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
