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Commit 7c8a83b7 authored by Marcelo Tosatti's avatar Marcelo Tosatti Committed by Avi Kivity
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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: default avatarMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 310b5d30

arch/x86/kvm/mmu.c

+0 −2
Original line number Diff line number Diff line
@@ -2723,7 +2723,6 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot) 
{

	struct kvm_mmu_page *sp;



	spin_lock(&kvm->mmu_lock);

	list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link) {

		int i;

		u64 *pt;
@@ -2738,7 +2737,6 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot) 
				pt[i] &= ~PT_WRITABLE_MASK;

	}

	kvm_flush_remote_tlbs(kvm);

	spin_unlock(&kvm->mmu_lock);

}



void kvm_mmu_zap_all(struct kvm *kvm)

arch/x86/kvm/x86.c

+6 −0
Original line number Diff line number Diff line
@@ -1625,10 +1625,12 @@ static int kvm_vm_ioctl_set_nr_mmu_pages(struct kvm *kvm, 
		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 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, 


	/* 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 @@ int kvm_arch_set_memory_region(struct kvm *kvm, 
		}

	}



	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;