i8254: Factor out base class for KVM reuse

Applying the concept used for the *PICs once again: establish a base
class for the i8254 that can be used both by the current user space
emulation and the upcoming KVM in-kernel version. We share most of the
public interface of the i8254, specifically to the pcspk, vmstate, reset
and certain init parts.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
i8254: Open-code timer restore

Same as for the APIC: To enable migration between accelerated and
non-accelerated models, we need to arm the channel 0 timer only inside
the emulated PIT model. The common code just saves/restores that timer
to the the next_transition_time field.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
kvm: Add kvm_has_pit_state2 helper

To be used for in-kernel PIT emulation.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
kvm: x86: Add user space part for in-kernel i8254

This provides the required user space stubs to enable the in-kernel
i8254 emulation of KVM.

The in-kernel model supports lost tick compensation according to the
"delay" policy. This is enabled by default and can be switched off via a
device property.

Depending on the feature set of the host kernel (before 2.6.32), we may
have to disable the HPET or lack sound output from the PC speaker.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
kvm: fill in padding to help valgrind

valgrind warns about padding fields which are passed
to vcpu ioctls uninitialized.
This is not an error in practice because kvm ignored padding.
Since the ioctls in question are off data path and
the cost is zero anyway, initialize padding to 0
to suppress these errors.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
usb-redir: Set ep type and interface

Since we don't use usb_desc.c we need to do this ourselves. This fixes
iso transfers no longer working for USB 2 devices due to the ep->type
check in ehci.c

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
usb-ehci: Never follow table entries with the T-bit set

Before this patch the T-bit was not checked in 2 places, while it should be.

Once we properly check the T-bit everywhere we no longer need the weird
entry < 0x1000 and entry > 0x1000 checks, so this patch removes them.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
usb-ehci: split our qh queue into async and periodic queues

qhs can be part of both the async and the periodic schedule, as is shown
in later patches in this series it is useful to keep track of the qhs on
a per schedule basis.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
usb-ehci: always call ehci_queues_rip_unused for period queues

Before this patch USB 2 devices with interrupt endpoints were not working
properly. The problem is that to avoid loops we stop processing as soon
as we encounter a queue-head (qh) we've already seen since qhs can be linked
in a circular fashion, this is tracked by the seen flag in our qh struct.

The resetting of the seen flag is done from ehci_queues_rip_unused which
before this patch was only called when executing the statemachine for the
async schedule.

But packets for interrupt endpoints are part of the periodic schedule! So what
would happen is that when there were no ctrl or bulk packets for a USB 2
device with an interrupt endpoint, the async schedule would become non
active, then ehci_queues_rip_unused would no longer get called and when
processing the qhs for the interrupt endpoints from the periodic schedule
their seen bit would still be 1 and they would be skipped.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
usb-ehci: Drop cached qhs when the doorbell gets rung

The purpose of the IAAD bit / the doorbell is to make the ehci controller
forget about cached qhs, this is mainly used when cancelling transactions,
the qh is unlinked from the async schedule and then the doorbell gets rung,
once the doorbell is acked by the controller the hcd knows that the qh is
no longer in use and that it can do something else with the memory, such
as re-use it for a new qh! But we keep our struct representing this qh around
for circa 250 ms. This allows for a (mightily large) race window where the
following could happen:
-hcd submits a qh at address 0xdeadbeef
-our ehci code sees the qh, sends a request to a usb-device, gets a result
 of USB_RET_ASYNC, sets the async_state of the qh to EHCI_ASYNC_INFLIGHT
-hcd unlinks the qh at address 0xdeadbeef
-hcd rings the doorbell, wait for us to ack it
-hcd re-uses the qh at address 0xdeadbeef
-our ehci code sees the qh, looks in the async_queue, sees there already is
 a qh at address 0xdeadbeef there with async_state of EHCI_ASYNC_INFLIGHT,
 does nothing
-the *original* (which the hcd thinks it has cancelled) transaction finishes
-our ehci code sees the qh on yet another pass through the async list,
 looks in the async_queue, sees there already is a qh at address 0xdeadbeef
 there with async_state of EHCI_ASYNC_COMPLETED, and finished the transaction
 with the results of the *original* transaction.

Not good (tm), this patch fixes this race by removing all qhs which have not
been seen during the last cycle through the async list immidiately when the
doorbell is rung.

Note this patch does not fix any actually observed problem, but upon
reading of the EHCI spec it became apparent to me that the above race could
happen and the usb-ehci behavior from before this patch is not good.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
usb-ehci: Rip the queues when the async or period schedule is halted

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
usb-ehci: Any packet completion except for NAK should set the interrupt

As clearly stated in the 2.3.2 of the EHCI spec, any time USBERRINT get
sets then if the td has its IOC bit set USBINT should be set as well.

This means that for any status except for USB_RET_NAK we should set
USBINT if the IOC bit is set.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
usb-ehci: Fix cerr tracking

cerr should only be decremented on errors which cause XactErr to be set, and
when that happens the failing transaction should be retried until cerr reaches
0 and only then should USBSTS_ERRINT be set (and inactive cleared and
USBSTS_INT set if requested).

Since we don't have any hardware level errors (and in case of redirection
the real hardware has already retried), re-trying makes no sense, so
immediately set cerr to 0 on errors which set XactErr.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
usb-ehci: Remove dead nakcnt code

This patch removes 2 bits of dead nakcnt code:

1) usb_ehci_execute calls ehci_qh_do_overlay which does:
nakcnt = reload;
and then has a block of code which is conditional on:
if (reload && !nakcnt) {
which ofcourse is never true now as nakcnt == reload.

2) ehci_state_fetchqh does:
nakcnt = reload;
but before nakcnt is ever used ehci_state_fetchqh is always followed
by a ehci_qh_do_overlay call which also does:
nakcnt = reload;
So doing this from ehci_state_fetchqh is redundant.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
usb-ehci: Fix and simplify nakcnt handling

The nakcnt code in ehci_execute_complete() marked transactions as finished
when a packet completed with a result of USB_RET_NAK, but USB_RET_NAK
means that the device cannot receive / send data at that time and that
the transaction should be retried later, which is also what the usb-uhci
and usb-ohci code does.

Note that there already was some special code in place to handle this
for interrupt endpoints in the form of doing a return from
ehci_execute_complete() when reload == 0, but that for bulk transactions
this was not handled correctly (where as for example the usb-ccid device does
return USB_RET_NAK for bulk packets).

Besides that the code in ehci_execute_complete() decrement nakcnt by 1
on a packet result of USB_RET_NAK, but
-since the transaction got marked as finished,
 nakcnt would never be decremented again
-there is no code checking for nakcnt becoming 0
-there is no use in re-trying the transaction within the same usb frame /
 usb-ehci frame-timer call, since the status of emulated devices won't change
 as long as the usb-ehci frame-timer is running
So we should simply set the nakcnt to 0 when we get a USB_RET_NAK, thus
claiming that we've tried reload times (or as many times as possible if
reload is 0).

Besides the code in ehci_execute_complete() handling USB_RET_NAK there
was also code handling it in ehci_state_executing(), which calls
ehci_execute_complete(), and then does its own handling on top of the handling
in ehci_execute_complete(), this code would decrement nakcnt *again* (if not
already 0), or restore the reload value (which was never changed) on success.

Since the double decrement was wrong to begin with, and is no longer needed
now that we set nakcnt directly to 0 on USB_RET_NAK, and the restore of reload
is not needed either, this patch simply removes all nakcnt handling from
ehci_state_executing().

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
usb-ehci: Cleanup itd error handling

All error statuses except for NAK are handled in a switch case, move the
handling of NAK into the same switch case.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
usb: return BABBLE rather then NAK when we receive too much data

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
usb: add USB_RET_IOERROR

We already have USB_RET_NAK, but that means that a device does not want
to send/receive right now. But with host / network redirection we can
actually have a transaction fail due to some io error, rather then ie
the device just not having any data atm.

This patch adds a new error code named USB_RET_IOERROR for this, and uses
it were appropriate.

Notes:
-Currently all usb-controllers handle this the same as NODEV, but that
 may change in the future, OHCI could indicate a CRC error instead for example.
-This patch does not touch hw/usb-musb.c, that is because the code in there
 handles STALL and NAK specially and has a if status < 0 generic catch all
 for all other errors

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
uhci_fill_queue: zap debug printf
usb: queue can have async packets

This can happen today in case the ->complete() callback queues up the
next packet.  Also we'll support pipelining soon, which allows to have
multiple packets per queue in flight (aka ASYNC) state.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>