DM USB: xHCI: change flow of creation of virtual USB device

The xHCI emulation greatly depends on the user space library libusb
which is based on the usbfs module in Linux kernel. The libusb will
bind usbfs to physical USB device which makes hardware control over
libusb in user space possible.

The pci_xhci_dev_create is called in pci_xhci_native_usb_dev_conn_cb
which is a callback function triggered by physical USB device plugging.
This function will bind the physical USB device to usbfs in SOS, which
we depend to create the communication between UOS xHCI driver with
physical USB device.

This design will fail if the reconnection happened in the SOS, which
will bind class driver to the physical USB device instead of usbfs,
hence the libusb device handle in DM is invalid.

Currently, the native S3 will disable the vbus for all xHCI ports and
re-drive during S3 resume. This behavior cause native USB driver unbind
the usbfs and bind to related class driver, then made the DM lost
control and failed to continue emulation.

To fix this issue, place the pci_xhci_dev_create in the function
pci_xhci_cmd_enable_slot. According to the xHCI spec 4.5.3 Figure 10,
the UOS always send Enable Slot command when a device is attached or
recovered from errors (by Disable Slot command). So every time the SOS
can't resuming normally or some unexpected disconnection happens, this
desigen will always survive by Disable Slot and Enable Slot command
series from UOS xHCI driver.

Signed-off-by: Xiaoguang Wu <xiaoguang.wu@intel.com>
Reviewed-by: Liang Yang <liang3.yang@intel.com>
Acked-by: Yu Wang <yu1.wang@intel.com>

Author: xiaoguangwu

devicemodel/hw/pci/xhci.c

@@ -373,7 +373,10 @@ struct pci_xhci_vdev {
 	int (*excap_write)(struct pci_xhci_vdev *, uint64_t, uint64_t);
 	int		usb2_port_start;
 	int		usb3_port_start;
-	uint8_t port_map_tbl[USB_NATIVE_NUM_BUS][USB_NATIVE_NUM_PORT];
+
+	uint16_t port_map_tbl[USB_NATIVE_NUM_BUS][USB_NATIVE_NUM_PORT];
+	struct usb_native_devinfo
+		native_dev_info[USB_NATIVE_NUM_BUS][USB_NATIVE_NUM_PORT];
 	struct timespec mf_prev_time;	/* previous time of accessing MFINDEX */
 };
 
@@ -385,8 +388,16 @@ struct pci_xhci_vdev {
 #define	XHCI_GADDR(xdev, a)	paddr_guest2host((xdev)->dev->vmctx, (a), \
 				XHCI_PADDR_SZ - ((a) & (XHCI_PADDR_SZ-1)))
 
+/* port mapping status */
 #define VPORT_FREE (0)
-#define VPORT_ASSIGNED (-1)
+#define VPORT_ASSIGNED (1)
+#define VPORT_CONNECTED (2)
+#define VPORT_EMULATED (3)
+
+/* helpers for get port mapping information */
+#define VPORT_NUM(state) (state & 0xFF)
+#define VPORT_STATE(state) ((state >> 8) & 0xFF)
+#define VPORT_NUM_STATE(status, num) (((status & 0xFF) << 8) | (num & 0xFF))
 
 struct pci_xhci_option_elem {
 	char *parse_opt;
@@ -470,91 +481,65 @@ static struct pci_xhci_option_elem xhci_option_table[] = {
 static int
 pci_xhci_native_usb_dev_conn_cb(void *hci_data, void *dev_data)
 {
-	struct pci_xhci_dev_emu *de;
 	struct pci_xhci_vdev *xdev;
-	struct usb_devemu *ue;
 	struct usb_native_devinfo *di;
-	int port_start, port_end;
-	int slot_start, slot_end;
-	int port, slot;
-	void *ud;
+	int vport_start, vport_end;
+	int port;
 
 	xdev = hci_data;
-	di = dev_data;
 
 	assert(xdev);
 	assert(dev_data);
 	assert(xdev->devices);
 	assert(xdev->slots);
 
