@@ -23,6 +23,7 @@
#include <linux/sizes.h>
#include <linux/pfn.h>
#include <linux/align.h>
+#include <linux/sort.h>
#include <asm/msr-index.h>
#include <asm/msr.h>
#include <asm/tdx.h>
@@ -648,6 +649,207 @@ static unsigned long tdmrs_count_pamt_kb(struct tdmr_info_list *tdmr_list)
return pamt_size / 1024;
}
+static int tdmr_add_rsvd_area(struct tdmr_info *tdmr, int *p_idx, u64 addr,
+ u64 size, u16 max_reserved_per_tdmr)
+{
+ struct tdmr_reserved_area *rsvd_areas = tdmr->reserved_areas;
+ int idx = *p_idx;
+
+ /* Reserved area must be 4K aligned in offset and size */
+ if (WARN_ON(addr & ~PAGE_MASK || size & ~PAGE_MASK))
+ return -EINVAL;
+
+ if (idx >= max_reserved_per_tdmr) {
+ pr_warn("initialization failed: TDMR [0x%llx, 0x%llx): reserved areas exhausted.\n",
+ tdmr->base, tdmr_end(tdmr));
+ return -ENOSPC;
+ }
+
+ /*
+ * Consume one reserved area per call. Make no effort to
+ * optimize or reduce the number of reserved areas which are
+ * consumed by contiguous reserved areas, for instance.
+ */
+ rsvd_areas[idx].offset = addr - tdmr->base;
+ rsvd_areas[idx].size = size;
+
+ *p_idx = idx + 1;
+
+ return 0;
+}
+
+/*
+ * Go through @tmb_list to find holes between memory areas. If any of
+ * those holes fall within @tdmr, set up a TDMR reserved area to cover
+ * the hole.
+ */
+static int tdmr_populate_rsvd_holes(struct list_head *tmb_list,
+ struct tdmr_info *tdmr,
+ int *rsvd_idx,
+ u16 max_reserved_per_tdmr)
+{
+ struct tdx_memblock *tmb;
+ u64 prev_end;
+ int ret;
+
+ /*
+ * Start looking for reserved blocks at the
+ * beginning of the TDMR.
+ */
+ prev_end = tdmr->base;
+ list_for_each_entry(tmb, tmb_list, list) {
+ u64 start, end;
+
+ start = PFN_PHYS(tmb->start_pfn);
+ end = PFN_PHYS(tmb->end_pfn);
+
+ /* Break if this region is after the TDMR */
+ if (start >= tdmr_end(tdmr))
+ break;
+
+ /* Exclude regions before this TDMR */
+ if (end < tdmr->base)
+ continue;
+
+ /*
+ * Skip over memory areas that
+ * have already been dealt with.
+ */
+ if (start <= prev_end) {
+ prev_end = end;
+ continue;
+ }
+
+ /* Add the hole before this region */
+ ret = tdmr_add_rsvd_area(tdmr, rsvd_idx, prev_end,
+ start - prev_end,
+ max_reserved_per_tdmr);
+ if (ret)
+ return ret;
+
+ prev_end = end;
+ }
+
+ /* Add the hole after the last region if it exists. */
+ if (prev_end < tdmr_end(tdmr)) {
+ ret = tdmr_add_rsvd_area(tdmr, rsvd_idx, prev_end,
+ tdmr_end(tdmr) - prev_end,
+ max_reserved_per_tdmr);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+/*
+ * Go through @tdmr_list to find all PAMTs. If any of those PAMTs
+ * overlaps with @tdmr, set up a TDMR reserved area to cover the
+ * overlapping part.
