Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755607Ab0KCURj (ORCPT ); Wed, 3 Nov 2010 16:17:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:12109 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754825Ab0KCURh (ORCPT ); Wed, 3 Nov 2010 16:17:37 -0400 From: Alex Williamson Subject: [PATCH] vfio: Fix PCI 2.3 shared interrupt To: pugs@cisco.com Cc: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, alex.williamson@redhat.com Date: Wed, 03 Nov 2010 14:17:33 -0600 Message-ID: <20101103201732.7400.28058.stgit@s20.home> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1440 Lines: 46 Trying to be too clever with setting the irq_disabled flag. PCI 2.3 disabled devices can still share IRQs, which can lead to clearing the irq_disabled flag, preventing the EOI from registering, and leaving the device without interrupts. Interrupt handler should only ever set irq_disabled and we can exit earlier to avoid the config space access if we know we're disabled. Signed-off-by: Alex Williamson --- drivers/vfio/vfio_intrs.c | 9 ++++++++- 1 files changed, 8 insertions(+), 1 deletions(-) diff --git a/drivers/vfio/vfio_intrs.c b/drivers/vfio/vfio_intrs.c index 604082c..73e3deb 100644 --- a/drivers/vfio/vfio_intrs.c +++ b/drivers/vfio/vfio_intrs.c @@ -57,6 +57,12 @@ irqreturn_t vfio_interrupt(int irq, void *dev_id) spin_lock_irq(&vdev->irqlock); + /* INTX disabled interrupts can still be shared */ + if (vdev->irq_disabled) { + spin_unlock_irq(&vdev->irqlock); + return ret; + } + if (vdev->pci_2_3) { pci_block_user_cfg_access(pdev); @@ -87,7 +93,8 @@ done: ret = IRQ_HANDLED; } - vdev->irq_disabled = (ret == IRQ_HANDLED); + if (ret == IRQ_HANDLED) + vdev->irq_disabled = true; spin_unlock_irq(&vdev->irqlock); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/