[XD3V3LOP3RX]

What

A stale-registry probe stamps an ordinary prefix host import as used before rejecting it. That false hold can block a valid import of the whole registered allocation. Separate lookup from accepted-use stamping; preserve actual descriptor holds and stamp accepted joined/exact-run reuse.

Related: #5870 promotes genuinely held windows, a different condition. Both patches apply in either order against the same base and produce identical combined blobs. Their combined runtime behavior has not been tested.

Tested

Windows x64, GCC 15.2, Ninja Release:

• Clean upstream 4808d9c plus the new regression: target build passed; agc_driver_graphics failed at the intended discarded-prefix assertion.
• Add only the production fix, regression unchanged: target build passed; the same test passed in 5.29 seconds.
• Rebased onto 038c83b9: rebuilt agc_driver_graphics_tests, reran its CPU/mock test, and passed the upstream convention checker.

The regression checks unheld prefix replacement, protection of an actual held descriptor, and accepted reuse/stamping, including allocation extent, registered owner/import identity, descriptor contents, and unchanged guest bytes. Physical GPU host-import lifetime and Linux CI remain untested. No game-menu or performance claim.

Checklist

• Based on current main at 038c83b9; open-PR overlap checked, no duplicate discarded-probe fix found
• One topic per PR; follow-ups go in a new PR
• No new code comments
• Unimplemented paths and silent stubs unchanged
• Only source and synthetic tests added; no reports, images, or game files
• No new third-party code
• Generic behavior, not specific to one title
• Depends on: none
• Unblocks: none
• GPUs tested: none; CPU/mock Vulkan allocation on Windows x64 only
• AI-assisted: yes

[coltken95]

Tested on Linux x86-64 (Release build, lavapipe / llvmpipe LLVM 20.1.2), with a7730cb merged into main ab9a476:

• With the PR: all 8 tests built from the changed test file pass, including agc_driver_graphics.
• With main's GuestBufferMemory.cpp: agc_driver_graphics fails with AGC graphics: a discarded stale probe made an unheld prefix window block the whole import.

Lavapipe refuses the host import (vkAllocateMemory -2) and falls back to copies, so the physical-GPU import path is still untested.

AI-assisted: yes (Claude Code)

[github-actions]

Some comparisons could not be completed because a pull request conflicts with the base branch. Review these shared files manually before concluding that there is no overlap.

Pull request	Shared files not compared
PR 1191	core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp
PR 1324	core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp
PR 2434	core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp
PR 4448	core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp core/libs/prx/libSceAgcDriver/tests/BdaResources.cpp
PR 5021	core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp core/libs/prx/libSceAgcDriver/tests/BdaResources.cpp
PR 5372	core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp core/libs/prx/libSceAgcDriver/tests/BdaResources.cpp
PR 6177	core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp
PR 6185	core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp
PR 6186	core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp
PR 6197	core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp core/libs/prx/libSceAgcDriver/tests/BdaResources.cpp
PR 6222	core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp
PR 6292	core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp
PR 6320	core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp
PR 6373	core/libs/prx/libSceAgcDriver/tests/BdaResources.cpp
PR 6412	core/libs/prx/libSceAgcDriver/tests/BdaResources.cpp
PR 6472	core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp
PR 6481	core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp
PR 6499	core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp
PR 6548	core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp
PR 6615	core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp
PR 6786	core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp
PR 7201	core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp core/libs/prx/libSceAgcDriver/tests/BdaResources.cpp

[adriadam10]

Checked on Linux (merged onto current main): build and the libSceAgcDriver ctest scope are green except agc_driver_tessellation, which segfaults at Vulkan device creation independently of this change. agc_driver_graphics passes with the PR and fails when GuestBufferMemory.cpp is reverted. Lookup/stamp split and the held-descriptor control look right; merging.