Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-lguest

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-lguest: (45 commits)
  Use "struct boot_params" in example launcher
  Loading bzImage directly.
  Revert lguest magic and use hook in head.S
  Update lguest documentation to reflect the new virtual block device name.
  generalize lgread_u32/lgwrite_u32.
  Example launcher handle guests not being ready for input
  Update example launcher for virtio
  Lguest support for Virtio
  Remove old lguest I/O infrrasructure.
  Remove old lguest bus and drivers.
  Virtio helper routines for a descriptor ringbuffer implementation
  Module autoprobing support for virtio drivers.
  Virtio console driver
  Block driver using virtio.
  Net driver using virtio
  Virtio interface
  Boot with virtual == physical to get closer to native Linux.
  Allow guest to specify syscall vector to use.
  Rename "cr3" to "gpgdir" to avoid x86-specific naming.
  Pagetables to use normal kernel types
  ...

4 files changed, 230 insertions, 178 deletions

diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index 6549110..bf18d75 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -613,6 +613,10 @@ config HVC_XEN
 	help
 	  Xen virtual console device driver
 
+config VIRTIO_CONSOLE
+	bool
+	select HVC_DRIVER
+
 config HVCS
 	tristate "IBM Hypervisor Virtual Console Server support"
 	depends on PPC_PSERIES
diff --git a/drivers/char/Makefile b/drivers/char/Makefile
index c78ff26..07304d5 100644
--- a/drivers/char/Makefile
+++ b/drivers/char/Makefile
@@ -42,7 +42,6 @@ obj-$(CONFIG_SYNCLINK_GT)	+= synclink_gt.o
 obj-$(CONFIG_N_HDLC)		+= n_hdlc.o
 obj-$(CONFIG_AMIGA_BUILTIN_SERIAL) += amiserial.o
 obj-$(CONFIG_SX)		+= sx.o generic_serial.o
-obj-$(CONFIG_LGUEST_GUEST)	+= hvc_lguest.o
 obj-$(CONFIG_RIO)		+= rio/ generic_serial.o
 obj-$(CONFIG_HVC_CONSOLE)	+= hvc_vio.o hvsi.o
 obj-$(CONFIG_HVC_ISERIES)	+= hvc_iseries.o
@@ -50,6 +49,7 @@ obj-$(CONFIG_HVC_RTAS)		+= hvc_rtas.o
 obj-$(CONFIG_HVC_BEAT)		+= hvc_beat.o
 obj-$(CONFIG_HVC_DRIVER)	+= hvc_console.o
 obj-$(CONFIG_HVC_XEN)		+= hvc_xen.o
+obj-$(CONFIG_VIRTIO_CONSOLE)	+= virtio_console.o
 obj-$(CONFIG_RAW_DRIVER)	+= raw.o
 obj-$(CONFIG_SGI_SNSC)		+= snsc.o snsc_event.o
 obj-$(CONFIG_MSPEC)		+= mspec.o
diff --git a/drivers/char/hvc_lguest.c b/drivers/char/hvc_lguest.c
deleted file mode 100644
index efccb21..0000000
--- a/drivers/char/hvc_lguest.c
+++ /dev/null
@@ -1,177 +0,0 @@
-/*D:300
- * The Guest console driver
- *
- * This is a trivial console driver: we use lguest's DMA mechanism to send
- * bytes out, and register a DMA buffer to receive bytes in.  It is assumed to
- * be present and available from the very beginning of boot.
- *
- * 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 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
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
- */
-#include <linux/err.h>
-#include <linux/init.h>
-#include <linux/lguest_bus.h>
-#include <asm/paravirt.h>
-#include "hvc_console.h"
-
-/*D:340 This is our single console input buffer, with associated "struct
- * lguest_dma" referring to it.  Note the 0-terminated length array, and the
- * use of physical address for the buffer itself. */
-static char inbuf[256];
-static struct lguest_dma cons_input = { .used_len = 0,
-					.addr[0] = __pa(inbuf),
-					.len[0] = sizeof(inbuf),
-					.len[1] = 0 };
-
-/*D:310 The put_chars() callback is pretty straightforward.
