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Re: [Qemu-devel] [Patch V1 3/3] xen: add pvUSB backend
From: |
Stefano Stabellini |
Subject: |
Re: [Qemu-devel] [Patch V1 3/3] xen: add pvUSB backend |
Date: |
Mon, 7 Sep 2015 18:38:19 +0100 |
User-agent: |
Alpine 2.02 (DEB 1266 2009-07-14) |
On Thu, 3 Sep 2015, 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 <address@hidden>
Aside from a few minor comments below, this looks pretty good from a Xen
perspective, however I am not too qualified to review the details of the
pvusb protocol or the way the requests are handled internally in QEMU.
I would be glad if Gerd could take a look at this too.
Juergen, if we commit this, would you be happy to maintain it going
forward?
> diff --git a/hw/usb/Makefile.objs b/hw/usb/Makefile.objs
> index 3fe4dff..0253184 100644
> --- a/hw/usb/Makefile.objs
> +++ b/hw/usb/Makefile.objs
> @@ -36,3 +36,7 @@ common-obj-$(CONFIG_USB_REDIR) += redirect.o quirks.o
>
> # usb pass-through
> common-obj-y += $(patsubst %,host-%.o,$(HOST_USB))
> +
> +ifeq ($(CONFIG_USB_LIBUSB),y)
> +common-obj-$(CONFIG_XEN_BACKEND) += xen-usb.o
> +endif
> diff --git a/hw/usb/xen-usb.c b/hw/usb/xen-usb.c
> new file mode 100644
> index 0000000..2570bd7
> --- /dev/null
> +++ b/hw/usb/xen-usb.c
> @@ -0,0 +1,1120 @@
> +/*
> + * xen paravirt usb device backend
> + *
> + * (c) Juergen Gross <address@hidden>
> + *
> + * 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 <http://www.gnu.org/licenses/>.
> + *
> + * Contributions after 2012-01-13 are licensed under the terms of the
> + * GNU GPL, version 2 or (at your option) any later version.
> + */
> +
> +#include <libusb.h>
> +#include <sys/types.h>
> +#include <sys/mman.h>
> +#include <sys/time.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 <xen/io/ring.h>
> +#include <xen/io/usbif.h>
> +
> +#define TR(fmt, args...) \
> + { \
> + struct timeval tv; \
> + \
> + gettimeofday(&tv, NULL); \
> + fprintf(stderr, "%8ld.%06ld xen-usb(%s):" fmt, tv.tv_sec, \
> + tv.tv_usec, __func__, ##args); \
Please use xen_be_printf. I am not sure I would go as far as using
gettimeofday, but I can see it could be useful here.
> + }
> +#define TR_REQ(fmt, args...) { if (tr_debug & 1) TR(fmt, ##args) }
> +#define TR_BUS(fmt, args...) { if (tr_debug & 2) TR(fmt, ##args) }
I would drop these and just use the loglevels of xen_be_printf.
> +#define USBBACK_MAXPORTS USBIF_PIPE_PORT_MASK
> +#define USBBACK_DEVNAME_SIZE 32
> +#define USB_DEV_ADDR_SIZE 128
> +
> +struct usbif_ctrlrequest {
> + uint8_t bRequestType;
> + uint8_t bRequest;
> + uint16_t wValue;
> + uint16_t wIndex;
> + uint16_t wLength;
> +};
> +
> +struct usbif_isoc_descriptor {
> + uint32_t offset;
> + uint32_t length;
> + uint32_t actual_length;
> + int32_t status;
> +};
> +
> +struct usbback_info;
> +struct usbback_req;
> +
> +struct usbback_stub {
> + USBDevice *dev;
> + USBPort port;
> + unsigned 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 unsigned int tr_debug = 3;
> +
> +static void usbback_copy_buffer(struct usbback_req *usbback_req,
> + struct usbif_isoc_descriptor *iso, bool out,
> + unsigned len, unsigned off)
> +{
> + struct usbif_request_segment *seg;
> + unsigned s, offset, copy_len, copy_off;
> + void *addr;
> +
> + offset = 0;
> + copy_off = iso->offset;
> + for (s = 0; len && s < usbback_req->nr_buffer_segs; s++) {
> + seg = usbback_req->req.seg + s;
> + if (offset + seg->length > copy_off) {
> + addr = usbback_req->buffer + s * PAGE_SIZE + seg->offset +
> + copy_off - offset;
> + copy_len = len;
> + if (copy_len > seg->length - copy_off + offset) {
