Re: [PATCH v2 3/6] KVM: x86: Remove the KVM_GET_NR_MMU_PAGES ioctl

From: Sean Christopherson
Date: Wed Feb 08 2023 - 09:49:08 EST


On Wed, Feb 08, 2023, Thomas Huth wrote:
> The KVM_GET_NR_MMU_PAGES ioctl is quite questionable on 64-bit hosts
> since it fails to return the full 64 bits of the value that can be
> set with the corresponding KVM_SET_NR_MMU_PAGES call. Its "long" return
> value is truncated into an "int" in the kvm_arch_vm_ioctl() function.
>
> Since this ioctl also never has been used by userspace applications
> (QEMU, Google's internal VMM, kvmtool and CrosVM have been checked),
> it's likely the best if we remove this badly designed ioctl before
> anybody really tries to use it.
>
> Signed-off-by: Thomas Huth <thuth@xxxxxxxxxx>
> ---

Reviewed-by: Sean Christopherson <seanjc@xxxxxxxxxx>