On Fri, Sep 24, 2021 at 05:55:25PM -0700, Sean Christopherson wrote: > From: Jing Zhang <[email protected]> > > Add a "blocking" stat that userspace can use to detect the case where a > vCPU is not being run because of a vCPU/guest action, e.g. HLT or WFS on > x86, WFI on arm64, etc... Current guest/host/halt stats don't show this > well, e.g. if a guest halts for a long period of time then the vCPU could > appear pathologically blocked due to a host condition, when in reality the > vCPU has been put into a not-runnable state by the guest. > > Originally-by: Cannon Matthews <[email protected]> > Suggested-by: Sean Christopherson <[email protected]> > Signed-off-by: Jing Zhang <[email protected]> > [sean: renamed stat to "blocking", massaged changelog] > Signed-off-by: Sean Christopherson <[email protected]>
Reviewed-by: David Matlack <[email protected]> > --- > include/linux/kvm_host.h | 3 ++- > include/linux/kvm_types.h | 1 + > virt/kvm/kvm_main.c | 2 ++ > 3 files changed, 5 insertions(+), 1 deletion(-) > > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > index 655c2b24db2d..9bb1972e396a 100644 > --- a/include/linux/kvm_host.h > +++ b/include/linux/kvm_host.h > @@ -1453,7 +1453,8 @@ struct _kvm_stats_desc { > STATS_DESC_LOGHIST_TIME_NSEC(VCPU_GENERIC, halt_poll_fail_hist, \ > HALT_POLL_HIST_COUNT), \ > STATS_DESC_LOGHIST_TIME_NSEC(VCPU_GENERIC, halt_wait_hist, \ > - HALT_POLL_HIST_COUNT) > + HALT_POLL_HIST_COUNT), \ > + STATS_DESC_ICOUNTER(VCPU_GENERIC, blocking) > > extern struct dentry *kvm_debugfs_dir; > > diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h > index 2237abb93ccd..c4f9257bf32d 100644 > --- a/include/linux/kvm_types.h > +++ b/include/linux/kvm_types.h > @@ -94,6 +94,7 @@ struct kvm_vcpu_stat_generic { > u64 halt_poll_success_hist[HALT_POLL_HIST_COUNT]; > u64 halt_poll_fail_hist[HALT_POLL_HIST_COUNT]; > u64 halt_wait_hist[HALT_POLL_HIST_COUNT]; > + u64 blocking; > }; > > #define KVM_STATS_NAME_SIZE 48 > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index fe34457530c2..2980d2b88559 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -3208,6 +3208,7 @@ bool kvm_vcpu_block(struct kvm_vcpu *vcpu) > { > bool waited = false; > > + vcpu->stat.generic.blocking = 1; > kvm_arch_vcpu_blocking(vcpu); > > prepare_to_rcuwait(&vcpu->wait); > @@ -3223,6 +3224,7 @@ bool kvm_vcpu_block(struct kvm_vcpu *vcpu) > finish_rcuwait(&vcpu->wait); > > kvm_arch_vcpu_unblocking(vcpu); > + vcpu->stat.generic.blocking = 0; > > return waited; > } > -- > 2.33.0.685.g46640cef36-goog > _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
