We have good news about the Pixel 11. It still has at least bare minimum support for MTE at a hardware level. We think…

We have good news about the Pixel 11. It still has at least bare minimum support for MTE at a hardware level. We think they removed most of the hardware acceleration from the CPU cache to save money. They ruined the performance so it ended up being fully disabled in firmware. It may still be usable. Android 17 QPR2 Beta 4 was released on August 28th. It's the first Beta release with Pixel 11 support. MTE support is still completely disabled in the OS and arm64.nomte is unconditionally passed by the firmware to the kernel. The good news is the firmware itself had MTE support added back to it. It's possible to enable reserving the tag memory for MTE via `fastboot oem mte on`, boot a non-stock kernel ignoring arm64.nomte and use MTE. We're in the process of determining whether it's fully functional and the performance characteristics. It's likely disabled due to performance being ruined. We expect performance must be quite bad for Google to have decided to entirely strip out support for it in not only the software but also the firmware so that no would could even try to use it before Android 17 QPR2 Beta 4. That's a very strange thing to do. It's at least added back to firmware now. We reached out to multiple people at Google asking about the MTE situation on the Pixel 11 prior to making our original thread and didn't receive any responses. We still don't know what's wrong with MTE on the Pixel 11. It isn't clear if there are serious CPU errata or it simply performs very badly. If the issue is simply that MTE performance is poor, then we can support the Pixel 11 with the major caveat that it will be a significant performance downgrade. Aside from MTE, Google downgraded the Pixel 11 series GPU compared to the Pixel 10 series in addition to reducing RAM for base Pro models. Google has been increasingly silent in response to our communications since dropping Pixel support from AOSP with Android 16 in June 2025. They could have told us MTE performance was significantly reduced so they disabled it at launch but will add it back to firmware for QPR2. That's still unclear. Android 17 QPR2 Beta 4 releases for the Pixel 11 series were only uploaded around 10 hours ago rather than with the initial release on August 28th so this hasn't been available for very long. It wasn't missed by us or people who looked into it after our initial thread but rather wasn't out yet.

We've been testing performance of MTE on the Pixel 11 using the Android 17 QPR2 Beta 4 release adding back firmware support for it. MTE in asymmetric mode only has around 5% overhead in the standard benchmarks and other tests we've done. That's more than good enough but we've done limited tests. Android 17 QPR2 Beta 4 on the Pixel 11 force disables MTE for the OS from the firmware. Using it requires ignoring the arm64.nomte parameter being passed to the kernel. It still isn't clear why they're making the feature unavailable. SVE was also force disabled in Android 17 but not in QPR2 Beta 4. Our initial testing indicates performance isn't substantially worse. The overhead may be higher but there was an incremental CPU performance with the Pixel 11 which should more than make up for it. However, MTE is unavailable with stable firmware and we're bypassing firmware disabling it for QPR2. Multiple Google engineers we've contacted have said they aren't able to give us any information about this so we're left doing reverse engineering and relying on leaks. The leaks do not seem reliable and do not match what we see. Our concern is that MTE may actually be broken due to CPU errata.

"SVE was also force disabled in Android 17 but not in QPR2 Beta 4." is meant to be this: "SME was also force disabled in Android 17 but not in QPR2 Beta 4."