The last (IPA) page can't be specified when a new memory slot is
added. The error -EFAULT is returned when the memory slot is added
with the following parameters for the VM, which has 40-bits IPA
limit. The host has 4KB base page size. It's not correct because
the last (IPA) page is still usable.
struct kvm_userspace_memory_region {
__u32 slot; /* 1 */
__u32 flags; /* 0 */
__u64 guest_phys_addr; /* 0xfffffff000 */
__u64 memory_size; /* 0x1000 */
__u64 userspace_addr;
};
Signed-off-by: Gavin Shan <[email protected]>
---
arch/arm64/kvm/mmu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 286b603ed0d3..a5a8ade9fde4 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1313,7 +1313,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
* Prevent userspace from creating a memory region outside of the IPA
* space addressable by the KVM guest IPA space.
*/
- if (memslot->base_gfn + memslot->npages >=
+ if (memslot->base_gfn + memslot->npages >
(kvm_phys_size(kvm) >> PAGE_SHIFT))
return -EFAULT;
--
2.23.0
