Re: [PATCH 3/4] KVM: x86: Revert "KVM: X86: Fix fpu state crash in kvm guest"

Paolo Bonzini
2020-03-04T07:59:04Z

On 04/03/20 08:41, Liu, Jing2 wrote:
>>       trace_kvm_entry(vcpu->vcpu_id);
>>       guest_enter_irqoff();
>>   -    /* The preempt notifier should have taken care of the FPU
>> already.  */
>> -    WARN_ON_ONCE(test_thread_flag(TIF_NEED_FPU_LOAD));
>> +    fpregs_assert_state_consistent();
>> +    if (test_thread_flag(TIF_NEED_FPU_LOAD))
>> +        switch_fpu_return();
>>         if (unlikely(vcpu->arch.switch_db_regs)) {
>>           set_debugreg(0, 7);
>
> Can kvm be preempt out again after this (before really enter to guest)?

No, irqs are disabled here.

Paolo