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Date: Mon, 2 May 2016 20:09:48 +0200
From: Roger Pau =?iso-8859-1?Q?Monn=E9?= <roger.pau@citrix.com>
To: Stefano Stabellini <sstabellini@kernel.org>
CC: <freebsd-xen@freebsd.org>, <xen-devel@lists.xenproject.org>
Subject: Re: [PATCH] xen/x86: don't lose event interrupts
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On Thu, Apr 21, 2016 at 02:34:25PM +0100, Stefano Stabellini wrote:
> xen/x86: don't lose event interrupts
> 
> On slow platforms with unreliable TSC, such as QEMU emulated machines,
> it is possible for the FreeBSD kernel to request the next event in the
> past. In that case, in the current implementation of
> xentimer_vcpu_start_timer, we simply return -ETIME. To be precise Xen
> returns -ETIME and we pass it on. As a consequence we need to loop
> around to function to make sure that the timer is properly set.
> 
> Instead it is better to always ask the hypervisor for a timer event,
> even if the timeout is past. To do that, remove the VCPU_SSHOTTMR_future
> flag.
> 
> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>

Thanks, it's now committed:

https://svnweb.freebsd.org/base?view=revision&revision=298926

Roger.