+ */
+static int tdmr_populate_rsvd_pamts(struct tdmr_info_list *tdmr_list,
+ struct tdmr_info *tdmr,
+ int *rsvd_idx,
+ u16 max_reserved_per_tdmr)
+{
+ int i, ret;
+
+ for (i = 0; i < tdmr_list->nr_consumed_tdmrs; i++) {
+ struct tdmr_info *tmp = tdmr_entry(tdmr_list, i);
+ unsigned long pamt_base, pamt_size, pamt_end;
+
+ tdmr_get_pamt(tmp, &pamt_base, &pamt_size);
+ /* Each TDMR must already have PAMT allocated */
+ WARN_ON_ONCE(!pamt_size || !pamt_base);
+
+ pamt_end = pamt_base + pamt_size;
+ /* Skip PAMTs outside of the given TDMR */
+ if ((pamt_end <= tdmr->base) ||
+ (pamt_base >= tdmr_end(tdmr)))
+ continue;
+
+ /* Only mark the part within the TDMR as reserved */
+ if (pamt_base < tdmr->base)
+ pamt_base = tdmr->base;
+ if (pamt_end > tdmr_end(tdmr))
+ pamt_end = tdmr_end(tdmr);
+
+ ret = tdmr_add_rsvd_area(tdmr, rsvd_idx, pamt_base,
+ pamt_end - pamt_base,
+ max_reserved_per_tdmr);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+/* Compare function called by sort() for TDMR reserved areas */
+static int rsvd_area_cmp_func(const void *a, const void *b)
+{
+ struct tdmr_reserved_area *r1 = (struct tdmr_reserved_area *)a;
+ struct tdmr_reserved_area *r2 = (struct tdmr_reserved_area *)b;
+
+ if (r1->offset + r1->size <= r2->offset)
+ return -1;
+ if (r1->offset >= r2->offset + r2->size)
+ return 1;
+
+ /* Reserved areas cannot overlap. The caller must guarantee. */
+ WARN_ON_ONCE(1);
+ return -1;
+}
+
+/*
+ * Populate reserved areas for the given @tdmr, including memory holes
+ * (via @tmb_list) and PAMTs (via @tdmr_list).
+ */
+static int tdmr_populate_rsvd_areas(struct tdmr_info *tdmr,
+ struct list_head *tmb_list,
+ struct tdmr_info_list *tdmr_list,
+ u16 max_reserved_per_tdmr)
+{
+ int ret, rsvd_idx = 0;
+
+ ret = tdmr_populate_rsvd_holes(tmb_list, tdmr, &rsvd_idx,
+ max_reserved_per_tdmr);
+ if (ret)
+ return ret;
+
+ ret = tdmr_populate_rsvd_pamts(tdmr_list, tdmr, &rsvd_idx,
+ max_reserved_per_tdmr);
+ if (ret)
+ return ret;
+
+ /* TDX requires reserved areas listed in address ascending order */
+ sort(tdmr->reserved_areas, rsvd_idx, sizeof(struct tdmr_reserved_area),
+ rsvd_area_cmp_func, NULL);
+
+ return 0;
+}
+
+/*
+ * Populate reserved areas for all TDMRs in @tdmr_list, including memory
+ * holes (via @tmb_list) and PAMTs.
+ */
+static int tdmrs_populate_rsvd_areas_all(struct tdmr_info_list *tdmr_list,
+ struct list_head *tmb_list,
+ u16 max_reserved_per_tdmr)
+{
+ int i;
+
+ for (i = 0; i < tdmr_list->nr_consumed_tdmrs; i++) {
+ int ret;
+
+ ret = tdmr_populate_rsvd_areas(tdmr_entry(tdmr_list, i),
+ tmb_list, tdmr_list, max_reserved_per_tdmr);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
/*
* Construct a list of TDMRs on the preallocated space in @tdmr_list
* to cover all TDX memory regions in @tmb_list based on the TDX module
@@ -667,14 +869,13 @@ static int construct_tdmrs(struct list_head *tmb_list,
tdmr_sysinfo->pamt_entry_size);
if (ret)
return ret;
- /*
- * TODO:
- *
- * - Designate reserved areas for each TDMR.
- *
- * Return -EINVAL until constructing TDMRs is done
- */
- return -EINVAL;
+
+ ret = tdmrs_populate_rsvd_areas_all(tdmr_list, tmb_list,
+ tdmr_sysinfo->max_reserved_per_tdmr);
+ if (ret)
+ tdmrs_free_pamt_all(tdmr_list);
+
+ return ret;
}
static int init_tdx_module(void)