| Message ID | 20210925005528.1145584-12-seanjc@google.com |
|---|---|
| State | New |
| Headers | show |
| Series | KVM: Halt-polling fixes, cleanups and a new stat | expand |
On Fri, Sep 24, 2021 at 05:55:25PM -0700, Sean Christopherson wrote: > From: Jing Zhang <jingzhangos@google.com> > > 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 <cannonmatthews@google.com> > Suggested-by: Sean Christopherson <seanjc@google.com> > Signed-off-by: Jing Zhang <jingzhangos@google.com> > [sean: renamed stat to "blocking", massaged changelog] > Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: David Matlack <dmatlack@google.com> > --- > 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 >
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; }