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From: Sergey Fedorov <serge.fdrv@gmail.com>
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Date: Sun, 5 Jun 2016 19:44:32 +0300
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Subject: Re: [Qemu-devel] [RFC v1 07/12] cpus: introduce
 async_safe_run_on_cpu.
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To: =?UTF-8?Q?Alex_Benn=c3=a9e?= <alex.bennee@linaro.org>, mttcg@listserver.greensocs.com, fred.konrad@greensocs.com, a.rigo@virtualopensystems.com, cota@braap.org
Cc: qemu-devel@nongnu.org, mark.burton@greensocs.com, pbonzini@redhat.com, jan.kiszka@siemens.com, rth@twiddle.net, peter.maydell@linaro.org, claudio.fontana@huawei.com, Peter Crosthwaite <crosthwaite.peter@gmail.com>, =?UTF-8?Q?Andreas_F=c3=a4rber?= <afaerber@suse.de>

On 15/04/16 17:23, Alex Bennée wrote:
> +/*
> + * Safe work interface
> + *
> + * Safe work is defined as work that requires the system to be
> + * quiescent before making changes.
> + */
> +
> +void async_safe_run_on_cpu(CPUState *cpu, run_on_cpu_func func, void *data)
> +{
> +    CPUState *iter;
> +    qemu_safe_work_item wi;

We can call the function right away if MTTCG is disabled or there's only
one CPU emulated.

Kind regards,
Sergey

> +    wi.cpu = cpu;
> +    wi.func = func;
> +    wi.data = data;
> +
> +    qemu_mutex_lock(&safe_work_mutex);
> +    g_array_append_val(safe_work, wi);
> +    atomic_inc(&safe_work_pending);
> +    qemu_mutex_unlock(&safe_work_mutex);
> +
> +    /* Signal all vCPUs to halt */
> +    CPU_FOREACH(iter) {
> +        qemu_cpu_kick(iter);
> +    }
> +}