Re: [PATCH 1/2] genirq/msi: Introduce update hwsize helper

[Guixin Liu]

在 2026/3/25 16:15, Thomas Gleixner 写道:
> On Tue, Mar 24 2026 at 09:47, Guixin Liu wrote:
> > +int msi_domain_update_hwsize(struct device *dev, unsigned int domid,
> > +			     unsigned int hwsize_new)
> > +{
> > +	struct msi_domain_info *info;
> > +	struct irq_domain *domain;
> > +
> > +	if (hwsize_new > MSI_XA_DOMAIN_SIZE)
> > +		return -EINVAL;
> > +	if (!hwsize_new)
> > +		hwsize_new = MSI_XA_DOMAIN_SIZE;
> > +
> > +	domain = msi_get_device_domain(dev, domid);
> > +	if (!domain)
> > +		return -ENODEV;
> > +
> > +	info = domain->host_data;
> > +	if (hwsize_new != info->hwsize)
> > +		info->hwsize = hwsize_new;
> This is incorrect because the underlying irqdomain has been created with
> the original hardware size. So just fiddling with info->hwsize results
> in inconsistent state.
I found that hwsize only affects the range checking when allocating and
releasing intterrupts after the irq_domain is established,
and the kernel does not allocate related resources based on it.
Cloud you plz tell me specifically where the inconsistency is? thanks.

Best Regards,
Guixin Liu