Messages in this thread |  | | Date | Thu, 07 Feb 2013 08:25:39 -0600 | From | Michael Wolf <> | Subject | Re: [PATCH 2/4] Expand the steal time msr to also contain the consigned time. |
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On 02/06/2013 03:14 PM, Rik van Riel wrote: > On 02/05/2013 04:49 PM, Michael Wolf wrote: >> Expand the steal time msr to also contain the consigned time. >> >> Signed-off-by: Michael Wolf <mjw@linux.vnet.ibm.com> >> --- >> arch/x86/include/asm/paravirt.h | 4 ++-- >> arch/x86/include/asm/paravirt_types.h | 2 +- >> arch/x86/kernel/kvm.c | 7 ++----- >> kernel/sched/core.c | 10 +++++++++- >> kernel/sched/cputime.c | 2 +- >> 5 files changed, 15 insertions(+), 10 deletions(-) >> >> diff --git a/arch/x86/include/asm/paravirt.h >> b/arch/x86/include/asm/paravirt.h >> index 5edd174..9b753ea 100644 >> --- a/arch/x86/include/asm/paravirt.h >> +++ b/arch/x86/include/asm/paravirt.h >> @@ -196,9 +196,9 @@ struct static_key; >> extern struct static_key paravirt_steal_enabled; >> extern struct static_key paravirt_steal_rq_enabled; >> >> -static inline u64 paravirt_steal_clock(int cpu) >> +static inline void paravirt_steal_clock(int cpu, u64 *steal) >> { >> - return PVOP_CALL1(u64, pv_time_ops.steal_clock, cpu); >> + PVOP_VCALL2(pv_time_ops.steal_clock, cpu, steal); >> } > > This may be a stupid question, but what happens if a KVM > guest with this change, runs on a kernel that still has > the old steal time interface? > > What happens if the host has the new steal time interface, > but the guest uses the old interface? > > Will both cases continue to work as expected with your > patch series? > > If so, could you document (in the source code) why things > continue to work? > I will test the scenarios you suggest and will report back the results.
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