On Mon, 10 Feb 2020 11:54:39 -0500
Christian Borntraeger <borntraeger@xxxxxxxxxx> wrote:
> The query parameter block might contain additional information and can
> be extended in the future. If the size of the block does not suffice we
> get an error code of rc=0x100. The buffer will contain all information
> up to the specified size and the hypervisor/guest simply do not need the
> additional information as they do not know about the new data. That
> means that we can (and must) accept rc=0x100 as success.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 5abb9351dfd9 ("s390/uv: introduce guest side ultravisor code")
> Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> ---
> arch/s390/boot/uv.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/s390/boot/uv.c b/arch/s390/boot/uv.c
> index af9e1cc93c68..c003593664cd 100644
> --- a/arch/s390/boot/uv.c
> +++ b/arch/s390/boot/uv.c
> @@ -21,7 +21,7 @@ void uv_query_info(void)
> if (!test_facility(158))
> return;
>
> - if (uv_call(0, (uint64_t)&uvcb))
> + if (uv_call(0, (uint64_t)&uvcb) && uvcb.header.rc != 0x100)
Add a comment like
/* rc==0x100 means that there is additional data we do not process */
to avoid headscratching in the future?
> return;
>
> if (IS_ENABLED(CONFIG_KVM)) {
Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
