qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [PATCH 3/6] s390/kvm: diag288 instruction interception


From: Cornelia Huck
Subject: Re: [Qemu-devel] [PATCH 3/6] s390/kvm: diag288 instruction interception and handling
Date: Wed, 22 Apr 2015 13:37:05 +0200

On Wed, 22 Apr 2015 11:16:00 +0200
Alexander Graf <address@hidden> wrote:

> On 04/22/2015 10:32 AM, Cornelia Huck wrote:
> > On Tue, 21 Apr 2015 21:09:05 +0200
> > Alexander Graf <address@hidden> wrote:
> >
> >> On 04/17/2015 09:52 AM, Cornelia Huck wrote:
> >>> From: Xu Wang <address@hidden>
> >>>
> >>> Intercept the diag288 requests from kvm guests, and hand the
> >>> requested command to the diag288 watchdog device for further
> >>> handling.
> >>>
> >>> Signed-off-by: Xu Wang <address@hidden>
> >>> Reviewed-by: David Hildenbrand <address@hidden>
> >>> Signed-off-by: Cornelia Huck <address@hidden>
> >> We're getting a lot of random devices allocating diag intercepts. Can't
> >> we make this an actual interface, similar to the hypercall registration
> >> on sPAPR?
> > I've looked at the sPAPR hcall code, and it seems to basically provide
> > a table with a nice registration interface (we already use something
> > similar for the diagnose 500 virtio subcodes, btw.)
> >
> > While we could move our basic diagnose handling over to a table-like
> > approach and registering new diagnoses, I think this is orthogonal to
> > introducing a diag288 watchdog device: It just makes sense to model the
> > watchdog as a device that just happens to be poked via a diagnose. If
> > we introduce any further diagnoses to manipulate timing etc., I agree
> > we don't want to add a device for each of these.
> 
> My thinking was in the opposite level. I really like the idea of having 
> separate devices for each function. But I think that they should be 
> completely self-contained with well defined interfaces.

I don't know... having a device for e.g. a hypercall that changes some
timing characteristics feels a bit artificial to me.




reply via email to

[Prev in Thread] Current Thread [Next in Thread]