On 9/6/24 18:30, Edgecombe, Rick P wrote:
/*
* The case to care about here is a PTE getting zapped concurrently and
* this function erroneously thinking a page is mapped in the mirror EPT.
* The private mem zapping paths are already covered by other locks held
* here, but grab an mmu read_lock to not trigger the assert in
* kvm_tdp_mmu_gpa_is_mapped().
*/
Yan, do you think it is sufficient?
If you're actually requiring that the other locks are sufficient, then
there can be no ENOENT.
Maybe:
/*
* The private mem cannot be zapped after kvm_tdp_map_page()
* because all paths are covered by slots_lock and the
* filemap invalidate lock. Check that they are indeed enough.
*/
if (IS_ENABLED(CONFIG_KVM_PROVE_MMU)) {
scoped_guard(read_lock, &kvm->mmu_lock) {
if (KVM_BUG_ON(kvm,
!kvm_tdp_mmu_gpa_is_mapped(vcpu, gpa)) {
ret = -EIO;
goto out;
}
}
}
Paolo
