Add a simple serial connection driver called
VIRTIO_ID_RPROC_SERIAL (11) for communicating with a
remote processor in an asymmetric multi-processing
configuration.
This implementation reuses the existing virtio_console
implementation, and adds support for DMA allocation
of data buffers and disables use of tty console and
the virtio control queue.
Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Acked-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Refactoring the splice functionality by unifying the approach for
sending scatter-lists and regular buffers. This simplifies
buffer handling and reduces code size. Splice will now allocate
a port_buffer and send_buf() and free_buf() can always be used
for any buffer.
Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Acked-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Free pending output buffers from the virtio out-queue when
host has acknowledged port_close.
Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (rebased & cut down)
Avoid the more cpu expensive kzalloc when allocating buffers.
Originally kzalloc was intended for isolating the guest from
the host by not sending random guest data to the host. But device
isolation is not yet in place so kzalloc is not really needed.
Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Free the allocated scatter list if send_pages fails in function
port_splice_write.
Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If register_virtio_driver() fails, virtio-ports class is not destroyed.
The patch adds error handling of register_virtio_driver().
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Allocate scatterlist according to the current pipe size.
This allows splicing bigger buffer if the pipe size has
been changed by fcntl.
Changes in v2:
- Just a minor fix for avoiding a confliction with previous patch.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Wait if the port is not connected or full on splice
like as write is doing.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Add a failback memcpy path for unstealable pipe buffer.
If buf->ops->steal() fails, virtio-serial tries to
copy the page contents to an allocated page, instead
of just failing splice().
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Enable to use splice_write from pipe to virtio-console port.
This steals pages from pipe and directly send it to host.
Note that this may accelerate only the guest to host path.
Changes in v2:
- Use GFP_KERNEL instead of GFP_ATOMIC in syscall context function.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If a port was open before going into one of the sleep states, the port
can continue normal operation after restore. However, the host has to
be told that the guest side of the connection is open to restore
pre-suspend state.
This wasn't noticed so far due to a bug in qemu that was fixed recently
(which marked the guest-side connection as always open).
CC: stable@vger.kernel.org # Only for 3.3
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Many users of debugfs copy the implementation of default_open() when
they want to support a custom read/write function op. This leads to a
proliferation of the default_open() implementation across the entire
tree.
Now that the common implementation has been consolidated into libfs we
can replace all the users of this function with simple_open().
This replacement was done with the following semantic patch:
<smpl>
@ open @
identifier open_f != simple_open;
identifier i, f;
@@
-int open_f(struct inode *i, struct file *f)
-{
(
-if (i->i_private)
-f->private_data = i->i_private;
|
-f->private_data = i->i_private;
)
-return 0;
-}
@ has_open depends on open @
identifier fops;
identifier open.open_f;
@@
struct file_operations fops = {
...
-.open = open_f,
+.open = simple_open,
...
};
</smpl>
[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To ensure we don't receive any more interrupts from the host after we
enter the freeze function, disable all vq interrupts.
There wasn't any problem seen due to this in tests, but applying this
patch makes the freeze case more robust.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Remove all vqs and associated buffers in the freeze callback which
prepares us to go into hibernation state. On restore, re-create all the
vqs and populate the input vqs with buffers to get to the pre-hibernate
state.
Note: Any outstanding unconsumed buffers are discarded; which means
there's a possibility of data loss in case the host or the guest didn't
consume any data already present in the vqs. This can be addressed in a
later patch series, perhaps in virtio common code.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This common code will be shared with the PM freeze function.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Remove wrapper functions. This makes the allocation type explicit in
all callers; I used GPF_KERNEL where it seemed obvious, left it at
GFP_ATOMIC otherwise.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Christoph Hellwig <hch@lst.de>
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
Revert "tracing: Include module.h in define_trace.h"
irq: don't put module.h into irq.h for tracking irqgen modules.
bluetooth: macroize two small inlines to avoid module.h
ip_vs.h: fix implicit use of module_get/module_put from module.h
nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
include: replace linux/module.h with "struct module" wherever possible
include: convert various register fcns to macros to avoid include chaining
crypto.h: remove unused crypto_tfm_alg_modname() inline
uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
pm_runtime.h: explicitly requires notifier.h
linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
miscdevice.h: fix up implicit use of lists and types
stop_machine.h: fix implicit use of smp.h for smp_processor_id
of: fix implicit use of errno.h in include/linux/of.h
of_platform.h: delete needless include <linux/module.h>
acpi: remove module.h include from platform/aclinux.h
miscdevice.h: delete unnecessary inclusion of module.h
device_cgroup.h: delete needless include <linux/module.h>
net: sch_generic remove redundant use of <linux/module.h>
net: inet_timewait_sock doesnt need <linux/module.h>
...
Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in
- drivers/media/dvb/frontends/dibx000_common.c
- drivers/media/video/{mt9m111.c,ov6650.c}
- drivers/mfd/ab3550-core.c
- include/linux/dmaengine.h
On s390 I have seen some random
"Warning: unable to open an initial console"
boot failure. Turns out that tty_open fails, because the
hvc_alloc was not yet done. In former times this could not happen,
since the probe function automatically called hvc_alloc. With newer
versions (multiport) some host<->guest interaction is required
before hvc_alloc is called. This might be too late, especially if
an initramfs is involved. Lets use a completion if we have
multiport and an early console.
[Amit:
* Use NULL instead of 0 for pointer comparison
* Rename 'port_added' to 'early_console_added'
* Re-format, re-word commit message
* Rebase patch on top of current queue]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Acked-by: Chrstian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit adds port-specific stats for the number of bytes received,
sent and discarded. They're exposed via the debugfs interface. This
data can be used to check for data loss bugs (or disprove such claims).
It can also be used for accounting, if there's such a need.
The stats remain valid throughout the lifetime of the port. Unplugging
a port will reset the stats. The numbers are not reset across port
opens/closes.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
discard_port_data() used virtqueue_get_buf() directly instead of using
get_inbuf(). Fix this, so that we get accounting for all received
bytes. This also simplifies the code a lot.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Instead of pulling in a buffer from the vq each time it's called,
get_inbuf() now checks if the current active buffer, in port->inbuf is
valid. If it is, just returns a pointer to it. This ends up
simplifying a lot of code calling get_inbuf() since the check for
port->inbuf being valid was done by all the callers.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
get_inbuf() returns void *. There's no reason to return void pointers
instead of the correct struct port_buffer *.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Get ready to support suspend/resume by using the freezable calls so that
blocking read/write syscalls are handled properly across suspend/resume.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We don't allow port name changes dynamically for a port. So any
requests by the host to change the name are ignored.
Before this patch, if the hypervisor sent a port name while we had one
set already, we would leak memory equivalent to the size of the old
name.
This scenario wasn't expected so far, but with the suspend-resume
support, we'll send the VIRTIO_CONSOLE_PORT_READY message after restore,
which can get us into this situation.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Convert spaces to tabs and fix indentation for an if statement split
into multiple lines.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This patch modifies virtio-console to use virtio_config_val() instead
of a 'if(virtio_has_feature()) vdev->config->get()' construct to retrieve
optional values from the config space.
Cc: Amit Shah <amit.shah@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
A pending cleanup will mean that module.h won't be implicitly
everywhere anymore. Make sure the modular drivers in char are
actually calling out for <module.h> explicitly in advance.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
That's already been done by the virtio infrastructure before the probe
function is called.
Reported-by: alexey.kardashevskiy@au1.ibm.com
Acked-by: Amit Shah <amit.shah@redhat.com>
Tested-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This call was disabled as hot-unplugging one virtconsole port led to
another virtconsole port freezing.
Upon testing it again, this now works, so enable it.
In addition, a bug was found in qemu wherein removing a port of one type
caused the guest output from another port to stop working. I doubt it
was just this bug that caused it (since disabling the hvc_remove() call
did allow other ports to continue working), but since it's all solved
now, we're fine with hot-unplugging of virtconsole ports.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If a virtio-console device gets unplugged while a port is open, a
subsequent close() call on the port accesses vqs to free up buffers.
This can lead to a crash.
The buffers are already freed up as a result of the call to
unplug_ports() from virtcons_remove(). The fix is to simply not access
vq information if port->portdev is NULL.
Reported-by: juzhang <juzhang@redhat.com>
CC: stable@kernel.org
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6:
serial: bfin_5xx: split uart RX lock from uart port lock to avoid deadlock
68360serial: Plumb in rs_360_get_icount()
n_gsm: copy mtu over when configuring via ioctl interface
virtio: console: Move file back to drivers/char/
Commit 728674a7e4 moved virtio_console.c
to drivers/tty/hvc/ under the perception of this being an hvc driver.
It was such once, but these days it has generic communication
capabilities as well, so move it to drivers/char/.
In the future, the hvc part from this file can be split off and moved
under drivers/tty/hvc/.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
CC: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
As requested by Arnd Bergmann, the hvc drivers are now
moved to the drivers/tty/hvc/ directory. The virtio_console.c driver
was also moved, as it required the hvc_console.h file to be able to be
built, and it really is a hvc driver.
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Stanse found that in init_vqs, memory is leaked under certain
circumstanses (the fail path order is incorrect). Fix that by checking
allocations in one turn and free all of them at once if some fails
(some may be NULL, but this is OK).
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Amit Shah <amit.shah@redhat.com>
Cc: virtualization@lists.linux-foundation.org
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The ports are char devices; do not have seeking capabilities. Calling
nonseekable_open() from the fops_open() call and setting the llseek fops
pointer to no_llseek ensures an lseek() call from userspace returns
-ESPIPE.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
CC: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If a port has registered for SIGIO signals, let the application
know that the port is getting unplugged.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Send a SIGIO signal when new data arrives on a port. This is sent only
when the process has requested for the signal to be sent using fcntl().
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
A process can request for SIGIO on host connect / disconnect events
using the O_ASYNC file flag using fcntl().
If that's requested, and if the guest-side connection for the port is
open, any host-side open/close events for that port will raise a SIGIO.
The process can then use poll() within the signal handler to find out
which port triggered the signal.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Explain in a comment why there's no need to reference-count the portdev
struct: when a device is yanked out, we can't do anything more with it
anyway so just give up doing anything more with the data or the vqs and
exit cleanly.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When a port got hot-unplugged, when a port was open, any file operation
after the unplugging resulted in a crash. This is fixed by ref-counting
the port structure, and releasing it only when the file is closed.
This splits the unplug operation in two parts: first marks the port
as unavailable, removes all the buffers in the vqs and removes the port
from the per-device list of ports. The second stage, invoked when all
references drop to zero, releases the chardev and frees all other memory.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This moves to using cdev on the heap instead of it being embedded in the
ports struct. This helps individual refcounting and will allow us to
properly remove cdev structs after hot-unplugs and close operations.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
To convert to using cdev as a pointer to avoid kref troubles, we have to
use a different method to get to a port from an inode than the current
container_of method.
Add find_port_by_devt() that looks up all portdevs and ports with those
portdevs to find the right port.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The virtio_console.c driver is capable of handling multiple devices at a
time. Maintain a list of devices for future traversal.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When a port is removed, we have to assume the port is gone. So a
success/failure return value doesn't make sense.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When a port is hot-unplugged while an app was blocked on a write() call,
the call was unblocked but would not get an error returned.
Return -ENODEV to ensure the app knows the port has gone away.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When a port is hot-unplugged while an app was blocked on a read() call,
the call was unblocked but would not get an error returned.
Return -ENODEV to ensure the app knows the port has gone away.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When a port is hot-unplugged while an app is blocked on poll(), unblock
the poll() and return.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If a chardev is closed, any blocked read / poll calls should just return
and not attempt to use other state.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
A portdev may have been hot-unplugged while a port was open()ed. Skip
sending control messages when the portdev isn't valid.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If a portdev isn't using multiport support, it won't have any control vq
data to remove.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The virtqueues should be disabled before attempting to remove the
device.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If the host is slow in reading data or doesn't read data at all,
blocking write calls not only blocked the program that called write()
but the entire guest itself.
To overcome this, let's not block till the host signals it has given
back the virtio ring element we passed it. Instead, send the buffer to
the host and return to userspace. This operation then becomes similar
to how non-blocking writes work, so let's use the existing code for this
path as well.
This code change also ensures blocking write calls do get blocked if
there's not enough room in the virtio ring as well as they don't return
-EAGAIN to userspace.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
CC: stable@kernel.org
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A userspace could submit a buffer with 0 length to be written to the
host. Prevent such a situation.
This was not needed previously, but recent changes in the way write()
works exposed this condition to trigger a virtqueue event to the host,
causing a NULL buffer to be sent across.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
CC: stable@kernel.org
I found this while working on a Linux agent for spice, the symptom I was
seeing was select blocking on the spice vdagent virtio serial port even
though there were messages queued up there.
virtio_console's port_fops_poll checks port->inbuf != NULL to determine
if read won't block. However if an application reads enough bytes from
inbuf through port_fops_read, to empty the current port->inbuf,
port->inbuf will be NULL even though there may be buffers left in the
virtqueue.
This causes poll() to block even though there is data to be read,
this patch fixes this by using will_read_block(port) instead of the
port->inbuf != NULL check.
Signed-off-By: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
When a program that has a virtio port opened and blocked for a write
operation, a port hot-unplug event will later led to a crash when
SIGTERM was sent to the program. Fix that.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When removing a port we don't check if a program was blocked for read.
This leads to a crash when SIGTERM is sent to the program after
hot-unplugging the port.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
In each case, the first argument to send_control_msg or __send_control_msg,
respectively, has either not been successfully allocated or has been freed
at the point of the call. In the first case, the first argument, port, is
only used to access the portdev and id fields, in order to call
__send_control_msg. Thus it seems possible instead to call
__send_control_msg directly. In the second case, the call to
__send_control_msg is moved up to a place where it seems like the first
argument, portdev, has been initialized sufficiently to make the call to
__send_control_msg meaningful.
This has only been compile tested.
A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@free@
expression E;
position p;
@@
kfree@p(E)
@@
expression free.E, subE<=free.E, E1;
position free.p;
@@
kfree@p(E)
...
(
subE = E1
|
* E
)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The VIRTIO_CONSOLE_RESIZE control message sent to us by the host now
contains the new {rows, cols} values for the console. This ensures each
console port gets its own size, and we don't depend on the config-space
rows and cols values at all now.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
CC: Christian Borntraeger <borntraeger@de.ibm.com>
CC: linuxppc-dev@ozlabs.org
CC: Kusanagi Kouichi <slash@ac.auone-net.jp>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
With support for multiple consoles, just using one {rows,cols} pair in
the config space is not going to suffice.
Store each console's size as part of the console struct.
This changes the behaviour for one case when multiport is not enabled:
when notifier_add_vio() is called, the console size is taken from that
of the last config-space update instead of fetching it afresh from the
config space.
Also add a helper to update the size in the console struct as we'll need
to use the same code to update the size via control messages when
multiport support is enabled.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
CC: Christian Borntraeger <borntraeger@de.ibm.com>
CC: linuxppc-dev@ozlabs.org
CC: Kusanagi Kouichi <slash@ac.auone-net.jp>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When using multiport, we'll use control messages. Ensure we don't
accidentally update port 0 size on config interrupts.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
CC: Christian Borntraeger <borntraeger@de.ibm.com>
CC: linuxppc-dev@ozlabs.org
CC: Kusanagi Kouichi <slash@ac.auone-net.jp>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If the host port is not open, a write() should either just return if the
file is opened in non-blocking mode, or block till the host port is
opened.
Also, don't spin till host consumes data for nonblocking ports. For
non-blocking ports, we can do away with the spinning and reclaim the
buffers consumed by the host on the next write call or on the condition
that'll make poll return.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We'll introduce a function that checks if write will block. Have
function names that are similar for the two cases.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If we're using multiport, there's no point in always creating a console
port. Create the console port only if the host doesn't support
multiport.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Instead of the host and guest independently enumerating ports, switch to
a control message to add ports where the host supplies the port number
so there's no ambiguity or a possibility of a race between the host and
the guest port numbers.
We now no longer need the 'nr_ports' config value. Since no kernel has
been released with the MULTIPORT changes yet, we have a chance to fiddle
with the config space without adding compatibility features.
This is beneficial for management software, which would now be able to
instantiate ports at known locations and avoid problems that arise with
implicit numbering in the host and the guest. This removes the 'guessing
game' part of it, and management software can now actually indicate
which id to spawn a particular port on.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We're going to use add_port() from handle_control_message() in the next
patch.
Move the add_port() and fill_queue(), which depends on it, above
handle_control_message() to avoid forward declarations.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We're going to switch to using control messages for port hot-plug and
initial port discovery. Remove the config work handler which handled
port hot-plug so far.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
hvc_remove() has some bug which freezes other active hvc ports when one
port is removed.
So disable calling of hvc_remove() which deregisters a port with the
hvc_console.
If the hvc_console code calls into our get_chars() routine as a result
of a poll operation, we will return -EPIPE and the hvc_console code will
then do the necessary cleanup.
This call will be restored when the bug in hvc_remove() is found and
fixed.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
hvc_console handles -EPIPE properly when the connection to the host is
lost.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The host may want to know and let management apps notify of port or
device add failures. Send a control message saying the device or port is
not ready in this case.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We will introduce control messages that operate on the device as a whole
rather than just ports. Make send_control_msg() a wrapper around
__send_control_msg() which does not need a valid port.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This reverts commit b7a413015d.
Multiport support was disabled for 2.6.34 because we wanted to introduce
a new ABI and since we didn't have any released kernel with the older
ABI and were out of the merge window, it didn't make sense keeping the
older ABI around.
Now we revert the patch disabling multiport and rework the ABI in the
following patches.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Switch virtio_console to new virtqueue_xxx wrappers.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Move MULTIPORT feature and related config changes
out of exported headers, and disable the feature
at runtime.
At this point, it seems less risky to keep code around
until we can enable it than rip it out completely.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The get_buf() API sets the second arg to the number of bytes *written*
by the other side; in this case it should be zero as these are output buffers.
lguest gets this right (obviously kvm's console doesn't), resulting in
continual buildup of console writes.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Amit Shah <amit.shah@redhat.com>
Currently early_put_chars is not used by virtio_console because it can
only be used once a port has been found, at which point it's too late
because it is no longer needed. This patch should fix it.
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
The console port could have been hot-unplugged. Check if it is valid
before working on it.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
When the host lets us know what 'name' a port is assigned, we create the
sysfs 'name' attribute. Generate a 'change' event after this so that
udev wakes up and acts on the rules for virtio-ports (currently there's
only one rule that creates a symlink from the 'name' to the actual char
device).
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
We want to keep track of the number of buffers added to a vq. Use
nr_added_bufs instead of 'ret'.
Also, the users of fill_queue() overloaded a local 'err' variable to
check the numbers of buffers allocated. Use nr_added_bufs instead of
err.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Reported-by: Juan Quintela <quintela@redhat.com>
We declare 'len' as int type but it should be 'unsigned int', as
get_buf() wants it to be.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Reported-by: Juan Quintela <quintela@redhat.com>
Instead of allocating just one buffer for a port's in_vq, fill
the entire in_vq with buffers so the host need not stall while
an application consumes the data and makes the buffer available
again for the host.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
With MULTIPORT support, the control queue is an integral part of the
functioning of the device. If we can't get any buffers allocated, the
host won't be able to relay important information and the device may not
function as intended.
Ensure 'probe' doesn't succeed until the control queue has at least one
buffer allocated for its ivq.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Add the ability to remove the virtio_console module.
This aids debugging.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If unused data exists in in_vq, ensure we flush that first and then
detach unused buffers, which will ensure all buffers from the in_vq are
removed.
Also ensure we free the buffers after detaching them.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Remove port data; deregister from the hvc core if it's a console port.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If the 'nr_ports' variable in the config space is updated to a higher
value, that means new ports have been hotplugged.
Introduce a new workqueue to handle such updates and create new ports.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Remove any data that we might have in a port's inbuf when closing a port
or when any data is received when a port is closed.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The host can set a name for ports so that they're easily discoverable
instead of going by the /dev/vportNpn naming. This attribute will be
placed in /sys/class/virtio-ports/vportNpn/name. udev scripts can then
create symlinks to the port using the name.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Add a guest_connected field that ensures only one process
can have a port open at a time.
This also ensures we don't have a race when we later add support for
dropping buffers when closing the char dev and buffer caching is turned
off for the particular port.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Allow guest userspace applications to open, read from, write to, poll
the ports via the char dev interface.
When a port gets opened, a notification is sent to the host via a
control message indicating a connection has been established. Similarly,
on closing of the port, a notification is sent indicating disconnection.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The char device will be used as an interface by applications on the
guest to communicate with apps on the host.
The devices created are placed in /dev/vportNpn where N is the
virtio-console device number and n is the port number for that device.
One dynamic major device number is allocated for each device and minor
numbers are allocated for the ports contained within that device.
The file operation for the char devs will be added in the following
commits.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When ports get advertised as char devices, the buffers will come from
userspace. Equip the fill_readbuf function with the ability to write
to userspace buffers.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit adds a new feature, MULTIPORT. If the host supports this
feature as well, the config space has the number of ports defined for
that device. New ports are spawned according to this information.
The config space also has the maximum number of ports that can be
spawned for a particular device. This is useful in initializing the
appropriate number of virtqueues in advance, as ports might be
hot-plugged in later.
Using this feature, generic ports can be created which are not tied to
hvc consoles.
We also open up a private channel between the host and the guest via
which some "control" messages are exchanged for the ports, like whether
the port being spawned is a console port, resizing the console window,
etc.
Next commits will add support for hotplugging and presenting char
devices in /dev/ for bi-directional guest-host communication.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
