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[V9,26/46] cpr: Mismatched GPAs fix

Message ID 1658851843-236870-27-git-send-email-steven.sistare@oracle.com
State New
Headers show
Series Live Update | expand

Commit Message

Steve Sistare July 26, 2022, 4:10 p.m. UTC 
For cpr-exec mode, ramblock_is_ignored is always true, and the address of
each migrated memory region must match the address of the statically
initialized region on the target.  However, for a PCI rom block, the region
address is set when the guest writes to a BAR on the source, which does not
occur on the target, causing a "Mismatched GPAs" error during cpr-exec
migration.

To fix, unconditionally set the target's address to the source's address
if the region does not have an address yet.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
---
 include/exec/memory.h | 12 ++++++++++++
 migration/ram.c       | 17 ++++++++++-------
 softmmu/memory.c      | 10 ++++++++--
 3 files changed, 30 insertions(+), 9 deletions(-)
diff mbox series

Patch

diff --git a/include/exec/memory.h b/include/exec/memory.h
index 128bf3e..9b3bad5 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -738,6 +738,7 @@  struct MemoryRegion {
     bool flush_coalesced_mmio;
     uint8_t dirty_log_mask;
     bool is_iommu;
+    bool has_addr;
     RAMBlock *ram_block;
     Object *owner;
 
@@ -2268,6 +2269,17 @@  void memory_region_set_enabled(MemoryRegion *mr, bool enabled);
 void memory_region_set_address(MemoryRegion *mr, hwaddr addr);
 
 /*
+ * memory_region_set_address_only: set the address of a region.
+ *
+ * Same as memory_region_set_address, but without causing transaction side
+ * effects.
+ *
+ * @mr: the region to be updated
+ * @addr: new address, relative to container region
+ */
+void memory_region_set_address_only(MemoryRegion *mr, hwaddr addr);
+
+/*
  * memory_region_set_size: dynamically update the size of a region.
  *
  * Dynamically updates the size of a region.
diff --git a/migration/ram.c b/migration/ram.c
index 4c868d2..6005c53 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -4314,13 +4314,16 @@  static int ram_load_precopy(QEMUFile *f)
                     }
                     if (migrate_ignore_shared()) {
                         hwaddr addr = qemu_get_be64(f);
-                        if (ramblock_is_ignored(block) &&
-                            block->mr->addr != addr) {
-                            error_report("Mismatched GPAs for block %s "
-                                         "%" PRId64 "!= %" PRId64,
-                                         id, (uint64_t)addr,
-                                         (uint64_t)block->mr->addr);
-                            ret = -EINVAL;
+                        if (ramblock_is_ignored(block)) {
+                            if (!block->mr->has_addr) {
+                                memory_region_set_address_only(block->mr, addr);
+                            } else if (block->mr->addr != addr) {
+                                error_report("Mismatched GPAs for block %s "
+                                             "%" PRId64 "!= %" PRId64,
+                                             id, (uint64_t)addr,
+                                             (uint64_t)block->mr->addr);
+                                ret = -EINVAL;
+                            }
                         }
                     }
                     ram_control_load_hook(f, RAM_CONTROL_BLOCK_REG,
diff --git a/softmmu/memory.c b/softmmu/memory.c
index 6aa3a2f..8825608 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -2552,7 +2552,7 @@  static void memory_region_add_subregion_common(MemoryRegion *mr,
     for (alias = subregion->alias; alias; alias = alias->alias) {
         alias->mapped_via_alias++;
     }
-    subregion->addr = offset;
+    memory_region_set_address_only(subregion, offset);
     memory_region_update_container_subregions(subregion);
 }
 
@@ -2632,10 +2632,16 @@  static void memory_region_readd_subregion(MemoryRegion *mr)
     }
 }
 
+void memory_region_set_address_only(MemoryRegion *mr, hwaddr addr)
+{
+    mr->addr = addr;
+    mr->has_addr = true;
+}
+
 void memory_region_set_address(MemoryRegion *mr, hwaddr addr)
 {
     if (addr != mr->addr) {
-        mr->addr = addr;
+        memory_region_set_address_only(mr, addr);
         memory_region_readd_subregion(mr);
     }
 }