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Date: Tue, 19 Jun 2018 23:43:50 +0300
From: "Michael S. Tsirkin" <mst@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH v3 1/2] kvm: support -dedicated
 cpu-pm=on|off
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To: Paolo Bonzini <pbonzini@redhat.com>
Cc: qemu-devel@nongnu.org, Richard Henderson <rth@twiddle.net>, Eduardo Habkost <ehabkost@redhat.com>, Marcelo Tosatti <mtosatti@redhat.com>, kvm@vger.kernel.org

On Tue, Jun 19, 2018 at 05:17:45PM +0200, 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?

Can be a patch on top, by whoever cares.

> 2) Maybe -hostresource?
> 
> Paolo

Is ability to cause high latency for other threads really a resource?

The issues in question:
1. a malicious guest can cause high latency for others sharing the host cpu.
2. to host scheduler cpu looks busier than it really is.

All are avoided if you use a dedicated host cpu, and 2 will
help scheduler get closer to giving you one.


-- 
MST