RHELMISC-30350: [virtio-win] Add scsi-filter to upstream repository

[marekkedzierski]

This commit introduces the StorSplitter-Filter driver to handle storage splitting.

[gemini-code-assist]

Code Review

This pull request implements StorSplitter, a WDF storage filter driver that intercepts and splits large I/O requests to match hardware transfer limits, accompanied by a user-mode control application. The review identified critical bugs in the SCSI pass-through logic, including the use of a non-existent structure member and an uninitialized data buffer pointer. Additionally, a potential integer overflow was noted in the calculation of safe transfer sizes.

[gemini-code-assist]

The SCSI_PASS_THROUGH structure does not contain a member named DataBufferOffset. This will cause a compilation error. This member exists in SCSI_PASS_THROUGH_EX, but you are using the non-EX version. For SCSI_PASS_THROUGH, you must use the DataBuffer pointer field.

[gemini-code-assist]

When sending IOCTL_SCSI_PASS_THROUGH from a kernel driver, the DataBuffer field in the SCSI_PASS_THROUGH structure must be initialized to a valid kernel-mode address where the data should be transferred. Since you are using a single allocated buffer for both the header and the data, you should set DataBuffer to point to the memory immediately following the header within that buffer.

	PSCSI_PASS_THROUGH pSptInBuffer = (PSCSI_PASS_THROUGH)buffer;
	pSptInBuffer->DataBuffer = (PVOID)(buffer + sizeof(SCSI_PASS_THROUGH));

	status = WdfIoTargetSendIoctlSynchronously(
		target, NULL, IOCTL_SCSI_PASS_THROUGH,
		&inputDescriptor, &outputDescriptor, NULL, NULL
	);

[gemini-code-assist]

Potential integer overflow. maxTransferBlocks is a 32-bit value and devCtx->SectorSize is typically 512 or 4096. Their product can exceed the range of a 32-bit ULONG (4GB) if the hardware reports a very large maximum transfer length. Since MaxSafeTransferSizeBytes is a size_t, you should perform the multiplication using 64-bit integers on 64-bit systems.

					size_t maxBytes = (size_t)maxTransferBlocks * devCtx->SectorSize;