Am 12.01.2014 um 13:08 schrieb Vadim Rozenfeld <vrozenfe@xxxxxxxxxx>:
> On Wed, 2014-01-08 at 23:20 +0100, Peter Lieven wrote:
>> Am 08.01.2014 21:08, schrieb Vadim Rozenfeld:
>>> 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.
>
> It seems to be working fine. However, I would to keep hv_ref_count as is
> for the following reason:
> " A partition's reference time counter is initialized to zero when the
> partition is created."
> http://msdn.microsoft.com/en-us/library/windows/hardware/ff542637%
> 28v=vs.85%29.aspx
>
> Technical, hypercall page initialization event (HV_X64_MSR_HYPERCALL MSR
> write handler) can be treated as such event. In this case hv_ref_count
> is no more than just an offset, which should be subtracted from the
> current time ( get_kernel_ns() + kvm->arch.kvmclock_offset ) when
> handling HV_X64_MSR_TIME_REF_COUNT MSR read request.
my 2 cents:
a) if you treat the start of the vm as partition create event get_kernel_ns() + kvm->arch.kvmclock_offset
is exactly the vm life time in nanoseconds.
b) afaik currently the value of hv_ref_count is not restored after a live migration on the destination. this
needs to be implemented for proper function. if we go for dropping this offset completely we can drop
the requirement of restoring hv_ref_count as well.
Peter
>
> Best regards,
> Vadim.
>
>>>>>>>>>
>>>>>>>>> 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
>>
>> do you also see the jump if you leave the hv_tsc out and just use hv_refcnt?
>>
>> Peter
>
>
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