From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefano Stabellini Subject: [PATCH v4 6/7] xen/arm: set the system time in Xen via the XENPF_settime64 hypercall Date: Thu, 12 Nov 2015 17:30:47 +0000 Message-ID: <1447349448-22610-6-git-send-email-stefano.stabellini@eu.citrix.com> References: Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: xen-devel@lists.xensource.com Cc: linux-arm-kernel@lists.infradead.org, Stefano.Stabellini@eu.citrix.com, Ian.Campbell@citrix.com, linux-kernel@vger.kernel.org, Stefano Stabellini , Arnd Bergmann List-Id: xen-devel@lists.xenproject.org If Linux is running as dom0, call XENPF_settime64 to update the system time in Xen on pvclock_gtod notifications. Signed-off-by: Stefano Stabellini Acked-by: Arnd Bergmann --- Changes in v3: - s/%llu.%0u/%llu.%09u - in xen_pvclock_gtod_notify use the passed struct timekeeper pointer rather than calling __current_kernel_time64 - use the passed struct timekeeper pointer to get the system time too Changes in v2: - properly convert arch_timer ticker to nsec - rename dom0_op to platform_op - use timespec64 interfaces - use XENPF_settime64 --- arch/arm/xen/enlighten.c | 55 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 54 insertions(+), 1 deletion(-) diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index 6ae4ef5..613f7e0 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -28,7 +28,10 @@ #include #include #include +#include +#include #include +#include #include @@ -117,6 +120,54 @@ static void xen_read_wallclock(struct timespec64 *ts) *ts = timespec64_add(now, ts_monotonic); } +static int xen_pvclock_gtod_notify(struct notifier_block *nb, + unsigned long was_set, void *priv) +{ + /* Protected by the calling core code serialization */ + static struct timespec64 next_sync; + + struct xen_platform_op op; + struct timespec64 now, system_time; + struct timekeeper *tk = priv; + + now.tv_sec = tk->xtime_sec; + now.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); + system_time = timespec64_add(now, tk->wall_to_monotonic); + + /* + * We only take the expensive HV call when the clock was set + * or when the 11 minutes RTC synchronization time elapsed. + */ + if (!was_set && timespec64_compare(&now, &next_sync) < 0) + return NOTIFY_OK; + + op.interface_version = XENPF_INTERFACE_VERSION; + op.cmd = XENPF_settime64; + op.u.settime64.mbz = 0; + op.u.settime64.secs = now.tv_sec; + op.u.settime64.nsecs = now.tv_nsec; + op.u.settime64.system_time = timespec64_to_ns(&system_time); + printk("GTOD: Setting to %llu.%09u at %llu\n", + op.u.settime64.secs, + op.u.settime64.nsecs, + op.u.settime64.system_time); + (void)HYPERVISOR_platform_op(&op); + + /* + * Move the next drift compensation time 11 minutes + * ahead. That's emulating the sync_cmos_clock() update for + * the hardware RTC. + */ + next_sync = now; + next_sync.tv_sec += 11 * 60; + + return NOTIFY_OK; +} + +static struct notifier_block xen_pvclock_gtod_notifier = { + .notifier_call = xen_pvclock_gtod_notify, +}; + static void xen_percpu_init(void) { struct vcpu_register_vcpu_info info; @@ -313,7 +364,9 @@ static int __init xen_guest_init(void) pv_time_ops.steal_clock = xen_stolen_accounting; static_key_slow_inc(¶virt_steal_enabled); - + if (xen_initial_domain()) + pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier); + return 0; } early_initcall(xen_guest_init); -- 1.7.10.4