Your system information

• Steam client version (build number or date): 1760566251
• Distribution (e.g. Ubuntu): SteamOS 3.8
• Opted into Steam client beta?: Yes
• Have you checked for system updates?: Yes
• Steam Logs: xe-vram-logs.tar.gz
• GPU: Intel Lunar Lake [Intel Arc Graphics 130V / 140V]

Please describe your issue in as much detail as possible:

In the System settings tab of GamepadUI, my MSI Claw 8 AI+ A2VM Intel GPU's reported VRAM Size shows up as -1,048,576 B

sudo lscpi -v -s 00:02.0 shows:

00:02.0 VGA compatible controller: Intel Corporation Lunar Lake [Intel Arc Graphics 130V / 140V] (rev 04) (prog-if 00 [VGA controller])
        DeviceName: Onboard - Video
        Subsystem: Micro-Star International Co., Ltd. [MSI] Device 146c
        Flags: bus master, fast devsel, latency 0, IRQ 189, IOMMU group 3
        Memory at 3010000000 (64-bit, prefetchable) [size=16M]
        Memory at 2000000000 (64-bit, prefetchable) [size=256M]
        Expansion ROM at 000c0000 [disabled] [size=128K]
        Capabilities: [40] Vendor Specific Information: Intel Capabilities v1
                CapA: Peg60Dis- Peg12Dis- Peg11Dis- Peg10Dis- PeLWUDis- DmiWidth=x4
                      EccDis- ForceEccEn- VTdDis- DmiG2Dis- PegG2Dis- DDRMaxSize=Unlimited
                      1NDis- CDDis- DDPCDis- X2APICEn- PDCDis- IGDis- CDID=0 CRID=0
                      DDROCCAP- OCEn- DDRWrtVrefEn+ DDR3LEn+
                CapB: ImguDis- OCbySSKUCap- OCbySSKUEn- SMTCap- CacheSzCap 0x0
                      SoftBinCap- DDR3MaxFreqWithRef100=Disabled PegG3Dis-
                      PkgTyp- AddGfxEn- AddGfxCap- PegX16Dis- DmiG3Dis- GmmDis-
                      DDR3MaxFreq=2932MHz LPDDR3En-
        Capabilities: [70] Express Root Complex Integrated Endpoint, IntMsgNum 0
        Capabilities: [ac] MSI: Enable+ Count=1/1 Maskable+ 64bit+
        Capabilities: [d0] Power Management version 3
        Capabilities: [100] Null
        Capabilities: [110] Process Address Space ID (PASID)
        Capabilities: [200] Address Translation Service (ATS)
        Capabilities: [420] Physical Resizable BAR
        Capabilities: [400] Latency Tolerance Reporting
        Kernel driver in use: xe
        Kernel modules: xe

In my Steam client logs, I can also see:

[2025-10-15 17:42:33] Response: gpu_topology {
[2025-10-15 17:42:33]   gpus {
[2025-10-15 17:42:33]     id: 1
[2025-10-15 17:42:33]     name: "Intel(R) Graphics (LNL)"
[2025-10-15 17:42:33]     vram_size_bytes: 24647688192
[2025-10-15 17:42:33]     driver_id: k_EGpuDriverId_MesaIntel
[2025-10-15 17:42:33]     driver_version_major: 25
[2025-10-15 17:42:33]     driver_version_minor: 2
[2025-10-15 17:42:33]     driver_version_patch: 99
[2025-10-15 17:42:33]     luid: 0
[2025-10-15 17:42:33]   }
[2025-10-15 17:42:33]   default_gpu_id: 1
[2025-10-15 17:42:33] }

This also happens on the currently-shipped version of Mesa on SteamOS 3.8, so it doesn't seem to be a mesa-git issue either.

Steps for reproducing this issue:

1. On a Lunar Lake device, check the System tab of GamepadUI