bdrv_open contains quite some code that is only useful for opening images (as
opposed to opening files by a protocol), for example snapshots.

This patch splits the code so that we have bdrv_open_file() for files (uses
protocols), bdrv_open() for images (uses format drivers) and bdrv_open_common()
for the code common for opening both images and files.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

We're running into various problems because the "raw" file access, which
is used internally by the various image formats is entangled with the
"raw" image format, which maps the VM view 1:1 to a file system.

This patch renames the raw file backends to the file protocol which
is treated like other protocols (e.g. nbd and http) and adds a new
"raw" image format which is just a wrapper around calls to the underlying
protocol.

The patch is surprisingly simple, besides changing the probing logical
in block.c to only look for image formats when using bdrv_open and
renaming of the old raw protocols to file there's almost nothing in there.

For creating images, a new bdrv_create_file is introduced which guesses the
protocol to use. This allows using qemu-img create -f raw (or just using the
default) for both files and host devices. Converting the other format drivers
to use this function to create their images is left for later patches.

The only issues still open are in the handling of the host devices.
Firstly in current qemu we can specifiy the host* format names
on various command line acceping images, but the new code can't
do that without adding some translation.  Second the layering breaks
the no_zero_init flag in the BlockDriver used by qemu-img.  I'm not
happy how this is done per-driver instead of per-state so I'll
prepare a separate patch to clean this up.

There's some more cleanup opportunity after this patch, e.g. using
separate lists and registration functions for image formats vs
protocols and maybe even host drivers, but this can be done at a
later stage.

Also there's a check for protocol in bdrv_open for the BDRV_O_SNAPSHOT
case that I don't quite understand, but which I fear won't work as
expected - possibly even before this patch.

Note that this patch requires various recent block patches from Kevin
and me, which should all be in his block queue.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

1) Qemu is not only a PC emulator.
2) "image image" has already been changed to "disk image" in qemu-doc.texi
Signed-off-by: NThomas Monjalon <thomas@monjalon.net>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

MAX_OPC_PARAM is intended to refer to the maximum number of entries used
in gen_opparam_buf[] for any single helper call.  It is currently defined
as 10, but for 32-bit archs, the correct value (with a maximum for four
helper arguments) is 14, and for 64-bit archs, only 9 entries are needed.

tcg_gen_callN() fills four entries with the function address, flags,
number of args, etc. and on 32-bit archs uses a further two entries per
argument (with a maximum of four helper arguments), plus two more for the
return value.  On 64-bit archs, only half as many entries are used for the
args and the return value.

In reality, TBs tend not to consist purely of helper calls exceeding the
stated 10 gen_opparam_buf[] entries, so this would never actually be a
problem on 32-bit archs, but the definition is still rather confusing.
Signed-off-by: NStuart Brady <sdb@zubnet.me.uk>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

We cannot install different opaque pointer for read and write
of the same i/o address.

- handle zero address in bmdma_writeb_common and install
  the same opaque pointer for both read and write access.
Signed-off-by: NIgor V. Kovalenko <igor.v.kovalenko@gmail.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

Instead of doing tricks to get the pci_dev, just pass it in the 1st
place.  Patch is a bit longer that reverting the pci_dev field, but it
states more clearly (IMHO) what we are doing.

It also fixes the bm test, now that you told me that ->unit is not
always valid.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NIgor V. Kovalenko <igor.v.kovalenko@gmail.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

Individual ports can now signal to the virtio-serial core to stop
sending data if the ports cannot immediately handle new data.  When a
port later unthrottles, any data queued up in the virtqueue are sent to
the port.

Disable throttling once a port is closed (and we discard all the
unconsumed buffers in the vq).

The guest kernel can reclaim the buffers when it receives the port close
event or when a port is being removed. Ensure we free up the buffers
before we send out any events to the guest.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Before the earlier patch, we relied on incorrect virtio api usage to
signal to the guest that a particular buffer wasn't consumed by the
host.

After fixing that, we now just discard the data the guest sends us while
a host port is disconnected or doesn't have a handler registered for
consuming data.

This commit really doesn't change anything from the current behaviour,
just makes the code slightly better by spinning off data handling to
ports in another function.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

We cannot indicate to the guest how much data was consumed by an app for
out_bufs.  So we just have to assume the apps will consume all the data
that are handed over to them.

Fix the virtio api abuse in control_out() and handle_output().
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Current guests don't send more than one iov but it can change later.
Ensure we handle that case.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
CC: Avi Kivity <avi@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Current control messages are small enough to not be split into multiple
buffers but we could run into such a situation in the future or a
malicious guest could cause such a situation.

So handle the entire iov request for control messages.

Also ensure the size of the control request is >= what we expect
otherwise we risk accessing memory that we don't own.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
CC: Avi Kivity <avi@redhat.com>
Reported-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

iov_to_buf() puts the buffer contents in the iov in a linearized buffer.

iov_size() gets the length of the contents in the iov.

The iov_to_buf() function is the memcpy_to_iovec() function that was
used in virtio-ballon.c.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

The virtio-net code uses iov_fill() which fills an iov from a linear
buffer. The virtio-serial-bus code does something similar in an
open-coded function.

Create a new iov.c file that has iov_from_buf().

Convert virtio-net and virtio-serial-bus over to use this functionality.
virtio-net used ints to hold sizes, the new function is going to use
size_t types.

Later commits will add the opposite functionality -- going from an iov
to a linear buffer.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Data should be written only when ports are open.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

If adding of ports or devices in the guest fails we can send out a QMP
event so that management software can deal with it.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

The check for a 0-sized write request to a guest port is not necessary;
the while loop below won't be executed in this case and all will be
fine.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

The virtio-serial code doesn't mix declarations and definitions, so
separate them out on different lines.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Allow the port 'id's to be set by a user on the command line. This is
needed by management apps that will want a stable port numbering scheme
for hot-plug/unplug and migration.

Since the port numbers are shared with the guest (to identify ports in
control messages), we just send a control message to the guest
indicating addition of new ports (hot-plug) or notifying the guest of
the available ports when the guest sends us a DEVICE_READY control
message.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

If the host connection to a port is closed on the destination machine
after migration, whereas the connection was open on the source, the
guest has to be informed of that.

Similar for a host connection open on the destination.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

If some ports that were hot-plugged on the source are not available on
the destination, fail migration instead of trying to deref a NULL
pointer.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Reported-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

The number of ports on the source as well as the destination machines
should match. If they don't, it means some ports that got hotplugged on
the source aren't instantiated on the destination. Or that ports that
were hot-unplugged on the source are created on the destination.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Reported-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

The target could be started with max_nr_ports for a virtio-serial device
lesser than what was available on the source machine. Fail the migration
in such a case.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Reported-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Using GCC-4.2.4-1ubuntu4, there is a warning:
	microblaze-dis.c:792: warning: unused variable 'fprintf'

Indeed, fprintf() is shadowed by a custom redefinition but is not used because
of FORTIFY_SOURCE option which replace calls to fprintf() by fprintf_chk().
So, fprintf refers to the libc implementation instead of the qemu one.
It's a bug.

It is fixed by renaming the variable to something different of "fprintf".
It prevents from hazardous shadowing.
Signed-off-by: NThomas Monjalon <thomas@monjalon.net>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

Signed-off-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

A minimal implementation that more or less corresponds to the
user-level version used by target-i386.  More hoops will want
to be jumped through when alpha gets system-level emulation.
Signed-off-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Use an exception plus start_exclusive to implement the compare-and-swap.
This follows the example set by the MIPS and PPC ports.
Signed-off-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

When (indirectly) calling raise_exception, don't emit cleanup
code at the end of the TB, as it is unused.
Signed-off-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Signed-off-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Signed-off-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Use an ExitStatus enumeration instead of magic numbers as the return
value from translate_one.  Emit goto_tb opcodes when ending a TB via
a direct branch.
Signed-off-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

It's a simple shift and mask sequence.
Signed-off-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

This is a per-cpu flag; there's no need for a spinlock of any kind.

We were also failing to manipulate the flag with $31 as a target reg
and failing to clear the flag on execution of a return-from-interrupt
instruction.
Signed-off-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Signed-off-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

If there is already a fd in s->msgfd before recvmsg it is
closed by parts that this patch does not touch.  So, only
one descriptor can be "leaked" by attaching it to a command
other than getfd.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

So far a multiplexed monitor started disabled. Restore this property for
the new way of configuring by moving the monitor initialization before
all devices (the last one to attach to a char-mux will gain the focus).

Once we have a real use case for that, we may also consider assigning
the initial focus explicitly.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

Canonicalize the ID assignment when creating monitor devices via the
legacy switch and use less easily colliding names.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>