=============================
[ BUG: Invalid wait context ]
syzkaller #0 Tainted: G             L     
-----------------------------
swapper/1/0 is trying to lock:
ffff88802b8f9bc8 (&gpc->lock){....}-{3:3}, at: kvm_xen_set_evtchn_fast+0x208/0x8d0 arch/x86/kvm/xen.c:1872
other info that might help us debug this:
context-{2:2}
locks held by swapper/1/0: 1, on CPU#1:
 #0: ffff88802b8fa118 (&kvm->srcu){.?.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:249 [inline]
 #0: ffff88802b8fa118 (&kvm->srcu){.?.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:356 [inline]
 #0: ffff88802b8fa118 (&kvm->srcu){.?.+}-{0:0}, at: kvm_xen_set_evtchn_fast+0x1d2/0x8d0 arch/x86/kvm/xen.c:1870
stack backtrace:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_lock_invalid_wait_context kernel/locking/lockdep.c:4874 [inline]
 check_wait_context kernel/locking/lockdep.c:4946 [inline]
 __lock_acquire+0xf5b/0x2de0 kernel/locking/lockdep.c:5238
 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:174 [inline]
 _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:271
 kvm_xen_set_evtchn_fast+0x208/0x8d0 arch/x86/kvm/xen.c:1872
 xen_timer_callback+0x109/0x220 arch/x86/kvm/xen.c:139
 __run_hrtimer kernel/time/hrtimer.c:2079 [inline]
 __hrtimer_run_queues+0x371/0xa10 kernel/time/hrtimer.c:2136
 hrtimer_interrupt+0x4cd/0xaa0 kernel/time/hrtimer.c:2255
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
 __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: 8a 91 02 e9 03 18 03 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d e3 2a 23 00 fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0000:ffffc900001a7e40 EFLAGS: 00000246
RAX: 0000000004629e03 RBX: ffffffff819ca890 RCX: 8000000000000001
RDX: 0000000000000001 RSI: ffffffff8e6a7247 RDI: ffffffff8c8e9880
RBP: ffffc900001a7f10 R08: ffff8880b8333d9b R09: 1ffff110170667b3
R10: dffffc0000000000 R11: ffffed10170667b4 R12: 0000000000000000
R13: 1ffff11003e54bb8 R14: 1ffff92000034fd0 R15: dffffc0000000000
 arch_safe_halt arch/x86/kernel/process.c:767 [inline]
 default_idle+0x9/0x20 arch/x86/kernel/process.c:768
 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x2e0/0x540 kernel/sched/idle.c:355
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:458
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x157
 </TASK>
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
----------------
Code disassembly (best guess):
   0:	8a 91 02 e9 03 18    	mov    0x1803e902(%rcx),%dl
   6:	03 00                	add    (%rax),%eax
   8:	cc                   	int3
   9:	cc                   	int3
   a:	cc                   	int3
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	90                   	nop
  1a:	90                   	nop
  1b:	f3 0f 1e fa          	endbr64
  1f:	66 90                	xchg   %ax,%ax
  21:	0f 00 2d e3 2a 23 00 	verw   0x232ae3(%rip)        # 0x232b0b
  28:	fb                   	sti
  29:	f4                   	hlt
* 2a:	c3                   	ret <-- trapping instruction
  2b:	cc                   	int3
  2c:	cc                   	int3
  2d:	cc                   	int3
  2e:	cc                   	int3
  2f:	cc                   	int3
  30:	cc                   	int3
  31:	cc                   	int3
  32:	cc                   	int3
  33:	cc                   	int3
  34:	cc                   	int3
  35:	cc                   	int3
  36:	cc                   	int3
  37:	cc                   	int3
  38:	cc                   	int3
  39:	cc                   	int3
  3a:	cc                   	int3
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop