| Message ID | 20220303193842.370645-7-pbonzini@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86/mmu: Overhaul TDP MMU zapping and flushing | expand |
On Thu, Mar 03, 2022, Paolo Bonzini wrote: > Eager page splitting is an optimization; it does not have to be performed on > invalid roots. It is also the only case in which a reader might acquire > a reference to an invalid root, so after this change we know that readers > will skip both dying and invalid roots. > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- Reviewed-by: Sean Christopherson <seanjc@google.com>
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 30424fbceb5f..d39593b9ac9e 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -1464,7 +1464,7 @@ void kvm_tdp_mmu_try_split_huge_pages(struct kvm *kvm, kvm_lockdep_assert_mmu_lock_held(kvm, shared); - for_each_tdp_mmu_root_yield_safe(kvm, root, slot->as_id, shared) { + for_each_valid_tdp_mmu_root_yield_safe(kvm, root, slot->as_id, shared) { r = tdp_mmu_split_huge_pages_root(kvm, root, start, end, target_level, shared); if (r) { kvm_tdp_mmu_put_root(kvm, root, shared);
Eager page splitting is an optimization; it does not have to be performed on invalid roots. It is also the only case in which a reader might acquire a reference to an invalid root, so after this change we know that readers will skip both dying and invalid roots. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- arch/x86/kvm/mmu/tdp_mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)