KVM: x86: Account fastpath-only VM-Exits in vCPU stats

commit 8b703a49c9df5e74870381ad7ba9c85d8a74ed2c upstream.

Increment vcpu->stat.exits when handling a fastpath VM-Exit without
going through any part of the "slow" path.  Not bumping the exits stat
can result in wildly misleading exit counts, e.g. if the primary reason
the guest is exiting is to program the TSC deadline timer.

Fixes: 404d5d7bff0d ("KVM: X86: Introduce more exit_fastpath_completion enum values")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230602011920.787844-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 999b2db0737bed28ffedf3e07768846f6d7c94b4..38c2f4f1f59a80b73d56f933fc2896c97766e853 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10682,6 +10682,9 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
                        exit_fastpath = EXIT_FASTPATH_EXIT_HANDLED;
                        break;
                }
+
+               /* Note, VM-Exits that go down the "slow" path are accounted below. */
+               ++vcpu->stat.exits;
        }
 
        /*