Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [PATCH] Guest system time jumps when new vCPUs is hot-added | Date | Wed, 28 Apr 2021 11:00:18 +0200 |
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On Wed, Apr 28 2021 at 10:22, Zelin Deng wrote:
> Hello, > I have below VM configuration: > ... > <vcpu placement='static' current='1'>2</vcpu> > <cpu mode='host-passthrough'> > </cpu> > <clock offset='utc'> > <timer name='tsc' frequency='3000000000'/> > </clock> > ... > After VM has been up for a few minutes, I use "virsh setvcpus" to hot-add > second vCPU into VM, below dmesg is observed: > [ 53.273484] CPU1 has been hot-added > [ 85.067135] SMP alternatives: switching to SMP code > [ 85.078409] x86: Booting SMP configuration: > [ 85.079027] smpboot: Booting Node 0 Processor 1 APIC 0x1 > [ 85.080240] kvm-clock: cpu 1, msr 77601041, secondary cpu clock > [ 85.080450] smpboot: CPU 1 Converting physical 0 to logical die 1 > [ 85.101228] TSC ADJUST compensate: CPU1 observed 169175101528 warp. Adjust: 169175101528 > [ 141.513496] TSC ADJUST compensate: CPU1 observed 166 warp. Adjust: 169175101694
Why is TSC_ADJUST on CPU1 different from CPU0 in the first place?
That's broken.
Thanks,
tglx
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