(CC to freebsd-virtualization_at_) 20.10.2017 19:32, Ian Lepore ΠΙΫΕΤ: > On Fri, 2017-10-20 at 18:36 +0300, Boris Samorodov wrote: >> 20.10.2017 18:31, Boris Samorodov ΠΙΫΕΤ: >>> >>> 20.10.2017 18:12, Ian Lepore ΠΙΫΕΤ: >>>> >>>> On Fri, 2017-10-20 at 14:46 +0300, Boris Samorodov wrote: >>>>> >>>>> Hi All, >>>>> >>>>> I have got a host: >>>>> --- >>>>> bhyve-host% uname -a >>>>> FreeBSD sm.bsnet 12.0-CURRENT FreeBSD 12.0-CURRENT #3 r322868: Fri Aug >>>>> 25 05:25:26 MSK 2017 >>>>> bsam_at_builder.bsnet:/usr/obj/usr/src/sys/GENERIC-FASTamd64 amd64 >>>>> --- >>>>> >>>>> And a bhyve vm: >>>>> --- >>>>> bhyve-vm: uname -a >>>>> FreeBSD builder.bsnet 12.0-CURRENT FreeBSD 12.0-CURRENT #58 r324782: Fri >>>>> Oct 20 05:12:17 MSK 2017 >>>>> bsam_at_builder.bsnet:/usr/obj/usr/src/sys/PKG64Xamd64 amd64 >>>>> --- >>>>> >>>>> The only difference at kernel configs is a colored console. :-) >>>>> >>>>> And here I get some weird (is it?) result at the VM (I expect ntpd to be >>>>> more stable): >>>>> --- >>>>> bhyve-vm% for t in `jot 10`; do ntpq -pn; sleep 64; done >>>>> remoterefidst t when poll reachdelayoffset >>>>> jitter >>>>> ============================================================================== >>>>> XX.XX.XX.1XX.XX.XX.2454 u96430.605-1.202 >>>>> 316.407 >>>>> XX.XX.XX.1XX.XX.XX.2454 u76470.605-1.202 >>>>> 358.395 >>>>> *XX.XX.XX.1XX.XX.XX.2454 u564170.615-328.42 >>>>> 181.405 >>>>> *XX.XX.XX.1XX.XX.XX.2454 u364370.615-328.42 >>>>> 214.868 >>>>> *XX.XX.XX.1XX.XX.XX.2454 u6764370.615-328.42 >>>>> 214.868 >>>>> *XX.XX.XX.1XX.XX.XX.2454 u6364770.615-328.42 >>>>> 268.618 >>>>> *XX.XX.XX.1XX.XX.XX.2454 u60641770.615-328.42 >>>>> 333.175 >>>>> XX.XX.XX.1.STEP.16 u 19106400.0000.000 >>>>> 0.000 >>>>> XX.XX.XX.1XX.XX.XX.2454 u276410.703-262.63 >>>>> 0.004 >>>>> XX.XX.XX.1XX.XX.XX.2454 u316410.649-331.43 >>>>> 68.800 >>>>> --- >>>>> >>>>> At the same time host's results are very stable: >>>>> --- >>>>> bhyve-host% for t in `jot 10`; do ntpq -pn; sleep 64; done >>>>> remoterefidst t when poll reachdelayoffset >>>>> jitter >>>>> ============================================================================== >>>>> >>>>> >>>>> >>>>> *XX.XX.XX.1XX.XX.XX.2454 u16410.4010.176 >>>>> 0.106 >>>>> *XX.XX.XX.1XX.XX.XX.2454 u66430.4010.176 >>>>> 0.459 >>>>> *XX.XX.XX.1XX.XX.XX.2454 u36470.4010.176 >>>>> 0.940 >>>>> *XX.XX.XX.1XX.XX.XX.2454 u676470.4010.176 >>>>> 0.940 >>>>> *XX.XX.XX.1XX.XX.XX.2454 u6464170.4010.176 >>>>> 1.566 >>>>> *XX.XX.XX.1XX.XX.XX.2454 u6064370.4481.275 >>>>> 1.739 >>>>> *XX.XX.XX.1XX.XX.XX.2454 u5564770.4481.275 >>>>> 2.365 >>>>> *XX.XX.XX.1XX.XX.XX.2454 u53641770.4481.275 >>>>> 3.110 >>>>> *XX.XX.XX.1XX.XX.XX.2454 u50643770.4481.275 >>>>> 3.929 >>>>> *XX.XX.XX.1XX.XX.XX.2454 u45643770.4438.750 >>>>> 4.722 >>>>> --- >>>>> >>>>> The network is organized via bridge -- host igb and vm tap interfaces >>>>> are members of one bridge. >>>>> >>>>> Are those results expected? Does it smell like a bug? Should I dig >>>>> furter? >>>>> >>>> So it is repeatedly stepping the clock in the VM? (Set >>>> kern.timecounter.stepwarnings=1 to log steps). >>> No kernel/ntpd messages for 20 minutes after setting this sysctl. >>> >>>> >>>> That is usually a sign >>>> that the chosen timecounter is running at a different frequency than it >>>> claimed to be when it registered itself -- the host may not be >>>> emulating the timer hardware properly in the guest. What is the output >>>> of sysctl kern.timecounter in the vm? >>> --- >>> bhyve-vm% sysctl kern.timecounter >>> >>> kern.timecounter.tsc_shift: 1 >>> kern.timecounter.smp_tsc_adjust: 0 >>> kern.timecounter.smp_tsc: 0 >>> kern.timecounter.invariant_tsc: 1 >>> kern.timecounter.fast_gettime: 1 >>> kern.timecounter.tick: 1 >>> kern.timecounter.choice: ACPI-fast(900) HPET(950) i8254(0) TSC-low(-100) >>> dummy(-1000000) >>> kern.timecounter.hardware: HPET >>> kern.timecounter.alloweddeviation: 5 >>> kern.timecounter.stepwarnings: 1 >>> kern.timecounter.tc.ACPI-fast.quality: 900 >>> kern.timecounter.tc.ACPI-fast.frequency: 3579545 >>> kern.timecounter.tc.ACPI-fast.counter: 4161213491 >>> kern.timecounter.tc.ACPI-fast.mask: 4294967295 >>> kern.timecounter.tc.HPET.quality: 950 >>> kern.timecounter.tc.HPET.frequency: 10000000 >>> kern.timecounter.tc.HPET.counter: 3518036865 >>> kern.timecounter.tc.HPET.mask: 4294967295 >>> kern.timecounter.tc.i8254.quality: 0 >>> kern.timecounter.tc.i8254.frequency: 1193182 >>> kern.timecounter.tc.i8254.counter: 47597 >>> kern.timecounter.tc.i8254.mask: 65535 >>> kern.timecounter.tc.TSC-low.quality: -100 >>> kern.timecounter.tc.TSC-low.frequency: 1199886114 >>> kern.timecounter.tc.TSC-low.counter: 1274338278 >>> kern.timecounter.tc.TSC-low.mask: 4294967295 >>> --- >> BTW, here is the host kern.timecounter: >> --- >> kern.timecounter.tsc_shift: 1 >> kern.timecounter.smp_tsc_adjust: 0 >> kern.timecounter.smp_tsc: 1 >> kern.timecounter.invariant_tsc: 1 >> kern.timecounter.fast_gettime: 1 >> kern.timecounter.tick: 1 >> kern.timecounter.choice: ACPI-fast(900) HPET(950) i8254(0) TSC-low(1000) >> dummy(-1000000) >> kern.timecounter.hardware: TSC-low >> kern.timecounter.alloweddeviation: 5 >> kern.timecounter.stepwarnings: 0 >> kern.timecounter.tc.ACPI-fast.quality: 900 >> kern.timecounter.tc.ACPI-fast.frequency: 3579545 >> kern.timecounter.tc.ACPI-fast.counter: 9047194 >> kern.timecounter.tc.ACPI-fast.mask: 16777215 >> kern.timecounter.tc.HPET.quality: 950 >> kern.timecounter.tc.HPET.frequency: 14318180 >> kern.timecounter.tc.HPET.counter: 2232552795 >> kern.timecounter.tc.HPET.mask: 4294967295 >> kern.timecounter.tc.i8254.quality: 0 >> kern.timecounter.tc.i8254.frequency: 