-	de = pci_xhci_dev_create(xdev, di);
-	if (!de) {
-		UPRINTF(LFTL, "fail to create device\r\n");
-		return -1;
-	}
-
-	/* find free port and slot for the new usb device */
-	ud = de->dev_instance;
-	ue = de->dev_ue;
-
-	assert(ud);
-	assert(ue);
+	di = dev_data;
 
 	/* print physical information about new device */
 	UPRINTF(LDBG, "%04x:%04x %d-%d connecting.\r\n",
 			di->vid, di->pid, di->bus, di->port);
 
-	if (xdev->port_map_tbl[di->bus][di->port] == VPORT_FREE) {
+	if (VPORT_STATE(xdev->port_map_tbl[di->bus][di->port]) ==
+			VPORT_FREE) {
 		UPRINTF(LDBG, "%04x:%04x %d-%d doesn't belong to this vm, bye."
 				"\r\n", di->vid, di->pid, di->bus, di->port);
 		goto errout;
 	}
-
 	UPRINTF(LDBG, "%04x:%04x %d-%d belong to this vm.\r\n", di->vid,
 			di->pid, di->bus, di->port);
 
-	if (di->bcd < 0x300)
-		port_start = xdev->usb2_port_start;
-	else
-		port_start = xdev->usb3_port_start;
-
-	slot_start = 1;
-	port_end = port_start + (XHCI_MAX_DEVS / 2);
-	slot_end = XHCI_MAX_SLOTS;
+	if (di->bcd < 0x300) {
+		vport_start = xdev->usb2_port_start;
+		vport_end = vport_start + (XHCI_MAX_DEVS / 2);
+	} else {
+		vport_start = xdev->usb3_port_start;
+		vport_end = vport_start + (XHCI_MAX_DEVS / 2);
+	}
 
 	/* find free port */
-	for (port = port_start; port < port_end; port++)
+	for (port = vport_start; port < vport_end; port++)
 		if (!xdev->devices[port])
 			break;
 
-	/* find free slot */
-	for (slot = slot_start; slot < slot_end; slot++)
-		if (!xdev->slots[slot])
-			break;
-
-	if (port >= port_end || slot >= slot_end) {
-		UPRINTF(LFTL, "no free resource: port %d slot %d\r\n",
-				port, slot);
+	if (port >= vport_end) {
+		UPRINTF(LFTL, "no free virtual port for native device %d-%d"
+				"\r\n", di->bus, di->port);
 		goto errout;
 	}
 
-	/* use index of devices as port number */
-	xdev->devices[port] = de;
-	xdev->slots[slot] = de;
-	xdev->ndevices++;
+	UPRINTF(LDBG, "%04X:%04X %d-%d is attached to virtual port %d.\r\n",
+			di->vid, di->pid, di->bus, di->port, port);
 
-	pci_xhci_reset_slot(xdev, slot);
-	UPRINTF(LDBG, "%X:%X %d-%d locates in slot %d port %d.\r\n",
-			di->vid, di->pid, di->bus, di->port,
-			slot, port);
+	xdev->native_dev_info[di->bus][di->port] = *di;
+	xdev->port_map_tbl[di->bus][di->port] =
+		VPORT_NUM_STATE(VPORT_CONNECTED, port);
 
 	/* Trigger port change event for the arriving device */
 	if (pci_xhci_connect_port(xdev, port, di->speed, 1))
 		UPRINTF(LFTL, "fail to report port event\n");
 
 	return 0;
 errout:
-	pci_xhci_dev_destroy(de);
 	return -1;
 }
 
@@ -563,8 +548,10 @@ pci_xhci_native_usb_dev_disconn_cb(void *hci_data, void *dev_data)
 {
 	struct pci_xhci_vdev *xdev;
 	struct pci_xhci_dev_emu *edev;
+	struct usb_native_devinfo di;
 	struct usb_dev *udev;
-	uint8_t port, native_port;
+	uint8_t port, slot, native_port;
+	uint8_t status;
 
