Amit Shah
2009-Dec-22 14:34 UTC
[PATCH 00/31] virtio: console: Fixes, multiple devices and generic ports
Hey Rusty,
This series adds support for generic ports with each port getting two
vqs: one for input and one for output. The host notifies us via the
config space of the max. number of ports that can be added for a
particular device.
As a result of that change, the buffer management for find_readbufs
and send_bufs is moved to the vqs. Only one outbuf per port is used
so we bide away some time in the send_buf routine if output data spans
multiple pages.
There are a few things which aren't done, they can be built upon this
series once it's accepted. One of them is maintaining a list of the
pages that are fed into the virtqueues. This list will be needed when
those buffers have to be freed.
I've passed each patch through an automated test suite that tests for
all the functionality here (caching, throttling, hotplug, hot-unplug,
console IO) twice: once with a qemu that supports this functionality
and once without, to test for backward compat. It all works fine.
The testsuite tests for:
* the 'name' attribute and the symlinks that get created via udev
scripts in /dev/virtio-ports
* caching
* throttling
* console - with running 'find /' in the guest
* open/close of chardevs
* read/write/poll
* sending a large file (> 100 MB) in either direction and matching
sha1sums.
Please review.
Thanks,
Amit
Amit Shah (25):
hvc_console: Remove __devinit annotation from hvc_alloc
virtio: console: We support only one device at a time
virtio: console: encapsulate buffer information in a struct
virtio: console: ensure add_inbuf can work for multiple ports as well
virtio: console: introduce a get_inbuf helper to fetch bufs from
in_vq
virtio: console: don't assume a single console port.
virtio: console: struct ports for multiple ports per device.
virtio: console: ensure console size is updated on hvc open
virtio: console: Separate out console-specific data into a separate
struct
virtio: console: Separate out console init into a new function
virtio: console: Separate out find_vqs operation into a different
function
virtio: console: Buffer data that comes from the host
virtio: console: Introduce a send_buf function for a common path for
sending data to host
virtio: console: Introduce a 'header' for each buffer towards
supporting multiport
virtio: console: Add a new MULTIPORT feature, support for generic
ports
virtio: console: Prepare for writing to / reading from userspace
buffers
virtio: console: Associate each port with a char device
virtio: console: Add file operations to ports for
open/read/write/poll
virtio: console: Ensure only one process can have a port open at a
time
virtio: console: Register with sysfs and create a 'name' attribute
for ports
virtio: console: Add throttling support to prevent flooding ports
virtio: console: Add option to remove cached buffers on port close
virtio: console: Handle port hot-plug
virtio: console: Add ability to hot-unplug ports
virtio: console: Add debugfs files for each port to expose debug info
Rusty Russell (6):
virtio: console: comment cleanup
virtio: console: statically initialize virtio_cons
hvc_console: make the ops pointer const.
virtio: console: port encapsulation
virtio: console: use vdev->priv to avoid accessing global var.
virtio: console: remove global var
drivers/char/Kconfig | 8 +
drivers/char/hvc_beat.c | 2 +-
drivers/char/hvc_console.c | 9 +-
drivers/char/hvc_console.h | 9 +-
drivers/char/hvc_iseries.c | 2 +-
drivers/char/hvc_iucv.c | 2 +-
drivers/char/hvc_rtas.c | 2 +-
drivers/char/hvc_udbg.c | 2 +-
drivers/char/hvc_vio.c | 2 +-
drivers/char/hvc_xen.c | 2 +-
drivers/char/virtio_console.c | 1575 ++++++++++++++++++++++++++++++++++++----
include/linux/virtio_console.h | 44 ++-
12 files changed, 1498 insertions(+), 161 deletions(-)
From: Rusty Russell <rusty at rustcorp.com.au>
Remove old lguest-style comments.
[Amit: - wingify comments acc. to kernel style
- indent comments ]
Signed-off-by: Rusty Russell <rusty at rustcorp.com.au>
Signed-off-by: Amit Shah <amit.shah at redhat.com>
---
drivers/char/virtio_console.c | 108 ++++++++++++++++++++--------------------
include/linux/virtio_console.h | 6 ++-
2 files changed, 58 insertions(+), 56 deletions(-)
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index a035ae3..26e238c 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -1,18 +1,5 @@
-/*D:300
- * The Guest console driver
- *
- * Writing console drivers is one of the few remaining Dark Arts in Linux.
- * Fortunately for us, the path of virtual consoles has been well-trodden by
- * the PowerPC folks, who wrote "hvc_console.c" to generically
support any
- * virtual console. We use that infrastructure which only requires us to write
- * the basic put_chars and get_chars functions and call the right register
- * functions.
- :*/
-
-/*M:002 The console can be flooded: while the Guest is processing input the
- * Host can send more. Buffering in the Host could alleviate this, but it is a
- * difficult problem in general. :*/
-/* Copyright (C) 2006, 2007 Rusty Russell, IBM Corporation
+/*
+ * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -34,8 +21,6 @@
#include <linux/virtio_console.h>
#include "hvc_console.h"
-/*D:340 These represent our input and output console queues, and the virtio
- * operations for them. */
static struct virtqueue *in_vq, *out_vq;
static struct virtio_device *vdev;
@@ -49,12 +34,14 @@ static struct hv_ops virtio_cons;
/* The hvc device */
static struct hvc_struct *hvc;
-/*D:310 The put_chars() callback is pretty straightforward.
+/*
+ * The put_chars() callback is pretty straightforward.
*
- * We turn the characters into a scatter-gather list, add it to the output
- * queue and then kick the Host. Then we sit here waiting for it to finish:
- * inefficient in theory, but in practice implementations will do it
- * immediately (lguest's Launcher does). */
+ * We turn the characters into a scatter-gather list, add it to the
+ * output queue and then kick the Host. Then we sit here waiting for
+ * it to finish: inefficient in theory, but in practice
+ * implementations will do it immediately (lguest's Launcher does).
+ */
static int put_chars(u32 vtermno, const char *buf, int count)
{
struct scatterlist sg[1];
@@ -63,8 +50,10 @@ static int put_chars(u32 vtermno, const char *buf, int count)
/* This is a convenient routine to initialize a single-elem sg list */
sg_init_one(sg, buf, count);
- /* add_buf wants a token to identify this buffer: we hand it any
- * non-NULL pointer, since there's only ever one buffer. */
+ /*
+ * add_buf wants a token to identify this buffer: we hand it
+ * any non-NULL pointer, since there's only ever one buffer.
+ */
if (out_vq->vq_ops->add_buf(out_vq, sg, 1, 0, (void *)1) >= 0) {
/* Tell Host to go! */
out_vq->vq_ops->kick(out_vq);
@@ -77,8 +66,10 @@ static int put_chars(u32 vtermno, const char *buf, int count)
return count;
}
-/* Create a scatter-gather list representing our input buffer and put it in the
- * queue. */
+/*
+ * Create a scatter-gather list representing our input buffer and put
+ * it in the queue.
+ */
static void add_inbuf(void)
{
struct scatterlist sg[1];
@@ -90,12 +81,14 @@ static void add_inbuf(void)
in_vq->vq_ops->kick(in_vq);
}
-/*D:350 get_chars() is the callback from the hvc_console infrastructure when
- * an interrupt is received.
+/*
+ * get_chars() is the callback from the hvc_console infrastructure
+ * when an interrupt is received.
*
- * Most of the code deals with the fact that the hvc_console() infrastructure
- * only asks us for 16 bytes at a time. We keep in_offset and in_used fields
- * for partially-filled buffers. */
+ * Most of the code deals with the fact that the hvc_console()
+ * infrastructure only asks us for 16 bytes at a time. We keep
+ * in_offset and in_used fields for partially-filled buffers.
+ */
static int get_chars(u32 vtermno, char *buf, int count)
{
/* If we don't have an input queue yet, we can't get input. */
@@ -123,14 +116,16 @@ static int get_chars(u32 vtermno, char *buf, int count)
return count;
}
-/*:*/
-/*D:320 Console drivers are initialized very early so boot messages can go out,
- * so we do things slightly differently from the generic virtio initialization
- * of the net and block drivers.
+/*
+ * Console drivers are initialized very early so boot messages can go
+ * out, so we do things slightly differently from the generic virtio
+ * initialization of the net and block drivers.
*
- * At this stage, the console is output-only. It's too early to set up a
- * virtqueue, so we let the drivers do some boutique early-output thing. */
+ * At this stage, the console is output-only. It's too early to set
+ * up a virtqueue, so we let the drivers do some boutique early-output
+ * thing.
