Some usb devices (host or network redirection) can benefit from knowing when
the guest stops using an endpoint. Redirection may involve submitting packets
independently from the guest (in combination with a fifo buffer between the
redirection code and the guest), to ensure that buffers of the real usb device
are timely emptied. This is done for example for isoc traffic and for interrupt
input endpoints. But when the (re)submission of packets is done by the device
code, then how does it know when to stop this?
For isoc endpoints this is handled by detecting a set interface (change alt
setting) command, which works well for isoc endpoints. But for interrupt
endpoints currently the redirection code never stops receiving data from
the device, which is less then ideal.
However the controller emulation is aware when a guest looses interest, as
then the qh for the endpoint gets unlinked (ehci, ohci, uhci) or the endpoint
is explicitly stopped (xhci). This patch adds a new ep_stopped USBDevice
method and modifies the hcd code to call this on queue unlink / ep stop.
This makes it possible for the redirection code to properly stop receiving
interrupt input (*) data when the guest no longer has interest in it.
*) And in the future also buffered bulk input.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
If somehow we've gotten behind a lot, simply skip ahead, like the ehci code
does.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Before this patch uhci would process an unlimited amount of frames when
behind on schedule, by setting the timer to a time already past, causing the
timer subsys to immediately recall the frame_timer function gain.
This would cause invalid cancellations of bulk queues when the catching up
processed more then 32 frames at a moment when the bulk qh was temporarily
unlinked (which the Linux uhci driver does).
This patch fixes this by processing maximum 16 frames in one go, and always
setting the timer one ms later, making the code behave more like the ehci
code.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Rather then using the magic 32 value in various places.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Re-arrange how we process frames / increase frnum / report pending interrupts,
to avoid a 1 ms delay in interrupt reporting to the guest. This increases
the packet throughput for cases where the guest submits a single packet,
then waits for its completion then re-submits from 500 pkts / sec to
1000 pkts / sec. This impacts for example the use of redirected / virtual
usb to serial convertors.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Hotplugging them simply doesn't work, so tag them accordingly to
avoid users trying and then crashing qemu.
For xhci there is nothing fundamental which prevents hotplug from
working, we'll "only" need a exit() function which cleans up
everything properly. That isn't for 1.3 though.
For ehci+uhci+ohci hotplug can't be supported until qemu gains the
capability to hotplug multifunction pci devices.
https://bugzilla.redhat.com/show_bug.cgi?id=879096
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
uhci_async_cancel() already does a uhci_async_unlink().
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
It is possible for device disconnect and the guest trying to reset the port
(because of USB xact errors prior to the disconnect getting signaled) to race,
when we hit this race, the guest will write the port-control register with its
pre-disconnect value + the reset bit set, after which we have a disconnected
device with its port-enabled bit set in its port-control register, which
is no good :)
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Add a completions_only flag, and set this when running process_frame for async
completion handling, this fixes 2 issues in a single patch:
1) It makes sure async completed packets get written to guest mem immediately,
even if all the bandwidth for the frame was consumed from the timer run
process_frame. This is necessary as delaying their writeback to the next frame
can cause the completion to get lost on migration.
2) The calling of process_frame from a bh on async completion causes iso
tds to get server more often they should, messing up usb sound class device
timing. By only processing completed packets, the iso tds get skipped fixing
this.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Since with the ehci and xhci controllers a single packet can be larger
then maxpacketsize, it is possible for the result of a single packet
to be both having transferred some data as well as the transfer to have
an error.
An example would be an input transfer from a bulk endpoint successfully
receiving 1 or more maxpacketsize packets from the device, followed
by a packet signalling halt.
While already touching all the devices and controllers handle_packet /
handle_data / handle_control code, also change the return type of
these functions to void, solely storing the status in the packet. To
make the code paths for regular versus async packet handling more
uniform.
This patch unfortunately is somewhat invasive, since makeing the qemu
usb core deal with this requires changes everywhere. This patch only
prepares the usb core for this, all the hcd / device changes are done
in such a way that there are no functional changes.
This patch has been tested with uhci and ehci hcds, together with usb-audio,
usb-hid and usb-storage devices, as well as with usb-redir redirection
with a wide variety of real devices.
