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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 2/2] xen: drain submit queue in xen-usb before removing device
When unplugging a device in the Xen pvusb backend drain the submit
queue before deallocation of the control structures. Otherwise there
will be bogus memory accesses when I/O contracts are finished.
Correlated to this issue is the handling of cancel requests: a packet
cancelled will still lead to the call of complete, so add a flag
to the request indicating it should be just dropped on complete.
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
hw/usb/xen-usb.c | 93 ++++++++++++++++++++++++++++++++++++--------------------
1 file changed, 60 insertions(+), 33 deletions(-)
diff --git a/hw/usb/xen-usb.c b/hw/usb/xen-usb.c
index 7992456..6ad666e 100644
--- a/hw/usb/xen-usb.c
+++ b/hw/usb/xen-usb.c
@@ -90,6 +90,8 @@ struct usbback_req {
void *buffer;
void *isoc_buffer;
struct libusb_transfer *xfer;
+
+ bool cancelled;
};
struct usbback_hotplug {
@@ -301,20 +303,23 @@ static void usbback_do_response(struct usbback_req
*usbback_req, int32_t status,
usbback_req->isoc_buffer = NULL;
}
- 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 (usbif->urb_sring) {
+ 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);
+ if (notify) {
+ xen_be_send_notify(xendev);
+ }
}
- usbback_put_req(usbback_req);
+ if (!usbback_req->cancelled)
+ usbback_put_req(usbback_req);
}
static void usbback_do_response_ret(struct usbback_req *usbback_req,
@@ -366,15 +371,14 @@ static void usbback_set_address(struct usbback_info
*usbif,
}
}
-static bool usbback_cancel_req(struct usbback_req *usbback_req)
+static void 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;
+ QTAILQ_REMOVE(&usbback_req->stub->submit_q, usbback_req, q);
+ usbback_req->cancelled = true;
+ usbback_do_response_ret(usbback_req, -EPROTO);
}
- return ret;
}
static void usbback_process_unlink_req(struct usbback_req *usbback_req)
@@ -391,7 +395,7 @@ static void usbback_process_unlink_req(struct usbback_req
*usbback_req)
devnum = usbif_pipedevice(usbback_req->req.pipe);
if (unlikely(devnum == 0)) {
usbback_req->stub = usbif->ports +
- usbif_pipeportnum(usbback_req->req.pipe);
+ usbif_pipeportnum(usbback_req->req.pipe) - 1;
if (unlikely(!usbback_req->stub)) {
ret = -ENODEV;
goto fail_response;
@@ -406,9 +410,7 @@ static void usbback_process_unlink_req(struct usbback_req
*usbback_req)
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);
- }
+ usbback_cancel_req(unlink_req);
break;
}
}
@@ -681,6 +683,31 @@ static void usbback_hotplug_enq(struct usbback_info
*usbif, unsigned port)
usbback_hotplug_notify(usbif);
}
+static void usbback_portid_drain(struct usbback_info *usbif, unsigned port)
+{
+ struct usbback_req *req, *tmp;
+ bool sched = false;
+
+ QTAILQ_FOREACH_SAFE(req, &usbif->ports[port - 1].submit_q, q, tmp) {
+ usbback_cancel_req(req);
+ sched = true;
+ }
+
+ if (sched)
+ qemu_bh_schedule(usbif->bh);
+}
+
+static void usbback_portid_detach(struct usbback_info *usbif, unsigned port)
+{
+ if (!usbif->ports[port - 1].attached)
+ return;
+
+ usbif->ports[port - 1].speed = USBIF_SPEED_NONE;
+ usbif->ports[port - 1].attached = false;
+ usbback_portid_drain(usbif, port);
+ usbback_hotplug_enq(usbif, port);
+}
+
static void usbback_portid_remove(struct usbback_info *usbif, unsigned port)
{
USBPort *p;
@@ -694,9 +721,7 @@ static void usbback_portid_remove(struct usbback_info
*usbif, unsigned port)
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_enq(usbif, port);
+ usbback_portid_detach(usbif, port);
TR_BUS(&usbif->xendev, "port %d removed\n", port);
}
@@ -801,7 +826,6 @@ static void usbback_process_port(struct usbback_info
*usbif, unsigned port)
static void usbback_disconnect(struct XenDevice *xendev)
{
struct usbback_info *usbif;
- struct usbback_req *req, *tmp;
unsigned int i;
TR_BUS(xendev, "start\n");
@@ -820,12 +844,8 @@ static void usbback_disconnect(struct XenDevice *xendev)
}
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);
- }
+ if (usbif->ports[i].dev)
+ usbback_portid_drain(usbif, i + 1);
}
TR_BUS(xendev, "finished\n");
@@ -944,8 +964,7 @@ static void xen_bus_detach(USBPort *port)
usbif = port->opaque;
TR_BUS(&usbif->xendev, "\n");
- usbif->ports[port->index].attached = false;
- usbback_hotplug_enq(usbif, port->index + 1);
+ usbback_portid_detach(usbif, port->index + 1);
}
static void xen_bus_child_detach(USBPort *port, USBDevice *child)
@@ -958,9 +977,16 @@ static void xen_bus_child_detach(USBPort *port, USBDevice
*child)
static void xen_bus_complete(USBPort *port, USBPacket *packet)
{
+ struct usbback_req *usbback_req;
struct usbback_info *usbif;
- usbif = port->opaque;
+ usbback_req = container_of(packet, struct usbback_req, packet);
+ if (usbback_req->cancelled) {
+ g_free(usbback_req);
+ return;
+ }
+
+ usbif = usbback_req->usbif;
TR_REQ(&usbif->xendev, "\n");
usbback_packet_complete(packet);
}
@@ -1037,6 +1063,7 @@ static int usbback_free(struct XenDevice *xendev)
}
usb_bus_release(&usbif->bus);
+ object_unparent(OBJECT(&usbif->bus));
TR_BUS(xendev, "finished\n");
--
2.6.6
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