Re: [PATCH v3 03/11] x86/vlapic: introduce an EOI callback mechanism

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Wed, Mar 31, 2021 at 12:47:54PM +0100, Andrew Cooper wrote:
> On 31/03/2021 11:32, Roger Pau Monne wrote:
> > @@ -1620,9 +1666,22 @@ int vlapic_init(struct vcpu *v)
> >  
> >      clear_page(vlapic->regs);
> >  
> > +    vlapic->callbacks = xmalloc_array(typeof(*vlapic->callbacks),
> > +                                      X86_NR_VECTORS - 16);
> > +    if ( !vlapic->callbacks )
> > +    {
> > +        dprintk(XENLOG_ERR, "%pv: alloc vlapic callbacks error\n", v);
> > +        unmap_domain_page_global(vlapic->regs);
> > +        free_domheap_page(vlapic->regs_page);
> > +        return -ENOMEM;
> > +    }
> > +    memset(vlapic->callbacks, 0,
> > +           sizeof(*vlapic->callbacks) * (X86_NR_VECTORS - 16));
> 
> xzalloc_array() instead of memset().  Also, we shouldn't be printing for
> -ENOMEM cases.
> 
> As for the construction/teardown logic, vlapic_init()'s caller already
> vlapic_destory().  Therefore, the existing error path you've copied is
> buggy because it will cause a double-free if __map_domain_page_global()
> fails.

Right, let me adjust that path.

> I'll do a cleanup patch to fix the idempotency, which needs backporting too.

Ack, I don't mind doiing one myself either.

Thanks, Roger.