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 bind-time values stale.
Add open_device and close_device to the CXL ops and call them from the common enable and close paths. A failed open unwinds the enable like any other error. The callbacks are stubs here and are filled in next. Signed-off-by: Manish Honap <[email protected]> --- drivers/vfio/pci/cxl/vfio_cxl_core.c | 11 +++++++ drivers/vfio/pci/vfio_pci_core.c | 44 ++++++++++++++++++++++------ include/linux/vfio_pci_core.h | 2 ++ 3 files changed, 48 insertions(+), 9 deletions(-) diff --git a/drivers/vfio/pci/cxl/vfio_cxl_core.c b/drivers/vfio/pci/cxl/vfio_cxl_core.c index 966b7c22a6ac..d19fd638f538 100644 --- a/drivers/vfio/pci/cxl/vfio_cxl_core.c +++ b/drivers/vfio/pci/cxl/vfio_cxl_core.c @@ -100,9 +100,20 @@ static void vfio_cxl_release_device(struct vfio_pci_core_device *vdev) vdev->cxl = NULL; } +static int vfio_cxl_open_device(struct vfio_pci_core_device *vdev) +{ + return 0; +} + +static void vfio_cxl_close_device(struct vfio_pci_core_device *vdev) +{ +} + static const struct vfio_cxl_ops vfio_cxl_ops = { .init_device = vfio_cxl_init_device, .release_device = vfio_cxl_release_device, + .open_device = vfio_cxl_open_device, + .close_device = vfio_cxl_close_device, .owner = THIS_MODULE, }; diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c index 49dfbdaf3f05..470730cdc88b 100644 --- a/drivers/vfio/pci/vfio_pci_core.c +++ b/drivers/vfio/pci/vfio_pci_core.c @@ -584,6 +584,21 @@ static const struct dev_pm_ops vfio_pci_core_pm_ops = { NULL) }; +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; @@ -660,8 +675,23 @@ 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: + /* + * open_device() runs after vfio_config_init() and map_bars() have + * succeeded, but a failed first open never reaches vfio_pci_core_disable(). + * Unwind the common vconfig and BAR state here so the allocations and BAR + * requests are not leaked for a later open to overwrite. + */ + vfio_config_free(vdev); + vfio_pci_core_unmap_bars(vdev); out_free_zdev: vfio_pci_zdev_close_device(vdev); out_free_state: @@ -682,7 +712,7 @@ 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); @@ -737,14 +767,7 @@ void vfio_pci_core_disable(struct vfio_pci_core_device *vdev) vfio_config_free(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) { @@ -827,6 +850,9 @@ 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 43755b91880f..7354dae1dd85 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_device)(struct vfio_pci_core_device *vdev); void (*release_device)(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
