Re: [PATCH v2 3/3] KVM: SVM: Add irqchip_split() checks before enabling AVIC

From: Paolo Bonzini
Date: Fri Sep 15 2017 - 17:14:33 EST


On 15/09/2017 21:21, Suravee Suthikulpanit wrote:
>>>>
>>>>
>>>> static bool svm_get_enable_apicv(struct kvm_vcpu *vcpu)
>>>> {
>>> A close contender was pr_info_once() here:
>>>
>>> if (avic && !irqchip_split(vcpu->kvm))
>>> pr_info_once(...)
>>>
>>
>> Looks good.
>
> Actually, thinking about it again, this would not work either since
> pr_xxx_once() would only print the message once per loading of kvm_amd
> module. However, we would prefer the message to be printed per VM
> initialization. I also tried adding the check and print this message in
> the kvm_x86_ops.vm_init(), but this also does not work since the
> vm_init() function is called before the
> kvm_vm_ioctl_enable_cap(KVM_CAP_SPLIT_IRQCHIP).
>
> Therefore, pr_info() might be better here, even though this would get
> print per VCPU initialization. Any other suggestions?

My suggestion is to make it pr_info_once. No one looks at dmesg anyway
unless things go very wrong.

Paolo