KVM: RISC-V: Unmap stage2 mapping when deleting/moving a memslot

Unmap stage2 page tables when a memslot is being deleted or moved.  It's
the architectures' responsibility to ensure existing mappings are removed
when kvm_arch_flush_shadow_memslot() returns.

Fixes: 9d05c1fe ("RISC-V: KVM: Implement stage2 page table programming")
Signed-off-by: NSean Christopherson <seanjc@google.com>
Signed-off-by: NAnup Patel <anup.patel@wdc.com>

arch/riscv/kvm/mmu.c

@@ -453,6 +453,12 @@ void kvm_arch_flush_shadow_all(struct kvm *kvm)
 void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
 				   struct kvm_memory_slot *slot)
 {
+	gpa_t gpa = slot->base_gfn << PAGE_SHIFT;
+	phys_addr_t size = slot->npages << PAGE_SHIFT;
+
+	spin_lock(&kvm->mmu_lock);
+	stage2_unmap_range(kvm, gpa, size, false);
+	spin_unlock(&kvm->mmu_lock);
 }
 
 void kvm_arch_commit_memory_region(struct kvm *kvm,