From: Manish Honap <[email protected]> Volatile CXL register state must be sampled from live hardware when the guest opens the device, not at bind, because a low-power transition between bind and open can leave the bind-time values stale.
Add open and close to the CXL ops and call them from the common enable and close paths. A failed open unwinds the enable in reverse order: unmap the BARs, drop the excluded ranges, then free the virtual config. Factor the BAR unmap out of vfio_pci_core_disable() into a helper so the enable failure path and the disable path share it. Assisted-by: LLM Signed-off-by: Manish Honap <[email protected]> --- drivers/vfio/pci/vfio_pci_core.c | 40 +++++++++++++++++++++++++------- include/linux/vfio_pci_core.h | 2 ++ 2 files changed, 33 insertions(+), 9 deletions(-) diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c index c5b7a59a4548..2f593b2721a1 100644 --- a/drivers/vfio/pci/vfio_pci_core.c +++ b/drivers/vfio/pci/vfio_pci_core.c @@ -591,6 +591,21 @@ static const struct dev_pm_ops vfio_pci_core_pm_ops = { static void vfio_pci_free_excluded_ranges(struct vfio_pci_core_device *vdev); +static void vfio_pci_core_unmap_bars(struct vfio_pci_core_device *vdev) +{ + struct pci_dev *pdev = vdev->pdev; + int i, bar; + + for (i = 0; i < PCI_STD_NUM_BARS; i++) { + bar = i + PCI_STD_RESOURCES; + if (IS_ERR_OR_NULL(vdev->barmap[bar])) + continue; + pci_iounmap(pdev, vdev->barmap[bar]); + pci_release_selected_regions(pdev, 1 << bar); + vdev->barmap[bar] = NULL; + } +} + int vfio_pci_core_enable(struct vfio_pci_core_device *vdev) { struct pci_dev *pdev = vdev->pdev; @@ -683,8 +698,19 @@ int vfio_pci_core_enable(struct vfio_pci_core_device *vdev) vfio_pci_core_map_bars(vdev); + if (vdev->cxl_ops) { + ret = vdev->cxl_ops->open_device(vdev); + if (ret) + goto out_free_config; + } + return 0; +out_free_config: + /* A failed first open never reaches vfio_pci_core_disable(). */ + vfio_pci_core_unmap_bars(vdev); + vfio_pci_free_excluded_ranges(vdev); + vfio_config_free(vdev); out_free_zdev: vfio_pci_zdev_close_device(vdev); out_free_state: @@ -705,7 +731,7 @@ void vfio_pci_core_disable(struct vfio_pci_core_device *vdev) struct pci_dev *pdev = vdev->pdev; struct vfio_pci_dummy_resource *dummy_res, *tmp; struct vfio_pci_ioeventfd *ioeventfd, *ioeventfd_tmp; - int i, bar; + int i; /* For needs_reset */ lockdep_assert_held(&vdev->vdev.dev_set->lock); @@ -761,14 +787,7 @@ void vfio_pci_core_disable(struct vfio_pci_core_device *vdev) vfio_config_free(vdev); vfio_pci_free_excluded_ranges(vdev); - for (i = 0; i < PCI_STD_NUM_BARS; i++) { - bar = i + PCI_STD_RESOURCES; - if (IS_ERR_OR_NULL(vdev->barmap[bar])) - continue; - pci_iounmap(pdev, vdev->barmap[bar]); - pci_release_selected_regions(pdev, 1 << bar); - vdev->barmap[bar] = NULL; - } + vfio_pci_core_unmap_bars(vdev); list_for_each_entry_safe(dummy_res, tmp, &vdev->dummy_resources_list, res_next) { @@ -851,6 +870,9 @@ void vfio_pci_core_close_device(struct vfio_device *core_vdev) #endif vfio_pci_dma_buf_cleanup(vdev); + if (vdev->cxl_ops) + vdev->cxl_ops->close_device(vdev); + vfio_pci_core_disable(vdev); mutex_lock(&vdev->igate); diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h index e8a1fc398571..643f32c2141f 100644 --- a/include/linux/vfio_pci_core.h +++ b/include/linux/vfio_pci_core.h @@ -70,6 +70,8 @@ struct vfio_pci_device_ops { struct vfio_cxl_ops { int (*init)(struct vfio_pci_core_device *vdev); void (*release)(struct vfio_pci_core_device *vdev); + int (*open_device)(struct vfio_pci_core_device *vdev); + void (*close_device)(struct vfio_pci_core_device *vdev); /* Pinned per bound CXL device so vfio-cxl cannot unload under usage */ struct module *owner; }; -- 2.25.1
