On Tue, 2022-11-22 at 11:10 +0100, Peter Zijlstra wrote:
> On Mon, Nov 21, 2022 at 01:26:32PM +1300, Kai Huang wrote:
>
> > +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;
> > +
> > + /* Verify memory is truly TDX convertible memory */
> > + if (!pfn_range_covered_by_cmr(start_pfn, end_pfn)) {
> > + pr_info("Memory region [0x%lx, 0x%lx) is not TDX convertible memorry.\n",
> > + start_pfn << PAGE_SHIFT,
> > + end_pfn << PAGE_SHIFT);
> > + return -EINVAL;
>
> Given how tdx_cc_memory_compatible() below relies on tdx_memlist being
> empty; this error patch is wrong and should goto err.
Oops. Thanks for catching.
Also thanks for review! Today is too late for me and I'll catch up with others
tomorrow.
>
> > + }
> > +
> > + /*
> > + * Add the memory regions as TDX memory. The regions in
> > + * memblock has already guaranteed they are in address
> > + * ascending order and don't overlap.
> > + */
> > + ret = add_tdx_memblock(start_pfn, end_pfn, nid);
> > + if (ret)
> > + goto err;
> > + }
> > +
> > + return 0;
> > +err:
> > + free_tdx_memory();
> > + return ret;
> > +}
>
> > +bool tdx_cc_memory_compatible(unsigned long start_pfn, unsigned long end_pfn)
> > +{
> > + struct tdx_memblock *tmb;
> > +
> > + /* Empty list means TDX isn't enabled successfully */
> > + if (list_empty(&tdx_memlist))
> > + return true;
> > +
> > + list_for_each_entry(tmb, &tdx_memlist, list) {
> > + /*
> > + * The new range is TDX memory if it is fully covered
> > + * by any TDX memory block.
> > + */
> > + if (start_pfn >= tmb->start_pfn && end_pfn <= tmb->end_pfn)
> > + return true;
> > + }
> > + return false;
> > +}
>
