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x86/vdso: Use generic VDSO clock mode storage

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Switch to the generic VDSO clock mode storage.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> (VDSO parts)
Acked-by: Juergen Gross <jgross@suse.com> (Xen parts)
Acked-by: Paolo Bonzini <pbonzini@redhat.com> (KVM parts)
Link: https://lkml.kernel.org/r/20200207124403.152039903@linutronix.de
This commit is contained in:
Thomas Gleixner
2020-02-07 13:38:56 +01:00
parent 5d51bee725
commit b95a8a27c3
13 changed files with 46 additions and 63 deletions
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21
arch/x86/xen/time.c
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@@ -147,7 +147,7 @@ static struct notifier_block xen_pvclock_gtod_notifier = {
static int xen_cs_enable(struct clocksource *cs)
{
vclocks_set_used(VCLOCK_PVCLOCK);
vclocks_set_used(VDSO_CLOCKMODE_PVCLOCK);
return 0;
}
@@ -419,12 +419,13 @@ void xen_restore_time_memory_area(void)
ret = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_time_memory_area, 0, &t);
/*
* We don't disable VCLOCK_PVCLOCK entirely if it fails to register the
* secondary time info with Xen or if we migrated to a host without the
* necessary flags. On both of these cases what happens is either
* process seeing a zeroed out pvti or seeing no PVCLOCK_TSC_STABLE_BIT
* bit set. Userspace checks the latter and if 0, it discards the data
* in pvti and fallbacks to a system call for a reliable timestamp.
* We don't disable VDSO_CLOCKMODE_PVCLOCK entirely if it fails to
* register the secondary time info with Xen or if we migrated to a
* host without the necessary flags. On both of these cases what
* happens is either process seeing a zeroed out pvti or seeing no
* PVCLOCK_TSC_STABLE_BIT bit set. Userspace checks the latter and
* if 0, it discards the data in pvti and fallbacks to a system
* call for a reliable timestamp.
*/
if (ret != 0)
pr_notice("Cannot restore secondary vcpu_time_info (err %d)",
@@ -450,7 +451,7 @@ static void xen_setup_vsyscall_time_info(void)
ret = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_time_memory_area, 0, &t);
if (ret) {
pr_notice("xen: VCLOCK_PVCLOCK not supported (err %d)\n", ret);
pr_notice("xen: VDSO_CLOCKMODE_PVCLOCK not supported (err %d)\n", ret);
free_page((unsigned long)ti);
return;
}
@@ -467,14 +468,14 @@ static void xen_setup_vsyscall_time_info(void)
if (!ret)
free_page((unsigned long)ti);
pr_notice("xen: VCLOCK_PVCLOCK not supported (tsc unstable)\n");
pr_notice("xen: VDSO_CLOCKMODE_PVCLOCK not supported (tsc unstable)\n");
return;
}
xen_clock = ti;
pvclock_set_pvti_cpu0_va(xen_clock);
xen_clocksource.archdata.vclock_mode = VCLOCK_PVCLOCK;
xen_clocksource.vdso_clock_mode = VDSO_CLOCKMODE_PVCLOCK;
}
static void __init xen_time_init(void)