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References: <20181010203735.27918-1-aclindsa@gmail.com>
	<20181010203735.27918-12-aclindsa@gmail.com>
From: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <be878ed3-509f-8ed8-8c28-71e3d0214837@linaro.org>
Date: Tue, 16 Oct 2018 17:04:54 -0700
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Subject: Re: [Qemu-devel] [PATCH v6 11/14] target/arm: PMU: Add instruction
 and cycle events
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To: Aaron Lindsay <aclindsa@gmail.com>, qemu-arm@nongnu.org, Peter Maydell <peter.maydell@linaro.org>, Alistair Francis <alistair.francis@xilinx.com>, Wei Huang <wei@redhat.com>, Peter Crosthwaite <crosthwaite.peter@gmail.com>
Cc: Michael Spradling <mspradli@codeaurora.org>, qemu-devel@nongnu.org, Digant Desai <digantd@codeaurora.org>

On 10/10/18 1:37 PM, Aaron Lindsay wrote:
> + * Return the underlying cycle count for the PMU cycle counters. If we're in
> + * usermode, simply return 0.
> + */
> +static uint64_t cycles_get_count(CPUARMState *env)
> +{
> +#ifndef CONFIG_USER_ONLY
> +    return muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL),
> +                   ARM_CPU_FREQ, NANOSECONDS_PER_SECOND);
> +#else
> +    return 0;
> +#endif
> +}

Usually we pass through the host cycle counter.
See cpu_get_host_ticks().


r~