From: david.vrabel@citrix•com (David Vrabel)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2] xen/events: Support event channel rebind on ARM
Date: Mon, 27 Jul 2015 13:35:20 +0100 [thread overview]
Message-ID: <55B62588.3050502@citrix.com> (raw)
In-Reply-To: <1437996911-18985-1-git-send-email-julien.grall@citrix.com>
On 27/07/15 12:35, Julien Grall wrote:
> Currently, the event channel rebind code is gated with the presence of
> the vector callback.
>
> The virtual interrupt controller on ARM has the concept of per-CPU
> interrupt (PPI) which allow us to support per-VCPU event channel.
> Therefore there is no need of vector callback for ARM.
>
> Xen is already using a free PPI to notify the guest VCPU of an event.
> Furthermore, the xen code initialization in Linux (see
> arch/arm/xen/enlighten.c) is requesting correctly a per-CPU IRQ.
>
> Introduce new helper xen_support_evtchn_rebind to allow architecture
> decide whether rebind an event is support or not. It will always return
> 1 on ARM and keep the same behavior on x86.
>
> This is also allow us to drop the usage of xen_have_vector_callback
> entirely in the ARM code.
This did not apply cleanly. Please always base patches on Linus's
master branch.
This also breaks the x86 build.
/local/davidvr/work/k.org/tip/arch/x86/include/asm/xen/events.h: In
function ?xen_support_evtchn_rebind?:
/local/davidvr/work/k.org/tip/arch/x86/include/asm/xen/events.h:29:85:
error: ?xen_have_vector_callback? undeclared (first use in this function)
return (!xen_hvm_domain() || xen_have_vector_callback);
> --- a/arch/arm/include/asm/xen/events.h
> +++ b/arch/arm/include/asm/xen/events.h
> @@ -20,4 +20,10 @@ static inline int xen_irqs_disabled(struct pt_regs *regs)
> atomic64_t, \
> counter), (val))
>
> +/* Rebind event channel is supported by default */
> +static inline bool xen_support_evtchn_rebind(void)
> +{
> + return 1;
This should be true (similarly for arm64).
David
next prev parent reply other threads:[~2015-07-27 12:35 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-27 11:35 [PATCH v2] xen/events: Support event channel rebind on ARM Julien Grall
2015-07-27 12:35 ` David Vrabel [this message]
2015-07-27 12:43 ` [Xen-devel] " Julien Grall
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