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From: Paolo Bonzini <pbonzini@redhat.com>
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Date: Tue, 6 Oct 2015 14:58:20 +0200
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Subject: Re: [Qemu-devel] [PATCH] target-arm: Use common CPU cycle
 infrastructure
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To: Peter Maydell <peter.maydell@linaro.org>
Cc: "qemu-devel@nongnu.org Developers" <qemu-devel@nongnu.org>, Laurent Vivier <lvivier@redhat.com>, Peter Crosthwaite <crosthwaitepeter@gmail.com>, Christopher Covington <cov@codeaurora.org>, Alistair Francis <alistair.francis@xilinx.com>



On 06/10/2015 14:49, Peter Maydell wrote:
> Yeah, there's no guarantee on userspace access. I think the
> fastest way to get some kind of count is to use a library
> function that boils down to gettimeofday(2), which we will
> do purely in userspace in the kernel VDSO if possible.

Could we just use CNTVCT_EL0?  Which cores have it?

Paolo