| Message ID | 20241031170633.1502783-3-seanjc@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | KVM: x86/mmu: Micro-optimize TDP MMU cond_resched() | expand |
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index a06f3d5cb651..c158ef8c1a36 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -698,7 +698,7 @@ static inline bool __must_check tdp_mmu_iter_cond_resched(struct kvm *kvm, struct tdp_iter *iter, bool flush, bool shared) { - WARN_ON_ONCE(iter->yielded); + KVM_MMU_WARN_ON(iter->yielded); if (!need_resched() && !rwlock_needbreak(&kvm->mmu_lock)) return false;
Convert the WARN in tdp_mmu_iter_cond_resched() that the iterator hasn't already yielded to a KVM_MMU_WARN_ON() so the code is compiled out for production kernels (assuming production kernels disable KVM_PROVE_MMU). Checking for a needed reschedule is a hot path, and KVM sanity checks iter->yielded in several other less-hot paths, i.e. the odds of KVM not flagging that something went sideways are quite low. Furthermore, the odds of KVM not noticing *and* the WARN detecting something worth investigating are even lower. Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/x86/kvm/mmu/tdp_mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)