+ */
int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
{
virtio_cons.put_chars = put_chars;
@@ -157,8 +152,8 @@ static void virtcons_apply_config(struct virtio_device *dev)
}
/*
- * we support only one console, the hvc struct is a global var
- * We set the configuration at this point, since we now have a tty
+ * we support only one console, the hvc struct is a global var We set
+ * the configuration at this point, since we now have a tty
*/
static int notifier_add_vio(struct hvc_struct *hp, int data)
{
@@ -179,13 +174,17 @@ static void hvc_handle_input(struct virtqueue *vq)
hvc_kick();
}
-/*D:370 Once we're further in boot, we get probed like any other virtio
device.
- * At this stage we set up the output virtqueue.
+/*
+ * Once we're further in boot, we get probed like any other virtio
+ * device. At this stage we set up the output virtqueue.
*
- * To set up and manage our virtual console, we call hvc_alloc(). Since we
- * never remove the console device we never need this pointer again.
+ * To set up and manage our virtual console, we call hvc_alloc().
+ * Since we never remove the console device we never need this pointer
+ * again.
*
- * Finally we put our input buffer in the input queue, ready to receive. */
+ * Finally we put our input buffer in the input queue, ready to
+ * receive.
+ */
static int __devinit virtcons_probe(struct virtio_device *dev)
{
vq_callback_t *callbacks[] = { hvc_handle_input, NULL};
@@ -203,8 +202,6 @@ static int __devinit virtcons_probe(struct virtio_device
*dev)
}
/* Find the queues. */
- /* FIXME: This is why we want to wean off hvc: we do nothing
- * when input comes in. */
err = vdev->config->find_vqs(vdev, 2, vqs, callbacks, names);
if (err)
goto free;
@@ -219,15 +216,18 @@ static int __devinit virtcons_probe(struct virtio_device
*dev)
virtio_cons.notifier_del = notifier_del_vio;
virtio_cons.notifier_hangup = notifier_del_vio;
- /* The first argument of hvc_alloc() is the virtual console number, so
- * we use zero. The second argument is the parameter for the
- * notification mechanism (like irq number). We currently leave this
- * as zero, virtqueues have implicit notifications.
+ /*
+ * The first argument of hvc_alloc() is the virtual console
+ * number, so we use zero. The second argument is the
+ * parameter for the notification mechanism (like irq
+ * number). We currently leave this as zero, virtqueues have
+ * implicit notifications.
*
- * The third argument is a "struct hv_ops" containing the
put_chars()
- * get_chars(), notifier_add() and notifier_del() pointers.
- * The final argument is the output buffer size: we can do any size,
- * so we put PAGE_SIZE here. */
+ * The third argument is a "struct hv_ops" containing the
+ * put_chars(), get_chars(), notifier_add() and notifier_del()
+ * pointers. The final argument is the output buffer size: we
+ * can do any size, so we put PAGE_SIZE here.
+ */
hvc = hvc_alloc(0, 0, &virtio_cons, PAGE_SIZE);
if (IS_ERR(hvc)) {
err = PTR_ERR(hvc);
diff --git a/include/linux/virtio_console.h b/include/linux/virtio_console.h
index fe88517..9e0da40 100644
--- a/include/linux/virtio_console.h
+++ b/include/linux/virtio_console.h
@@ -3,8 +3,10 @@
#include <linux/types.h>
#include <linux/virtio_ids.h>
#include <linux/virtio_config.h>
-/* This header, excluding the #ifdef __KERNEL__ part, is BSD licensed so
- * anyone can use the definitions to implement compatible drivers/servers. */
+/*
+ * This header, excluding the #ifdef __KERNEL__ part, is BSD licensed so
+ * anyone can use the definitions to implement compatible drivers/servers.
+ */
/* Feature bits */
#define VIRTIO_CONSOLE_F_SIZE 0 /* Does host provide console size? */
--
1.6.2.5
Rusty Russell
2009-Dec-23 06:39 UTC
[PATCH 00/31] virtio: console: Fixes, multiple devices and generic ports
On Wed, 23 Dec 2009 01:04:10 am Amit Shah wrote:> Hey Rusty, > > This series adds support for generic ports with each port getting two > vqs: one for input and one for output. The host notifies us via the > config space of the max. number of ports that can be added for a > particular device.Hi Amit, I've just started a couple of weeks' leave, but I'll try to review these in the last week of this year. Thanks, Rusty.
Benjamin Herrenschmidt
2010-Jan-12 02:21 UTC
[PATCH 03/31] hvc_console: make the ops pointer const.
