Re: [GIT PULL] First batch of KVM changes for Linux 5.9

[Ingo Molnar]

hi,

* Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:

> Paolo Bonzini (11):
>       Merge branch 'kvm-async-pf-int' into HEAD

kvmtool broke in this merge window, hanging during bootup right after CPU bringup:

 [    1.289404]  #63
 [    0.012468] kvm-clock: cpu 63, msr 6ff69fc1, secondary cpu clock
 [    0.012468] [Firmware Bug]: CPU63: APIC id mismatch. Firmware: 3f APIC: 14
 [    1.302320] kvm-guest: KVM setup async PF for cpu 63
 [    1.302320] kvm-guest: stealtime: cpu 63, msr 1379d7600

Eventually trigger an RCU stall warning:

 [   22.302392] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
 [   22.302392] rcu: 	1-...!: (68 GPs behind) idle=00c/0/0x0 softirq=0/0 fqs=0  (false positive?)

I've bisected this down to the above merge commit. The individual commit:

   b1d405751cd5: ("KVM: x86: Switch KVM guest to using interrupts for page ready APF delivery")

appears to be working fine standalone.

I'm using x86-64 defconfig+kvmconfig on SVM. Can send more info on request.

The kvmtool.git commit I've tested is 90b2d3adadf2.

Thanks,

	Ingo