Note that there is usually no need to directly set packet->actual_length
form devices handle_data callback, as that is done by usb_packet_copy()
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
My recent uhci cleanup series has introduced a regression, where
qemu sometimes crashes on a device disconnect. The problem is that
the uhci code never checked for a device not / no longer existing, instead
it was relying on usb_handle_packet accepting a NULL device.
But since we now pass usb_handle_packet q->ep->dev, rather then just
a local dev variable, we crash as q->ep == NULL due to the device no longer
existing.
This patch fixes this. Note that this patch also improves over
the old behavior were we would:
1) create a queue for the device
2) create an async for the packet
3) have usb_handle_packet fail
4) destroy the async
5) wait for the queue to be idle for 32 frames
6) destroy the queue
Which was rather sub-optimal.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Kills the ugly "switch (device_id) { ... }" struct and makes it easier
to figure what the differences between the uhci variants are.
Need our own DeviceClass struct for that so we can allocate some space
to store UHCIInfo.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
ctrl endpoints use different pids for different phases of a control
transfer, this patch makes us use only one queue for a ctrl ep, rather
then 3.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
If the guest is using multiple transfers to try and keep the usb bus busy /
used at maximum efficiency, currently we would see / do the following:
1) submit transfer 1 to the device
2) submit transfer 2 to the device
3) report transfer 1 completion to guest
4) report transfer 2 completion to guest
5) submit transfer 1 to the device
6) report transfer 1 completion to guest
7) submit transfer 2 to the device
8) report transfer 2 completion to guest
etc.
So after the initial submission we would effectively only have 1 transfer
in flight, rather then 2. This is caused by us not checking the queue for
addition of new transfers by the guest (ie the resubmission of a recently
finished transfer), while waiting for a pending transfer to complete.
This patch does add a check for this, changing the sequence to:
1) submit transfer 1 to the device
2) submit transfer 2 to the device
3) report transfer 1 completion to guest
4) submit transfer 1 to the device
5) report transfer 2 completion to guest
6) submit transfer 2 to the device
etc.
Thus keeping 2 transfers in flight (most of the time, and always 1),
as intended by the guest.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Before this patch we would not mark a queue valid when its head was a
non-active td. This causes us to misbehave in the following scenario:
1) queue with multiple input transfers queued
2) We hit some latency issue, causing qemu to get behind processing frames
3) When qemu gets to run again, it notices the first transfer ends short,
marking the head td non-active
4) It now processes 32+ frames in a row without giving the guest a chance
to run since it is behind
5) valid is decreased to 0, causing the queue to get cancelled also cancelling
already queued up further input transfers
6) guest gets to run, notices the inactive td, cleanups up further tds
from the short transfer, and lets the queue continue at the first td of
the next input transfer
7) we re-start the queue, issuing the second input transfer for the *second*
time, and any data read by the first time we issued it has been lost
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
A td can be reused by the guest in a different queue, before we notice
the original queue has been unlinked. So search for tds by addr only, detect
guest td reuse, and cancel the original queue, this is necessary to keep our
packet ids unique.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
According to the spec a guest can unlink a qh, and then as soon as frindex
has changed by 1 since the unlink, assume it is idle and re-use it. However
for various reasons, we cannot simply consider a qh as unlinked if we've not
seen it for 1 frame. This means that it is possible for a guest to re-use /
restart the queue while we still see its old state. This patch adds a safety
check for this, and "early" retires queues when they were changed by the guest.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
There is no need to just cancel any in-flight packets, and then wait
for validate-end to clean things up, we can simply clean things up
immediately on device removal.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This avoids the need to repeatedly lookup the device, and ep.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
And move its calling point to handle_td, this removes the ep_ret ugliness,
and prepates the way for further cleanups in the follow-up patches in this
patch-set.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
We use the name td both to refer to a UHCI_TD read from guest memory as
well as to refer to the guest address where a td is stored, switch over
to always use td_addr in the second case for consistency.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Cleanup: all callers of uhci_queue_free first unconditionally cancel
all remaining asyncs in the queue, so lets move this to uhci_queue_free().
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Since we are either dealing with emulated devices, where retrying is
not going to help, or with redirected devices where the host OS will
have already retried, don't bother retrying on failed transfers.
Also move some common/indentical code out of all the error cases
into the generic error path.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
All callers of uhci_async_cancel() call uhci_async_unlink() first, so
lets move the unlink call to uhci_async_cancel()
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
No devices ever return async for isoc endpoints and the core
already enforces this.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
After a short-not-ok packet ending short, we should not advance the queue.
Move enforcing this to the core, rather then handling it in the hcd code.
This may result in the queue now actually containing multiple input packets
(which would not happen before), and this requires special handling in
combination with pipelining, so disable pipleining for input endpoints
(for now).
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
hcds which queue up more then one packet at once (uhci, ehci and xhci),
must clear the queue after an error which has caused the queue to halt.
Currently this is handled as a special case inside the hcd code, this
patch instead adds an USB_RET_REMOVE_FROM_QUEUE packet result code, teaches
the 3 hcds about this and moves the clearing of the queue on a halt into
the USB core.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This can be used by usb-device code which wishes to process an entire endpoint
queue at once, to do this the usb-device code returns USB_RET_ADD_TO_QUEUE
from its handle_data class method and defines a flush_ep_queue class method
to call when the hcd is done queuing up packets.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Rather then having a special check to start queuing after the first packet,
and then another check for the other packets in uhci_fill_queue(), simply
check the previous packet beforehand in uhci_fill_queue()
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Packets with an invalid pid, or which were cancelled have
usb_packet_map() called on them on init, but not usb_packet_unmap()
before being freed.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
According to the spec we must raise an interrupt when one is requested
even for non active tds.
Linux depends on this, for bulk transfers it runs an inactivity timer
to work around a bug in early uhci revisions, when we take longer then
200 ms to process a packet, this timer goes of, and as part of the
handling Linux then unlinks the qh, and relinks it after the frindex
has increased by atleast 1, the problem is Linux only checks for the
frindex increases on an interrupt, and we don't send that, causing
the qh to go inactive for more then 32 frames, at which point we
consider the packet cancelled.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Don't queue up packets after a packet with the SPD (short packet detect)
flag set. Since we won't know if the packet will actually be short until it
has completed, and if it is short we should stop the queue.
This fixes a miniature photoframe emulating a USB cdrom with the windows
software for it not working.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
If an (emulated) usb-device tries to write more data to a packet then
its iov len, this will trigger an assert in usb_packet_copy(), and if
a driver somehow circumvents that check and writes more data to the
iov then there is space, we have a much bigger problem then not correctly
reporting babble to the guest.
In practice babble will only happen with (real) redirected devices, and there
both the usb-host os and the qemu usb-device code already check for it.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This patch adds IDs to usb packets. Those IDs are (a) supposed to be
unique for the lifecycle of a packet (from packet setup until the packet
is either completed or canceled) and (b) stable across migration.
uhci, ohci, ehci and xhci use the guest physical address of the transfer
descriptor for this.
musb needs a different approach because there is no transfer descriptor.
But musb also doesn't support pipelining, so we have never more than one
packet per endpoint in flight. So we go create an ID based on endpoint
and device address.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
For controllers which queue up more then 1 packet at a time, we must halt the
ep queue, and inside the controller code cancel all pending packets on an
error.
There are multiple reasons for this:
1) Guests expect the controllers to halt ep queues on error, so that they
get the opportunity to cancel transfers which the scheduled after the failing
one, before processing continues
2) Not cancelling queued up packets after a failed transfer also messes up
the controller state machine, in the case of EHCI causing the following
assert to trigger: "assert(p->qtdaddr == q->qtdaddr)" at hcd-ehci.c:2075
3) For bulk endpoints with pipelining enabled (redirection to a real USB
device), we must cancel all the transfers after this a failed one so that:
a) If they've completed already, they are not processed further causing more
stalls to be reported, originating from the same failed transfer
b) If still in flight, they are cancelled before the guest does
a clear stall, otherwise the guest and device can loose sync!
Note this patch only touches the ehci and uhci controller changes, since AFAIK
no other controllers actually queue up multiple transfer. If I'm wrong on this
other controllers need to be updated too!
Also note that this patch was heavily tested with the ehci code, where I had
a reproducer for a device causing a transfer to fail. The uhci code is not
tested with actually failing transfers and could do with a thorough review!
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
$subject says all: when loading old (v1) vmstate which doesn't contain
expire_time initialize it with a reasonable default (current time).
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Not a single driver has any possibility of failure on their
exit function, let's keep it that way.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
