[PULL v3 27/85] hw/mem/cxl_type3: Add DPA range validation for accesses to DC regions

Michael S. Tsirkin posted 85 patches 2 months, 2 weeks ago
Maintainers: David Hildenbrand <david@redhat.com>, Igor Mammedov <imammedo@redhat.com>, Raphael Norwitz <raphael@enfabrica.net>, "Michael S. Tsirkin" <mst@redhat.com>, Gerd Hoffmann <kraxel@redhat.com>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Shannon Zhao <shannon.zhaosl@gmail.com>, Ani Sinha <anisinha@redhat.com>, Peter Maydell <peter.maydell@linaro.org>, Kevin Wolf <kwolf@redhat.com>, Hanna Reitz <hreitz@redhat.com>, Eduardo Habkost <eduardo@habkost.net>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Yanan Wang <wangyanan55@huawei.com>, Jonathan Cameron <jonathan.cameron@huawei.com>, Fan Ni <fan.ni@samsung.com>, "Marc-André Lureau" <marcandre.lureau@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, Sergio Lopez <slp@redhat.com>, Akihiko Odaki <akihiko.odaki@daynix.com>, Sriram Yagnaraman <sriram.yagnaraman@ericsson.com>, Jason Wang <jasowang@redhat.com>, Keith Busch <kbusch@kernel.org>, Klaus Jensen <its@irrelevant.dk>, Jesper Devantier <foss@defmacro.it>, Nicholas Piggin <npiggin@gmail.com>, Daniel Henrique Barboza <danielhb413@gmail.com>, David Gibson <david@gibson.dropbear.id.au>, Harsh Prateek Bora <harshpb@linux.ibm.com>, Halil Pasic <pasic@linux.ibm.com>, Christian Borntraeger <borntraeger@linux.ibm.com>, Eric Farman <farman@linux.ibm.com>, Ilya Leoshkevich <iii@linux.ibm.com>, Thomas Huth <thuth@redhat.com>, Fam Zheng <fam@euphon.net>, "Alex Bennée" <alex.bennee@linaro.org>, Stefan Hajnoczi <stefanha@redhat.com>, Eric Auger <eric.auger@redhat.com>, Stefano Stabellini <sstabellini@kernel.org>, Anthony PERARD <anthony@xenproject.org>, Paul Durrant <paul@xen.org>, Cornelia Huck <cohuck@redhat.com>, "Daniel P. Berrangé" <berrange@redhat.com>, Eric Blake <eblake@redhat.com>, Markus Armbruster <armbru@redhat.com>, Marcelo Tosatti <mtosatti@redhat.com>, David Woodhouse <dwmw2@infradead.org>, Laurent Vivier <lvivier@redhat.com>, Coiby Xu <Coiby.Xu@gmail.com>
[PULL v3 27/85] hw/mem/cxl_type3: Add DPA range validation for accesses to DC regions
Posted by Michael S. Tsirkin 2 months, 2 weeks ago
From: Fan Ni <fan.ni@samsung.com>

All DPA ranges in the DC regions are invalid to access until an extent
covering the range has been successfully accepted by the host. A bitmap
is added to each region to record whether a DC block in the region has
been backed by a DC extent. Each bit in the bitmap represents a DC block.
When a DC extent is accepted, all the bits representing the blocks in the
extent are set, which will be cleared when the extent is released.

Tested-by: Svetly Todorov <svetly.todorov@memverge.com>
Reviewed-by: Gregory Price <gregory.price@memverge.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Fan Ni <fan.ni@samsung.com>
Message-Id: <20240523174651.1089554-13-nifan.cxl@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 include/hw/cxl/cxl_device.h |  7 ++++
 hw/cxl/cxl-mailbox-utils.c  |  3 ++
 hw/mem/cxl_type3.c          | 76 +++++++++++++++++++++++++++++++++++++
 3 files changed, 86 insertions(+)

diff --git a/include/hw/cxl/cxl_device.h b/include/hw/cxl/cxl_device.h
index c69ff6b5de..0a4fcb2800 100644
--- a/include/hw/cxl/cxl_device.h
+++ b/include/hw/cxl/cxl_device.h
@@ -456,6 +456,7 @@ typedef struct CXLDCRegion {
     uint64_t block_size;
     uint32_t dsmadhandle;
     uint8_t flags;
+    unsigned long *blk_bitmap;
 } CXLDCRegion;
 
