Re: Re: [PATCH v17 11/35] virt: gunyah: Translate gh_rm_hyp_resource into gunyah_resource

[Elliot Berman]

On Mon, Mar 11, 2024 at 11:09:05AM +0530, Srivatsa Vaddagiri wrote:
> * Elliot Berman <quic_eberman@xxxxxxxxxxx> [2024-02-22 15:16:34]:
> 
> > When booting a Gunyah virtual machine, the host VM may gain capabilities
> > to interact with resources for the guest virtual machine. Examples of
> > such resources are vCPUs or message queues. To use those resources, we
> > need to translate the RM response into a gunyah_resource structure which
> > are useful to Linux drivers. Presently, Linux drivers need only to know
> > the type of resource, the capability ID, and an interrupt.
> > 
> > On ARM64 systems, the interrupt reported by Gunyah is the GIC interrupt
> > ID number and always a SPI or extended SPI.
> > 
> > Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
> 
> Minor nit below. LGTM otherwise
> 
> Reviewed-by: Srivatsa Vaddagiri <quic_svaddagi@xxxxxxxxxxx>
> 
> > +struct gunyah_resource *
> > +gunyah_rm_alloc_resource(struct gunyah_rm *rm,
> > +			 struct gunyah_rm_hyp_resource *hyp_resource)
> > +{
> > +	struct gunyah_resource *ghrsc;
> > +	int ret;
> > +
> > +	ghrsc = kzalloc(sizeof(*ghrsc), GFP_KERNEL);
> > +	if (!ghrsc)
> > +		return NULL;
> > +
> > +	ghrsc->type = hyp_resource->type;
> > +	ghrsc->capid = le64_to_cpu(hyp_resource->cap_id);
> > +	ghrsc->irq = IRQ_NOTCONNECTED;
> > +	ghrsc->rm_label = le32_to_cpu(hyp_resource->resource_label);
> > +	if (hyp_resource->virq) {
> > +		struct irq_fwspec fwspec;
> > +
> > +
> > +		fwspec.fwnode = rm->parent_fwnode;
> > +		ret = arch_gunyah_fill_irq_fwspec_params(le32_to_cpu(hyp_resource->virq), &fwspec);
> > +		if (ret) {
> > +			dev_err(rm->dev,
> > +				"Failed to translate interrupt for resource %d label: %d: %d\n",
> > +				ghrsc->type, ghrsc->rm_label, ret);
> 
> Not bailing on error here appears wrong. Can you check?
> 

Ah, yes. I'll return ghrsc here. I think it's better than returning
NULL because user of resource might be able to cope without the
interrupt and can let us get a more helpful kernel log messages because
the higher level VM function will complain.

> > +		}
> > +
> > +		ret = irq_create_fwspec_mapping(&fwspec);
> > +		if (ret < 0) {
> > +			dev_err(rm->dev,
> > +				"Failed to allocate interrupt for resource %d label: %d: %d\n",
> > +				ghrsc->type, ghrsc->rm_label, ret);
> > +			kfree(ghrsc);
> > +			return NULL;
> > +		}
> > +		ghrsc->irq = ret;
> > +	}
> > +
> > +	return ghrsc;
> > +}