> + copy_len = seg->length - copy_off + offset;
> + }
> + if (out) {
> + memcpy(usbback_req->xfer->buffer + off, addr, copy_len);
> + } else {
> + memcpy(addr, usbback_req->xfer->buffer + off, copy_len);
> + }
> + len -= copy_len;
> + off += copy_len;
> + }
> + offset += usbback_req->req.seg[s].length;
> + }
> + assert(!len);
> +}
> +
> +int usbback_get_packets(USBPacket *p)
> +{
> + struct usbback_req *usbback_req;
> +
> + usbback_req = container_of(p, struct usbback_req, packet);
> + assert(usbif_pipeisoc(usbback_req->req.pipe));
> + return usbback_req->req.u.isoc.nr_frame_desc_segs;
> +}
> +
> +void usbback_set_iso_desc(USBPacket *p, struct libusb_transfer *xfer)
> +{
> + struct usbback_req *usbback_req;
> + struct usbif_isoc_descriptor *iso;
> + struct usbif_request_segment *seg;
> + unsigned i, j, np, descr, off;
> +
> + usbback_req = container_of(p, struct usbback_req, packet);
> + assert(usbif_pipeisoc(usbback_req->req.pipe));
> + usbback_req->xfer = xfer;
> + np = usbback_req->req.u.isoc.nr_frame_desc_segs;
> + descr = 0;
> + off = 0;
> +
> + for (i = 0; i < usbback_req->nr_extra_segs; i++) {
> + seg = usbback_req->req.seg + usbback_req->nr_buffer_segs + i;
> + iso = usbback_req->isoc_buffer + i * PAGE_SIZE + seg->offset;
> + if ((seg->length % sizeof(*iso)) ||
> + (seg->length / sizeof(*iso) > np - descr) ||
> + (iso->offset + iso->length > usbback_req->req.buffer_length)) {
> + xen_be_printf(&usbback_req->usbif->xendev, 0,
> + "iso segment length invalid\n");
> + xfer->num_iso_packets = descr;
> + while (descr < usbback_req->req.u.isoc.nr_frame_desc_segs) {
> + xfer->iso_packet_desc[descr].length = 0;
> + xfer->iso_packet_desc[descr].actual_length = 0;
> + descr++;
> + }
> + return;
> + }
> + for (j = 0; j < seg->length / sizeof(*iso); j++) {
> + xfer->iso_packet_desc[descr].length = iso->length;
> + xfer->iso_packet_desc[descr].actual_length = 0;
> + if (!usbif_pipein(usbback_req->req.pipe)) {
> + usbback_copy_buffer(usbback_req, iso, true, iso->length,
> off);
> + off += iso->length;
> + }
> + iso++;
> + descr++;
> + }
> + }
> +}
> +
> +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));
> + } 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)
> +{
> + 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 =
> xc_gnttab_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;
> + }
> +
> + 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 = xc_gnttab_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)
> +{
> + USBPacket *packet = &usbback_req->packet;
> + USBDevice *dev = usbback_req->stub->dev;
> + USBEndpoint *ep;
> + unsigned int pid, ep_nr;
> + bool sok;
> +
> + 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);
> + if (usbif_pipetype(usbback_req->req.pipe) == USBIF_PIPE_TYPE_CTRL) {
> + 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("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);
> + break;
> +
> + case USBIF_PIPE_TYPE_INT:
> + TR_REQ("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("ctrl parameter: %lx, buflen: %x\n", packet->parameter,
> + usbback_req->req.buffer_length);
> + break;
> +
> + case USBIF_PIPE_TYPE_BULK:
> + TR_REQ("bulk transfer %s: buflen: %x\n",
> + (pid == USB_TOKEN_IN) ? "in" : "out",
> + usbback_req->req.buffer_length);
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +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;
> +
> + TR_REQ("id %d, status %d, length %d, errcnt %d\n", usbback_req->req.id,
> + status, actual_length, error_count);
> +
> + usbif = usbback_req->usbif;
> + xendev = &usbif->xendev;
> +