1193182 >> kern.timecounter.tc.i8254.counter: 43410 >> kern.timecounter.tc.i8254.mask: 65535 >> kern.timecounter.tc.TSC-low.quality: 1000 >> kern.timecounter.tc.TSC-low.frequency: 1200067168 >> kern.timecounter.tc.TSC-low.counter: 2463146362 >> kern.timecounter.tc.TSC-low.mask: 4294967295 >> --- >> >>> >>>> >>>> Also, what is the output of ntptime(8) in the vm? >>> --- >>> bhyve-vm% ntptime >>> >>> ntp_gettime() returns code 0 (OK) >>> time dd94930f.20ea2900Fri, Oct 20 2017 18:21:51.128, (.128573699), >>> maximum error 1309110 us, estimated error 3 us, TAI offset 37 >>> ntp_adjtime() returns code 0 (OK) >>> modes 0x0 (), >>> offset 0.000 us, frequency 0.000 ppm, interval 1 s, >>> maximum error 1309110 us, estimated error 3 us, >>> status 0x2001 (PLL,NANO), >>> time constant 6, precision 0.001 us, tolerance 496 ppm, >>> --- >>> >>> Ian, thank you for your help! >>> >> > > It seems odd to me that the frequency of the host HPET is 14.3mhz and > that of the guest is 10.0mhz, but maybe that's a normal condition for > bhyve. I did find some google hits[1] for bhyve guest timekeeping > trouble with the HPET timer which was solved by switching to a > different timecounter. Timecounter choices can't be controlled from > loader.conf, so I guess a sysctl.conf entry of > kern.timecounter.hardware="ACPI-fast" is the only way to fix that. You > can also just do that command interactively first and see if it stops > the time steps and ntp settles down. The process seems to become more monotonic. But steps nevertheless: --- *XX.1 XX.245 4 u 20 64 1 0.717 -12.771 4.193 *XX.1 XX.245 4 u 28 64 3 0.751 -41.970 32.342 *XX.1 XX.245 4 u 23 64 7 0.748 -59.505 46.624 *XX.1 XX.245 4 u 18 64 17 0.699 -75.164 56.482 *XX.1 XX.245 4 u 14 64 37 0.669 -90.112 63.767 *XX.1 XX.245 4 u 11 64 77 0.605 -10.567 60.914 *XX.1 XX.245 4 u 7 64 177 0.591 -169.54 116.762 *XX.1 XX.245 4 u 3 64 377 0.591 -169.54 102.107 *XX.1 XX.245 4 u 68 64 377 0.591 -169.54 102.107 *XX.1 XX.245 4 u 63 64 377 0.591 -169.54 88.424 *XX.1 XX.245 4 u 58 64 377 0.591 -169.54 92.949 *XX.1 XX.245 4 u 55 64 377 0.591 -169.54 111.512 *XX.1 XX.245 4 u 50 64 377 0.591 -169.54 140.827 *XX.1 XX.245 4 u 45 64 377 0.591 -169.54 177.360 *XX.1 XX.245 4 u 43 64 377 0.591 -169.54 219.057 XX.1 .STEP. 16 u 588 64 0 0.000 0.000 0.000 --- > This would be a workaround, not a fix per se. If the time steps go > away, then something in bhyve's emulation of HPET (maybe only on some > hardware?) must be buggy. > > > [1] https://lists.freebsd.org/pipermail/freebsd-virtualization/2015-April/003492.html Also thanks for the link. Unfortunately the problem seems to persist. -- WBR, Boris Samorodov (bsam) FreeBSD Committer, http://www.FreeBSD.org The Power To ServeReceived on Fri Oct 20 2017 - 15:20:14 UTC
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