Re: [PATCH] kvm: rename HINTS_DEDICATED to KVM_HINTS_REALTIME

[Paolo Bonzini]

On 18/05/2018 18:04, Eduardo Habkost wrote:
>> Without mlock you should always use pv spinlocks.
>>
>> Otherwise you risk blocking on a lock taken by
>> a VCPU that is in turn blocked on IO, where the IO
>> is not completing because CPU is being used up
>> spinning.
>
> So the stronger guarantee seems necessary.
> 
> Now what should host userspace do if the user is trying to run an
> existing configuration where the CPUID hint was set but memory is
> not pinned?

As mentioned elsewhere in the thread, there are many ways to pin memory,
and mlock is not always necessary.  However, I agree with Michael in
making the hint provide a stronger guarantee.

Paolo