> + if (usbback_req->packet.iov.iov) {
> + qemu_iovec_destroy(&usbback_req->packet.iov);
> + }
> +
> + if (usbback_req->buffer) {
> + xc_gnttab_munmap(xendev->gnttabdev, usbback_req->buffer,
> + usbback_req->nr_buffer_segs);
> + usbback_req->buffer = NULL;
> + }
> +
> + if (usbback_req->isoc_buffer) {
> + xc_gnttab_munmap(xendev->gnttabdev, usbback_req->isoc_buffer,
> + usbback_req->nr_extra_segs);
> + }
> +
> + res = RING_GET_RESPONSE(&usbif->urb_ring, usbif->urb_ring.rsp_prod_pvt);
> + 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)
> +{
> + 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;
> + }
> +
> + return ret;
> +}
> +
> +static void usbback_packet_complete(USBPacket *packet)
> +{
> + struct usbback_req *usbback_req;
> + int32_t status, error_count, actual_length;
> + unsigned int i, j, off;
> + struct usbif_isoc_descriptor *iso;
> + struct usbif_request_segment *seg;
> + struct libusb_iso_packet_descriptor *libusb_iso;
> +
> + error_count = 0;
> + actual_length = 0;
> + off = 0;
> + 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);
> + if (usbback_req->isoc_buffer) {
> + libusb_iso = usbback_req->xfer->iso_packet_desc;
> + j = 0;
> + for (i = 0; i < usbback_req->nr_extra_segs; i++) {
> + seg = usbback_req->req.seg + usbback_req->nr_buffer_segs + i;
> + iso = usbback_req->isoc_buffer + i * PAGE_SIZE + seg->offset;
> + for (j = 0; j < seg->length / sizeof(*iso); j++) {
> + iso->actual_length = libusb_iso->actual_length;
> + iso->status = usbback_xlat_status(libusb_iso->status);
> + actual_length += libusb_iso->actual_length;
> + error_count += iso->status ? 1 : 0;
> + if (usbif_pipein(usbback_req->req.pipe)) {
> + usbback_copy_buffer(usbback_req, iso, false,
> + iso->actual_length, off);
> + off += iso->length;
> + }
> + libusb_iso++;
> + iso++;
> + }
> + }
> + } else {
> + actual_length = packet->actual_length;
> + }
> +
> + usbback_do_response(usbback_req, status, actual_length, error_count);
> +}
> +
> +static void usbback_set_address(struct usbback_info *usbif,
> + struct usbback_stub *stub, int cur_addr,
> + int 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("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);
> +}
> +
> +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 to normal transfer.
> + */
> + TR_REQ("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("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;
> +
> + TR_REQ("start req_id %d pipe %08x\n", usbback_req->req.id,
> + usbback_req->req.pipe);
> +
> + usbif = usbback_req->usbif;
> +
> + /* 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\n");
> + 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;
> + 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);
> + id = req->id;
> + ring->req_cons++;
> + ring->sring->req_event = ring->req_cons + 1;
> +
> + res = RING_GET_RESPONSE(ring, ring->rsp_prod_pvt);
> + 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("hotplug port %d speed %d\n", port, res->speed);
> +}
> +static void usbback_portid_remove(struct usbback_info *usbif, unsigned port)
> +{
> + USBPort *p;
> +
> + if (!usbif->ports[port - 1].dev) {
> + return;
> + }
> +
> + p = &(usbif->ports[port - 1].port);
> + snprintf(p->path, sizeof(p->path), "%d", 99);
> +
> + object_unparent(OBJECT(usbif->ports[port - 1].dev));
> + usbif->ports[port - 1].dev = NULL;
> + usbif->ports[port - 1].speed = USBIF_SPEED_NONE;
> + usbif->ports[port - 1].attached = false;
> + usbback_hotplug_notify(usbif, port);
> +
> + TR_BUS("port %d removed\n", port);
> +}
> +
> +static void usbback_portid_add(struct usbback_info *usbif, unsigned port,
