Merge pull request #3324 from AchrafReyani/carry/host-import-span-windows-alias

fix(agc): import a span's ranges one at a time when Windows refuses its alias

core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp

@@ -145,6 +145,7 @@ struct HostImports {
     std::map<std::uint64_t, HostImport> imports;
     std::uint64_t liveBytes = 0;
     std::set<std::uint64_t> failed;
+    std::set<std::uint64_t> unaliasedSpans;
     // Registry generation the imports were last reconciled with.
     std::uint64_t refreshedGeneration = 0;
     // Bumped whenever an import is dropped, so HostImport pointers taken under the lock earlier can be
@@ -546,6 +547,7 @@ ImportRun importRun(const GuestAllocations::Lease& lease, std::uint64_t address)
     while (first > 0 && continuesRun(*lease[first - 1], *lease[first])) --first;
     auto last = index;
     while (last + 1 < lease.size() && continuesRun(*lease[last], *lease[last + 1])) ++last;
+    if (first != last && Imports().unaliasedSpans.contains(lease[first]->address)) return {lease[index]->address, lease[index]->bytes, {lease[index]}};
     ImportRun run{lease[first]->address, lease[last]->address + lease[last]->bytes - lease[first]->address, {}};
     run.ranges.assign(lease.begin() + static_cast<std::ptrdiff_t>(first), lease.begin() + static_cast<std::ptrdiff_t>(last) + 1);
     return run;
@@ -643,7 +645,13 @@ const HostImport* importAllocation(const Context& context, HostImports& state, s
             std::snprintf(text, sizeof(text), "AGC graphics: host import of 0x%llx+0x%llx: memory at 0x%llx (type 0x%lx, protection 0x%lx) is neither read-write, read-only nor a shared mapping", static_cast<unsigned long long>(base), static_cast<unsigned long long>(bytes), reinterpret_cast<unsigned long long>(refused.BaseAddress), refused.Type, refused.Protect);
             throw std::runtime_error(text);
         }
-        entry.alias = GuestArena::GuestArenaMapAlias_nid_postfix(static_cast<std::uintptr_t>(base), static_cast<std::size_t>(bytes));
+        try {
+            entry.alias = GuestArena::GuestArenaMapAlias_nid_postfix(static_cast<std::uintptr_t>(base), static_cast<std::size_t>(bytes));
+        } catch (const std::runtime_error&) {
+            if (entry.ranges.size() == 1) throw;
+            state.unaliasedSpans.insert(base);
+            return importAllocation(context, state, address, lease);
+        }
     }
 #else
     if (!GuestMemory::Accessible(reinterpret_cast<const void*>(base), static_cast<std::size_t>(bytes), true)) {

