Re: [Qemu-devel] [PATCH v4 1/2] kvm: support -overcommit cpu-pm=on|off

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Jun 22, 2018 at 03:22:36PM -0300, Eduardo Habkost wrote:
> On Fri, Jun 22, 2018 at 03:31:48AM +0300, Michael S. Tsirkin wrote:
> > With this flag, kvm allows guest to control host CPU power state.  This
> > increases latency for other processes using same host CPU in an
> > unpredictable way, but if decreases idle entry/exit times for the
> > running VCPU, so to use it QEMU needs a hint about whether host CPU is
> > overcommitted, hence the flag name.
> 
> The flag name in the code below is still "-dedicated".

Weird, somehow got the wrong patch sent.
Will repost the fixed one now

> [...]
> > +static QemuOptsList qemu_dedicated_opts = {
> > +    .name = "dedicated",
> [...]
> > +            case QEMU_OPTION_dedicated:
> > +                opts = qemu_opts_parse_noisily(qemu_find_opts("dedicated"),
> > +                                               optarg, false);
> [...]
> > +DEF("dedicated", HAS_ARG, QEMU_OPTION_dedicated,
> > +    "-dedicated [mem-lock=on|off][cpu-pm=on|off]\n"
> > +    "                run qemu with realtime features\n"
> > +    "                mem-lock=on|off controls memory lock support (default: off)\n"
> > +    "                cpu-pm=on|off controls cpu power management (default: off)\n",
> > +    QEMU_ARCH_ALL)
> > +STEXI
> > +@item -dedicated mem-lock=on|off
> > +@item -dedicated cpu-pm=on|off
> > +@findex -dedicated
> > +Run qemu using dedicated host resources.
> > +Locking qemu and guest memory can be enabled via @option{mem-lock=on}
> > +(disabled by default). This is equivalent to @option{realtime}.
> > +Guest ability to manage power state of host cpus (increasing latency for other
> > +processes on the same host cpu, but decreasing latency for guest)
> > +can be enabled via @option{cpu-pm=on} (disabled by default).
> > +ETEXI
> [...]
> 
> -- 
> Eduardo