> >
> > +struct tdx_memblock {
> > + struct list_head list;
> > + unsigned long start_pfn;
>
> Why not use 'phys_addr_t'?
TDX memory must be page aligned, so start_pfn/end_pfn would be easier.
>
> > + unsigned long end_pfn;
> > + int nid;
> > +};
> > +
> >
[...]
> >
> > +/* Check whether the given pfn range is covered by any CMR or not. */
> > +static bool pfn_range_covered_by_cmr(unsigned long start_pfn,
> > + unsigned long end_pfn)
> > +{
> > + int i;
> > +
> > + for (i = 0; i < tdx_cmr_num; i++) {
> > + struct cmr_info *cmr = &tdx_cmr_array[i];
> > + unsigned long cmr_start_pfn;
> > + unsigned long cmr_end_pfn;
> > +
> > + cmr_start_pfn = cmr->base >> PAGE_SHIFT;
> > + cmr_end_pfn = (cmr->base + cmr->size) >> PAGE_SHIFT;
>
> Why not use PHYS_PFN() or PFN_DOWN()? And PFN_PHYS() in reverse direction?
Didn't know them. Will use them.
[...]
> > +
> > +/*
> > + * Add all memblock memory regions to the @tdx_memlist as TDX memory.
> > + * Must be called when get_online_mems() is called by the caller.
> > + */
> > +static int build_tdx_memory(void)
> > +{
> > + unsigned long start_pfn, end_pfn;
> > + int i, nid, ret;
> > +
> > + for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
> > + /*
> > + * The first 1MB may not be reported as TDX convertible
> > + * memory. Manually exclude them as TDX memory.
> > + *
> > + * This is fine as the first 1MB is already reserved in
> > + * reserve_real_mode() and won't end up to ZONE_DMA as
> > + * free page anyway.
> > + */
> > + start_pfn = max(start_pfn, (unsigned long)SZ_1M >> PAGE_SHIFT);
> > + if (start_pfn >= end_pfn)
> > + continue;
>
> How about check whether first 1MB is reserved instead of depending on
> the corresponding code isn't changed? Via for_each_reserved_mem_range()?
IIUC, some reserved memory can be freed to page allocator directly, i.e. kernel
init code/data. I feel it's not safe to just treat reserved memory will never
be in page allocator. Otherwise we have for_each_free_mem_range() can use.
[...]
>
> > +/*
> > + * Check whether the given range is TDX memory. Must be called between
> > + * mem_hotplug_begin()/mem_hotplug_done().
>
> Must be called with mem_hotplug_lock write-locked.
>
Will do.
