KVM: MMU: protect kvm_mmu_change_mmu_pages with mmu_lock
kvm_handle_hva, called by MMU notifiers, manipulates mmu data only with
the protection of mmu_lock.
Update kvm_mmu_change_mmu_pages callers to take mmu_lock, thus protecting
against kvm_handle_hva.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 48f744f..d2a4eca 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1625,10 +1625,12 @@
return -EINVAL;
down_write(&kvm->slots_lock);
+ spin_lock(&kvm->mmu_lock);
kvm_mmu_change_mmu_pages(kvm, kvm_nr_mmu_pages);
kvm->arch.n_requested_mmu_pages = kvm_nr_mmu_pages;
+ spin_unlock(&kvm->mmu_lock);
up_write(&kvm->slots_lock);
return 0;
}
@@ -1804,7 +1806,9 @@
/* If nothing is dirty, don't bother messing with page tables. */
if (is_dirty) {
+ spin_lock(&kvm->mmu_lock);
kvm_mmu_slot_remove_write_access(kvm, log->slot);
+ spin_unlock(&kvm->mmu_lock);
kvm_flush_remote_tlbs(kvm);
memslot = &kvm->memslots[log->slot];
n = ALIGN(memslot->npages, BITS_PER_LONG) / 8;
@@ -4548,12 +4552,14 @@
}
}
+ spin_lock(&kvm->mmu_lock);
if (!kvm->arch.n_requested_mmu_pages) {
unsigned int nr_mmu_pages = kvm_mmu_calculate_mmu_pages(kvm);
kvm_mmu_change_mmu_pages(kvm, nr_mmu_pages);
}
kvm_mmu_slot_remove_write_access(kvm, mem->slot);
+ spin_unlock(&kvm->mmu_lock);
kvm_flush_remote_tlbs(kvm);
return 0;