On Tue, 2009-12-22 at 20:04 +0530, Amit Shah wrote:> From: Rusty Russell <rusty at rustcorp.com.au> > > This is nicer for modern R/O protection. And noone needs it non-const, so > constify the callers as well.Rusty, do you want me to take these via powerpc ? Cheers, Ben.> Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> > Signed-off-by: Amit Shah <amit.shah at redhat.com> > To: Christian Borntraeger <borntraeger at de.ibm.com> > Cc: linuxppc-dev at ozlabs.org > --- > drivers/char/hvc_beat.c | 2 +- > drivers/char/hvc_console.c | 7 ++++--- > drivers/char/hvc_console.h | 7 ++++--- > drivers/char/hvc_iseries.c | 2 +- > drivers/char/hvc_iucv.c | 2 +- > drivers/char/hvc_rtas.c | 2 +- > drivers/char/hvc_udbg.c | 2 +- > drivers/char/hvc_vio.c | 2 +- > drivers/char/hvc_xen.c | 2 +- > drivers/char/virtio_console.c | 2 +- > 10 files changed, 16 insertions(+), 14 deletions(-) > > diff --git a/drivers/char/hvc_beat.c b/drivers/char/hvc_beat.c > index 0afc8b8..6913fc3 100644 > --- a/drivers/char/hvc_beat.c > +++ b/drivers/char/hvc_beat.c > @@ -84,7 +84,7 @@ static int hvc_beat_put_chars(uint32_t vtermno, const char *buf, int cnt) > return cnt; > } > > -static struct hv_ops hvc_beat_get_put_ops = { > +static const struct hv_ops hvc_beat_get_put_ops = { > .get_chars = hvc_beat_get_chars, > .put_chars = hvc_beat_put_chars, > }; > diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c > index 416d342..d8dac58 100644 > --- a/drivers/char/hvc_console.c > +++ b/drivers/char/hvc_console.c > @@ -125,7 +125,7 @@ static struct hvc_struct *hvc_get_by_index(int index) > * console interfaces but can still be used as a tty device. This has to be > * static because kmalloc will not work during early console init. > */ > -static struct hv_ops *cons_ops[MAX_NR_HVC_CONSOLES]; > +static const struct hv_ops *cons_ops[MAX_NR_HVC_CONSOLES]; > static uint32_t vtermnos[MAX_NR_HVC_CONSOLES] > {[0 ... MAX_NR_HVC_CONSOLES - 1] = -1}; > > @@ -247,7 +247,7 @@ static void destroy_hvc_struct(struct kref *kref) > * vty adapters do NOT get an hvc_instantiate() callback since they > * appear after early console init. > */ > -int hvc_instantiate(uint32_t vtermno, int index, struct hv_ops *ops) > +int hvc_instantiate(uint32_t vtermno, int index, const struct hv_ops *ops) > { > struct hvc_struct *hp; > > @@ -749,7 +749,8 @@ static const struct tty_operations hvc_ops = { > }; > > struct hvc_struct __devinit *hvc_alloc(uint32_t vtermno, int data, > - struct hv_ops *ops, int outbuf_size) > + const struct hv_ops *ops, > + int outbuf_size) > { > struct hvc_struct *hp; > int i; > diff --git a/drivers/char/hvc_console.h b/drivers/char/hvc_console.h > index 10950ca..52ddf4d 100644 > --- a/drivers/char/hvc_console.h > +++ b/drivers/char/hvc_console.h > @@ -55,7 +55,7 @@ struct hvc_struct { > int outbuf_size; > int n_outbuf; > uint32_t vtermno; > - struct hv_ops *ops; > + const struct hv_ops *ops; > int irq_requested; > int data; > struct winsize ws; > @@ -76,11 +76,12 @@ struct hv_ops { > }; > > /* Register a vterm and a slot index for use as a console (console_init) */ > -extern int hvc_instantiate(uint32_t vtermno, int index, struct hv_ops *ops); > +extern int hvc_instantiate(uint32_t vtermno, int index, > + const struct hv_ops *ops); > > /* register a vterm for hvc tty operation (module_init or hotplug add) */ > extern struct hvc_struct * __devinit hvc_alloc(uint32_t vtermno, int data, > - struct hv_ops *ops, int outbuf_size); > + const struct hv_ops *ops, int outbuf_size); > /* remove a vterm from hvc tty operation (module_exit or hotplug remove) */ > extern int hvc_remove(struct