From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55965) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YXLS7-0001wr-T7 for qemu-devel@nongnu.org; Sun, 15 Mar 2015 23:12:28 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YXLS3-0008CP-S3 for qemu-devel@nongnu.org; Sun, 15 Mar 2015 23:12:27 -0400 Received: from [59.151.112.132] (port=38310 helo=heian.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YXLS3-0008C9-Gb for qemu-devel@nongnu.org; Sun, 15 Mar 2015 23:12:23 -0400 Message-ID: <55064870.6040209@cn.fujitsu.com> Date: Mon, 16 Mar 2015 11:05:20 +0800 From: Chen Fan MIME-Version: 1.0 References: <3c81eaae84d6b1fa6e229e765a534fdf180e1ce4.1426155432.git.chen.fan.fnst@cn.fujitsu.com> <1426286084.3643.144.camel@redhat.com> In-Reply-To: <1426286084.3643.144.camel@redhat.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v5 5/7] vfio-pci: pass the aer error to guest List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alex Williamson Cc: izumi.taku@jp.fujitsu.com, qemu-devel@nongnu.org On 03/14/2015 06:34 AM, Alex Williamson wrote: > On Thu, 2015-03-12 at 18:23 +0800, Chen Fan wrote: >> when the vfio device encounters an uncorrectable error in host, >> the vfio_pci driver will signal the eventfd registered by this >> vfio device, the results in the qemu eventfd handler getting >> invoked. >> >> this patch is to pass the error to guest and have the guest driver >> recover from the error. > What is going to be the typical recovery mechanism for the guest? I'm > concerned that the topology of the device in the guest doesn't > necessarily match the topology of the device in the host, so if the > guest were to attempt a bus reset to recover a device, for instance, > what happens? the recovery mechanism is that when guest got an aer error from a device, guest will clean the corresponding status bit in device register. and for need reset device, the guest aer driver would reset all devices under bus. Thanks, Chen >> Signed-off-by: Chen Fan >> --- >> hw/vfio/pci.c | 34 ++++++++++++++++++++++++++++------ >> 1 file changed, 28 insertions(+), 6 deletions(-) >> >> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c >> index 0a515b6..8966c49 100644 >> --- a/hw/vfio/pci.c >> +++ b/hw/vfio/pci.c >> @@ -3240,18 +3240,40 @@ static void vfio_put_device(VFIOPCIDevice *vdev) >> static void vfio_err_notifier_handler(void *opaque) >> { >> VFIOPCIDevice *vdev = opaque; >> + PCIDevice *dev = &vdev->pdev; >> + PCIEAERMsg msg = { >> + .severity = 0, >> + .source_id = (pci_bus_num(dev->bus) << 8) | dev->devfn, >> + }; >> >> if (!event_notifier_test_and_clear(&vdev->err_notifier)) { >> return; >> } >> >> + /* we should read the error details from the real hardware >> + * configuration spaces, here we only need to do is signaling >> + * to guest an uncorrectable error has occurred. >> + */ > Inconsistent comment style > >> + if(dev->exp.aer_cap) { > ^ space > >> + uint8_t *aer_cap = dev->config + dev->exp.aer_cap; >> + uint32_t uncor_status; >> + bool isfatal; >> + >> + uncor_status = vfio_pci_read_config(dev, >> + dev->exp.aer_cap + PCI_ERR_UNCOR_STATUS, 4); >> + >> + isfatal = uncor_status & pci_get_long(aer_cap + PCI_ERR_UNCOR_SEVER); >> + >> + msg.severity = isfatal ? PCI_ERR_ROOT_CMD_FATAL_EN : >> + PCI_ERR_ROOT_CMD_NONFATAL_EN; >> + >> + pcie_aer_msg(dev, &msg); >> + return; >> + } >> + >> /* >> - * TBD. Retrieve the error details and decide what action >> - * needs to be taken. One of the actions could be to pass >> - * the error to the guest and have the guest driver recover >> - * from the error. This requires that PCIe capabilities be >> - * exposed to the guest. For now, we just terminate the >> - * guest to contain the error. >> + * If the aer capability is not exposed to the guest. we just >> + * terminate the guest to contain the error. >> */ >> >> error_report("%s(%04x:%02x:%02x.%x) Unrecoverable error detected. " > > > . >