KVM: LAPIC: Also cancel preemption timer during SET_LAPIC

In the Linux kernel, the following vulnerability has been resolved:

KVM: LAPIC: Also cancel preemption timer during SET_LAPIC

The below warning is splatting during guest reboot.

------------[ cut here ]------------

WARNING: CPU: 0 PID: 1931 at arch/x86/kvm/x86.c:10322 kvm_arch_vcpu_ioctl_run+0x874/0x880 [kvm]

CPU: 0 PID: 1931 Comm: qemu-system-x86 Tainted: G I 5.17.0-rc1+ #5

RIP: 0010:kvm_arch_vcpu_ioctl_run+0x874/0x880 [kvm]

Call Trace:

<TASK>

kvm_vcpu_ioctl+0x279/0x710 [kvm]

__x64_sys_ioctl+0x83/0xb0

do_syscall_64+0x3b/0xc0

entry_SYSCALL_64_after_hwframe+0x44/0xae

RIP: 0033:0x7fd39797350b

This can be triggered by not exposing tsc-deadline mode and doing a reboot in

the guest. The lapic_shutdown() function which is called in sys_reboot path

will not disarm the flying timer, it just masks LVTT. lapic_shutdown() clears

APIC state w/ LVT_MASKED and timer-mode bit is 0, this can trigger timer-mode

switch between tsc-deadline and oneshot/periodic, which can result in preemption

timer be cancelled in apic_update_lvtt(). However, We can't depend on this when

not exposing tsc-deadline mode and oneshot/periodic modes emulated by preemption

timer. Qemu will synchronise states around reset, let's cancel preemption timer

under KVM_SET_LAPIC.