Re: [Qemu-devel] [PATCH v3 1/2] kvm: support -dedicated cpu-pm=on|off

[Michael S. Tsirkin]

On Wed, Jun 20, 2018 at 08:46:10AM +0800, Wanpeng Li wrote:
> On Wed, 20 Jun 2018 at 08:07, Michael S. Tsirkin <address@hidden> wrote:
> >
> > On Tue, Jun 19, 2018 at 05:07:46PM -0500, Eric Blake wrote:
> > > On 06/19/2018 10:17 AM, Paolo Bonzini wrote:
> > > > On 16/06/2018 00:29, Michael S. Tsirkin wrote:
> > > > > +static QemuOptsList qemu_dedicated_opts = {
> > > > > +    .name = "dedicated",
> > > > > +    .head = QTAILQ_HEAD_INITIALIZER(qemu_dedicated_opts.head),
> > > > > +    .desc = {
> > > > > +        {
> > > > > +            .name = "mem-lock",
> > > > > +            .type = QEMU_OPT_BOOL,
> > > > > +        },
> > > > > +        {
> > > > > +            .name = "cpu-pm",
> > > > > +            .type = QEMU_OPT_BOOL,
> > > > > +        },
> > > > > +        { /* end of list */ }
> > > > > +    },
> > > > > +};
> > > > > +
> > > >
> > > > Let the bikeshedding begin!
> > > >
> > > > 1) Should we deprecate -realtime?
> > > >
> > > > 2) Maybe -hostresource?
> > >
> > > What further things might we add in the future?
> > >
> > > -dedicated sounds wrong (it is an adjective, while most of our options are
> > > nouns - thing -machine, -drive, -object, ...)
> > >
> > > -hostresource at least sounds like a noun, but is long to type.  But at
> > > least '-hostresource cpu-pm=on' reads reasonably well.
> >
> > Yes but host resource what? I feel it says nothing at all about what
> > one can expect to find in this flag.
> >
> > > About the only other noun I could think of would be '-feature cpu-pm=on'.
> >
> > If we have nothing at all to say about what is grouping these things,
> > we don't need a new flag. We can make it a machine property.
> >
> > It's user's hint that some host resource is dedicated to a VM.
> 
> The commit 633711e82 (kvm: rename KVM_HINTS_DEDICATED to
> KVM_HINTS_REALTIME) should be reverted according to several threads
> discussion I think.
> 
> Regards,
> Wanpeng Li

IMHO that is unrelated - these KVM hints are hints to *guest*.

In this thread we are talking about hints to QEMU that are only
necessary because QEMU is separate from the host scheduler/memory
management.

-- 
MST