- *
- * First we put the pointer and length in a "struct lguest_dma": we only have
- * one pointer, so we set the second length to 0.  Then we use SEND_DMA to send
- * the data to (Host) buffers attached to the console key.  Usually a device's
- * key is a physical address within the device's memory, but because the
- * console device doesn't have any associated physical memory, we use the
- * LGUEST_CONSOLE_DMA_KEY constant (aka 0). */
-static int put_chars(u32 vtermno, const char *buf, int count)
-{
-	struct lguest_dma dma;
-
-	/* FIXME: DMA buffers in a "struct lguest_dma" are not allowed
-	 * to go over page boundaries.  This never seems to happen,
-	 * but if it did we'd need to fix this code. */
-	dma.len[0] = count;
-	dma.len[1] = 0;
-	dma.addr[0] = __pa(buf);
-
-	lguest_send_dma(LGUEST_CONSOLE_DMA_KEY, &dma);
-	/* We're expected to return the amount of data we wrote: all of it. */
-	return count;
-}
-
-/*D:350 get_chars() is the callback from the hvc_console infrastructure when
- * an interrupt is received.
- *
- * Firstly we see if our buffer has been filled: if not, we return.  The rest
- * of the code deals with the fact that the hvc_console() infrastructure only
- * asks us for 16 bytes at a time.  We keep a "cons_offset" variable for
- * partially-read buffers. */
-static int get_chars(u32 vtermno, char *buf, int count)
-{
-	static int cons_offset;
-
-	/* Nothing left to see here... */
-	if (!cons_input.used_len)
-		return 0;
-
-	/* You want more than we have to give?  Well, try wanting less! */
-	if (cons_input.used_len - cons_offset < count)
-		count = cons_input.used_len - cons_offset;
-
-	/* Copy across to their buffer and increment offset. */
-	memcpy(buf, inbuf + cons_offset, count);
-	cons_offset += count;
-
-	/* Finished?  Zero offset, and reset cons_input so Host will use it
-	 * again. */
-	if (cons_offset == cons_input.used_len) {
-		cons_offset = 0;
-		cons_input.used_len = 0;
-	}
-	return count;
-}
-/*:*/
-
-static struct hv_ops lguest_cons = {
-	.get_chars = get_chars,
-	.put_chars = put_chars,
-};
-
-/*D:320 Console drivers are initialized very early so boot messages can go
- * out.  At this stage, the console is output-only.  Our driver checks we're a
- * Guest, and if so hands hvc_instantiate() the console number (0), priority
- * (0), and the struct hv_ops containing the put_chars() function. */
-static int __init cons_init(void)
-{
-	if (strcmp(pv_info.name, "lguest") != 0)
-		return 0;
-
-	return hvc_instantiate(0, 0, &lguest_cons);
-}
-console_initcall(cons_init);
-
-/*D:370 To set up and manage our virtual console, we call hvc_alloc() and
- * stash the result in the private pointer of the "struct lguest_device".
- * Since we never remove the console device we never need this pointer again,
- * but using ->private is considered good form, and you never know who's going
- * to copy your driver.
- *
- * Once the console is set up, we bind our input buffer ready for input. */
-static int lguestcons_probe(struct lguest_device *lgdev)
-{
-	int err;
-
-	/* The first argument of hvc_alloc() is the virtual console number, so
-	 * we use zero.  The second argument is the interrupt number.
-	 *
-	 * The third argument is a "struct hv_ops" containing the put_chars()
-	 * and get_chars() pointers.  The final argument is the output buffer
-	 * size: we use 256 and expect the Host to have room for us to send
-	 * that much. */
-	lgdev->private = hvc_alloc(0, lgdev_irq(lgdev), &lguest_cons, 256);
-	if (IS_ERR(lgdev->private))
-		return PTR_ERR(lgdev->private);
-
-	/* We bind a single DMA buffer at key LGUEST_CONSOLE_DMA_KEY.
-	 * "cons_input" is that statically-initialized global DMA buffer we saw
-	 * above, and we also give the interrupt we want. */
-	err = lguest_bind_dma(LGUEST_CONSOLE_DMA_KEY, &cons_input, 1,
-			      lgdev_irq(lgdev));
-	if (err)
-		printk("lguest console: failed to bind buffer.\n");
-	return err;
-}
-/* Note the use of lgdev_irq() for the interrupt number.  We tell hvc_alloc()
- * to expect input when this interrupt is triggered, and then tell
- * lguest_bind_dma() that is the interrupt to send us when input comes in. */
-
-/*D:360 From now on the console driver follows standard Guest driver form:
- * register_lguest_driver() registers the device type and probe function, and
- * the probe function sets up the device.