 	assert(hci_data);
 	assert(dev_data);
@@ -584,15 +571,28 @@ pci_xhci_native_usb_dev_disconn_cb(void *hci_data, void *dev_data)
 			continue;
 
 		udev = edev->dev_instance;
-		if (udev->info.port == native_port)
+		if (udev->info.port == native_port) {
+			di = udev->info;
 			break;
+		}
 	}
 
 	if (port == XHCI_MAX_DEVS + 1) {
 		UPRINTF(LFTL, "fail to find physical port %d\r\n", native_port);
 		return -1;
 	}
 
+	for (slot = 1; slot < XHCI_MAX_SLOTS; ++slot)
+		if (xdev->slots[slot] == edev)
+			break;
+
+	assert(slot < USB_NATIVE_NUM_BUS);
+
+	status = VPORT_STATE(xdev->port_map_tbl[di.bus][di.port]);
+	assert(status == VPORT_EMULATED || status == VPORT_CONNECTED);
+	xdev->port_map_tbl[di.bus][di.port] = VPORT_NUM_STATE(VPORT_ASSIGNED,
+			0);
+
 	UPRINTF(LDBG, "report virtual port %d status\r\n", port);
 	if (pci_xhci_disconnect_port(xdev, port, 1)) {
 		UPRINTF(LFTL, "fail to report event\r\n");
@@ -1393,28 +1393,67 @@ pci_xhci_insert_event(struct pci_xhci_vdev *xdev,
 	return err;
 }
 
+static struct usb_native_devinfo *
+pci_xhci_find_native_devinfo(struct pci_xhci_vdev *xdev)
+{
+	int i, j;
+
+	assert(xdev);
+	for (i = 0; i < USB_NATIVE_NUM_BUS; ++i)
+		for (j = 0; j < USB_NATIVE_NUM_PORT; ++j)
+			if (VPORT_STATE(xdev->port_map_tbl[i][j]) ==
+					VPORT_CONNECTED)
+				return &xdev->native_dev_info[i][j];
+
+	return NULL;
+}
+
 static uint32_t
 pci_xhci_cmd_enable_slot(struct pci_xhci_vdev *xdev, uint32_t *slot)
 {
 	struct pci_xhci_dev_emu *dev;
-	uint32_t	cmderr;
-	int		i;
+	uint32_t cmderr;
+	struct usb_native_devinfo *di;
+	int i, vport;
 
 	cmderr = XHCI_TRB_ERROR_NO_SLOTS;
-	if (xdev->portregs != NULL)
-		for (i = 1; i <= XHCI_MAX_SLOTS; i++) {
-			dev = XHCI_SLOTDEV_PTR(xdev, i);
-			if (dev && dev->dev_slotstate == XHCI_ST_DISABLED) {
-				*slot = i;
-				dev->dev_slotstate = XHCI_ST_ENABLED;
-				cmderr = XHCI_TRB_ERROR_SUCCESS;
-				dev->hci.hci_address = i;
-				break;
-			}
+
+	di = pci_xhci_find_native_devinfo(xdev);
+	if (!di) {
+		UPRINTF(LWRN, "unexpected Enable Slot commnad\r\n");
+		return -1;
+	}
+
+	assert(di->priv_data);
+	dev = pci_xhci_dev_create(xdev, di);
+	if (!dev) {
+		UPRINTF(LFTL, "fail to create device\r\n");
+		return -1;
+	}
+
+	vport = VPORT_NUM(xdev->port_map_tbl[di->bus][di->port]);
+	assert(vport > 0);
+	assert(!xdev->devices[vport]);
+
+	xdev->devices[vport] = dev;
+	xdev->ndevices++;
+
+	for (i = 1; i <= XHCI_MAX_SLOTS; i++) {
+		if (XHCI_SLOTDEV_PTR(xdev, i) == NULL) {
+			xdev->slots[i] = dev;
+			*slot = i;
+			dev->dev_slotstate = XHCI_ST_ENABLED;
+			cmderr = XHCI_TRB_ERROR_SUCCESS;
+			dev->hci.hci_address = i;
+			xdev->port_map_tbl[di->bus][di->port] =
+				VPORT_NUM_STATE(VPORT_EMULATED, vport);
+			break;
 		}
+	}
 
