Re: [PATCH] xen-hvm: Avoid livelock while handling buffered ioreqs

[Peter Maydell]

On Tue, 9 Apr 2024 at 15:20, Ross Lagerwall <ross.lagerwall@citrix.com> wrote:
>
> On Tue, Apr 9, 2024 at 11:20 AM Anthony PERARD <anthony.perard@cloud.com> 
> wrote:
> >
> > On Thu, Apr 04, 2024 at 03:08:33PM +0100, Ross Lagerwall wrote:
> > > diff --git a/hw/xen/xen-hvm-common.c b/hw/xen/xen-hvm-common.c
> > > index 1627da739822..1116b3978938 100644
> > > --- a/hw/xen/xen-hvm-common.c
> > > +++ b/hw/xen/xen-hvm-common.c
> > > @@ -521,22 +521,30 @@ static bool handle_buffered_iopage(XenIOState 
> > > *state)
> > [...]
> > >
> > >  static void handle_buffered_io(void *opaque)
> > >  {
> > > +    unsigned int handled;
> > >      XenIOState *state = opaque;
> > >
> > > -    if (handle_buffered_iopage(state)) {
> > > +    handled = handle_buffered_iopage(state);
> > > +    if (handled >= IOREQ_BUFFER_SLOT_NUM) {
> > > +        /* We handled a full page of ioreqs. Schedule a timer to continue
> > > +         * processing while giving other stuff a chance to run.
> > > +         */
> >
> > ./scripts/checkpatch.pl report a style issue here:
> >     WARNING: Block comments use a leading /* on a separate line
> >
> > I can try to remember to fix that on commit.
>
> I copied the comment style from a few lines above but I guess it was
> wrong.

Yes, this is one of those cases where we've settled on a
style choice but there's still quite a lot of older code
in the codebase that doesn't adhere to it. Checkpatch
usually will catch this kind of nit for you.

thanks
-- PMM