>+static int init_pamt_metadata(void)
>+{
>+ size_t size = max_pfn / PTRS_PER_PTE * sizeof(*pamt_refcounts);
>+ struct vm_struct *area;
>+
>+ if (!tdx_supports_dynamic_pamt(&tdx_sysinfo))
>+ return 0;
>+
>+ /*
>+ * Reserve vmalloc range for PAMT reference counters. It covers all
>+ * physical address space up to max_pfn. It is going to be populated
>+ * from init_tdmr() only for present memory that available for TDX use.
>+ */
>+ area = get_vm_area(size, VM_IOREMAP);
>+ if (!area)
>+ return -ENOMEM;
>+
>+ pamt_refcounts = area->addr;
>+ return 0;
>+}
>+
>+static void free_pamt_metadata(void)
>+{
>+ size_t size = max_pfn / PTRS_PER_PTE * sizeof(*pamt_refcounts);
>+
Shouldn't the free path also be gated by tdx_supports_dynamic_pamt()?
There is a possibility that pamt_refcounts could be NULL here, e.g., the
TDX module doesn't support dynamic PAMT and init_tdmrs() encountered an
error. I am assuming that apply_to_existing_page_range() below will cause
issues if pamt_refcounts is NULL, e.g., unmap mappings set up by others.
>+ size = round_up(size, PAGE_SIZE);
>+ apply_to_existing_page_range(&init_mm,
>+ (unsigned long)pamt_refcounts,
>+ size, pamt_refcount_depopulate,
>+ NULL);
>+ vfree(pamt_refcounts);
>+ pamt_refcounts = NULL;
>+}
>+
> static int init_tdmr(struct tdmr_info *tdmr)
> {
> u64 next;
>+ int ret;
>+
>+ ret = alloc_tdmr_pamt_refcount(tdmr);
>+ if (ret)
>+ return ret;
>
> /*
> * Initializing a TDMR can be time consuming. To avoid long
>@@ -1048,7 +1150,6 @@ static int init_tdmr(struct tdmr_info *tdmr)
> struct tdx_module_args args = {
> .rcx = tdmr->base,
> };
>- int ret;
>
> ret = seamcall_prerr_ret(TDH_SYS_TDMR_INIT, &args);
> if (ret)
>@@ -1134,10 +1235,15 @@ static int init_tdx_module(void)
> if (ret)
> goto err_reset_pamts;
>
>+ /* Reserve vmalloc range for PAMT reference counters */
>+ ret = init_pamt_metadata();
>+ if (ret)
>+ goto err_reset_pamts;
>+
> /* Initialize TDMRs to complete the TDX module initialization */
> ret = init_tdmrs(&tdx_tdmr_list);
> if (ret)
>- goto err_reset_pamts;
>+ goto err_free_pamt_metadata;
>
> pr_info("%lu KB allocated for PAMT\n", tdmrs_count_pamt_kb(&tdx_tdmr_list));
>
>@@ -1149,6 +1255,9 @@ static int init_tdx_module(void)
> put_online_mems();
> return ret;
>
>+err_free_pamt_metadata:
>+ free_pamt_metadata();
>+
> err_reset_pamts:
> /*
> * Part of PAMTs may already have been initialized by the
>--
>2.47.2
>
