syzbot

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BUG: KCSAN: data-race in kvm_cpu_has_injectable_intr / kvm_pic_set_irq

write to 0xffff888018400658 of 4 bytes by task 16862 on cpu 0:
 pic_irq_request arch/x86/kvm/i8259.c:567 [inline]
 pic_update_irq arch/x86/kvm/i8259.c:176 [inline]
 kvm_pic_set_irq+0x631/0x870 arch/x86/kvm/i8259.c:196
 kvm_set_pic_irq+0x44/0x50 arch/x86/kvm/irq_comm.c:33
 kvm_set_irq+0x1cd/0x310 arch/x86/kvm/../../../virt/kvm/irqchip.c:89
 pit_do_work+0x90/0x180 arch/x86/kvm/i8254.c:250
 kthread_worker_fn+0x28f/0x530 kernel/kthread.c:710
 kthread+0x1fd/0x220 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

read to 0xffff888018400658 of 4 bytes by task 16850 on cpu 1:
 kvm_cpu_has_extint arch/x86/kvm/irq.c:65 [inline]
 kvm_cpu_has_injectable_intr+0xba/0x1c0 arch/x86/kvm/irq.c:76
 inject_pending_event+0x73f/0xa70 arch/x86/kvm/x86.c:8340
 vcpu_enter_guest+0x476/0x24f0 arch/x86/kvm/x86.c:8911
 vcpu_run+0x24e/0x690 arch/x86/kvm/x86.c:9131
 kvm_arch_vcpu_ioctl_run+0x443/0x820 arch/x86/kvm/x86.c:9358
 kvm_vcpu_ioctl+0x562/0x8f0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3283
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 16850 Comm: syz-executor.4 Not tainted 5.10.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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