From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56386) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YGOS1-0002UX-Ja for qemu-devel@nongnu.org; Wed, 28 Jan 2015 03:58:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YGORy-0006ot-6V for qemu-devel@nongnu.org; Wed, 28 Jan 2015 03:58:17 -0500 Received: from [59.151.112.132] (port=49891 helo=heian.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YGORx-0006oY-14 for qemu-devel@nongnu.org; Wed, 28 Jan 2015 03:58:14 -0500 Message-ID: <54C8A317.7030600@cn.fujitsu.com> Date: Wed, 28 Jan 2015 16:51:35 +0800 From: Chen Fan MIME-Version: 1.0 References: <33e32b09871167f1a258330511acbf9c26f6b479.1421028274.git.chen.fan.fnst@cn.fujitsu.com> <1421076263.6130.12.camel@redhat.com> In-Reply-To: <1421076263.6130.12.camel@redhat.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH 4/4] 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 01/12/2015 11:24 PM, Alex Williamson wrote: > On Mon, 2015-01-12 at 11:04 +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. >> >> Signed-off-by: Chen Fan >> --- >> hw/pci/pcie_aer.c | 2 +- >> hw/vfio/pci.c | 35 ++++++++++++++++++++++++++++------- >> include/hw/pci/pcie_aer.h | 3 ++- >> 3 files changed, 31 insertions(+), 9 deletions(-) >> >> diff --git a/hw/pci/pcie_aer.c b/hw/pci/pcie_aer.c >> index 571dc92..4812e3d 100644 >> --- a/hw/pci/pcie_aer.c >> +++ b/hw/pci/pcie_aer.c >> @@ -371,7 +371,7 @@ static void pcie_aer_msg_root_port(PCIDevice *dev, const PCIEAERMsg *msg) >> * >> * Walk up the bus tree from the device, propagate the error message. >> */ >> -static void pcie_aer_msg(PCIDevice *dev, const PCIEAERMsg *msg) >> +void pcie_aer_msg(PCIDevice *dev, const PCIEAERMsg *msg) >> { >> uint8_t type; >> > Better to split the AER core changes to a separate patch. > >> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c >> index 0ee6326..6f0b265 100644 >> --- a/hw/vfio/pci.c >> +++ b/hw/vfio/pci.c >> @@ -3106,20 +3106,41 @@ 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; >> } >> >> - /* >> - * 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. >> + /* we should read the error details from the real hardware >> + * configration spaces, here we only need to do is signaling > s/configration/configuration/ > >> + * to guest an uncorrectable error has occurred. >> */ >> + if (dev->exp.aer_cap) { >> + 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; Hi Alex, > Two things here, first, what happens when the guest attempts to do bus > resets or any sort of operation with the parent downstream port to > recover the device? Those ops aren't passed through to hardware. Is a > guest reboot necessarily going to be sufficient to clear the error and > doesn't that depend on what kind of reset vfio can do to the device on > the host? for now, the supported aer capability bridges are ioh3420, and upstream/downstream, when need to reset link for fatal error, which will cause these device reset by trigger secondary bus reset, then do qbus_reset_all(): which will trigger vfio_pci_reset to reset vfio device, in vfio_pci_reset, vfio device will via ioctl to notify hardware to reset by method VFIO_DEVICE_RESET. I think it seems be ok. > > Second, what happens on 440fx? It looks like the message goes nowhere, > which causes a regression from our current error containment there. So > any 440fx machine would need to disable the property that Paolo is > requesting. For 440fx, it don't support pcie root port, so there will not trigger aer report in qemu. Thanks, Chen >> + } >> + >> + /* >> + * 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. " >> "Please collect any data possible and then kill the guest", >> __func__, vdev->host.domain, vdev->host.bus, >> diff --git a/include/hw/pci/pcie_aer.h b/include/hw/pci/pcie_aer.h >> index bcac80a..6c4bf3b 100644 >> --- a/include/hw/pci/pcie_aer.h >> +++ b/include/hw/pci/pcie_aer.h >> @@ -51,7 +51,7 @@ struct PCIEAERLog { >> PCIEAERErr *log; >> }; >> >> -/* aer error message: error signaling message has only error sevirity and >> +/* aer error message: error signaling message has only error severity and >> source id. See 2.2.8.3 error signaling messages */ >> struct PCIEAERMsg { >> /* >> @@ -102,5 +102,6 @@ void pcie_aer_root_write_config(PCIDevice *dev, >> >> /* error injection */ >> int pcie_aer_inject_error(PCIDevice *dev, const PCIEAERErr *err); >> +void pcie_aer_msg(PCIDevice *dev, const PCIEAERMsg *msg); >> >> #endif /* QEMU_PCIE_AER_H */ > > > . >