td-payload: add shadow pages for shared memory #661
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jyao1
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Mar 4, 2024
td-payload/src/mm/shared.rs
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| SHARED_MEMORY_ALLOCATOR.lock().init(start as *mut u8, size); | ||
| SHARED_MEMORY_ALLOCATOR | ||
| .lock() | ||
| .init(shared_start as *mut u8, shared_size); |
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If we use double allocators, then we assume that the allocator is deterministic, not randomized. Right?
I am not sure why we need 2nd allocator, why not just use "address + offset" for the shadow?
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Got it, will follow this way
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Data in shared memory provided by VMM is untrusted so from a security perspective the data shall be consumed after being copied into private memory. Private shadow for `SharedMemory` is provided to add a more easy and functional safe mechanism to use the untrusted data. It is 1:1 allocated for a shared memory request, and users can use the data with `copy_to_private_shadow` directly to get a private copy with additional memory allocation/free operations. Signed-off-by: Jiaqi Gao <jiaqi.gao@intel.com>
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jyao1
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Mar 6, 2024
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Data in shared memory provided by VMM is untrusted so from a security perspective the data shall be consumed after being copied into private memory.
Private shadow for
SharedMemoryis provided to add a more easy and functional safe mechanism to use the untrusted data. It is 1:1 allocated for a shared memory request, and users can use the data withcopy_to_private_shadowdirectly to get a private copy with additional memory allocation/free operations.