Apply the same logic we use in vfio_pci_try_bus_reset() to perform a bus or slot reset as devices are released to the device open path. This not only improves our chances of handing the device to the user in a clean state, but we can also avoid duplicate resets if the device is released and re-opened while bound to vfio-pci. We can also potentially reset multiple device with a single bus/slot reset and avoid multiple function-level resets later. We switch to using pci_probe_reset_function() since we still want to expose function level reset to the user, but we may not use it as the reset mechanism of choice when enabling the device. Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx> --- Depends on export of pci_probe_reset_function() http://article.gmane.org/gmane.linux.kernel.pci/40662 drivers/vfio/pci/vfio_pci.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 69fab0f..d9f7ec5 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -119,16 +119,32 @@ static int vfio_pci_enable(struct vfio_pci_device *vdev) u16 cmd; u8 msix_pos; - pci_set_power_state(pdev, PCI_D0); + /* + * Start by resetting the device(s). A bus reset is our best method + * and may not be available once other devices are in use. It may + * also mark multiple devices as clean, avoiding duplicate function + * level resets later. + */ + vfio_pci_try_bus_reset(vdev); + if (vdev->needs_reset) + vdev->needs_reset = !(pci_try_reset_function(pdev) == 0); - /* Don't allow our initial saved state to include busmaster */ + /* + * These are reset defaults, but let's be sure the device is awake + * and not doing DMA. We do not want BusMaster enabled in save state. + */ + pci_set_power_state(pdev, PCI_D0); pci_clear_master(pdev); + /* Initialize device */ ret = pci_enable_device(pdev); if (ret) return ret; - vdev->reset_works = (pci_reset_function(pdev) == 0); + /* + * Checkpoint, this is the base level state we want to + * restore when the device is released. + */ pci_save_state(pdev); vdev->pci_saved_state = pci_store_saved_state(pdev); if (!vdev->pci_saved_state) @@ -948,6 +964,8 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) vdev->irq_type = VFIO_PCI_NUM_IRQS; mutex_init(&vdev->igate); spin_lock_init(&vdev->irqlock); + vdev->reset_works = (pci_probe_reset_function(pdev) == 0); + vdev->needs_reset = true; ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev); if (ret) { -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
