Re: [Qemu-devel] [PATCH] s390x/css: disabled subchannels cannot be status pending

[Cornelia Huck <cohuck@redhat.com>]

On Fri,  4 May 2018 15:16:05 +0200
Cornelia Huck <cohuck@redhat.com> wrote:

> The 3270 code will try to post an attention interrupt when the
> 3270 emulator (e.g. x3270) attaches. If the guest has not yet
> enabled the subchannel for the 3270 device, we will give it a
> spurious status during msch when it does so later.
> 
> To fix this, just don't do anything in css_conditional_io_interrupt()
> if the subchannel is not enabled. The 3270 code will work fine with
> that, and the other user of this function (virtio-ccw) never
> attempts to post an interrupt for a disabled device to begin with.
> 
> Reported-by: Thomas Huth <thuth@redhat.com>
> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
> ---
>  hw/s390x/css.c | 8 ++++++++
>  1 file changed, 8 insertions(+)

Queued to s390-next (with commit message tweaked and cc:stable added).