From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marcelo Tosatti <mtosatti@redhat.com>
Subject: Re: [patch 5/5] PTP: add kvm PTP driver
Date: Fri, 20 Jan 2017 11:11:53 -0200
Message-ID: <20170120131150.GB27440@amt.cnet>
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Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
        Radim Krcmar <rkrcmar@redhat.com>,
        Richard Cochran <richardcochran@gmail.com>,
        Miroslav Lichvar <mlichvar@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
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On Fri, Jan 20, 2017 at 01:58:33PM +0100, Paolo Bonzini wrote:
> 
> 
> On 20/01/2017 13:20, Marcelo Tosatti wrote:
> > +		ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING,
> > +				     clock_off_gpa,
> > +				     KVM_CLOCK_PAIRING_WALLCLOCK);
> > +		if (ret != 0) {
> > +			pr_err("clock offset hypercall ret %lu\n", ret);
> > +			spin_unlock(&kvm_ptp_lock);
> > +			preempt_enable_notrace();
> > +			return -EOPNOTSUPP;
> > +		}
> > +
> 
> Is it worth making this hypercall, or even all of ptp_kvm_get_time_fn, a
> pv_ops entry?

Well, i don't know how Xen is going to implement this. Maybe you can, 
when you have more low level implementations to be able to generalize.

> But this looks good already, apart from my different preference on
> emulate_ptp_sys_offset_mean.

Sending v4 with the direct export of kvm clocksource.

Thanks!