
 EXPORT_SYMBOL(rtc_cmos_write);
 
-int update_persistent_clock(struct timespec now)
+int update_persistent_clock64(struct timespec64 now)
 {
 	return x86_platform.set_wallclock(&now);
 }
 
 /* not static: needed by APM */
-void read_persistent_clock(struct timespec *ts)
+void read_persistent_clock64(struct timespec64 *ts)
 {
 	x86_platform.get_wallclock(ts);
 }
diff --git a/arch/x86/platform/intel-mid/intel_mid_vrtc.c b/arch/x86/platform/intel-mid/intel_mid_vrtc.c
index 58024862a7eb..a52914aa3b6c 100644
--- a/arch/x86/platform/intel-mid/intel_mid_vrtc.c
+++ b/arch/x86/platform/intel-mid/intel_mid_vrtc.c
@@ -57,7 +57,7 @@  void vrtc_cmos_write(unsigned char val, unsigned char reg)
 }
 EXPORT_SYMBOL_GPL(vrtc_cmos_write);
 
-void vrtc_get_time(struct timespec *now)
+void vrtc_get_time(struct timespec64 *now)
 {
 	u8 sec, min, hour, mday, mon;
 	unsigned long flags;
@@ -83,18 +83,18 @@  void vrtc_get_time(struct timespec *now)
 	pr_info("vRTC: sec: %d min: %d hour: %d day: %d "
 		"mon: %d year: %d\n", sec, min, hour, mday, mon, year);
 
-	now->tv_sec = mktime(year, mon, mday, hour, min, sec);
+	now->tv_sec = mktime64(year, mon, mday, hour, min, sec);
 	now->tv_nsec = 0;
 }
 
-int vrtc_set_mmss(const struct timespec *now)
+int vrtc_set_mmss(const struct timespec64 *now)
 {
 	unsigned long flags;
 	struct rtc_time tm;
 	int year;
 	int retval = 0;
 
-	rtc_time_to_tm(now->tv_sec, &tm);
+	rtc_time64_to_tm(now->tv_sec, &tm);
 	if (!rtc_valid_tm(&tm) && tm.tm_year >= 72) {
 		/*
 		 * tm.year is the number of years since 1900, and the
@@ -110,8 +110,8 @@  int vrtc_set_mmss(const struct timespec *now)
 		vrtc_cmos_write(tm.tm_sec, RTC_SECONDS);
 		spin_unlock_irqrestore(&rtc_lock, flags);
 	} else {
-		pr_err("%s: Invalid vRTC value: write of %lx to vRTC failed\n",
-			__func__, now->tv_sec);
+		pr_err("%s: Invalid vRTC value: write of %llx to vRTC failed\n",
+			__func__, (s64)now->tv_sec);
 		retval = -EINVAL;
 	}
 	return retval;
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 29163c43ebbd..e0f1bcf01d63 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -57,7 +57,7 @@  static u64 xen_clocksource_get_cycles(struct clocksource *cs)
 	return xen_clocksource_read();
 }
 
-static void xen_read_wallclock(struct timespec *ts)
+static void xen_read_wallclock(struct timespec64 *ts)
 {
 	struct shared_info *s = HYPERVISOR_shared_info;
 	struct pvclock_wall_clock *wall_clock = &(s->wc);
@@ -68,12 +68,12 @@  static void xen_read_wallclock(struct timespec *ts)
 	put_cpu_var(xen_vcpu);
 }
 
-static void xen_get_wallclock(struct timespec *now)
+static void xen_get_wallclock(struct timespec64 *now)
 {
 	xen_read_wallclock(now);
 }
 
-static int xen_set_wallclock(const struct timespec *now)
+static int xen_set_wallclock(const struct timespec64 *now)
 {
 	return -ENODEV;
 }
@@ -461,7 +461,7 @@  static void __init xen_time_init(void)
 {
 	struct pvclock_vcpu_time_info *pvti;
 	int cpu = smp_processor_id();
-	struct timespec tp;
+	struct timespec64 tp;
 
 	/* As Dom0 is never moved, no penalty on using TSC there */
 	if (xen_initial_domain())
@@ -479,7 +479,7 @@  static void __init xen_time_init(void)
 
 	/* Set initial system time with full resolution */
 	xen_read_wallclock(&tp);
-	do_settimeofday(&tp);
+	do_settimeofday64(&tp);
 
 	setup_force_cpu_cap(X86_FEATURE_TSC);