Hi Gavin,
FYI, this has been fixed by Marc in commit 262b003d059c.
Thanks,
Keqian
On 2021/3/15 12:18, Gavin Shan wrote:
> 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;
>
>
