[SYCL][E2E] Add extending virtual mem range test for `sycl_ext_oneapi…

…_virtual_mem` extension (#15944)

Based on the test plan #15509, this PR
adds an e2e test described as `"Extending" virtual memory range`.

sycl/test-e2e/VirtualMem/extending_virtual_memory_range.cpp

@@ -0,0 +1,97 @@
+// This test checks whether memory accesses to contiguous virtual memory ranges
+// are performed correctly
+
+// RUN: %{build} -o %t.out
+// RUN: %{run} %t.out
+
+#include <cassert>
+
+#include "helpers.hpp"
+
+struct VirtualAddressRange {
+  VirtualAddressRange(uintptr_t Ptr, size_t Size) : MPtr{Ptr}, MSize{Size} {}
+
+  uintptr_t MPtr;
+  size_t MSize;
+};
+
+struct PhysicalMemoryMapping {
+  PhysicalMemoryMapping(syclext::physical_mem &&PhysicalMem, void *MappingPtr)
+      : MPhysicalMem(std::move(PhysicalMem)), MMappingPtr(MappingPtr) {}
+  syclext::physical_mem MPhysicalMem;
+  void *MMappingPtr;
+};
+
+int main() {
+  int Failed = 0;
+  sycl::queue Q;
+  sycl::context Context = Q.get_context();
+  sycl::device Device = Q.get_device();
+
+  constexpr size_t NumberOfVirtualMemoryRanges = 5;
+  constexpr size_t ElementsInRange = 100;
+  constexpr int ValueSetInKernel = 999;
+
+  size_t BytesRequiredPerRange = ElementsInRange * sizeof(int);
+
+  size_t UsedGranularity = GetLCMGranularity(Device, Context);
+
+  size_t AlignedByteSizePerRange =
+      GetAlignedByteSize(BytesRequiredPerRange, UsedGranularity);
+
+  std::vector<VirtualAddressRange> VirtualMemoryRanges;
+  std::vector<PhysicalMemoryMapping> PhysicalMemoryMappings;
+
+  for (size_t Index = 0; Index < NumberOfVirtualMemoryRanges; ++Index) {
+    uintptr_t VirtualMemoryPtr =
+        syclext::reserve_virtual_mem(AlignedByteSizePerRange, Context);
+    syclext::physical_mem PhysicalMem{Device, Context, AlignedByteSizePerRange};
+    void *MappedPtr = PhysicalMem.map(VirtualMemoryPtr, AlignedByteSizePerRange,
+                                      syclext::address_access_mode::read_write);
+
+    VirtualMemoryRanges.emplace_back(VirtualMemoryPtr, AlignedByteSizePerRange);
+    PhysicalMemoryMappings.emplace_back(std::move(PhysicalMem), MappedPtr);
+  }
+
+  std::vector<int> ResultHostData(ElementsInRange);
+
+  for (size_t Index = 0; Index < NumberOfVirtualMemoryRanges; ++Index) {
+    int *DataRangePtr =
+        reinterpret_cast<int *>(PhysicalMemoryMappings[Index].MMappingPtr);
+
+    Q.parallel_for(ElementsInRange, [=](sycl::id<1> Idx) {
+       DataRangePtr[Idx] = ValueSetInKernel;
+     }).wait_and_throw();
+
+    {
+      sycl::buffer<int> ResultBuffer(ResultHostData);
+
+      Q.submit([&](sycl::handler &Handle) {
+        sycl::accessor A(ResultBuffer, Handle, sycl::write_only);
+        Handle.parallel_for(ElementsInRange, [=](sycl::id<1> Idx) {
+          A[Idx] = DataRangePtr[Idx];
+        });
+      });
+    }
+
+    for (size_t i = 0; i < ElementsInRange; i++) {
+      if (ResultHostData[i] != ValueSetInKernel) {
+        std::cout << "Comparison failed with virtual range " << Index + 1
+                  << " at index " << i << ": " << ResultHostData[i]
+                  << " != " << ValueSetInKernel << std::endl;
+        ++Failed;
+      }
+    }
+  }
+
+  for (auto PhysMemMap : PhysicalMemoryMappings) {
+    syclext::unmap(PhysMemMap.MMappingPtr, PhysMemMap.MPhysicalMem.size(),
+                   Context);
+  }
+  for (auto VirtualMemRange : VirtualMemoryRanges) {
+    syclext::free_virtual_mem(VirtualMemRange.MPtr, VirtualMemRange.MSize,
+                              Context);
+  }
+
+  return Failed;
+}