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authorJuergen Gross <jgross@suse.com>2016-05-20 09:26:48 +0200
committerDavid Vrabel <david.vrabel@citrix.com>2016-07-06 10:34:48 +0100
commitecb23dc6f2eff0ce64dd60351a81f376f13b12cc (patch)
tree09536e5db2dc00af9dd5209fef72a1e1222f6cf2 /arch
parentc7ebf9d9c6b4e9402b978da0b0785db4129c1f79 (diff)
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xen: add steal_clock support on x86
The pv_time_ops structure contains a function pointer for the "steal_clock" functionality used only by KVM and Xen on ARM. Xen on x86 uses its own mechanism to account for the "stolen" time a thread wasn't able to run due to hypervisor scheduling. Add support in Xen arch independent time handling for this feature by moving it out of the arm arch into drivers/xen and remove the x86 Xen hack. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/xen/enlighten.c18
-rw-r--r--arch/x86/xen/time.c44
2 files changed, 4 insertions, 58 deletions
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index d4f36eba3499..47acb3613f40 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -12,7 +12,6 @@
#include <xen/page.h>
#include <xen/interface/sched.h>
#include <xen/xen-ops.h>
-#include <asm/paravirt.h>
#include <asm/xen/hypervisor.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/xen-ops.h>
@@ -86,19 +85,6 @@ int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
}
EXPORT_SYMBOL_GPL(xen_unmap_domain_gfn_range);
-static unsigned long long xen_stolen_accounting(int cpu)
-{
- struct vcpu_runstate_info state;
-
- BUG_ON(cpu != smp_processor_id());
-
- xen_get_runstate_snapshot(&state);
-
- WARN_ON(state.state != RUNSTATE_running);
-
- return state.time[RUNSTATE_runnable] + state.time[RUNSTATE_offline];
-}
-
static void xen_read_wallclock(struct timespec64 *ts)
{
u32 version;
@@ -432,8 +418,8 @@ static int __init xen_guest_init(void)
register_cpu_notifier(&xen_cpu_notifier);
- pv_time_ops.steal_clock = xen_stolen_accounting;
- static_key_slow_inc(&paravirt_steal_enabled);
+ xen_time_setup_guest();
+
if (xen_initial_domain())
pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 6deba5bc7e34..c31006f0f37f 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -11,8 +11,6 @@
#include <linux/interrupt.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
-#include <linux/kernel_stat.h>
-#include <linux/math64.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/pvclock_gtod.h>
@@ -31,44 +29,6 @@
/* Xen may fire a timer up to this many ns early */
#define TIMER_SLOP 100000
-#define NS_PER_TICK (1000000000LL / HZ)
-
-/* snapshots of runstate info */
-static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate_snapshot);
-
-/* unused ns of stolen time */
-static DEFINE_PER_CPU(u64, xen_residual_stolen);
-
-static void do_stolen_accounting(void)
-{
- struct vcpu_runstate_info state;
- struct vcpu_runstate_info *snap;
- s64 runnable, offline, stolen;
- cputime_t ticks;
-
- xen_get_runstate_snapshot(&state);
-
- WARN_ON(state.state != RUNSTATE_running);
-
- snap = this_cpu_ptr(&xen_runstate_snapshot);
-
- /* work out how much time the VCPU has not been runn*ing* */
- runnable = state.time[RUNSTATE_runnable] - snap->time[RUNSTATE_runnable];
- offline = state.time[RUNSTATE_offline] - snap->time[RUNSTATE_offline];
-
- *snap = state;
-
- /* Add the appropriate number of ticks of stolen time,
- including any left-overs from last time. */
- stolen = runnable + offline + __this_cpu_read(xen_residual_stolen);
-
- if (stolen < 0)
- stolen = 0;
-
- ticks = iter_div_u64_rem(stolen, NS_PER_TICK, &stolen);
- __this_cpu_write(xen_residual_stolen, stolen);
- account_steal_ticks(ticks);
-}
/* Get the TSC speed from Xen */
static unsigned long xen_tsc_khz(void)
@@ -335,8 +295,6 @@ static irqreturn_t xen_timer_interrupt(int irq, void *dev_id)
ret = IRQ_HANDLED;
}
- do_stolen_accounting();
-
return ret;
}
@@ -431,6 +389,8 @@ static void __init xen_time_init(void)
xen_setup_timer(cpu);
xen_setup_cpu_clockevents();
+ xen_time_setup_guest();
+
if (xen_initial_domain())
pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
}