feature: exit with warning if small bar detected on Linux

Return early and provide justification, otherwise SIGBUS error is
returned.

Related-To: NEO-14506
Signed-off-by: Maciej Bielski <maciej.bielski@intel.com>

shared/source/os_interface/linux/drm_neo.cpp

@@ -510,6 +510,9 @@ int Drm::setupHardwareInfo(const DeviceDescriptor *device, bool setupFeatureTabl
     if (!queryMemoryInfo()) {
         setPerContextVMRequired(true);
         printDebugString(debugManager.flags.PrintDebugMessages.get(), stderr, "%s", "WARNING: Failed to query memory info\n");
+    } else if (getMemoryInfo()->isSmallBarDetected()) {
+        IoFunctions::fprintf(stderr, "WARNING: Small BAR detected for device %s\n", getPciPath().c_str());
+        return -1;
     }
 
     if (!queryEngineInfo()) {

shared/source/os_interface/linux/ioctl_helper.h

@@ -46,6 +46,7 @@ struct MemoryRegion {
     MemoryClassInstance region;
     uint64_t probedSize;
     uint64_t unallocatedSize;
+    uint64_t cpuVisibleSize;
     std::bitset<4> tilesMask;
 };
 

shared/source/os_interface/linux/ioctl_helper_i915.cpp

@@ -26,6 +26,7 @@
 #include "shared/source/utilities/directory.h"
 
 #include <fcntl.h>
+#include <span>
 #include <sstream>
 
 namespace NEO {
@@ -183,11 +184,13 @@ std::vector<EngineCapabilities> IoctlHelperI915::translateToEngineCaps(const std
 }
 
 std::vector<MemoryRegion> IoctlHelperI915::translateToMemoryRegions(const std::vector<uint64_t> &regionInfo) {
+
     auto *data = reinterpret_cast<const drm_i915_query_memory_regions *>(regionInfo.data());
     auto memRegions = std::vector<MemoryRegion>(data->num_regions);
     for (uint32_t i = 0; i < data->num_regions; i++) {
         memRegions[i].probedSize = data->regions[i].probed_size;
         memRegions[i].unallocatedSize = data->regions[i].unallocated_size;
+        memRegions[i].cpuVisibleSize = data->regions[i].probed_cpu_visible_size;
         memRegions[i].region.memoryClass = data->regions[i].region.memory_class;
         memRegions[i].region.memoryInstance = data->regions[i].region.memory_instance;
     }

shared/source/os_interface/linux/memory_info.cpp

@@ -17,6 +17,7 @@
 #include "shared/source/os_interface/linux/numa_library.h"
 #include "shared/source/os_interface/product_helper.h"
 
+#include <algorithm>
 #include <iostream>
 
 namespace NEO {
@@ -27,10 +28,16 @@ MemoryInfo::MemoryInfo(const RegionContainer &regionInfo, const Drm &inputDrm)
     const auto memoryClassSystem = ioctlHelper->getDrmParamValue(DrmParam::memoryClassSystem);
     const auto memoryClassDevice = ioctlHelper->getDrmParamValue(DrmParam::memoryClassDevice);
     UNRECOVERABLE_IF(this->systemMemoryRegion.region.memoryClass != memoryClassSystem);
-    std::copy_if(drmQueryRegions.begin(), drmQueryRegions.end(), std::back_inserter(localMemoryRegions),
-                 [&](const MemoryRegion &memoryRegionInfo) {
-                     return (memoryRegionInfo.region.memoryClass == memoryClassDevice);
-                 });
+
+    std::ranges::copy_if(drmQueryRegions, std::back_inserter(localMemoryRegions),
+                         [memoryClassDevice](const MemoryRegion &memoryRegionInfo) {
+                             return (memoryRegionInfo.region.memoryClass == memoryClassDevice);
+                         });
+
+    smallBarDetected = std::ranges::any_of(localMemoryRegions,
+                                           [](const MemoryRegion &region) {
+                                               return (region.cpuVisibleSize && region.cpuVisibleSize < region.probedSize);
+                                           });
 
     populateTileToLocalMemoryRegionIndexMap();
 

shared/source/os_interface/linux/memory_info.h

@@ -47,6 +47,7 @@ class MemoryInfo {
     const RegionContainer &getLocalMemoryRegions() const { return localMemoryRegions; }
     const RegionContainer &getDrmRegionInfos() const { return drmQueryRegions; }
     bool isMemPolicySupported() const { return memPolicySupported; }
+    bool isSmallBarDetected() const { return smallBarDetected; }
 
   protected:
     const Drm &drm;
@@ -57,6 +58,7 @@ class MemoryInfo {
     int memPolicyMode;
     RegionContainer localMemoryRegions;
     std::array<uint32_t, 4> tileToLocalMemoryRegionIndexMap{};
+    bool smallBarDetected;
 };
 
 } // namespace NEO

shared/source/os_interface/linux/xe/ioctl_helper_xe.cpp

@@ -373,13 +373,15 @@ std::unique_ptr<EngineInfo> IoctlHelperXe::createEngineInfo(bool isSysmanEnabled
 }
 
 inline MemoryRegion createMemoryRegionFromXeMemRegion(const drm_xe_mem_region &xeMemRegion, std::bitset<4> tilesMask) {
-    MemoryRegion memoryRegion{};
-    memoryRegion.region.memoryInstance = xeMemRegion.instance;
-    memoryRegion.region.memoryClass = xeMemRegion.mem_class;
-    memoryRegion.probedSize = xeMemRegion.total_size;
-    memoryRegion.unallocatedSize = xeMemRegion.total_size - xeMemRegion.used;
-    memoryRegion.tilesMask = tilesMask;
-    return memoryRegion;
+    return {
+        .region{
+            .memoryClass = xeMemRegion.mem_class,
+            .memoryInstance = xeMemRegion.instance},
+        .probedSize = xeMemRegion.total_size,
+        .unallocatedSize = xeMemRegion.total_size - xeMemRegion.used,
+        .cpuVisibleSize = xeMemRegion.cpu_visible_size,
+        .tilesMask = tilesMask,
+    };
 }
 
 std::unique_ptr<MemoryInfo> IoctlHelperXe::createMemoryInfo() {