On Wed, 2014-01-08 at 15:54 +0100, Peter Lieven wrote:
> On 08.01.2014 13:12, Vadim Rozenfeld wrote:
> > On Wed, 2014-01-08 at 12:48 +0100, Peter Lieven wrote:
> >> On 08.01.2014 11:44, Vadim Rozenfeld wrote:
> >>> On Wed, 2014-01-08 at 11:15 +0100, Peter Lieven wrote:
> >>>> On 08.01.2014 10:40, Vadim Rozenfeld wrote:
> >>>>> On Tue, 2014-01-07 at 18:52 +0100, Peter Lieven wrote:
> >>>>>> Am 07.01.2014 10:36, schrieb Vadim Rozenfeld:
> >>>>>>> On Thu, 2014-01-02 at 17:52 +0100, Peter Lieven wrote:
> >>>>>>>> Am 11.12.2013 19:59, schrieb Marcelo Tosatti:
> >>>>>>>>> On Wed, Dec 11, 2013 at 04:53:05PM -0200, Marcelo Tosatti wrote:
> >>>>>>>>>> On Sun, Dec 08, 2013 at 10:33:38PM +1100, Vadim Rozenfeld wrote:
> >>>>>>>>>>> Signed-off: Peter Lieven <pl@xxxxxxx>
> >>>>>>>>>>> Signed-off: Gleb Natapov <gleb@xxxxxxxxxx>
> >>>>>>>>>>> Signed-off: Vadim Rozenfeld <vrozenfe@xxxxxxxxxx>
> >>>>>>>>>>>
> >>>>>>>>>>> v1 -> v2
> >>>>>>>>>>> 1. mark TSC page dirty as suggested by
> >>>>>>>>>>> Eric Northup <digitaleric@xxxxxxxxxx> and Gleb
> >>>>>>>>>>> 2. disable local irq when calling get_kernel_ns,
> >>>>>>>>>>> as it was done by Peter Lieven <pl@xxxxxxxxx>
> >>>>>>>>>>> 3. move check for TSC page enable from second patch
> >>>>>>>>>>> to this one.
> >>>>>>>>>>>
> >>>>>>>>>>> ---
> >>>>>>>>>>> arch/x86/include/asm/kvm_host.h | 2 ++
> >>>>>>>>>>> arch/x86/include/uapi/asm/hyperv.h | 13 +++++++++++++
> >>>>>>>>>>> arch/x86/kvm/x86.c | 39 +++++++++++++++++++++++++++++++++++++-
> >>>>>>>>>>> include/uapi/linux/kvm.h | 1 +
> >>>>>>>>>>> 4 files changed, 54 insertions(+), 1 deletion(-)
> >>>>>>>>>>>
> >>>>>>>>>>> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> >>>>>>>>>>> index ae5d783..2fd0753 100644
> >>>>>>>>>>> --- a/arch/x86/include/asm/kvm_host.h
> >>>>>>>>>>> +++ b/arch/x86/include/asm/kvm_host.h
> >>>>>>>>>>> @@ -605,6 +605,8 @@ struct kvm_arch {
> >>>>>>>>>>> /* fields used by HYPER-V emulation */
> >>>>>>>>>>> u64 hv_guest_os_id;
> >>>>>>>>>>> u64 hv_hypercall;
> >>>>>>>>>>> + u64 hv_ref_count;
> >>>>>>>>>>> + u64 hv_tsc_page;
> >>>>>>>>>>>
> >>>>>>>>>>> #ifdef CONFIG_KVM_MMU_AUDIT
> >>>>>>>>>>> int audit_point;
> >>>>>>>>>>> diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h
> >>>>>>>>>>> index b8f1c01..462efe7 100644
> >>>>>>>>>>> --- a/arch/x86/include/uapi/asm/hyperv.h
> >>>>>>>>>>> +++ b/arch/x86/include/uapi/asm/hyperv.h
> >>>>>>>>>>> @@ -28,6 +28,9 @@
> >>>>>>>>>>> /* Partition Reference Counter (HV_X64_MSR_TIME_REF_COUNT) available*/
> >>>>>>>>>>> #define HV_X64_MSR_TIME_REF_COUNT_AVAILABLE (1 << 1)
> >>>>>>>>>>>
> >>>>>>>>>>> +/* A partition's reference time stamp counter (TSC) page */
> >>>>>>>>>>> +#define HV_X64_MSR_REFERENCE_TSC 0x40000021
> >>>>>>>>>>> +
> >>>>>>>>>>> /*
