From: Manish Honap <[email protected]> devm_cxl_probe_mem() maps the component registers through the CXL core, which by default claims each HDM and RAS sub-block. That collides with the full-BAR request vfio-pci-core makes when the guest opens the device.
After the component registers are discovered, declare the containing BAR owned with cxl_reg_map_set_owned_resource(). The core then ioremaps the sub-blocks without requesting them, so vfio-pci-core owns the whole BAR and the requests do not collide. Assisted-by: LLM Signed-off-by: Manish Honap <[email protected]> --- drivers/vfio/pci/cxl/vfio_cxl_core.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/vfio/pci/cxl/vfio_cxl_core.c b/drivers/vfio/pci/cxl/vfio_cxl_core.c index ef1fc715020e..052be27bc46f 100644 --- a/drivers/vfio/pci/cxl/vfio_cxl_core.c +++ b/drivers/vfio/pci/cxl/vfio_cxl_core.c @@ -33,8 +33,9 @@ struct vfio_cxl_state { * Create the CXL device state and join the device to the CXL topology. The * caller groups these devres allocations, so return on the first error. */ -static struct vfio_cxl_state *vfio_cxl_create_memdev(struct pci_dev *pdev, - u64 hdm_size) +static struct vfio_cxl_state * +vfio_cxl_create_memdev(struct pci_dev *pdev, const struct cxl_hdm_info *hdm, + u64 hdm_size) { struct vfio_cxl_state *cxl; struct cxl_memdev *cxlmd; @@ -59,6 +60,17 @@ static struct vfio_cxl_state *vfio_cxl_create_memdev(struct pci_dev *pdev, return ERR_PTR(ret); } + /* + * vfio-pci-core requests the whole component-register BAR when the + * guest opens the device. Declare that BAR owned so the CXL core + * ioremaps the HDM and RAS sub-blocks without claiming them, and the + * full-BAR request does not collide. + */ + ret = cxl_reg_map_set_owned_resource(&cxl->cxlds.reg_map, + pci_resource_n(pdev, hdm->hdm_bar)); + if (ret) + return ERR_PTR(ret); + if (!cxl->cxlds.reg_map.component_map.hdm_decoder.valid) { pci_err(pdev, "vfio-cxl: HDM decoder registers not found\n"); return ERR_PTR(-ENODEV); @@ -133,7 +145,7 @@ static int vfio_cxl_init_device(struct vfio_pci_core_device *vdev) if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) return -ENOMEM; - cxl = vfio_cxl_create_memdev(pdev, hdm_size); + cxl = vfio_cxl_create_memdev(pdev, hdm, hdm_size); if (IS_ERR(cxl)) { devres_release_group(&pdev->dev, NULL); return PTR_ERR(cxl); -- 2.53.0
