Re: [PATCH] KVM: fix overflow of zero page refcount ksm use_zero_pages

Hi Zhuang, Thank you for the patch! Yet something to improve: [auto build test ERROR on kvm/linux-next] [cannot apply to v5.4-rc3 next-20191011] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system. BTW, we also suggest to use '--base' option to

[PATCH] KVM: fix overflow of zero page refcount ksm use_zero_pages

We are testing Virtual Machine with KSM on v5.4-rc2 kernel, and found the zero_page refcount overflow. The cause of refcount overflow is increased in try_async_pf (get_user_page) without being decreased in mmu_set_spte() while handling ept violation. In kvm_release_pfn_clean(), only unreserved