 struct CXLType3Dev {
@@ -577,4 +578,10 @@ CXLDCExtentGroup *cxl_insert_extent_to_extent_group(CXLDCExtentGroup *group,
 void cxl_extent_group_list_insert_tail(CXLDCExtentGroupList *list,
                                        CXLDCExtentGroup *group);
 void cxl_extent_group_list_delete_front(CXLDCExtentGroupList *list);
+void ct3_set_region_block_backed(CXLType3Dev *ct3d, uint64_t dpa,
+                                 uint64_t len);
+void ct3_clear_region_block_backed(CXLType3Dev *ct3d, uint64_t dpa,
+                                   uint64_t len);
+bool ct3_test_region_block_backed(CXLType3Dev *ct3d, uint64_t dpa,
+                                  uint64_t len);
 #endif
diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index 64387f34ce..c4852112fe 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -1655,6 +1655,7 @@ 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);
     }
     /* Remove the first extent group in the pending list */
     cxl_extent_group_list_delete_front(&ct3d->dc.extents_pending);
@@ -1813,10 +1814,12 @@ static CXLRetCode cmd_dcd_release_dyn_cap(const struct cxl_cmd *cmd,
      * list and update the extent count;
      */
     QTAILQ_FOREACH_SAFE(ent, &ct3d->dc.extents, node, ent_next) {
+        ct3_clear_region_block_backed(ct3d, ent->start_dpa, ent->len);
         cxl_remove_extent_from_extent_list(&ct3d->dc.extents, ent);
     }
     copy_extent_list(&ct3d->dc.extents, &updated_list);
     QTAILQ_FOREACH_SAFE(ent, &updated_list, node, ent_next) {
+        ct3_set_region_block_backed(ct3d, ent->start_dpa, ent->len);
         cxl_remove_extent_from_extent_list(&updated_list, ent);
     }
     ct3d->dc.total_extent_count = updated_list_size;
diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
index f53bcca6d3..0d18259ec0 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)
             .flags = 0,
         };
         ct3d->dc.total_capacity += region->len;
+        region->blk_bitmap = bitmap_new(region->len / region->block_size);
     }
     QTAILQ_INIT(&ct3d->dc.extents);
     QTAILQ_INIT(&ct3d->dc.extents_pending);
@@ -683,6 +684,8 @@ static void cxl_destroy_dc_regions(CXLType3Dev *ct3d)
 {
     CXLDCExtent *ent, *ent_next;
     CXLDCExtentGroup *group, *group_next;
+    int i;
+    CXLDCRegion *region;
 
     QTAILQ_FOREACH_SAFE(ent, &ct3d->dc.extents, node, ent_next) {
         cxl_remove_extent_from_extent_list(&ct3d->dc.extents, ent);
@@ -695,6 +698,11 @@ static void cxl_destroy_dc_regions(CXLType3Dev *ct3d)
         }
         g_free(group);
     }
+
+    for (i = 0; i < ct3d->dc.num_regions; i++) {
+        region = &ct3d->dc.regions[i];
+        g_free(region->blk_bitmap);
+    }
 }
 
 static bool cxl_setup_memory(CXLType3Dev *ct3d, Error **errp)
@@ -926,6 +934,70 @@ static void ct3_exit(PCIDevice *pci_dev)
     }
 }
 
+/*
+ * Mark the DPA range [dpa, dap + len - 1] 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 - 1] 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 - 1] 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,
+                                   uint64_t len)
+{
+    CXLDCRegion *region;
+    uint64_t nbits;
+    long nr;
+
+    region = cxl_find_dc_region(ct3d, dpa, len);
+    if (!region) {
+        return;
+    }
+
+    nr = (dpa - region->base) / region->block_size;
+    nbits = len / region->block_size;
+    bitmap_clear(region->blk_bitmap, nr, nbits);
+}
+
 static bool cxl_type3_dpa(CXLType3Dev *ct3d, hwaddr host_addr, uint64_t *dpa)
 {
     int hdm_inc = R_CXL_HDM_DECODER1_BASE_LO - R_CXL_HDM_DECODER0_BASE_LO;
@@ -1030,6 +1102,10 @@ static int cxl_type3_hpa_to_as_and_dpa(CXLType3Dev *ct3d,
         *as = &ct3d->hostpmem_as;
         *dpa_offset -= vmr_size;
     } else {
+        if (!ct3_test_region_block_backed(ct3d, *dpa_offset, size)) {
+            return -ENODEV;
+        }
+
         *as = &ct3d->dc.host_dc_as;
         *dpa_offset -= (vmr_size + pmr_size);
     }
-- 
MST