On 6/22/20 9:39 PM, Jarkko Sakkinen wrote:
> +static int __init sgx_pfn_to_nid(unsigned long pfn)
> +{
> + pg_data_t *pgdat;
> + int nid;
> +
> + for (nid = 0; nid < nr_node_ids; nid++) {
> + pgdat = NODE_DATA(nid);
> +
> + if (pfn >= pgdat->node_start_pfn &&
> + pfn < (pgdat->node_start_pfn + pgdat->node_spanned_pages))
pgdat_end_pfn(), perhaps?
> + return nid;
> + }
> +
> + return 0;
> +}
Does this actually work?
The node span (->node_start_pfn through start+->node_spanned_pages) only
contains pages which the OS is actively managing, usually RAM but
sometimes also persistent memory. This has some assumption that the SGX
PFNs are within the node's span. I would only _expect_ that to happen
if the node was built like this:
| Node-X RAM | EPC | Node-X RAM |
If the EPC was on either end:
| Node-X RAM | EPC |
or
| EPC | Node-X RAM |
I suspect that the pgdat span wouldn't include EPC. EPC is, if I
remember correctly, a E820_RESERVED region.