> + char *busid)
> +{
> + unsigned speed;
> + char *portname;
> + USBPort *p;
> + Error *local_err = NULL;
> + QDict *qdict;
> + QemuOpts *opts;
> +
> + if (usbif->ports[port - 1].dev) {
> + return;
> + }
> +
> + portname = strchr(busid, '-');
> + if (!portname) {
> + xen_be_printf(&usbif->xendev, 0, "device %s illegal specification\n",
> + busid);
> + return;
> + }
> + portname++;
> + p = &(usbif->ports[port - 1].port);
> + snprintf(p->path, sizeof(p->path), "%s", portname);
> +
> + qdict = qdict_new();
> + qdict_put(qdict, "driver", qstring_from_str("usb-host"));
> + qdict_put(qdict, "hostbus", qint_from_int(atoi(busid)));
> + qdict_put(qdict, "hostport", qstring_from_str(portname));
> + qdict_put(qdict, "xen-iso-passthrough", qbool_from_int(1));
> + opts = qemu_opts_from_qdict(qemu_find_opts("device"), qdict, &local_err);
> + if (local_err) {
> + goto err;
> + }
> + usbif->ports[port - 1].dev = USB_DEVICE(qdev_device_add(opts));
> + if (!usbif->ports[port - 1].dev) {
> + goto err;
> + }
> + QDECREF(qdict);
> + snprintf(p->path, sizeof(p->path), "%d", port);
> + speed = usbif->ports[port - 1].dev->speed;
> + switch (speed) {
> + case USB_SPEED_LOW:
> + speed = USBIF_SPEED_LOW;
> + break;
> + case USB_SPEED_FULL:
> + speed = USBIF_SPEED_FULL;
> + break;
> + case USB_SPEED_HIGH:
> + speed = (usbif->usb_ver < USB_VER_USB20) ?
> + USBIF_SPEED_NONE : USBIF_SPEED_HIGH;
> + break;
> + default:
> + speed = USBIF_SPEED_NONE;
> + break;
> + }
> + if (speed == USBIF_SPEED_NONE) {
> + xen_be_printf(&usbif->xendev, 0, "device %s wrong speed\n", busid);
> + object_unparent(OBJECT(usbif->ports[port - 1].dev));
> + usbif->ports[port - 1].dev = NULL;
> + return;
> + }
> + usb_device_reset(usbif->ports[port - 1].dev);
> + usbif->ports[port - 1].speed = speed;
> + usbif->ports[port - 1].attached = true;
> + QTAILQ_INIT(&usbif->ports[port - 1].submit_q);
> + usbback_hotplug_notify(usbif, port);
> +
> + TR_BUS("port %d attached\n", port);
> + return;
> +
> +err:
> + QDECREF(qdict);
> + snprintf(p->path, sizeof(p->path), "%d", 99);
> + xen_be_printf(&usbif->xendev, 0, "device %s could not be opened\n",
> busid);
> +}
> +
> +static void usbback_process_port(struct usbback_info *usbif, unsigned port)
> +{
> + char node[8];
> + char *busid;
> +
> + snprintf(node, sizeof(node), "port/%d", port);
> + busid = xenstore_read_be_str(&usbif->xendev, node);
> + if (busid == NULL) {
> + xen_be_printf(&usbif->xendev, 0, "xenstore_read %s failed\n", node);
> + return;
> + }
> +
> + /* Remove portid, if the port is not connected. */
> + if (strlen(busid) == 0) {
> + usbback_portid_remove(usbif, port);
> + } else {
> + usbback_portid_add(usbif, port, busid);
> + }
> +
> + g_free(busid);
> +}
> +
> +static void usbback_disconnect(struct XenDevice *xendev)
> +{
> + struct usbback_info *usbif;
> + struct usbback_req *req, *tmp;
> + unsigned int i;
> +
> + TR_BUS("start\n");
> +
> + usbif = container_of(xendev, struct usbback_info, xendev);
> +
> + xen_be_unbind_evtchn(xendev);
> +
> + if (usbif->urb_sring) {
> + xc_gnttab_munmap(xendev->gnttabdev, usbif->urb_sring, 1);
> + usbif->urb_sring = NULL;
> + }
> + if (usbif->conn_sring) {
> + xc_gnttab_munmap(xendev->gnttabdev, usbif->conn_sring, 1);
> + usbif->conn_sring = NULL;
> + }
> +
> + for (i = 0; i < usbif->num_ports; i++) {
> + if (!usbif->ports[i].dev) {
> + continue;
> + }
> + QTAILQ_FOREACH_SAFE(req, &usbif->ports[i].submit_q, q, tmp) {
> + usbback_cancel_req(req);
> + }
> + }
> +
> + TR_BUS("finished\n");
> +}
> +
> +static int usbback_connect(struct XenDevice *xendev)
> +{
> + struct usbback_info *usbif;
> + struct usbif_urb_sring *urb_sring;
> + struct usbif_conn_sring *conn_sring;
> + int urb_ring_ref;
> + int conn_ring_ref;
> + unsigned int i;
> +
> + TR_BUS("start\n");
> +
> + usbif = container_of(xendev, struct usbback_info, xendev);
> +
> + if (xenstore_read_fe_int(xendev, "urb-ring-ref", &urb_ring_ref)) {
> + TR("error reading urb-ring-ref\n");
> + return -1;
> + }
> + if (xenstore_read_fe_int(xendev, "conn-ring-ref", &conn_ring_ref)) {
> + TR("error reading conn-ring-ref\n");
> + return -1;
> + }
> + if (xenstore_read_fe_int(xendev, "event-channel", &xendev->remote_port))
> {
> + TR("error reading event-channel\n");
> + return -1;
> + }
> +
> + usbif->urb_sring = xc_gnttab_map_grant_ref(xendev->gnttabdev,
> xendev->dom,
> + urb_ring_ref,
> + PROT_READ | PROT_WRITE);
> + usbif->conn_sring = xc_gnttab_map_grant_ref(xendev->gnttabdev,
> xendev->dom,
> + conn_ring_ref,
> + PROT_READ | PROT_WRITE);
> + if (!usbif->urb_sring || !usbif->conn_sring) {
> + TR("error mapping rings\n");
> + usbback_disconnect(xendev);
> + return -1;
> + }
> +
> + urb_sring = usbif->urb_sring;
> + conn_sring = usbif->conn_sring;
> + BACK_RING_INIT(&usbif->urb_ring, urb_sring, XC_PAGE_SIZE);
> + BACK_RING_INIT(&usbif->conn_ring, conn_sring, XC_PAGE_SIZE);
> +
> + xen_be_bind_evtchn(xendev);
> +
> + xen_be_printf(xendev, 1, "urb-ring-ref %d, conn-ring-ref %d, "
> + "remote port %d, local port %d\n", urb_ring_ref,
> + conn_ring_ref, xendev->remote_port, xendev->local_port);
> +
> + for (i = 1; i <= usbif->num_ports; i++) {
> + if (usbif->ports[i - 1].dev) {
> + usbback_hotplug_notify(usbif, i);
> + }
> + }
> +
> + return 0;
> +}
> +
> +static void usbback_backend_changed(struct XenDevice *xendev, const char
> *node)
> +{
> + struct usbback_info *usbif;
> + unsigned int i;
> +
> + TR_BUS("path %s\n", node);
> +
> + usbif = container_of(xendev, struct usbback_info, xendev);
> + for (i = 1; i <= usbif->num_ports; i++) {
> + usbback_process_port(usbif, i);
> + }
> +}
> +
> +static int usbback_init(struct XenDevice *xendev)
> +{
> + struct usbback_info *usbif;
> +
> + TR_BUS("start\n");
> +
> + usbif = container_of(xendev, struct usbback_info, xendev);
> +
> + if (xenstore_read_be_int(xendev, "num-ports", &usbif->num_ports) ||
> + usbif->num_ports < 1 || usbif->num_ports > USBBACK_MAXPORTS) {
> + xen_be_printf(xendev, 0, "num-ports not readable or out of
> bounds\n");
> + return -1;
> + }
> + if (xenstore_read_be_int(xendev, "usb-ver", &usbif->usb_ver) ||
> + (usbif->usb_ver != USB_VER_USB11 && usbif->usb_ver !=
> USB_VER_USB20)) {
> + xen_be_printf(xendev, 0, "usb-ver not readable or out of bounds\n");
> + return -1;
> + }
> +
> + usbback_backend_changed(xendev, "port");
> +
> + TR_BUS("finished\n");
> +
> + return 0;
> +}
> +
> +static void xen_bus_attach(USBPort *port)
> +{
> + struct usbback_info *usbif;
> +
> + TR_BUS("called\n");
> + usbif = port->opaque;
> + usbif->ports[port->index].attached = true;
> + usbback_hotplug_notify(usbif, port->index + 1);
> +}
> +
> +static void xen_bus_detach(USBPort *port)
> +{
> + struct usbback_info *usbif;
> +
> + TR_BUS("called\n");
> + usbif = port->opaque;
> + usbif->ports[port->index].attached = false;
> + usbback_hotplug_notify(usbif, port->index + 1);
> +}
> +
> +static void xen_bus_child_detach(USBPort *port, USBDevice *child)
> +{
> + TR_BUS("called\n");
> +}
> +
> +static void xen_bus_complete(USBPort *port, USBPacket *packet)
> +{
> + TR_REQ("called\n");
Could you please either remove these debug messages or make them more
informative.
> + usbback_packet_complete(packet);
> +}
> +
> +static USBPortOps xen_usb_port_ops = {
> + .attach = xen_bus_attach,
> + .detach = xen_bus_detach,
> + .child_detach = xen_bus_child_detach,
> + .complete = xen_bus_complete,
> +};
> +
> +static USBBusOps xen_usb_bus_ops = {
> +};
> +
> +static void usbback_alloc(struct XenDevice *xendev)
> +{
> + struct usbback_info *usbif;
> + USBPort *p;
> + unsigned int i, max_grants;
> +
> + usbif = container_of(xendev, struct usbback_info, xendev);
> +
> + usb_bus_new(&usbif->bus, sizeof(usbif->bus), &xen_usb_bus_ops,
> xen_sysdev);
> + for (i = 0; i < USBBACK_MAXPORTS; i++) {
> + p = &(usbif->ports[i].port);
> + usb_register_port(&usbif->bus, p, usbif, i, &xen_usb_port_ops,
> + USB_SPEED_MASK_LOW | USB_SPEED_MASK_FULL |
> + USB_SPEED_MASK_HIGH);
> + snprintf(p->path, sizeof(p->path), "%d", 99);
> + }
> +
> + QTAILQ_INIT(&usbif->req_free_q);
> + usbif->bh = qemu_bh_new(usbback_bh, usbif);
> +
> + max_grants = USBIF_MAX_SEGMENTS_PER_REQUEST * USB_URB_RING_SIZE + 2;
> + if (xc_gnttab_set_max_grants(xendev->gnttabdev, max_grants) < 0) {
> + xen_be_printf(xendev, 0, "xc_gnttab_set_max_grants failed: %s\n",
> + strerror(errno));
> + }
> +}
> +
> +static int usbback_free(struct XenDevice *xendev)
> +{
> + struct usbback_info *usbif;
> + struct usbback_req *usbback_req;
> + unsigned int i;
> +
> + TR_BUS("start\n");
> +
> + usbback_disconnect(xendev);
> + usbif = container_of(xendev, struct usbback_info, xendev);
> + for (i = 1; i <= usbif->num_ports; i++) {
> + usbback_portid_remove(usbif, i);
> + }
> +
> + while (!QTAILQ_EMPTY(&usbif->req_free_q)) {
> + usbback_req = QTAILQ_FIRST(&usbif->req_free_q);
> + QTAILQ_REMOVE(&usbif->req_free_q, usbback_req, q);
> + g_free(usbback_req);
> + }
> +
> + qemu_bh_delete(usbif->bh);
> +
> + usb_bus_release(&usbif->bus);
> +
> + TR_BUS("finished\n");
> +
> + return 0;
> +}
> +
> +static void usbback_event(struct XenDevice *xendev)
> +{
> + struct usbback_info *usbif;
> +
> + usbif = container_of(xendev, struct usbback_info, xendev);
> + qemu_bh_schedule(usbif->bh);
> +}
> +
> +struct XenDevOps xen_usb_ops = {
> + .size = sizeof(struct usbback_info),
> + .flags = DEVOPS_FLAG_NEED_GNTDEV,
> + .init = usbback_init,
> + .alloc = usbback_alloc,
> + .free = usbback_free,
> + .backend_changed = usbback_backend_changed,
> + .initialise = usbback_connect,
> + .disconnect = usbback_disconnect,
> + .event = usbback_event,
> +};
[Qemu-devel] [Patch V1 3/3] xen: add pvUSB backend, Juergen Gross, 2015/09/03
- Re: [Qemu-devel] [Patch V1 3/3] xen: add pvUSB backend,
Stefano Stabellini <=