From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christian Borntraeger <borntraeger@de.ibm.com>
Subject: Re: [PATCH 1/2] KVM: provide irq_unsafe kvm_guest_{enter|exit}
Date: Thu, 30 Apr 2015 14:07:38 +0200
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To: Paolo Bonzini <pbonzini@redhat.com>
Cc: linux-mips@linux-mips.org, KVM <kvm@vger.kernel.org>, kvm-ppc@vger.kernel.org, Cornelia Huck <cornelia.huck@de.ibm.com>, kvmarm@lists.cs.columbia.edu
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Am 30.04.2015 um 14:02 schrieb Christian Borntraeger:
> Am 30.04.2015 um 14:01 schrieb Christian Borntraeger:
>> Am 30.04.2015 um 13:50 schrieb Paolo Bonzini:
>>>
>>>
>>> On 30/04/2015 13:43, Christian Borntraeger wrote:
>>>> +/* must be called with irqs disabled */
>>>> +static inline void __kvm_guest_enter(void)
>>>>  {
>>>> -	unsigned long flags;
>>>> -
>>>> -	BUG_ON(preemptible());
>>>
>>> Please keep the BUG_ON() in kvm_guest_enter.  Otherwise looks good, thanks!
> 
> Ah, you mean have the BUG_ON in the non underscore version? Yes, makes sense.

Hmmm, too quick.
the BUG_ON was there to make sure that rcu_virt_note_context_switch is safe.
The reworked code pulls the rcu_virt_note_context_switch within the irq_save
section so we no longer need this BUG_ON, no?

Christian