summaryrefslogtreecommitdiffstats
path: root/virt
diff options
context:
space:
mode:
authorJing Zhang <jingzhangos@google.com>2021-10-08 19:12:08 -0700
committerPaolo Bonzini <pbonzini@redhat.com>2021-12-08 04:24:52 -0500
commitc3858335c711569b82a234a560dc19247e8f3fcc (patch)
tree2c4e6688e22372a5da0e8209a7799c16bee890b0 /virt
parentfac4268894394213127e43856f41d10f29131e69 (diff)
downloadlinux-c3858335c711569b82a234a560dc19247e8f3fcc.tar.bz2
KVM: stats: Add stat to detect if vcpu is currently blocking
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>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/kvm_main.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 370b95ad5f03..2630db6e8cb5 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3282,6 +3282,8 @@ bool kvm_vcpu_block(struct kvm_vcpu *vcpu)
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);
@@ -3298,6 +3300,8 @@ bool kvm_vcpu_block(struct kvm_vcpu *vcpu)
kvm_arch_vcpu_unblocking(vcpu);
+ vcpu->stat.generic.blocking = 0;
+
return waited;
}