> >>>>>>>>>>> * There is a single feature flag that signifies the presence of the MSR
> >>>>>>>>>>> * that can be used to retrieve both the local APIC Timer frequency as
> >>>>>>>>>>> @@ -198,6 +201,9 @@
> >>>>>>>>>>> #define HV_X64_MSR_APIC_ASSIST_PAGE_ADDRESS_MASK \
> >>>>>>>>>>> (~((1ull << HV_X64_MSR_APIC_ASSIST_PAGE_ADDRESS_SHIFT) - 1))
> >>>>>>>>>>>
> >>>>>>>>>>> +#define HV_X64_MSR_TSC_REFERENCE_ENABLE 0x00000001
> >>>>>>>>>>> +#define HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT 12
> >>>>>>>>>>> +
> >>>>>>>>>>> #define HV_PROCESSOR_POWER_STATE_C0 0
> >>>>>>>>>>> #define HV_PROCESSOR_POWER_STATE_C1 1
> >>>>>>>>>>> #define HV_PROCESSOR_POWER_STATE_C2 2
> >>>>>>>>>>> @@ -210,4 +216,11 @@
> >>>>>>>>>>> #define HV_STATUS_INVALID_ALIGNMENT 4
> >>>>>>>>>>> #define HV_STATUS_INSUFFICIENT_BUFFERS 19
> >>>>>>>>>>>
> >>>>>>>>>>> +typedef struct _HV_REFERENCE_TSC_PAGE {
> >>>>>>>>>>> + __u32 tsc_sequence;
> >>>>>>>>>>> + __u32 res1;
> >>>>>>>>>>> + __u64 tsc_scale;
> >>>>>>>>>>> + __s64 tsc_offset;
> >>>>>>>>>>> +} HV_REFERENCE_TSC_PAGE, *PHV_REFERENCE_TSC_PAGE;
> >>>>>>>>>>> +
> >>>>>>>>>>> #endif
> >>>>>>>>>>> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> >>>>>>>>>>> index 21ef1ba..5e4e495a 100644
> >>>>>>>>>>> --- a/arch/x86/kvm/x86.c
> >>>>>>>>>>> +++ b/arch/x86/kvm/x86.c
> >>>>>>>>>>> @@ -840,7 +840,7 @@ EXPORT_SYMBOL_GPL(kvm_rdpmc);
> >>>>>>>>>>> static u32 msrs_to_save[] = {
> >>>>>>>>>>> MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK,
> >>>>>>>>>>> MSR_KVM_SYSTEM_TIME_NEW, MSR_KVM_WALL_CLOCK_NEW,
> >>>>>>>>>>> - HV_X64_MSR_GUEST_OS_ID, HV_X64_MSR_HYPERCALL,
> >>>>>>>>>>> + HV_X64_MSR_GUEST_OS_ID, HV_X64_MSR_HYPERCALL, HV_X64_MSR_TIME_REF_COUNT,
> >>>>>>>>>>> HV_X64_MSR_APIC_ASSIST_PAGE, MSR_KVM_ASYNC_PF_EN, MSR_KVM_STEAL_TIME,
> >>>>>>>>>>> MSR_KVM_PV_EOI_EN,
> >>>>>>>>>>> MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
> >>>>>>>>>>> @@ -1826,6 +1826,8 @@ static bool kvm_hv_msr_partition_wide(u32 msr)
> >>>>>>>>>>> switch (msr) {
> >>>>>>>>>>> case HV_X64_MSR_GUEST_OS_ID:
> >>>>>>>>>>> case HV_X64_MSR_HYPERCALL:
> >>>>>>>>>>> + case HV_X64_MSR_REFERENCE_TSC:
> >>>>>>>>>>> + case HV_X64_MSR_TIME_REF_COUNT:
> >>>>>>>>>>> r = true;
> >>>>>>>>>>> break;
> >>>>>>>>>>> }
> >>>>>>>>>>> @@ -1865,6 +1867,29 @@ static int set_msr_hyperv_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data)
> >>>>>>>>>>> if (__copy_to_user((void __user *)addr, instructions, 4))
> >>>>>>>>>>> return 1;
> >>>>>>>>>>> kvm->arch.hv_hypercall = data;
> >>>>>>>>>>> + local_irq_disable();
> >>>>>>>>>>> + kvm->arch.hv_ref_count = get_kernel_ns() + kvm->arch.kvmclock_offset;
> >>>>>>>>>>> + local_irq_enable();
> >>>>>>>>>>
> >>>>>>>>>> Where does the docs say that HV_X64_MSR_HYPERCALL is the where the clock
> >>>>>>>>>> starts counting?