- *
- * The standard "struct lguest_driver": */
-static struct lguest_driver lguestcons_drv = {
-	.name = "lguestcons",
-	.owner = THIS_MODULE,
-	.device_type = LGUEST_DEVICE_T_CONSOLE,
-	.probe = lguestcons_probe,
-};
-
-/* The standard init function */
-static int __init hvc_lguest_init(void)
-{
-	return register_lguest_driver(&lguestcons_drv);
-}
-module_init(hvc_lguest_init);
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
new file mode 100644
index 0000000..100e8a2
--- /dev/null
+++ b/drivers/char/virtio_console.c
@@ -0,0 +1,225 @@
+/*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
+ *
+ * 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
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/virtio.h>
+#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;
+
+/* This is our input buffer, and how much data is left in it. */
+static unsigned int in_len;
+static char *in, *inbuf;
+
+/* The operations for our console. */
+static struct hv_ops virtio_cons;
+
+/*D:310 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). */
+static int put_chars(u32 vtermno, const char *buf, int count)
+{
+	struct scatterlist sg[1];
+	unsigned int len;
+
+	/* 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. */
+	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);
+		/* Chill out until it's done with the buffer. */
+		while (!out_vq->vq_ops->get_buf(out_vq, &len))
+			cpu_relax();
+	}
+
+	/* We're expected to return the amount of data we wrote: all of it. */
+	return count;
+}
+
+/* Create a scatter-gather list representing our input buffer and put it in the
+ * queue. */
+static void add_inbuf(void)
+{
+	struct scatterlist sg[1];
+	sg_init_one(sg, inbuf, PAGE_SIZE);
+
+	/* We should always be able to add one buffer to an empty queue. */
+	if (in_vq->vq_ops->add_buf(in_vq, sg, 0, 1, inbuf) != 0)
+		BUG();
+	in_vq->vq_ops->kick(in_vq);
+}
+
+/*D:350 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. */
+static int get_chars(u32 vtermno, char *buf, int count)
+{
+	/* If we don't have an input queue yet, we can't get input. */
+	BUG_ON(!in_vq);
+
+	/* No buffer?  Try to get one. */
+	if (!in_len) {
+		in = in_vq->vq_ops->get_buf(in_vq, &in_len);
+		if (!in)
+			return 0;
+	}
+
+	/* You want more than we have to give?  Well, try wanting less! */
+	if (in_len < count)
+		count = in_len;
+
+	/* Copy across to their buffer and increment offset. */
+	memcpy(buf, in, count);
+	in += count;
+	in_len -= count;
+
+	/* Finished?  Re-register buffer so Host will use it again. */
+	if (in_len == 0)
+		add_inbuf();
+
+	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.
+ *
+ * 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;
+	return hvc_instantiate(0, 0, &virtio_cons);
+}
+
+/*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.
+ *
+ * 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. */
+static int virtcons_probe(struct virtio_device *dev)
+{
+	int err;
+	struct hvc_struct *hvc;
+
+	vdev = dev;
+
+	/* This is the scratch page we use to receive console input */
+	inbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	if (!inbuf) {
+		err = -ENOMEM;
+		goto fail;
+	}
+
+	/* Find the input queue. */
+	/* FIXME: This is why we want to wean off hvc: we do nothing
+	 * when input comes in. */
+	in_vq = vdev->config->find_vq(vdev, NULL);
+	if (IS_ERR(in_vq)) {
+		err = PTR_ERR(in_vq);
+		goto free;
+	}
+
+	out_vq = vdev->config->find_vq(vdev, NULL);
+	if (IS_ERR(out_vq)) {
+		err = PTR_ERR(out_vq);
+		goto free_in_vq;
+	}
+
+	/* Start using the new console output. */
+	virtio_cons.get_chars = get_chars;
+	virtio_cons.put_chars = put_chars;
+
+	/* The first argument of hvc_alloc() is the virtual console number, so
+	 * we use zero.  The second argument is the interrupt number; we
+	 * currently leave this as zero: it would be better not to use the
+	 * hvc mechanism and fix this (FIXME!).
+	 *
+	 * The third argument is a "struct hv_ops" containing the put_chars()
+	 * and get_chars() 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);
+		goto free_out_vq;
+	}
+
+	/* Register the input buffer the first time. */
+	add_inbuf();
+	return 0;
+
+free_out_vq:
+	vdev->config->del_vq(out_vq);
+free_in_vq:
+	vdev->config->del_vq(in_vq);
+free:
+	kfree(inbuf);
+fail:
+	return err;
+}
+
+static struct virtio_device_id id_table[] = {
+	{ VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
+	{ 0 },
+};
+
+static struct virtio_driver virtio_console = {
+	.driver.name =	KBUILD_MODNAME,
+	.driver.owner =	THIS_MODULE,
+	.id_table =	id_table,
+	.probe =	virtcons_probe,
+};
+
+static int __init init(void)
+{
+	return register_virtio_driver(&virtio_console);
+}
+module_init(init);
+
+MODULE_DEVICE_TABLE(virtio, id_table);
+MODULE_DESCRIPTION("Virtio console driver");
+MODULE_LICENSE("GPL");