There is the code segment in mmu_unshadow():
kvm->arch.n_free_mmu_pages = 0;I don't understand why this is needed.
@@ -1589,7 +1589,8 @@ static void mmu_unshadow(struct kvm *kvm, gfn_t
gfn)
&& !sp->role.invalid) {
pgprintk("%s: zap %lx %x\n",
__func__, gfn, sp->role.word);
- kvm_mmu_zap_page(kvm, sp);
+ if (kvm_mmu_zap_page(kvm, sp))
+ nn = bucket->first;
}
}
|hlist_for_each_entry_safe(sp, node, nn, bucket, hash_link) {
| if (sp->gfn == gfn&& !sp->role.direct
| && !sp->role.invalid) {
| pgprintk("%s: zap %lx %x\n",
| __func__, gfn, sp->role.word);
| kvm_mmu_zap_page(kvm, sp);
| }
| }
in the loop, if nn is zapped, hlist_for_each_entry_safe() access nn will
cause crash. and it's checked in other functions, such as kvm_mmu_zap_all(),
kvm_mmu_unprotect_page()...