docs/dev/TechnicalDebt.md

@@ -466,7 +466,7 @@ Throughout the project, every function at every stage either **does exactly what
 - [Descriptor pool chain](../../core/libs/prx/libSceAgcDriver/Graphics/src/ShaderResources.cpp) (libSceAgcDriver) - each pool holds two storage buffer descriptors more than a set can take, as a workaround: RADV (Mesa 26.0 and later) lets a `FREE_DESCRIPTOR_SET` pool place a set up to 32 bytes past the pool's buffer ([`util_vma_heap_init`](https://gitlab.freedesktop.org/mesa/mesa/-/blob/main/src/amd/vulkan/radv_descriptor_pool.c) is given `bo_size + RADV_POOL_HEAP_OFFSET` as a size), and with a page-multiple pool size those bytes are an unmapped page
 - [CMASK fast clears](../../core/libs/prx/libSceAgcDriver/Graphics/src/Draw.cpp) (libSceAgcDriver) - each fast-cleared CMASK tile (code 0) is stored as `CB_COLOR_CLEAR_WORD` into its 8x8 texels at the first draw into the target or at its fast-clear eliminate or DCC decompress pass, not as the color block writes the tile, and the CMASK is then stored as expanded (0xF): a texture or copy read of the target after that draw and before the title's eliminate sees the clear value in tiles no draw wrote, where the console keeps their previous bytes. Tile addresses follow the pipe-aligned SW_64KB_Z_X CMASK equation for 16 pipes; other CMASK swizzle modes, codes other than 0 and 0xF, a cleared tile of a DCC target and a fast clear of a mipmapped, 3D or array color target throw. When the clear runs as a compute pass (a resident target whose CMASK is host-imported), an invalid code throws at the next fast-clear materialization, not at the one that read it
 - [HTILE depth fast clears](../../core/libs/prx/libSceAgcDriver/Graphics/src/DepthSurface.cpp) (libSceAgcDriver) - HTILE is not modeled. Only RADV's `clear_htile_mask` compute kernel (17 GFX10 words, 64x1x1 groups) is recognized, and only when it leaves ZMASK at 0 (`user[4]` and `user[5]` low nibbles both 0); the dispatch still runs, and the host depth image is cleared to `DB_DEPTH_CLEAR` the next time the surface with that `DB_HTILE_DATA_BASE` address is bound. The address match is exact, so a clear of a different HTILE range does not hit. HTILE initialization, the stencil-only update, and fast clears made by the SDK's own paths, CP DMA fills or other kernels are not covered and leave the depth image as it was. The kernel words are the ones the PR author saw RADV submit; they are not compared with Mesa's source.
-- [Host imports](../../core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp) (libSceAgcDriver) on Linux skip ranges that are not mapped read-write, which are copied instead. The NVIDIA driver (595.91.07) refuses `VK_EXT_external_memory_host` imports of read-only or executable mappings (and shared mappings of regular files) with `VK_ERROR_OUT_OF_DEVICE_MEMORY`, after which every `vkAllocateMemory` on the device fails the same way. Read-only ranges are never imported, even on drivers that accept them. Shared mappings of regular files are not checked for.
+- [Host imports](../../core/libs/prx/libSceAgcDriver/Graphics/src/GuestBufferMemory.cpp) (libSceAgcDriver) on Linux skip ranges that are not mapped read-write, which are copied instead. The NVIDIA driver (595.91.07) refuses `VK_EXT_external_memory_host` imports of read-only or executable mappings (and shared mappings of regular files) with `VK_ERROR_OUT_OF_DEVICE_MEMORY`, after which every `vkAllocateMemory` on the device fails the same way. Read-only ranges are never imported, even on drivers that accept them. Shared mappings of regular files are not checked for. On Windows, a run of adjacent registered ranges whose shared views are not one contiguous run of views of a section gets no read-write alias, so its ranges are imported one at a time, as before runs were imported whole, and a buffer that crosses two of them is copied.
 - [Cube texture descriptors](../../core/libs/prx/libSceAgcDriver/Graphics/src/GuestTextureResource.cpp) with equal `BASE_ARRAY` and `DEPTH` expose six faces starting at `BASE_ARRAY`. Measured with `image_load`, `image_sample` and `image_get_resinfo` on RX 6600 (gfx1032), using 64x64 R32_UINT faces and base slices 0, 5 and 6. Other ranges containing fewer than six faces or incomplete cube arrays still throw: hardware load bounds and filtered-sample addressing differ. Out-of-range cube-array sampling remains unimplemented. Samplers with `DISABLE_CUBE_WRAP` are created with `VK_SAMPLER_CREATE_NON_SEAMLESS_CUBE_MAP_BIT_EXT`, the flag RADV maps to that bit (Mesa `src/amd/vulkan/radv_sampler.c`, `src/amd/common/ac_descriptors.c`); without `VK_EXT_non_seamless_cube_map` a cube texture sampled through such a sampler throws. PS5 equivalence has not been measured on console hardware.
 - [DCC display buffers](../../core/libs/prx/libSceAgcDriver/Execution/src/VulkanDevice.cpp) are presented only when all keys of the console's DCC extent agree on uncompressed or a fast-clear code, padding keys included; other keys, and register-clear keys over a pending image, throw.
 - [Storage image write-back](../../core/libs/prx/libSceAgcDriver/Graphics/src/Texture.cpp) (libSceAgcDriver) stores the GPU results over a CPU-stamped range whose guest bytes equal the copy taken when the image's layers got their generation (images up to 1 MiB whose guest bytes were settled at that point, with no unit shadow, pending image results or recorded GPU store over them; other images keep the previous rule: the CPU's bytes win). A CPU store that rewrites the baseline value after the GPU changed it is not told apart from no store, and the GPU result wins there. The 1 MiB limit is a choice, not a console value.