Add a "blocking" stat that userspace can use to detect the case where a
vCPU is not being run because of an 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
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>
Reviewed-by: David Matlack <dmatlack@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>
Message-Id: <
20211009021236.4122790-16-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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;
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
struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu);
bool waited = false;
+ vcpu->stat.generic.blocking = 1;
+
kvm_arch_vcpu_blocking(vcpu);
prepare_to_rcuwait(wait);
kvm_arch_vcpu_unblocking(vcpu);
+ vcpu->stat.generic.blocking = 0;
+
return waited;
}