Commit fcb93eb6 authored by Paolo Bonzini's avatar Paolo Bonzini

kvm: x86/mmu: Flush TLB before zap_gfn_range releases RCU

Since "KVM: x86/mmu: Zap only TDP MMU leafs in kvm_zap_gfn_range()"
is going to be reverted, it's not going to be true anymore that
the zap-page flow does not free any 'struct kvm_mmu_page'.  Introduce
an early flush before tdp_mmu_zap_leafs() returns, to preserve
bisectability.
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 714797c9
......@@ -941,13 +941,17 @@ static bool tdp_mmu_zap_leafs(struct kvm *kvm, struct kvm_mmu_page *root,
flush = true;
}
rcu_read_unlock();
/*
* Because this flow zaps _only_ leaf SPTEs, the caller doesn't need
* to provide RCU protection as no 'struct kvm_mmu_page' will be freed.
* Need to flush before releasing RCU. TODO: do it only if intermediate
* page tables were zapped; there is no need to flush under RCU protection
* if no 'struct kvm_mmu_page' is freed.
*/
return flush;
if (flush)
kvm_flush_remote_tlbs_with_address(kvm, start, end - start);
rcu_read_unlock();
return false;
}
/*
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment