From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony PERARD Subject: Re: [PATCH v2 2/2] xen: add pvUSB backend Date: Tue, 3 May 2016 16:06:14 +0100 Message-ID: <20160503150614.GG1885@perard.uk.xensource.com> References: <1457623170-30896-1-git-send-email-jgross@suse.com> <1457623170-30896-3-git-send-email-jgross@suse.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: <1457623170-30896-3-git-send-email-jgross@suse.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: "Qemu-devel" To: Juergen Gross Cc: xen-devel@lists.xensource.com, kraxel@redhat.com, qemu-devel@nongnu.org, stefano.stabellini@eu.citrix.com, konrad.wilk@oracle.com List-Id: xen-devel@lists.xenproject.org On Thu, Mar 10, 2016 at 04:19:30PM +0100, Juergen Gross wrote: > Add a backend for para-virtualized USB devices for xen domains. > > The backend is using host-libusb to forward USB requests from a > domain via libusb to the real device(s) passed through. > > Signed-off-by: Juergen Gross > --- [...] > diff --git a/hw/usb/xen-usb.c b/hw/usb/xen-usb.c > new file mode 100644 > index 0000000..b12077f > --- /dev/null > +++ b/hw/usb/xen-usb.c > @@ -0,0 +1,1021 @@ > +/* > + * xen paravirt usb device backend > + * > + * (c) Juergen Gross > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; under version 2 of the License. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License along > + * with this program; if not, see . > + * > + * Contributions after 2012-01-13 are licensed under the terms of the > + * GNU GPL, version 2 or (at your option) any later version. > + */ > + > +#include > +#include > +#include > +#include > +#include > + > +#include "qemu/osdep.h" > +#include "qemu-common.h" > +#include "qemu/config-file.h" > +#include "hw/sysbus.h" > +#include "hw/usb.h" > +#include "hw/xen/xen_backend.h" > +#include "monitor/qdev.h" > +#include "qapi/qmp/qbool.h" > +#include "qapi/qmp/qint.h" > +#include "qapi/qmp/qstring.h" > +#include "sys/user.h" > + > +#include > +#include > + > +#define TR(xendev, lvl, fmt, args...) \ > + { \ > + struct timeval tv; \ > + \ > + gettimeofday(&tv, NULL); \ > + xen_be_printf(xendev, lvl, "%8ld.%06ld xen-usb(%s):" fmt, \ > + tv.tv_sec, tv.tv_usec, __func__, ##args); \ > + } > +#define TR_BUS(xendev, fmt, args...) TR(xendev, 2, fmt, ##args) > +#define TR_REQ(xendev, fmt, args...) TR(xendev, 3, fmt, ##args) > + > +#define USBBACK_MAXPORTS USBIF_PIPE_PORT_MASK > +#define USB_DEV_ADDR_SIZE (USBIF_PIPE_DEV_MASK + 1) > + > +/* USB wire protocol: structure describing control request parameter. */ > +struct usbif_ctrlrequest { > + uint8_t bRequestType; > + uint8_t bRequest; > + uint16_t wValue; > + uint16_t wIndex; > + uint16_t wLength; > +}; > + > +struct usbback_info; > +struct usbback_req; > + > +struct usbback_stub { > + USBDevice *dev; > + USBPort port; > + unsigned int speed; > + bool attached; > + QTAILQ_HEAD(submit_q_head, usbback_req) submit_q; > +}; > + > +struct usbback_req { > + struct usbback_info *usbif; > + struct usbback_stub *stub; > + struct usbif_urb_request req; > + USBPacket packet; > + > + unsigned int nr_buffer_segs; /* # of transfer_buffer segments */ > + unsigned int nr_extra_segs; /* # of iso_frame_desc segments */ > + > + QTAILQ_ENTRY(usbback_req) q; > + > + void *buffer; > + void *isoc_buffer; > + struct libusb_transfer *xfer; > +}; > + > +struct usbback_info { > + struct XenDevice xendev; /* must be first */ > + USBBus bus; > + void *urb_sring; > + void *conn_sring; > + struct usbif_urb_back_ring urb_ring; > + struct usbif_conn_back_ring conn_ring; > + int num_ports; > + int usb_ver; > + bool ring_error; > + QTAILQ_HEAD(req_free_q_head, usbback_req) req_free_q; > + struct usbback_stub ports[USBBACK_MAXPORTS]; > + struct usbback_stub *addr_table[USB_DEV_ADDR_SIZE]; > + QEMUBH *bh; > +}; > + > +static struct usbback_req *usbback_get_req(struct usbback_info *usbif) > +{ > + struct usbback_req *usbback_req; > + > + if (QTAILQ_EMPTY(&usbif->req_free_q)) { > + usbback_req = g_malloc0(sizeof(*usbback_req)); You could use g_new0(struct usbback_req, 1) here. > + } else { > + usbback_req = QTAILQ_FIRST(&usbif->req_free_q); > + QTAILQ_REMOVE(&usbif->req_free_q, usbback_req, q); > + } > + return usbback_req; > +} > + > +static void usbback_put_req(struct usbback_req *usbback_req) > +{ > + struct usbback_info *usbif; > + > + usbif = usbback_req->usbif; > + memset(usbback_req, 0, sizeof(*usbback_req)); > + QTAILQ_INSERT_HEAD(&usbif->req_free_q, usbback_req, q); > +} > + > +static int usbback_gnttab_map(struct usbback_info *usbif, > + struct usbback_req *usbback_req) Looks like this function is the only one to have both usbif and usbback_req as parameters. > +{ > + unsigned int nr_segs, i, prot; > + uint32_t ref[USBIF_MAX_SEGMENTS_PER_REQUEST]; > + struct XenDevice *xendev = &usbif->xendev; > + struct usbif_request_segment *seg; > + void *addr; > + > + nr_segs = usbback_req->nr_buffer_segs + usbback_req->nr_extra_segs; > + if (!nr_segs) { > + return 0; > + } > + > + if (nr_segs > USBIF_MAX_SEGMENTS_PER_REQUEST) { > + xen_be_printf(xendev, 0, "bad number of segments in request (%d)\n", > + nr_segs); > + return -EINVAL; > + } > + > + for (i = 0; i < nr_segs; i++) { > + if ((unsigned)usbback_req->req.seg[i].offset + > + (unsigned)usbback_req->req.seg[i].length > PAGE_SIZE) { > + xen_be_printf(xendev, 0, "segment crosses page boundary\n"); > + return -EINVAL; > + } > + } > + > + if (usbback_req->nr_buffer_segs) { > + prot = PROT_READ; > + if (usbif_pipein(usbback_req->req.pipe)) { > + prot |= PROT_WRITE; > + } > + for (i = 0; i < usbback_req->nr_buffer_segs; i++) { > + ref[i] = usbback_req->req.seg[i].gref; > + } > + usbback_req->buffer = xengnttab_map_domain_grant_refs(xendev->gnttabdev, > + usbback_req->nr_buffer_segs, xendev->dom, ref, prot); > + > + if (!usbback_req->buffer) { > + return -ENOMEM; > + } > + > + for (i = 0; i < usbback_req->nr_buffer_segs; i++) { > + seg = usbback_req->req.seg + i; > + addr = usbback_req->buffer + i * PAGE_SIZE + seg->offset; > + qemu_iovec_add(&usbback_req->packet.iov, addr, seg->length); > + } > + } > + > + if (!usbif_pipeisoc(usbback_req->req.pipe)) { > + return 0; > + } The code below would never be reached since isoc request are discared in usbback_init_packet. Is this some left over from previous version? > + if (!usbback_req->nr_extra_segs) { > + xen_be_printf(xendev, 0, "iso request without descriptor segments\n"); > + return -EINVAL; > + } > + > + prot = PROT_READ | PROT_WRITE; > + for (i = 0; i < usbback_req->nr_extra_segs; i++) { > + ref[i] = usbback_req->req.seg[i + usbback_req->req.nr_buffer_segs].gref; > + } > + usbback_req->isoc_buffer = xengnttab_map_domain_grant_refs( > + xendev->gnttabdev, usbback_req->nr_extra_segs, xendev->dom, ref, prot); > + > + if (!usbback_req->isoc_buffer) { > + return -ENOMEM; > + } > + > + return 0; > +} > + > +static int usbback_init_packet(struct usbback_req *usbback_req) > +{ > + struct XenDevice *xendev = &usbback_req->usbif->xendev; > + USBPacket *packet = &usbback_req->packet; > + USBDevice *dev = usbback_req->stub->dev; > + USBEndpoint *ep; > + unsigned int pid, ep_nr; > + bool sok; > + int ret = 0; > + > + qemu_iovec_init(&packet->iov, USBIF_MAX_SEGMENTS_PER_REQUEST); > + pid = usbif_pipein(usbback_req->req.pipe) ? USB_TOKEN_IN : USB_TOKEN_OUT; > + ep_nr = usbif_pipeendpoint(usbback_req->req.pipe); > + sok = !!(usbback_req->req.transfer_flags & 1); Why 1, where this came from? > + if (usbif_pipetype(usbback_req->req.pipe) == USBIF_PIPE_TYPE_CTRL) { usbif_pipectrl()? > + ep_nr = 0; > + sok = false; > + } > + ep = usb_ep_get(dev, pid, ep_nr); > + usb_packet_setup(packet, pid, ep, 0, 1, sok, true); > + > + switch (usbif_pipetype(usbback_req->req.pipe)) { > + case USBIF_PIPE_TYPE_ISOC: > + TR_REQ(xendev, "iso transfer %s: buflen: %x, %d frames\n", > + (pid == USB_TOKEN_IN) ? "in" : "out", > + usbback_req->req.buffer_length, > + usbback_req->req.u.isoc.nr_frame_desc_segs); > + ret = -EINVAL; /* isoc not implemented yet */ > + break; > + > + case USBIF_PIPE_TYPE_INT: > + TR_REQ(xendev, "int transfer %s: buflen: %x\n", > + (pid == USB_TOKEN_IN) ? "in" : "out", > + usbback_req->req.buffer_length); > + break; > + > + case USBIF_PIPE_TYPE_CTRL: > + packet->parameter = *(uint64_t *)usbback_req->req.u.ctrl; > + TR_REQ(xendev, "ctrl parameter: %lx, buflen: %x\n", packet->parameter, > + usbback_req->req.buffer_length); > + break; > + > + case USBIF_PIPE_TYPE_BULK: > + TR_REQ(xendev, "bulk transfer %s: buflen: %x\n", > + (pid == USB_TOKEN_IN) ? "in" : "out", > + usbback_req->req.buffer_length); > + break; > + default: > + ret = -EINVAL; > + break; > + } > + > + return ret; > +} > + > +static void usbback_do_response(struct usbback_req *usbback_req, int32_t status, > + int32_t actual_length, int32_t error_count) > +{ > + struct usbback_info *usbif; > + struct usbif_urb_response *res; > + struct XenDevice *xendev; > + unsigned int notify; > + > + usbif = usbback_req->usbif; > + xendev = &usbif->xendev; > + > + TR_REQ(xendev, "id %d, status %d, length %d, errcnt %d\n", > + usbback_req->req.id, status, actual_length, error_count); > + > + if (usbback_req->packet.iov.iov) { > + qemu_iovec_destroy(&usbback_req->packet.iov); > + } > + > + if (usbback_req->buffer) { > + xengnttab_unmap(xendev->gnttabdev, usbback_req->buffer, > + usbback_req->nr_buffer_segs); > + usbback_req->buffer = NULL; > + } > + > + if (usbback_req->isoc_buffer) { > + xengnttab_unmap(xendev->gnttabdev, usbback_req->isoc_buffer, > + usbback_req->nr_extra_segs); > + usbback_req->isoc_buffer = NULL; > + } > + > + res = RING_GET_RESPONSE(&usbif->urb_ring, usbif->urb_ring.rsp_prod_pvt); What happen if the ring is full? > + res->id = usbback_req->req.id; > + res->status = status; > + res->actual_length = actual_length; > + res->error_count = error_count; > + res->start_frame = 0; > + usbif->urb_ring.rsp_prod_pvt++; > + RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&usbif->urb_ring, notify); > + > + if (notify) { > + xen_be_send_notify(xendev); > + } > + > + usbback_put_req(usbback_req); > +} > + > +static void usbback_do_response_ret(struct usbback_req *usbback_req, > + int32_t status) > +{ > + usbback_do_response(usbback_req, status, 0, 0); > +} > + > +static int32_t usbback_xlat_status(int32_t status) USBPacket->status is int, so I think the parameter status should be int as well. > +{ > + int32_t ret = -ESHUTDOWN; > + > + switch (status) { > + case USB_RET_SUCCESS: > + ret = 0; > + break; > + case USB_RET_NODEV: > + ret = -ENODEV; > + break; > + case USB_RET_STALL: > + ret = -EPIPE; > + break; > + case USB_RET_BABBLE: > + ret = -EOVERFLOW; > + break; > + case USB_RET_IOERROR: > + ret = -EPROTO; > + break; > + } You could return from the switch instead of using a variable. > + > + return ret; > +} > + > +static void usbback_packet_complete(USBPacket *packet) > +{ > + struct usbback_req *usbback_req; > + int32_t status; > + > + usbback_req = container_of(packet, struct usbback_req, packet); > + > + QTAILQ_REMOVE(&usbback_req->stub->submit_q, usbback_req, q); > + > + status = usbback_xlat_status(packet->status); > + usbback_do_response(usbback_req, status, packet->actual_length, 0); > +} > + > +static void usbback_set_address(struct usbback_info *usbif, > + struct usbback_stub *stub, int cur_addr, > + int new_addr) unsigned int for both cur_addr and new_addr? > +{ > + if (cur_addr) { > + usbif->addr_table[cur_addr] = NULL; > + } > + if (new_addr) { > + usbif->addr_table[new_addr] = stub; > + } > +} > + > +static bool usbback_cancel_req(struct usbback_req *usbback_req) > +{ > + bool ret = false; > + > + if (usb_packet_is_inflight(&usbback_req->packet)) { > + usb_cancel_packet(&usbback_req->packet); > + ret = true; > + } > + return ret; > +} > + > +static void usbback_process_unlink_req(struct usbback_req *usbback_req) > +{ > + struct usbback_info *usbif; > + struct usbback_req *unlink_req; > + unsigned int id, devnum; > + int ret; > + > + usbif = usbback_req->usbif; > + ret = 0; > + id = usbback_req->req.u.unlink.unlink_id; > + TR_REQ(&usbif->xendev, "unlink id %d\n", id); > + devnum = usbif_pipedevice(usbback_req->req.pipe); > + if (unlikely(devnum == 0)) { > + usbback_req->stub = usbif->ports + > + usbif_pipeportnum(usbback_req->req.pipe); > + if (unlikely(!usbback_req->stub)) { > + ret = -ENODEV; > + goto fail_response; > + } > + } else { > + if (unlikely(!usbif->addr_table[devnum])) { > + ret = -ENODEV; > + goto fail_response; > + } > + usbback_req->stub = usbif->addr_table[devnum]; > + } > + > + QTAILQ_FOREACH(unlink_req, &usbback_req->stub->submit_q, q) { > + if (unlink_req->req.id == id) { > + if (usbback_cancel_req(unlink_req)) { > + usbback_do_response_ret(unlink_req, -EPROTO); > + } > + break; > + } > + } > + > +fail_response: > + usbback_do_response_ret(usbback_req, ret); > +} > + > +/* > + * Checks whether a request can be handled at once or should be forwarded > + * to the usb framework. > + * Return value is: > + * 0 in case of usb framework is needed > + * >0 in case of local handling (no error) > + * <0 parameter error The function only return 1 or 0. The comment those not match the function? > + * The request response has been queued already if return value not 0. > + */ > +static int usbback_check_and_submit(struct usbback_req *usbback_req) > +{ > + struct usbback_info *usbif; > + unsigned int devnum; > + struct usbback_stub *stub; > + struct usbif_ctrlrequest *ctrl; > + int ret; > + uint16_t wValue; > + > + usbif = usbback_req->usbif; > + stub = NULL; > + devnum = usbif_pipedevice(usbback_req->req.pipe); > + ctrl = (struct usbif_ctrlrequest *)usbback_req->req.u.ctrl; > + wValue = le16_to_cpu(ctrl->wValue); > + > + /* > + * When the device is first connected or resetted, USB device has no > + * address. In this initial state, following requests are sent to device > + * address (#0), > + * > + * 1. GET_DESCRIPTOR (with Descriptor Type is "DEVICE") is sent, > + * and OS knows what device is connected to. > + * > + * 2. SET_ADDRESS is sent, and then device has its address. > + * > + * In the next step, SET_CONFIGURATION is sent to addressed device, and > + * then the device is finally ready to use. > + */ > + if (unlikely(devnum == 0)) { > + stub = usbif->ports + usbif_pipeportnum(usbback_req->req.pipe) - 1; > + if (!stub->dev || !stub->attached) { > + ret = -ENODEV; > + goto do_response; > + } > + > + switch (ctrl->bRequest) { > + case USB_REQ_GET_DESCRIPTOR: > + /* > + * GET_DESCRIPTOR request to device #0. > + * through normal transfer. > + */ > + TR_REQ(&usbif->xendev, "devnum 0 GET_DESCRIPTOR\n"); > + usbback_req->stub = stub; > + return 0; > + case USB_REQ_SET_ADDRESS: > + /* > + * SET_ADDRESS request to device #0. > + * add attached device to addr_table. > + */ > + TR_REQ(&usbif->xendev, "devnum 0 SET_ADDRESS\n"); > + usbback_set_address(usbif, stub, 0, wValue); > + ret = 0; > + break; > + default: > + ret = -EINVAL; > + break; > + } > + goto do_response; > + } > + > + if (unlikely(!usbif->addr_table[devnum])) { > + ret = -ENODEV; > + goto do_response; > + } > + usbback_req->stub = usbif->addr_table[devnum]; > + > + /* > + * Check special request > + */ > + if (ctrl->bRequest != USB_REQ_SET_ADDRESS) { > + return 0; > + } > + > + /* > + * SET_ADDRESS request to addressed device. > + * change addr or remove from addr_table. > + */ > + usbback_set_address(usbif, usbback_req->stub, devnum, wValue); > + ret = 0; > + > +do_response: > + usbback_do_response_ret(usbback_req, ret); > + return 1; > +} > + > +static void usbback_dispatch(struct usbback_req *usbback_req) > +{ > + int ret; > + unsigned int devnum; > + struct usbback_info *usbif; > + > + usbif = usbback_req->usbif; > + > + TR_REQ(&usbif->xendev, "start req_id %d pipe %08x\n", usbback_req->req.id, > + usbback_req->req.pipe); > + > + /* unlink request */ > + if (unlikely(usbif_pipeunlink(usbback_req->req.pipe))) { > + usbback_process_unlink_req(usbback_req); > + return; > + } > + > + if (usbif_pipectrl(usbback_req->req.pipe)) { > + if (usbback_check_and_submit(usbback_req)) { > + return; > + } > + } else { > + devnum = usbif_pipedevice(usbback_req->req.pipe); > + usbback_req->stub = usbif->addr_table[devnum]; > + > + if (!usbback_req->stub || !usbback_req->stub->attached) { > + ret = -ENODEV; > + goto fail_response; > + } > + } > + > + QTAILQ_INSERT_TAIL(&usbback_req->stub->submit_q, usbback_req, q); > + > + usbback_req->nr_buffer_segs = usbback_req->req.nr_buffer_segs; > + usbback_req->nr_extra_segs = usbif_pipeisoc(usbback_req->req.pipe) ? > + usbback_req->req.u.isoc.nr_frame_desc_segs : 0; > + > + ret = usbback_init_packet(usbback_req); > + if (ret) { > + xen_be_printf(&usbif->xendev, 0, "invalid request\n"); > + ret = -ESHUTDOWN; > + goto fail_free_urb; > + } > + > + ret = usbback_gnttab_map(usbif, usbback_req); > + if (ret) { > + xen_be_printf(&usbif->xendev, 0, "invalid buffer, ret=%d\n", ret); > + ret = -ESHUTDOWN; > + goto fail_free_urb; > + } > + > + usb_handle_packet(usbback_req->stub->dev, &usbback_req->packet); > + if (usbback_req->packet.status != USB_RET_ASYNC) { > + usbback_packet_complete(&usbback_req->packet); > + } > + return; > + > +fail_free_urb: > + QTAILQ_REMOVE(&usbback_req->stub->submit_q, usbback_req, q); > + > +fail_response: > + usbback_do_response_ret(usbback_req, ret); > +} > + > +static void usbback_bh(void *opaque) > +{ > + struct usbback_info *usbif; > + struct usbif_urb_back_ring *urb_ring; > + struct usbback_req *usbback_req; > + RING_IDX rc, rp; > + unsigned int more_to_do; > + > + usbif = opaque; > + if (usbif->ring_error) { > + return; > + } > + > + urb_ring = &usbif->urb_ring; > + rc = urb_ring->req_cons; > + rp = urb_ring->sring->req_prod; Maybe use atomic_read() here to avoid req_prod been read more than once. > + xen_rmb(); /* Ensure we see queued requests up to 'rp'. */ > + > + if (RING_REQUEST_PROD_OVERFLOW(urb_ring, rp)) { > + rc = urb_ring->rsp_prod_pvt; > + xen_be_printf(&usbif->xendev, 0, "domU provided bogus ring requests " > + "(%#x - %#x = %u). Halting ring processing.\n", > + rp, rc, rp - rc); > + usbif->ring_error = true; > + return; > + } > + > + while (rc != rp) { > + if (RING_REQUEST_CONS_OVERFLOW(urb_ring, rc)) { > + break; > + } > + usbback_req = usbback_get_req(usbif); > + > + usbback_req->req = *RING_GET_REQUEST(urb_ring, rc); > + usbback_req->usbif = usbif; > + > + usbback_dispatch(usbback_req); > + > + urb_ring->req_cons = ++rc; > + } > + > + RING_FINAL_CHECK_FOR_REQUESTS(urb_ring, more_to_do); > + if (more_to_do) { > + qemu_bh_schedule(usbif->bh); > + } > +} > + > +static void usbback_hotplug_notify(struct usbback_info *usbif, unsigned port) > +{ > + struct usbif_conn_back_ring *ring = &usbif->conn_ring; > + struct usbif_conn_request *req; > + struct usbif_conn_response *res; > + uint16_t id; > + unsigned int notify; > + > + if (!usbif->conn_sring) { > + return; > + } > + > + req = RING_GET_REQUEST(ring, ring->req_cons); Should not we check if there is something to consume here? > + id = req->id; > + ring->req_cons++; > + ring->sring->req_event = ring->req_cons + 1; > + > + res = RING_GET_RESPONSE(ring, ring->rsp_prod_pvt); What if the ring is already full? > + res->id = id; > + res->portnum = port; > + res->speed = usbif->ports[port - 1].speed; > + ring->rsp_prod_pvt++; > + RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(ring, notify); > + > + if (notify) { > + xen_be_send_notify(&usbif->xendev); > + } > + > + TR_BUS(&usbif->xendev, "hotplug port %d speed %d\n", port, res->speed); > +} > + Thanks, -- Anthony PERARD