Subject: Re: [PATCH] xen/events: Fix interrupt lost during irq_disable and
 irq_enable
To: Liu Shuo <shuo.a.liu@intel.com>, linux-kernel@vger.kernel.org
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        David Vrabel <david.vrabel@citrix.com>, Ingo Molnar <mingo@kernel.org>,
        Anoob Soman <anoob.soman@citrix.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Len Brown <len.brown@intel.com>, KarimAllah Ahmed <karahmed@amazon.de>,
        "moderated list:XEN HYPERVISOR INTERFACE" 
        <xen-devel@lists.xenproject.org>
References: <1501347598-15084-1-git-send-email-shuo.a.liu@intel.com>
From: Juergen Gross <jgross@suse.com>
Message-ID: <05e28568-6d4b-e081-0522-bf1234226a17@suse.com>
Date: Fri, 11 Aug 2017 16:50:08 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.2.1
MIME-Version: 1.0
In-Reply-To: <1501347598-15084-1-git-send-email-shuo.a.liu@intel.com>
Content-Type: text/plain; charset=utf-8
Content-Language: de-DE
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 771
Lines: 22

On 29/07/17 18:59, Liu Shuo wrote:
> Here is a device has xen-pirq-MSI interrupt. Dom0 might lost interrupt
> during driver irq_disable/irq_enable. Here is the scenario,
>  1. irq_disable -> disable_dynirq -> mask_evtchn(irq channel)
>  2. dev interrupt raised by HW and Xen mark its evtchn as pending
>  3. irq_enable -> startup_pirq -> eoi_pirq ->
>     clear_evtchn(channel of irq) -> clear pending status
>  4. consume_one_event process the irq event without pending bit assert
>     which result in interrupt lost once
>  5. No HW interrupt raising anymore.
> 
> Now use enable_dynirq for enable_pirq of xen_pirq_chip to remove
> eoi_pirq when irq_enable.
> 
> Signed-off-by: Liu Shuo <shuo.a.liu@intel.com>

Pushed to xen/tip.git for-linus-4.13b


Thanks,

Juergen