> >>>>>>>>>>
> >>>>>>>>>> No need to store kvmclock_offset in hv_ref_count? (moreover
> >>>>>>>>>> the name is weird, better name would be "hv_ref_start_time".
> >>>>>>>>>
> >>>>>>>>> Just add kvmclock_offset when reading the values (otherwise you have a
> >>>>>>>>> "stale copy" of kvmclock_offset in hv_ref_count).
> >>>>>>>>>
> >>>>>>>>
> >>>>>>>> After some experiments I think we do no need kvm->arch.hv_ref_count at all.
> >>>>>>>>
> >>>>>>>> I was debugging some weird clockjump issues and I think the problem is that after live migration
> >>>>>>>> kvm->arch.hv_ref_count is initialized to 0. Depending on the uptime of the vServer when the
> >>>>>>>> hypercall was set up this can lead to series jumps.
> >>>>>>>>
> >>>>>>>> So I would suggest to completely drop kvm->arch.hv_ref_count.
> >>>>>>>>
> >>>>>>>> And use simply this in get_msr_hyperv_pw().
> >>>>>>>>
> >>>>>>>> case HV_X64_MSR_TIME_REF_COUNT: {
> >>>>>>>> data = div_u64(get_kernel_ns() + kvm->arch.kvmclock_offset, 100);
> >>>>>>>> break;
> >>>>>>>> }
> >>>>>>>>
> >>>>>>>
> >>>>>>> Agreed. It should work as long as we rely on kvmclock_offset.
> >>>>>>> Vadim.
> >>>>>>
> >>>>>> I think we can rely on kvmclock_offset. Had you had a chance to do further testing
> >>>>>> during the weekend?
> >>>>>
> >>>>> Yes, and still testing.
> >>>>>
> >>>>> There is still some inconsistency in the value returned by
> >>>>> QueryPerformanceCounter during migration.
> >>>>
> >>>> With my proposal?
> >>>>
> >>>
> >>> Right.
> >>> Please see below QTC vs. NTP time stamp
> >>> before and after migration:
> >>>
> >>> C:\timedrift\objchk_win7_x86\i386>timedrift.exe
> >>> quantum = 15
> >>> QPC NTP Delta
> >>> 1311 1307 4
> >>> 2621 2618 3
> >>> 3932 3931 1
> >>> .......
> >>> .......
> >>> 38018 38014 4
> >>> Unable to wait for NTP reply from the SNTP server, GetLastError returns
> >>> 7279088
> >>> 142210 40113 102097
> >>> 143458 41357 102101
> >>> .......
> >>> .......
> >>> 156500 54615 101885
> >>>
> >>> NTP time changed from 38014 to 40113 ((40113 - 38014) / 100 = 21 mSec)
> >>> while QPC jumped from 38018 to 142210 ((142210 - 38014) / 100 = 1042
> >>> mSec)
> >>
> >> How long was the downtime when you migrated the vServer?
> > I use Win7-32 for testing.
> >>
> >> I have done similar tests and have not seen this...
> >> Can you show the relevant parts of your patch. Remember I use the REFERENCE_COUTNER not iTSC.
> > Yes, I also test it for reference counter.
>
> Can you use these parameters for testing:
>
> -cpu qemu64,hv_relaxed,hv_vapic,hv_spinlocks=4096,hv_refcnt
> -rtc base=localtime -vga std -usb -usbdevice tablet -no-hpet
My settings are:
-cpu qemu64,
+x2apic,family=0xf,hv_vapic,hv_spinlocks=0xfff,hv_relaxed,hv_tsc -m 1G
-smp 4
>
> If you look in the HMP at "info migrate" after the migration what does the downtime info say?
downtime: 4 milliseconds
>
> Peter
>
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