From mboxrd@z Thu Jan  1 00:00:00 1970
From: Julien Grall <julien.grall@linaro.org>
Subject: Re: [PATCH v9 04/12] xen/arm: support HW interrupts,
 do not request maintenance_interrupts
Date: Wed, 11 Jun 2014 14:40:15 +0100
Message-ID: <53985C3F.4030307@linaro.org>
References: <alpine.DEB.2.02.1406101204190.13771@kaball.uk.xensource.com>
	<1402409240-28114-4-git-send-email-stefano.stabellini@eu.citrix.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xen.org>
In-Reply-To: <1402409240-28114-4-git-send-email-stefano.stabellini@eu.citrix.com>
List-Unsubscribe: <http://lists.xen.org/cgi-bin/mailman/options/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xen.org>
List-Help: <mailto:xen-devel-request@lists.xen.org?subject=help>
List-Subscribe: <http://lists.xen.org/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=subscribe>
Sender: xen-devel-bounces@lists.xen.org
Errors-To: xen-devel-bounces@lists.xen.org
To: Stefano Stabellini <stefano.stabellini@eu.citrix.com>, xen-devel@lists.xensource.com
Cc: julien.grall@citrix.com, Ian.Campbell@citrix.com
List-Id: xen-devel@lists.xenproject.org

Hi Stefano,

On 06/10/2014 03:07 PM, Stefano Stabellini wrote:
> +static void gic_update_one_lr(struct vcpu *v, int i)
> +{
> +    struct pending_irq *p;
> +    uint32_t lr;
> +    int irq;
> +
> +    ASSERT(spin_is_locked(&v->arch.vgic.lock));
> +
> +    lr = GICH[GICH_LR + i];
> +    if ( !(lr & (GICH_LR_PENDING|GICH_LR_ACTIVE)) )
> +    {
> +        GICH[GICH_LR + i] = 0;
> +        clear_bit(i, &this_cpu(lr_mask));
> +
> +        irq = (lr >> GICH_LR_VIRTUAL_SHIFT) & GICH_LR_VIRTUAL_MASK;
> +        p = irq_to_pending(v, irq);
> +        if ( p->desc != NULL )
> +            p->desc->status &= ~IRQ_INPROGRESS;

Reading again this patch... shouldn't we take the desc->lock here?

It's possible to receive the same interrupt while we update the LRs
(depending how the IRQ has been physically route) so we may overwrite
the IRQ_INPROGRESS bit.

Regards,

-- 
Julien Grall