As the last step of constructing TDMRs, create reserved area information
for the memory region holes in each TDMR. If any PAMT (or part of it)
resides within a particular TDMR, also mark it as reserved.
All reserved areas in each TDMR must be in address ascending order,
required by TDX architecture.
Signed-off-by: Kai Huang <kai.huang@xxxxxxxxx>
---
arch/x86/virt/vmx/tdx/tdx.c | 148 +++++++++++++++++++++++++++++++++++-
1 file changed, 146 insertions(+), 2 deletions(-)
diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
index 1b807dcbc101..bf0d13644898 100644
--- a/arch/x86/virt/vmx/tdx/tdx.c
+++ b/arch/x86/virt/vmx/tdx/tdx.c
@@ -15,6 +15,7 @@
#include <linux/atomic.h>
#include <linux/slab.h>
#include <linux/math.h>
+#include <linux/sort.h>
#include <asm/msr-index.h>
#include <asm/msr.h>
#include <asm/cpufeature.h>
@@ -1112,6 +1113,145 @@ static int tdmrs_setup_pamt_all(struct tdmr_info **tdmr_array, int tdmr_num)
return -ENOMEM;
}
+static int tdmr_add_rsvd_area(struct tdmr_info *tdmr, int *p_idx,
+ u64 addr, u64 size)
+{
+ 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;
+
+ /* Cannot exceed maximum reserved areas supported by TDX */
+ if (idx >= tdx_sysinfo.max_reserved_per_tdmr)
+ return -E2BIG;
+
+ rsvd_areas[idx].offset = addr - tdmr->base;
+ rsvd_areas[idx].size = size;
+
+ *p_idx = idx + 1;
+
+ 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. Caller should guarantee. */
+ WARN_ON(1);
+ return -1;
+}
+
+/* Set up reserved areas for a TDMR, including memory holes and PAMTs */
+static int tdmr_setup_rsvd_areas(struct tdmr_info *tdmr,
+ struct tdmr_info **tdmr_array,
+ int tdmr_num)
+{
+ u64 start, end, prev_end;
+ int rsvd_idx, i, ret = 0;
+
+ /* Mark holes between e820 RAM entries as reserved */
+ rsvd_idx = 0;
+ prev_end = TDMR_START(tdmr);
+ e820_for_each_mem(i, start, end) {
+ /* Break if this entry is after the TDMR */
+ if (start >= TDMR_END(tdmr))
+ break;
+
+ /* Exclude entries before this TDMR */
+ if (end < TDMR_START(tdmr))
+ continue;
+
+ /*
+ * Skip if no hole exists before this entry. "<=" is
+ * used because one e820 entry might span two TDMRs.
+ * In that case the start address of this entry is
+ * smaller then the start address of the second TDMR.
+ */
+ if (start <= prev_end) {
+ prev_end = end;
+ continue;
+ }
+
+ /* Add the hole before this e820 entry */
+ ret = tdmr_add_rsvd_area(tdmr, &rsvd_idx, prev_end,
+ start - prev_end);
+ if (ret)
+ return ret;
+
+ prev_end = end;
+ }
+
+ /* Add the hole after the last RAM entry if it exists. */
+ if (prev_end < TDMR_END(tdmr)) {
+ ret = tdmr_add_rsvd_area(tdmr, &rsvd_idx, prev_end,
+ TDMR_END(tdmr) - prev_end);
+ if (ret)
+ return ret;
+ }
+
+ /*
+ * Walk over all TDMRs to find out whether any PAMT falls into
+ * the given TDMR. If yes, mark it as reserved too.
+ */
+ for (i = 0; i < tdmr_num; i++) {
+ struct tdmr_info *tmp = tdmr_array[i];
+ u64 pamt_start, pamt_end;
+
+ pamt_start = tmp->pamt_4k_base;
+ pamt_end = pamt_start + tmp->pamt_4k_size +
+ tmp->pamt_2m_size + tmp->pamt_1g_size;
+
+ /* Skip PAMTs outside of the given TDMR */
+ if ((pamt_end <= TDMR_START(tdmr)) ||
+ (pamt_start >= TDMR_END(tdmr)))
+ continue;
+
+ /* Only mark the part within the TDMR as reserved */
+ if (pamt_start < TDMR_START(tdmr))
+ pamt_start = TDMR_START(tdmr);
+ if (pamt_end > TDMR_END(tdmr))
+ pamt_end = TDMR_END(tdmr);
+
+ ret = tdmr_add_rsvd_area(tdmr, &rsvd_idx, pamt_start,
+ pamt_end - pamt_start);
+ 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;
+}
+
+static int tdmrs_setup_rsvd_areas_all(struct tdmr_info **tdmr_array,
+ int tdmr_num)
+{
+ int i;
+
+ for (i = 0; i < tdmr_num; i++) {
+ int ret;
+
+ ret = tdmr_setup_rsvd_areas(tdmr_array[i], tdmr_array,
+ tdmr_num);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
static int construct_tdmrs(struct tdmr_info **tdmr_array, int *tdmr_num)
{
int ret;
@@ -1128,8 +1268,12 @@ static int construct_tdmrs(struct tdmr_info **tdmr_array, int *tdmr_num)
if (ret)
goto err_free_tdmrs;
- /* Return -EFAULT until constructing TDMRs is done */
- ret = -EFAULT;
+ ret = tdmrs_setup_rsvd_areas_all(tdmr_array, *tdmr_num);
+ if (ret)
+ goto err_free_pamts;
+
+ return 0;
+err_free_pamts:
tdmrs_free_pamt_all(tdmr_array, *tdmr_num);
err_free_tdmrs:
free_tdmrs(tdmr_array, *tdmr_num);
--
2.35.1
