From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42680) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XztXu-0003Mq-Ns for qemu-devel@nongnu.org; Sat, 13 Dec 2014 15:44:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XztXl-0006Cg-EB for qemu-devel@nongnu.org; Sat, 13 Dec 2014 15:44:10 -0500 Received: from mx-v6.kamp.de ([2a02:248:0:51::16]:57141 helo=mx01.kamp.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XztXl-0006CS-3y for qemu-devel@nongnu.org; Sat, 13 Dec 2014 15:44:01 -0500 Message-ID: <548CA4FE.4090004@kamp.de> Date: Sat, 13 Dec 2014 21:43:42 +0100 From: Peter Lieven MIME-Version: 1.0 References: <548B605B.6030002@kamp.de> <1418422905.1095.189.camel@bling.home> In-Reply-To: <1418422905.1095.189.camel@bling.home> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] vfio-pci issues with multiple devices on the same root port List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alex Williamson Cc: "qemu-devel@nongnu.org" Am 12.12.2014 um 23:21 schrieb Alex Williamson: > On Fri, 2014-12-12 at 22:38 +0100, Peter Lieven wrote: >> Hi, >> >> we have a Cisco UCS infrastructure where we have fnic Fibre-Channel Adapters that we expose to guests. The UCS >> infrastruture allows to create virtual HBAs that can be exposed to a host so its possible to have quite a lot of them. >> >> We ran into a strange issue when we started having more than one vServer with a FibreChannel Adapter passed >> thru with vfio-pci. >> >> When a hypervisor shuts down it the kernel sees the following error: >> >> pcieport 0000:00:07.0: AER: Uncorrected (Non-Fatal) error received: id=0038 >> pcieport 0000:00:07.0: PCIe Bus Error: severity=Uncorrected (Non-Fatal), type=Transaction Layer, id=0038(Receiver ID) >> pcieport 0000:00:07.0: device [8086:340e] error status/mask=00200000/00100000 >> pcieport 0000:00:07.0: [21] Unknown Error Bit (First) >> pcieport 0000:00:07.0: broadcast error_detected message >> pcieport 0000:00:07.0: AER: Device recovery failed >> >> Bit 21 seems to be ACS Violation. And 0000:00:07.0 is the PCIE Root Port on that System. >> >> This wouldn't be a big problem, altough I would like to find out what the ACS Violation causes. >> >> The real problem is that all other vfio-pci cards on that root port get notified of this error and the connected vServers are suspended >> with RUN_STATE_INTERNAL_ERROR. >> >> Any ideas to work around this other than hacking qemu to not register an error handler or modifying vfio_err_notifier_handler >> to not suspend the vServer? > You could set bit 21 in the AER uncorrected error mask register to avoid > the root port signaling the error. Is bit 21 already clear in the > severity register to make this non-fatal? > >> Is it correct that all children of a root port are notified? Should qemu distinguish between fatal and non-fatal errors when >> suspending a vServer? > Yes, each child is notified. QEMU only gets an eventfd signal, which is > supposed to occur only for fatal errors. I don't quite understand why > this apparently non-fatal error is getting through. The kernel-side > VFIO code is where filtering of fatal vs non-fatal should occur. Had a look at vfio-pci.c from master. I can't see where there is a filtering of fatal vs. non-fatal static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev, pci_channel_state_t state) { struct vfio_pci_device *vdev; struct vfio_device *device; device = vfio_device_get_from_dev(&pdev->dev); if (device == NULL) return PCI_ERS_RESULT_DISCONNECT; vdev = vfio_device_data(device); if (vdev == NULL) { vfio_device_put(device); return PCI_ERS_RESULT_DISCONNECT; } mutex_lock(&vdev->igate); if (vdev->err_trigger) eventfd_signal(vdev->err_trigger, 1); mutex_unlock(&vdev->igate); vfio_device_put(device); return PCI_ERS_RESULT_CAN_RECOVER; } static struct pci_error_handlers vfio_err_handlers = { .error_detected = vfio_pci_aer_err_detected, }; static struct pci_driver vfio_pci_driver = { .name = "vfio-pci", .id_table = NULL, /* only dynamic ids */ .probe = vfio_pci_probe, .remove = vfio_pci_remove, .err_handler = &vfio_err_handlers, }; Peter