Re: [PATCH] selftests: KVM: Fix non-x86 compiling

[Paolo Bonzini <pbonzini@xxxxxxxxxx>]

On 12/14/21 16:18, Andrew Jones wrote:
> Attempting to compile on a non-x86 architecture fails with
>
> include/kvm_util.h: In function ‘vm_compute_max_gfn’:
> include/kvm_util.h:79:21: error: dereferencing pointer to incomplete type ‘struct kvm_vm’
>    return ((1ULL << vm->pa_bits) >> vm->page_shift) - 1;
>                       ^~
>
> This is because the declaration of struct kvm_vm is in
> lib/kvm_util_internal.h as an effort to make it private to
> the test lib code. We can still provide arch specific functions,
> though, by making the generic function symbols weak. Do that to
> fix the compile error.
>
> Fixes: c8cc43c1eae2 ("selftests: KVM: avoid failures due to reserved HyperTransport region")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Andrew Jones <drjones@xxxxxxxxxx>
> ---
>   tools/testing/selftests/kvm/include/kvm_util.h | 10 +---------
>   tools/testing/selftests/kvm/lib/kvm_util.c     |  5 +++++
>   2 files changed, 6 insertions(+), 9 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
> index da2b702da71a..2d62edc49d67 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util.h
> @@ -71,15 +71,6 @@ enum vm_guest_mode {
>   
>   #endif
>   
> -#if defined(__x86_64__)
> -unsigned long vm_compute_max_gfn(struct kvm_vm *vm);
> -#else
> -static inline unsigned long vm_compute_max_gfn(struct kvm_vm *vm)
> -{
> -	return ((1ULL << vm->pa_bits) >> vm->page_shift) - 1;
> -}
> -#endif
> -
>   #define MIN_PAGE_SIZE		(1U << MIN_PAGE_SHIFT)
>   #define PTES_PER_MIN_PAGE	ptes_per_page(MIN_PAGE_SIZE)
>   
> @@ -330,6 +321,7 @@ bool vm_is_unrestricted_guest(struct kvm_vm *vm);
>   
>   unsigned int vm_get_page_size(struct kvm_vm *vm);
>   unsigned int vm_get_page_shift(struct kvm_vm *vm);
> +unsigned long vm_compute_max_gfn(struct kvm_vm *vm);
>   uint64_t vm_get_max_gfn(struct kvm_vm *vm);
>   int vm_get_fd(struct kvm_vm *vm);
>   
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index daf6fdb217a7..53d2b5d04b82 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -2328,6 +2328,11 @@ unsigned int vm_get_page_shift(struct kvm_vm *vm)
>   	return vm->page_shift;
>   }
>   
> +unsigned long __attribute__((weak)) vm_compute_max_gfn(struct kvm_vm *vm)
> +{
> +	return ((1ULL << vm->pa_bits) >> vm->page_shift) - 1;
> +}
> +
>   uint64_t vm_get_max_gfn(struct kvm_vm *vm)
>   {
>   	return vm->max_gfn;

Applied, thanks.

Paolo