Refine GPU DSM identical mapping

[psun3x]

Describe the bug
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Platform
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Codebase
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Scenario
Describe the scenario: Hybrid, Industry or logical_partition

To Reproduce
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1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

Expected behavior
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Additional context
Attach the following logs if available:

• native Linux boot kernel message log
• ACRN serial port log (when issues happens)
• Service VM kernel message when issue happens
• acrn-dm log: all files in /var/log/acrn-tm
• console log when running script to launch guest VM

[psun3x]

[External_System_ID] ACRN-6886

[NanlinXie]

Closed with no regression issue.