Public bug reported: My kernel running under UTM on an MacBook with M4 silicon is reporting processor : 0 BogoMIPS : 48.00 Features : fp asimd evtstrm aes pmull sha1 sha2 crc32 atomics fphp asimdhp cpuid asimdrdm jscvt fcma lrcpc dcpop sha3 asimddp sha512 asimdfhm dit uscat ilrcpc flagm sb paca pacg dcpodp sve2 flagm2 frint svei8mm svebf16 bf16 afp smei16i64 smef64f64 smei8i32 smef16f32 smeb16f32 smef32f32 sme2 smei16i32 smebi32i32 CPU implementer : 0x61 CPU architecture: 8 CPU variant : 0x0 CPU part : 0x000 CPU revision : 0
The sve* features are incorrect as the the M4 does not implement SVE. I believe this is a kernel bug that requires https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=064737920bdbca86df91b96aed256e88018fef3a backporting (backports were done to 6.6, 6.12 LTS releases, but not to 6.8). There is a work-around, which is to disable SVE in grub, but really the kernel should get this right. GRUB_CMDLINE_LINUX_DEFAULT="arm64.nosve" ** Affects: linux (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/2104038 Title: Arm64 kernel incorrectly detects SVE hardware on VM with apple M4 silicon Status in linux package in Ubuntu: New Bug description: My kernel running under UTM on an MacBook with M4 silicon is reporting processor : 0 BogoMIPS : 48.00 Features : fp asimd evtstrm aes pmull sha1 sha2 crc32 atomics fphp asimdhp cpuid asimdrdm jscvt fcma lrcpc dcpop sha3 asimddp sha512 asimdfhm dit uscat ilrcpc flagm sb paca pacg dcpodp sve2 flagm2 frint svei8mm svebf16 bf16 afp smei16i64 smef64f64 smei8i32 smef16f32 smeb16f32 smef32f32 sme2 smei16i32 smebi32i32 CPU implementer : 0x61 CPU architecture: 8 CPU variant : 0x0 CPU part : 0x000 CPU revision : 0 The sve* features are incorrect as the the M4 does not implement SVE. I believe this is a kernel bug that requires https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=064737920bdbca86df91b96aed256e88018fef3a backporting (backports were done to 6.6, 6.12 LTS releases, but not to 6.8). There is a work-around, which is to disable SVE in grub, but really the kernel should get this right. GRUB_CMDLINE_LINUX_DEFAULT="arm64.nosve" To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2104038/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