-	UPRINTF(LDBG, "enable slot (error=%d) slot %u\r\n",
-		cmderr != XHCI_TRB_ERROR_SUCCESS, *slot);
+	UPRINTF(LDBG, "enable slot (error=%d) slot %u for native device "
+			"%d-%d\r\n", cmderr != XHCI_TRB_ERROR_SUCCESS, *slot,
+			di->bus, di->port);
 
 	return cmderr;
 }
@@ -1423,6 +1462,8 @@ static uint32_t
 pci_xhci_cmd_disable_slot(struct pci_xhci_vdev *xdev, uint32_t slot)
 {
 	struct pci_xhci_dev_emu *dev;
+	struct usb_dev *udev;
+	struct usb_native_devinfo *di;
 	uint32_t cmderr;
 	int i;
 
@@ -1446,6 +1487,9 @@ pci_xhci_cmd_disable_slot(struct pci_xhci_vdev *xdev, uint32_t slot)
 			cmderr = XHCI_TRB_ERROR_SUCCESS;
 			/* TODO: reset events and endpoints */
 		}
+	} else {
+		UPRINTF(LDBG, "disable NULL device, slot %d\r\n", slot);
+		goto done;
 	}
 
 	for (i = 1; i <= XHCI_MAX_DEVS; ++i)
@@ -1455,8 +1499,20 @@ pci_xhci_cmd_disable_slot(struct pci_xhci_vdev *xdev, uint32_t slot)
 	if (i <= XHCI_MAX_DEVS && XHCI_PORTREG_PTR(xdev, i)) {
 		XHCI_PORTREG_PTR(xdev, i)->portsc &= ~(XHCI_PS_CSC |
 				XHCI_PS_CCS | XHCI_PS_PED | XHCI_PS_PP);
+
+		udev = dev->dev_instance;
+		assert(udev);
+
 		xdev->devices[i] = NULL;
 		xdev->slots[slot] = NULL;
+
+		di = &udev->info;
+		xdev->port_map_tbl[di->bus][di->port] =
+			VPORT_NUM_STATE(VPORT_ASSIGNED, 0);
+
+		UPRINTF(LINF, "disable slot %d for native device %d-%d"
+				"\r\n", slot, di->bus, di->port);
+
 		pci_xhci_dev_destroy(dev);
 	} else
 		UPRINTF(LWRN, "invalid slot %d\r\n", slot);
@@ -1624,7 +1680,10 @@ pci_xhci_cmd_config_ep(struct pci_xhci_vdev *xdev,
 	UPRINTF(LDBG, "config_ep slot %u\r\n", slot);
 
 	dev = XHCI_SLOTDEV_PTR(xdev, slot);
-	assert(dev != NULL);
+	if (dev == NULL) {
+		cmderr = XHCI_TRB_ERROR_SLOT_NOT_ON;
+		goto done;
+	}
 
 	if ((trb->dwTrb3 & XHCI_TRB_3_DCEP_BIT) != 0) {
 		UPRINTF(LDBG, "config_ep - deconfigure ep slot %u\r\n", slot);
@@ -3364,7 +3423,10 @@ pci_xhci_parse_bus_port(struct pci_xhci_vdev *xdev, char *opts)
 		goto errout;
 	}
 
-	xdev->port_map_tbl[bus][port] = VPORT_ASSIGNED;
+	xdev->port_map_tbl[bus][port] =
+		VPORT_NUM_STATE(VPORT_ASSIGNED, 0);
+	return 0;
+
 errout:
 	if (rc)
 		UPRINTF(LWRN, "%s fails, rc=%d\r\n", __func__, rc);