Subject: Re: [PATCH 6/8] iommu/intel: Add a gfp parameter to alloc_pgtable_page()

From: Jason Gunthorpe <[email-masked]>
Date: Tue, 17 Jan 2023 09:30:26 -0400

On Tue, Jan 17, 2023 at 03:35:08AM +0000, Tian, Kevin wrote:
> > From: Jason Gunthorpe <[email-masked]>
> > Sent: Saturday, January 7, 2023 12:43 AM
> > 
> > @@ -2676,7 +2676,7 @@ static int copy_context_table(struct intel_iommu
> > *iommu,
> >  			if (!old_ce)
> >  				goto out;
> > 
> > -			new_ce = alloc_pgtable_page(iommu->node);
> > +			new_ce = alloc_pgtable_page(iommu->node,
> > GFP_KERNEL);
> 
> GFP_ATOMIC

Can't be:

			old_ce = memremap(old_ce_phys, PAGE_SIZE,
					MEMREMAP_WB);
			if (!old_ce)
				goto out;

			new_ce = alloc_pgtable_page(iommu->node, GFP_KERNEL);
			if (!new_ce)

memremap() is sleeping.

And the only caller is:

	ctxt_tbls = kcalloc(ctxt_table_entries, sizeof(void *), GFP_KERNEL);
	if (!ctxt_tbls)
		goto out_unmap;

	for (bus = 0; bus < 256; bus++) {
		ret = copy_context_table(iommu, &old_rt[bus],
					 ctxt_tbls, bus, ext);

Jason