On 27.03.2025 06:22, Mykola Kvach wrote: > Invocation of the CPU_UP_PREPARE notification > on ARM64 during resume causes a crash: > > (XEN) [ 315.807606] Error bringing CPU1 up: -16 > (XEN) [ 315.811926] Xen BUG at common/cpu.c:258 > [...] > (XEN) [ 316.142765] Xen call trace: > (XEN) [ 316.146048] [<00000a0000202264>] enable_nonboot_cpus+0x128/0x1ac > (PC) > (XEN) [ 316.153219] [<00000a000020225c>] enable_nonboot_cpus+0x120/0x1ac > (LR) > (XEN) [ 316.160391] [<00000a0000278180>] > suspend.c#system_suspend+0x4c/0x1a0 > (XEN) [ 316.167476] [<00000a0000206b70>] > domain.c#continue_hypercall_tasklet_handler+0x54/0xd0 > (XEN) [ 316.176117] [<00000a0000226538>] > tasklet.c#do_tasklet_work+0xb8/0x100 > (XEN) [ 316.183288] [<00000a0000226920>] do_tasklet+0x68/0xb0 > (XEN) [ 316.189077] [<00000a000026e120>] domain.c#idle_loop+0x7c/0x194 > (XEN) [ 316.195644] [<00000a0000277638>] shutdown.c#halt_this_cpu+0/0x14 > (XEN) [ 316.202383] [<0000000000000008>] 0000000000000008 > > Freeing per-CPU areas and setting __per_cpu_offset to INVALID_PERCPU_AREA > only occur when !park_offline_cpus and system_state is not SYS_STATE_suspend. > On ARM64, park_offline_cpus is always false, so setting __per_cpu_offset to > INVALID_PERCPU_AREA depends solely on the system state. > > If the system is suspended, this area is not freed, and during resume, an > error > occurs in init_percpu_area, causing a crash because INVALID_PERCPU_AREA is not > set and park_offline_cpus remains 0: > > if ( __per_cpu_offset[cpu] != INVALID_PERCPU_AREA ) > return park_offline_cpus ? 0 : -EBUSY; > > It appears that the same crash can occur on x86 if park_offline_cpus is set > to 0 during Xen suspend.
Oh, also - it's not "appears"; iirc Marek meanwhile confirmed the misbehavior on x86 AMD hardware. Jan
