diff options
| author | Juergen Gross <jgross@suse.com> | 2016-05-20 10:26:48 +0300 |
|---|---|---|
| committer | David Vrabel <david.vrabel@citrix.com> | 2016-07-06 12:34:48 +0300 |
| commit | ecb23dc6f2eff0ce64dd60351a81f376f13b12cc (patch) | |
| tree | 09536e5db2dc00af9dd5209fef72a1e1222f6cf2 /drivers/xen | |
| parent | c7ebf9d9c6b4e9402b978da0b0785db4129c1f79 (diff) | |
| download | linux-ecb23dc6f2eff0ce64dd60351a81f376f13b12cc.tar.xz | |
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 'drivers/xen')
| -rw-r--r-- | drivers/xen/time.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/xen/time.c b/drivers/xen/time.c index 71078425c9ea..2257b6663766 100644 --- a/drivers/xen/time.c +++ b/drivers/xen/time.c @@ -6,6 +6,7 @@ #include <linux/math64.h> #include <linux/gfp.h> +#include <asm/paravirt.h> #include <asm/xen/hypervisor.h> #include <asm/xen/hypercall.h> @@ -75,6 +76,15 @@ bool xen_vcpu_stolen(int vcpu) return per_cpu(xen_runstate, vcpu).state == RUNSTATE_runnable; } +static u64 xen_steal_clock(int cpu) +{ + struct vcpu_runstate_info state; + + BUG_ON(cpu != smp_processor_id()); + xen_get_runstate_snapshot(&state); + return state.time[RUNSTATE_runnable] + state.time[RUNSTATE_offline]; +} + void xen_setup_runstate_info(int cpu) { struct vcpu_register_runstate_memory_area area; @@ -86,3 +96,13 @@ void xen_setup_runstate_info(int cpu) BUG(); } +void __init xen_time_setup_guest(void) +{ + pv_time_ops.steal_clock = xen_steal_clock; + + static_key_slow_inc(¶virt_steal_enabled); + /* + * We can't set paravirt_steal_rq_enabled as this would require the + * capability to read another cpu's runstate info. + */ +} |