From cce94f6ee028877b982ee8eda57b8ea907bfaa03 Mon Sep 17 00:00:00 2001
From: cadolphe-amd <chris.adolphe@amd.com>
Date: Tue, 25 Nov 2025 18:05:25 -0500
Subject: [PATCH] SWDEV-557412 - Incorporate proper chunk offset when remapping
 virtual memory (#1848)

* SWDEV-557412 - Incorporate proper offset when remapping virtual memory

* Fix condition to check if VMHeap allocation address matches a chunk address

* Move offset calculation outside if/else block

---------

Co-authored-by: JeniferC99 <150404595+JeniferC99@users.noreply.github.com>
---
 projects/clr/rocclr/device/pal/palvirtual.cpp | 10 ++++++----
 projects/clr/rocclr/platform/vmheap.cpp       |  5 ++++-
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/projects/clr/rocclr/device/pal/palvirtual.cpp b/projects/clr/rocclr/device/pal/palvirtual.cpp
index b60f1ae964..53905adbfa 100644
--- a/projects/clr/rocclr/device/pal/palvirtual.cpp
+++ b/projects/clr/rocclr/device/pal/palvirtual.cpp
@@ -2325,12 +2325,14 @@ void VirtualGPU::submitVirtualMap(amd::VirtualMapCommand& vcmd) {
     vaddr_sub_obj = phys_mem_obj->getContext().devices()[0]->CreateVirtualBuffer(
         phys_mem_obj->getContext(), const_cast<void*>(vcmd.ptr()), vcmd.size(),
         phys_mem_obj->getUserData().deviceId, phys_mem_obj->getUserData().locationType, kParent);
-
-    // Calculate the offset from the original pointer.
-    vaddr_offset = (reinterpret_cast<address>(vaddr_sub_obj->getSvmPtr()) -
-                    reinterpret_cast<address>(vaddr_base_obj->getSvmPtr()));
+  } else {
+    vaddr_sub_obj = amd::MemObjMap::FindMemObj(vcmd.ptr());
   }
 
+  // Calculate the offset from the original pointer.
+  vaddr_offset = (reinterpret_cast<address>(vaddr_sub_obj->getSvmPtr()) -
+                  reinterpret_cast<address>(vaddr_base_obj->getSvmPtr()));
+
   // The imem() in the backend is shared between base and sub/view object.
   pal::Memory* vaddr_pal_mem = dev().getGpuMemory(vaddr_base_obj);
   Pal::IGpuMemory* phymem_igpu_mem =
diff --git a/projects/clr/rocclr/platform/vmheap.cpp b/projects/clr/rocclr/platform/vmheap.cpp
index d7b6d17851..c9740a0361 100644
--- a/projects/clr/rocclr/platform/vmheap.cpp
+++ b/projects/clr/rocclr/platform/vmheap.cpp
@@ -239,7 +239,10 @@ address VmHeap::Alloc(size_t size) {
   size_t offset = 0;
   auto hb = AllocBlock(size + block_alignment_);
   if (hb != nullptr) {
-    offset = ((hb->Offset() & ~kChunkSize) == 0) ? hb->Offset() + block_alignment_ : hb->Offset();
+    // Add 256-byte offset if virtual address matches chunk address to avoid map conflicts
+    offset = ((hb->Offset() & (kChunkSize - 1)) == 0)
+               ? hb->Offset() + block_alignment_
+               : hb->Offset();
     ptr = base_address_ + offset;
   } else {
     return nullptr;