Re: [PATCH] KVM: Pre-allocate 1 cpumask variable per cpu for both pv tlb and pv ipis

From: Vitaly Kuznetsov
Date: Tue Feb 04 2020 - 09:42:13 EST


Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx> writes:

>> > > /*
>> > > @@ -624,6 +625,7 @@ static void __init kvm_guest_init(void)
>> > > kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) {
>> > > pv_ops.mmu.flush_tlb_others = kvm_flush_tlb_others;
>> > > pv_ops.mmu.tlb_remove_table = tlb_remove_table;
>> > > + pr_info("KVM setup pv remote TLB flush\n");
>> > > }
>> > >
>
> I am more concerned about printing the "KVM setup pv remote TLB flush" message,
> not only when KVM pv is used, but pv TLB flush is not going to be used, but
> also when the system is not even paravirtualized.

Huh? In Wanpeng's patch this print is under

if (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH) &&
!kvm_para_has_hint(KVM_HINTS_REALTIME) &&
kvm_para_has_feature(KVM_FEATURE_STEAL_TIME))

and if you mean another patch we descussed before which was adding
(!kvm_para_available() || nopv) check than it's still needed. Or,
alternatively, we can make kvm_para_has_feature() check for that.

--
Vitaly