Re: [PATCH RFCv3 3/9] s390x: remove hypercall registration mechanism

[Cornelia Huck <cohuck@redhat.com>]

On Fri, 24 Jul 2020 16:37:44 +0200
David Hildenbrand <david@redhat.com> wrote:

> Nowadays, we only have a single machine type in QEMU, everything is based
> on virtio-ccw and the traditional virtio machine does no longer exist. No
> need to dynamically register diag500 handlers. Move the two existing

Hm, do we want to make certain subcodes available only if certain code
has been configured? If yes, it might make sense to keep the mechanism.

> handlers into diag500.c.

In any case, that file does not exist :)

> 
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  hw/s390x/s390-virtio-ccw.c   | 46 -----------------------------
>  hw/s390x/s390-virtio-hcall.c | 56 ++++++++++++++++++++++++------------
>  hw/s390x/s390-virtio-hcall.h |  2 --
>  3 files changed, 38 insertions(+), 66 deletions(-)
> 

(...)

> diff --git a/hw/s390x/s390-virtio-hcall.c b/hw/s390x/s390-virtio-hcall.c
> index ec7cf8beb3..5e14bd49b7 100644
> --- a/hw/s390x/s390-virtio-hcall.c
> +++ b/hw/s390x/s390-virtio-hcall.c
> @@ -12,30 +12,50 @@
>  #include "qemu/osdep.h"
>  #include "cpu.h"
>  #include "hw/s390x/s390-virtio-hcall.h"
> +#include "hw/s390x/ioinst.h"

(Maybe you could remove the ioinst.h include from s390-virtio-ccw.c
with this change?)

> +#include "hw/s390x/css.h"
> +#include "virtio-ccw.h"
>  
> -#define MAX_DIAG_SUBCODES 255
> -
> -static s390_virtio_fn s390_diag500_table[MAX_DIAG_SUBCODES];
> -
> -void s390_register_virtio_hypercall(uint64_t code, s390_virtio_fn fn)
> +static int handle_virtio_notify(uint64_t mem)
>  {
> -    assert(code < MAX_DIAG_SUBCODES);
> -    assert(!s390_diag500_table[code]);
> -
> -    s390_diag500_table[code] = fn;
> +    if (mem < ram_size) {
> +        /* Tolerate early printk. */

I'm wondering if we still need this. Probably doesn't hurt too much to
keep it around, though.

> +        return 0;
> +    }
> +    return -EINVAL;
>  }
>  

(...)