fix: do not access UMD-managed SVM-allocation while in-use

It is illegal with UMD-managed migrations to access a SVM-allocation
from CPU side while it is still in-use on GPU side. In such scenario
a CPU-side access triggers data fetch from GPU-side and then any
subsequent GPU-side modification will not be observable on the CPU-side.
With UMD-managed migrations there is no way to tell the GPU that it
should fetch the allocation again from CPU-side before modifying it.

The removed `EXPECT_NE` statements are not mandatory for the goals of
the tests while their side-effects make things worse.

Signed-off-by: Maciej Bielski <[email protected]>

conformance_tests/core/test_copy/src/test_copy_events.cpp

@@ -225,7 +225,6 @@ void RunGivenMemoryCopiesWithDependenciesWhenExecutingCommandListTest(
   // Verify Copy Waits for Signal
   lzt::event_host_synchronize(test.hEvent, UINT64_MAX);
   EXPECT_EQ(ZE_RESULT_NOT_READY, zeEventQueryStatus(hEvent1));
-  EXPECT_NE(0, memcmp(src_buffer, dst_buffer, test.size));
 
   EXPECT_EQ(ZE_RESULT_SUCCESS, zeEventHostSignal(hEvent1));
 
@@ -288,11 +287,9 @@ void RunGivenMemoryCopyThatWaitsOnEventWhenExecutingCommandListTest(
     lzt::execute_command_lists(cmd_bundle.queue, 1, &cmd_bundle.list, nullptr);
   }
 
-  // Verify Copy Waits for Signal
   // This sleep simulates work (e.g. file i/o) on the host that would cause
   // with a high probability the device to have to wait
   std::this_thread::sleep_for(std::chrono::milliseconds(1));
-  EXPECT_NE(0, memcmp(src_buffer, dst_buffer, test.size));
 
   EXPECT_EQ(ZE_RESULT_SUCCESS, zeEventHostSignal(test.hEvent));
 
@@ -355,8 +352,6 @@ void RunGivenMemoryFillsThatSignalAndWaitWhenExecutingCommandListTest(
 
   lzt::event_host_synchronize(test.hEvent, UINT64_MAX);
   EXPECT_EQ(ZE_RESULT_NOT_READY, zeEventQueryStatus(hEvent1));
-  // Verify Device waits for Signal
-  EXPECT_NE(0, memcmp(ref_buffer, dst_buffer, test.size));
 
   EXPECT_EQ(ZE_RESULT_SUCCESS, zeEventHostSignal(hEvent1));
 
@@ -417,11 +412,9 @@ void RunGivenMemoryFillThatWaitsOnEventWhenExecutingCommandListTest(
     lzt::execute_command_lists(cmd_bundle.queue, 1, &cmd_bundle.list, nullptr);
   }
 
-  // Verify Device waits for Signal
   // This sleep simulates work (e.g. file i/o) on the host that would cause
   // with a high probability the device to have to wait
   std::this_thread::sleep_for(std::chrono::milliseconds(1));
-  EXPECT_NE(0, memcmp(ref_buffer, dst_buffer, test.size));
 
   EXPECT_EQ(ZE_RESULT_SUCCESS, zeEventHostSignal(test.hEvent));
 
@@ -493,7 +486,6 @@ void RunGivenMemoryCopyRegionWithDependenciesWhenExecutingCommandListTest(
   // Verify Copy Waits for Signal
   lzt::event_host_synchronize(test.hEvent, UINT64_MAX);
   EXPECT_EQ(ZE_RESULT_NOT_READY, zeEventQueryStatus(hEvent1));
-  EXPECT_NE(0, memcmp(src_buffer, dst_buffer, test.size));
 
   // Signal Event On Host
   EXPECT_EQ(ZE_RESULT_SUCCESS, zeEventHostSignal(hEvent1));
@@ -561,11 +553,9 @@ void RunGivenMemoryCopyRegionThatWaitsOnEventWhenExecutingCommandListTest(
     lzt::execute_command_lists(cmd_bundle.queue, 1, &cmd_bundle.list, nullptr);
   }
 
-  // Verify Copy Waits for Signal
   // This sleep simulates work (e.g. file i/o) on the host that would cause
   // with a high probability the device to have to wait
   std::this_thread::sleep_for(std::chrono::milliseconds(1));
-  EXPECT_NE(0, memcmp(src_buffer, dst_buffer, test.size));
 
   // Signal Event On Host
   EXPECT_EQ(ZE_RESULT_SUCCESS, zeEventHostSignal(test.hEvent));