hvc_struct *hp); > > diff --git a/drivers/char/hvc_iseries.c b/drivers/char/hvc_iseries.c > index 936d05b..fd02426 100644 > --- a/drivers/char/hvc_iseries.c > +++ b/drivers/char/hvc_iseries.c > @@ -197,7 +197,7 @@ done: > return sent; > } > > -static struct hv_ops hvc_get_put_ops = { > +static const struct hv_ops hvc_get_put_ops = { > .get_chars = get_chars, > .put_chars = put_chars, > .notifier_add = notifier_add_irq, > diff --git a/drivers/char/hvc_iucv.c b/drivers/char/hvc_iucv.c > index fe62bd0..21681a8 100644 > --- a/drivers/char/hvc_iucv.c > +++ b/drivers/char/hvc_iucv.c > @@ -922,7 +922,7 @@ static int hvc_iucv_pm_restore_thaw(struct device *dev) > > > /* HVC operations */ > -static struct hv_ops hvc_iucv_ops = { > +static const struct hv_ops hvc_iucv_ops = { > .get_chars = hvc_iucv_get_chars, > .put_chars = hvc_iucv_put_chars, > .notifier_add = hvc_iucv_notifier_add, > diff --git a/drivers/char/hvc_rtas.c b/drivers/char/hvc_rtas.c > index 88590d0..61c4a61 100644 > --- a/drivers/char/hvc_rtas.c > +++ b/drivers/char/hvc_rtas.c > @@ -71,7 +71,7 @@ static int hvc_rtas_read_console(uint32_t vtermno, char *buf, int count) > return i; > } > > -static struct hv_ops hvc_rtas_get_put_ops = { > +static const struct hv_ops hvc_rtas_get_put_ops = { > .get_chars = hvc_rtas_read_console, > .put_chars = hvc_rtas_write_console, > }; > diff --git a/drivers/char/hvc_udbg.c b/drivers/char/hvc_udbg.c > index bd63ba8..b0957e6 100644 > --- a/drivers/char/hvc_udbg.c > +++ b/drivers/char/hvc_udbg.c > @@ -58,7 +58,7 @@ static int hvc_udbg_get(uint32_t vtermno, char *buf, int count) > return i; > } > > -static struct hv_ops hvc_udbg_ops = { > +static const struct hv_ops hvc_udbg_ops = { > .get_chars = hvc_udbg_get, > .put_chars = hvc_udbg_put, > }; > diff --git a/drivers/char/hvc_vio.c b/drivers/char/hvc_vio.c > index 10be343..27370e9 100644 > --- a/drivers/char/hvc_vio.c > +++ b/drivers/char/hvc_vio.c > @@ -77,7 +77,7 @@ static int filtered_get_chars(uint32_t vtermno, char *buf, int count) > return got; > } > > -static struct hv_ops hvc_get_put_ops = { > +static const struct hv_ops hvc_get_put_ops = { > .get_chars = filtered_get_chars, > .put_chars = hvc_put_chars, > .notifier_add = notifier_add_irq, > diff --git a/drivers/char/hvc_xen.c b/drivers/char/hvc_xen.c > index b1a7163..60446f8 100644 > --- a/drivers/char/hvc_xen.c > +++ b/drivers/char/hvc_xen.c > @@ -122,7 +122,7 @@ static int read_console(uint32_t vtermno, char *buf, int len) > return recv; > } > > -static struct hv_ops hvc_ops = { > +static const struct hv_ops hvc_ops = { > .get_chars = read_console, > .put_chars = write_console, > .notifier_add = notifier_add_irq, > diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c > index 1d844a4..791be4e 100644 > --- a/drivers/char/virtio_console.c > +++ b/drivers/char/virtio_console.c > @@ -163,7 +163,7 @@ static void hvc_handle_input(struct virtqueue *vq) > } > > /* The operations for the console. */ > -static struct hv_ops hv_ops = { > +static const struct hv_ops hv_ops = { > .get_chars = get_chars, > .put_chars = put_chars, > .notifier_add = notifier_add_vio,
Rusty Russell
2010-Jan-12 11:36 UTC
[PATCH 03/31] hvc_console: make the ops pointer const.
On Tue, 12 Jan 2010 12:51:46 pm Benjamin Herrenschmidt wrote:> On Tue, 2009-12-22 at 20:04 +0530, Amit Shah wrote: > > From: Rusty Russell <rusty at rustcorp.com.au> > > > > This is nicer for modern R/O protection. And noone needs it non-const, so > > constify the callers as well. > > Rusty, do you want me to take these via powerpc ?Sure, thanks. Rusty.
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