From: Fan Ni
Not all dpa range in the DC regions is valid to access until an extent
covering the range has been added. Add a bitmap for each region to
record whether a DC block in the region has been backed by DC extent.
For the bitmap, a bit in the bitmap represents a DC block. When a DC
extent is added, all the bits of the blocks in the extent will be set,
which will be cleared when the extent is released.
Signed-off-by: Fan Ni
---
hw/cxl/cxl-mailbox-utils.c | 4 ++
hw/mem/cxl_type3.c | 76 +
include/hw/cxl/cxl_device.h | 7
3 files changed, 87 insertions(+)
diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index 53ebc526ae..b538297bb5 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -1606,6 +1606,7 @@ static CXLRetCode cmd_dcd_add_dyn_cap_rsp(const struct
cxl_cmd *cmd,
cxl_insert_extent_to_extent_list(extent_list, dpa, len, NULL, 0);
ct3d->dc.total_extent_count += 1;
+ct3_set_region_block_backed(ct3d, dpa, len);
}
/*
@@ -1681,17 +1682,20 @@ static CXLRetCode cmd_dcd_release_dyn_cap(const struct
cxl_cmd *cmd,
found = true;
cxl_remove_extent_from_extent_list(extent_list, ent);
ct3d->dc.total_extent_count -= 1;
+ct3_clear_region_block_backed(ct3d, ent_start_dpa,
ent_len);
if (len1) {
cxl_insert_extent_to_extent_list(extent_list,
ent_start_dpa, len1,
NULL, 0);
ct3d->dc.total_extent_count += 1;
+ct3_set_region_block_backed(ct3d, ent_start_dpa, len1);
}
if (len2) {
cxl_insert_extent_to_extent_list(extent_list, dpa +
len,
len2, NULL, 0);
ct3d->dc.total_extent_count += 1;
+ct3_set_region_block_backed(ct3d, dpa + len, len2);
}
break;
} else {
diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
index e9c8994cdb..c164cf4580 100644
--- a/hw/mem/cxl_type3.c
+++ b/hw/mem/cxl_type3.c
@@ -672,6 +672,7 @@ static bool cxl_create_dc_regions(CXLType3Dev *ct3d, Error
**errp)
region_base += region->len;
ct3d->dc.total_capacity += region->len;
+region->blk_bitmap = bitmap_new(region->len / region->block_size);
}
QTAILQ_INIT(>dc.extents);
QTAILQ_INIT(>dc.extents_pending_to_add);
@@ -682,6 +683,8 @@ static bool cxl_create_dc_regions(CXLType3Dev *ct3d, Error
**errp)
static void cxl_destroy_dc_regions(CXLType3Dev *ct3d)
{
CXLDCExtent *ent;
+int i;
+CXLDCRegion *region;
while (!QTAILQ_EMPTY(>dc.extents)) {
ent = QTAILQ_FIRST(>dc.extents);
@@ -693,6 +696,11 @@ static void cxl_destroy_dc_regions(CXLType3Dev *ct3d)
cxl_remove_extent_from_extent_list(>dc.extents_pending_to_add,
ent);
}
+
+for (i = 0; i < ct3d->dc.num_regions; i++) {
+region = >dc.regions[i];
+g_free(region->blk_bitmap);
+}
}
static bool cxl_setup_memory(CXLType3Dev *ct3d, Error **errp)
@@ -924,6 +932,70 @@ static void ct3_exit(PCIDevice *pci_dev)
}
}
+/*
+ * Mark the DPA range [dpa, dap + len) to be backed and accessible. This
+ * happens when a DC extent is added and accepted by the host.
+ */
+void ct3_set_region_block_backed(CXLType3Dev *ct3d, uint64_t dpa,
+ uint64_t len)
+{
+CXLDCRegion *region;
+
+region = cxl_find_dc_region(ct3d, dpa, len);
+if (!region) {
+return;
+}
+
+bitmap_set(region->blk_bitmap, (dpa - region->base) / region->block_size,
+ len / region->block_size);
+}
+
+/*
+ * Check whether the DPA range [dpa, dpa + len) is backed with DC extents.
+ * Used when validating read/write to dc regions
+ */
+bool ct3_test_region_block_backed(CXLType3Dev *ct3d, uint64_t dpa,
+ uint64_t len)
+{
+CXLDCRegion *region;
+uint64_t nbits;
+long nr;
+
+region = cxl_find_dc_region(ct3d, dpa, len);
+if (!region) {
+return false;
+}
+
+nr = (dpa - region->base) / region->block_size;
+nbits = DIV_ROUND_UP(len, region->block_size);
+/*
+ * if bits between [dpa, dpa + len) are all 1s, meaning the DPA range is
+ * backed with DC extents, return true; else return false.
+ */
+return find_next_zero_bit(region->blk_bitmap, nr + nbits, nr) == nr +
nbits;
+}
+
+/*
+ * Mark the DPA range [dpa, dap + len) to be unbacked and inaccessible. This
+ * happens when a dc extent is released by the host.
+ */
+void ct3_clear_region_block_backed(CXLType3Dev *ct3d, uint64_t dpa,
+
