vdpa/pds: fixes for VF vdpa flr-aer handling

This addresses a couple of things found while testing the FLR and AER
handling with the VFs.
 - release irqs before calling vp_modern_remove()
 - make sure we have a valid struct pointer before using it to release irqs
 - make sure the FW is alive before trying to add a new device
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Message-Id: <20240220011050.30913-1-shannon.nelson@amd.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vdpa/pds/aux_drv.c

@@ -93,8 +93,8 @@ static void pds_vdpa_remove(struct auxiliary_device *aux_dev)
 	struct device *dev = &aux_dev->dev;
 
 	vdpa_mgmtdev_unregister(&vdpa_aux->vdpa_mdev);
+	pds_vdpa_release_irqs(vdpa_aux->pdsv);
 	vp_modern_remove(&vdpa_aux->vd_mdev);
-	pci_free_irq_vectors(vdpa_aux->padev->vf_pdev);
 
 	pds_vdpa_debugfs_del_vdpadev(vdpa_aux);
 	kfree(vdpa_aux);

drivers/vdpa/pds/vdpa_dev.c

@@ -426,12 +426,18 @@ static int pds_vdpa_request_irqs(struct pds_vdpa_device *pdsv)
 	return err;
 }
 
-static void pds_vdpa_release_irqs(struct pds_vdpa_device *pdsv)
+void pds_vdpa_release_irqs(struct pds_vdpa_device *pdsv)
 {
-	struct pci_dev *pdev = pdsv->vdpa_aux->padev->vf_pdev;
-	struct pds_vdpa_aux *vdpa_aux = pdsv->vdpa_aux;
+	struct pds_vdpa_aux *vdpa_aux;
+	struct pci_dev *pdev;
 	int qid;
 
+	if (!pdsv)
+		return;
+
+	pdev = pdsv->vdpa_aux->padev->vf_pdev;
+	vdpa_aux = pdsv->vdpa_aux;
+
 	if (!vdpa_aux->nintrs)
 		return;
 
@@ -612,6 +618,7 @@ static int pds_vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
 	struct device *dma_dev;
 	struct pci_dev *pdev;
 	struct device *dev;
+	u8 status;
 	int err;
 	int i;
 
@@ -638,6 +645,13 @@ static int pds_vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
 	dma_dev = &pdev->dev;
 	pdsv->vdpa_dev.dma_dev = dma_dev;
 
+	status = pds_vdpa_get_status(&pdsv->vdpa_dev);
+	if (status == 0xff) {
+		dev_err(dev, "Broken PCI - status %#x\n", status);
+		err = -ENXIO;
+		goto err_unmap;
+	}
+
 	pdsv->supported_features = mgmt->supported_features;
 
 	if (add_config->mask & BIT_ULL(VDPA_ATTR_DEV_FEATURES)) {

drivers/vdpa/pds/vdpa_dev.h

@@ -46,5 +46,6 @@ struct pds_vdpa_device {
 
 #define PDS_VDPA_PACKED_INVERT_IDX	0x8000
 
+void pds_vdpa_release_irqs(struct pds_vdpa_device *pdsv);
 int pds_vdpa_get_mgmt_info(struct pds_vdpa_aux *vdpa_aux);
 #endif /* _VDPA_DEV_H_ */