nvme: fix lightnvm check

nvme_nvm_ns_supported assumes every device is a pci_dev, which leads to
reading an incorrect field, or possible even a dereference of unallocated
memory for fabrics controllers.

Fix this by introducing a quirk for lighnvm capable devices instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Matias Bjørling <mb@lightnvm.io>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>

drivers/nvme/host/core.c

@@ -2377,10 +2377,11 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid)
 
 	nvme_report_ns_ids(ctrl, ns->ns_id, id, ns->eui, ns->nguid, &ns->uuid);
 
-	if (nvme_nvm_ns_supported(ns, id) &&
-				nvme_nvm_register(ns, disk_name, node)) {
-		dev_warn(ctrl->device, "%s: LightNVM init failure\n", __func__);
-		goto out_free_id;
+	if ((ctrl->quirks & NVME_QUIRK_LIGHTNVM) && id->vs[0] == 0x1) {
+		if (nvme_nvm_register(ns, disk_name, node)) {
+			dev_warn(ctrl->device, "LightNVM init failure\n");
+			goto out_free_id;
+		}
 	}
 
 	disk = alloc_disk_node(0, node);

drivers/nvme/host/lightnvm.c

@@ -955,29 +955,3 @@ void nvme_nvm_unregister_sysfs(struct nvme_ns *ns)
 	sysfs_remove_group(&disk_to_dev(ns->disk)->kobj,
 					&nvm_dev_attr_group);
 }
-
-/* move to shared place when used in multiple places. */
-#define PCI_VENDOR_ID_CNEX 0x1d1d
-#define PCI_DEVICE_ID_CNEX_WL 0x2807
-#define PCI_DEVICE_ID_CNEX_QEMU 0x1f1f
-
-int nvme_nvm_ns_supported(struct nvme_ns *ns, struct nvme_id_ns *id)
-{
-	struct nvme_ctrl *ctrl = ns->ctrl;
-	/* XXX: this is poking into PCI structures from generic code! */
-	struct pci_dev *pdev = to_pci_dev(ctrl->dev);
-
-	/* QEMU NVMe simulator - PCI ID + Vendor specific bit */
-	if (pdev->vendor == PCI_VENDOR_ID_CNEX &&
-				pdev->device == PCI_DEVICE_ID_CNEX_QEMU &&
-							id->vs[0] == 0x1)
-		return 1;
-
-	/* CNEX Labs - PCI ID + Vendor specific bit */
-	if (pdev->vendor == PCI_VENDOR_ID_CNEX &&
-				pdev->device == PCI_DEVICE_ID_CNEX_WL &&
-							id->vs[0] == 0x1)
-		return 1;
-
-	return 0;
-}

drivers/nvme/host/nvme.h

@@ -75,6 +75,11 @@ enum nvme_quirks {
 	 * The deepest sleep state should not be used.
 	 */
 	NVME_QUIRK_NO_DEEPEST_PS		= (1 << 5),
+
+	/*
+	 * Supports the LighNVM command set if indicated in vs[1].
+	 */
+	NVME_QUIRK_LIGHTNVM			= (1 << 6),
 };
 
 /*
@@ -320,7 +325,6 @@ void nvme_stop_keep_alive(struct nvme_ctrl *ctrl);
 int nvme_reset_ctrl(struct nvme_ctrl *ctrl);
 
 #ifdef CONFIG_NVM
-int nvme_nvm_ns_supported(struct nvme_ns *ns, struct nvme_id_ns *id);
 int nvme_nvm_register(struct nvme_ns *ns, char *disk_name, int node);
 void nvme_nvm_unregister(struct nvme_ns *ns);
 int nvme_nvm_register_sysfs(struct nvme_ns *ns);
@@ -339,10 +343,6 @@ static inline int nvme_nvm_register_sysfs(struct nvme_ns *ns)
 	return 0;
 }
 static inline void nvme_nvm_unregister_sysfs(struct nvme_ns *ns) {};
-static inline int nvme_nvm_ns_supported(struct nvme_ns *ns, struct nvme_id_ns *id)
-{
-	return 0;
-}
 static inline int nvme_nvm_ioctl(struct nvme_ns *ns, unsigned int cmd,
 							unsigned long arg)
 {

drivers/nvme/host/pci.c

@@ -2497,6 +2497,10 @@ static const struct pci_device_id nvme_id_table[] = {
 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
 	{ PCI_DEVICE(0x144d, 0xa822),   /* Samsung PM1725a */
 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
+	{ PCI_DEVICE(0x1d1d, 0x1f1f),	/* LighNVM qemu device */
+		.driver_data = NVME_QUIRK_LIGHTNVM, },
+	{ PCI_DEVICE(0x1d1d, 0x2807),	/* CNEX WL */
+		.driver_data = NVME_QUIRK_LIGHTNVM, },
 	{ PCI_DEVICE_CLASS(PCI_CLASS_STORAGE_EXPRESS, 0xffffff) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2001) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2003) },