------------[ cut here ]------------
WARNING: arch/x86/kvm/../../../virt/kvm/pfncache.c:267 at __kvm_gpc_refresh+0x1187/0x1310 virt/kvm/pfncache.c:267, CPU#0: syz.0.0/5339
Modules linked in:
CPU: 0 UID: 0 PID: 5339 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:__kvm_gpc_refresh+0x1187/0x1310 virt/kvm/pfncache.c:267
Code: c6 05 ec ff 2b 0e 01 48 c7 c7 a8 51 78 8d be 35 04 00 00 48 c7 c2 80 f2 61 8b e8 64 fa 5d 00 e9 fe f1 ff ff e8 9a c9 80 00 90 <0f> 0b 90 bb ea ff ff ff e9 7e fe ff ff e8 87 c9 80 00 90 0f 0b 90
RSP: 0018:ffffc9000e58f600 EFLAGS: 00010283
RAX: ffffffff81403dc6 RBX: ffff888000000000 RCX: 0000000000100000
RDX: ffffc90020ce2000 RSI: 000000000000036d RDI: 000000000000036e
RBP: ffffc9000e58f790 R08: ffffffff8f824677 R09: 1ffffffff1f048ce
R10: dffffc0000000000 R11: fffffbfff1f048cf R12: ffff888042fcd290
R13: dffffc0000000000 R14: ffff888000000000 R15: ffffffffffffff01
FS:  00007f9647e696c0(0000) GS:ffff88808d414000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f96471de0a8 CR3: 0000000044301000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 kvm_gpc_refresh+0xe1/0x140 virt/kvm/pfncache.c:382
 kvm_xen_set_evtchn+0x164/0x230 arch/x86/kvm/xen.c:1943
 kvm_set_irq+0x260/0x4e0 virt/kvm/irqchip.c:88
 kvm_vm_ioctl_irq_line+0x8c/0x130 arch/x86/kvm/irq.c:285
 kvm_vm_ioctl+0x88d/0xc60 virt/kvm/kvm_main.c:5304
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9646f8f7c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9647e69038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f96471e5fa0 RCX: 00007f9646f8f7c9
RDX: 0000200000000000 RSI: 00000000c008ae67 RDI: 0000000000000004
RBP: 00007f9647013f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f96471e6038 R14: 00007f96471e5fa0 R15: 00007ffce1ae83d8
 </TASK>