On Wed, 2015-01-28 at 16:37 +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 <chen.fan.f...@cn.fujitsu.com>
> ---
> 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 2072261..8c81bb3 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -3141,18 +3141,40 @@ 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.
> + */
> + 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;
> + }
What if the guest machine type is 440FX? We've just killed the existing
vm_stop functionality for the majority of users.
> +
> /*
> - * 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.
Just because it's exposed doesn't mean the guest chipset allows access
to it, right?
> */
>
> error_report("%s(%04x:%02x:%02x.%x) Unrecoverable error detected. "
