From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43988) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YQIRl-0003Td-NV for qemu-devel@nongnu.org; Tue, 24 Feb 2015 11:34:58 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YQIRi-0002kU-EM for qemu-devel@nongnu.org; Tue, 24 Feb 2015 11:34:57 -0500 Received: from mail-we0-x232.google.com ([2a00:1450:400c:c03::232]:39589) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YQIRi-0002kM-7Q for qemu-devel@nongnu.org; Tue, 24 Feb 2015 11:34:54 -0500 Received: by wesx3 with SMTP id x3so26319006wes.6 for ; Tue, 24 Feb 2015 08:34:53 -0800 (PST) From: =?UTF-8?q?Marc=20Mar=C3=AD?= Date: Tue, 24 Feb 2015 17:34:14 +0100 Message-Id: <1424795655-16952-1-git-send-email-marc.mari.barcelo@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] [PATCH] libqos: Solve bug in interrupt checking when using MSIX in virtio-pci.c List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: =?UTF-8?q?Marc=20Mar=C3=AD?= , jsnow@redhat.com, afaerber@suse.de, stefanha@redhat.com The MSIX interrupt was always acked without checking its value, which caused a race condition. If the ISR was raised between the read and the acking, the ISR was never detected and it timed out. Signed-off-by: Marc Marí --- tests/libqos/virtio-pci.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/tests/libqos/virtio-pci.c b/tests/libqos/virtio-pci.c index 788ebaf..c74a669 100644 --- a/tests/libqos/virtio-pci.c +++ b/tests/libqos/virtio-pci.c @@ -140,8 +140,12 @@ static bool qvirtio_pci_get_queue_isr_status(QVirtioDevice *d, QVirtQueue *vq) return qpci_msix_pending(dev->pdev, vqpci->msix_entry); } else { data = readl(vqpci->msix_addr); - writel(vqpci->msix_addr, 0); - return data == vqpci->msix_data; + if (data == vqpci->msix_data) { + writel(vqpci->msix_addr, 0); + return true; + } else { + return false; + } } } else { return qpci_io_readb(dev->pdev, dev->addr + QVIRTIO_ISR_STATUS) & 1; @@ -160,8 +164,12 @@ static bool qvirtio_pci_get_config_isr_status(QVirtioDevice *d) return qpci_msix_pending(dev->pdev, dev->config_msix_entry); } else { data = readl(dev->config_msix_addr); - writel(dev->config_msix_addr, 0); - return data == dev->config_msix_data; + if (data == dev->config_msix_data) { + writel(dev->config_msix_addr, 0); + return true; + } else { + return false; + } } } else { return qpci_io_readb(dev->pdev, dev->addr + QVIRTIO_ISR_STATUS) & 2; -- 1.7.10.4