From: "Philippe Mathieu-Daudé" <philmd@linaro.org>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>,
QEMU Developers <qemu-devel@nongnu.org>
Subject: Re: Should -overcommit cpu-pm=on|off be converted to some machine sugar property?
Date: Tue, 20 Dec 2022 15:16:17 +0100 [thread overview]
Message-ID: <cc14240c-6fc7-7412-8023-a2d4a047efbc@linaro.org> (raw)
In-Reply-To: <CABgObfaWX=x-RinK0F+XbYi1oVHF53kiahb7FLQjBuoR4eQ_UQ@mail.gmail.com>
On 20/12/22 09:16, Paolo Bonzini wrote:
> It's implemented only for x86, but it is not architecture-dependent. For
> example on ARM you would implement it by mapping guest WFx to the host
> instructions.
OK, thanks for clarifying!
> Hi Paolo,
>
> I just noticed 'enable_cpu_pm' which seems architecture specific
> option that ended into common code:
>
> $ git grep -E 'cpu[_-]pm'
> accel/tcg/user-exec-stub.c:5:bool enable_cpu_pm = false;
> include/sysemu/sysemu.h:49:extern bool enable_cpu_pm;
> Binary file pc-bios/skiboot.lid matches
> qemu-options.hx:4196: "-overcommit
> [mem-lock=on|off][cpu-pm=on|off]\n"
> qemu-options.hx:4199: " cpu-pm=on|off controls cpu
> power management (default: off)\n",
> qemu-options.hx:4204:``-overcommit cpu-pm=on|off``
> qemu-options.hx:4214: guest) can be enabled via ``cpu-pm=on``
> (disabled by default). This
> softmmu/globals.c:38:bool enable_cpu_pm;
> softmmu/vl.c:350: .name = "cpu-pm",
> softmmu/vl.c:3440: enable_cpu_pm =
> qemu_opt_get_bool(opts, "cpu-pm", false);
> target/i386/host-cpu.c:44:static void host_cpu_enable_cpu_pm(X86CPU
> *cpu)
> target/i386/host-cpu.c:88: if (cpu->max_features && enable_cpu_pm) {
> target/i386/host-cpu.c:89: host_cpu_enable_cpu_pm(cpu);
> target/i386/kvm/kvm-cpu.c:43: if (enable_cpu_pm &&
> kvm_has_waitpkg()) {
> target/i386/kvm/kvm.c:390: if (enable_cpu_pm) {
> target/i386/kvm/kvm.c:2576: if (enable_cpu_pm) {
>
> Do we want to maintain this as a generic property or
> can it be deprecated / converted to a machine-specific one?
>
> Thanks,
>
> Phil.
>
prev parent reply other threads:[~2022-12-20 14:21 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-19 16:11 Should -overcommit cpu-pm=on|off be converted to some machine sugar property? Philippe Mathieu-Daudé
2022-12-19 16:23 ` Michael S. Tsirkin
2022-12-20 8:16 ` Paolo Bonzini
2022-12-20 14:16 ` Philippe Mathieu-Daudé [this message]
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