9p Virtualization Transports

This adds a shared memory transport for a synthetic 9p device for paravirtualized file system support under KVM/QEMU.

+static struct p9pci_trans *p9pci_trans; /* single channel for now */

net/9p/trans_pci.c new file +20 -0

+	wake_up_interruptible(&p9pci_trans->wait);
+	return IRQ_HANDLED;
+}
+
+static int p9pci_read(struct p9_trans *trans, void *v, int len)
+{
+	struct p9pci_trans *ts;
+
+	if (!trans || trans->status == Disconnected || !trans->priv)
+		return -EREMOTEIO;
+
+	ts = trans->priv;
+
+	P9_DPRINTK(P9_DEBUG_TRANS, "trans %p rx %p tx %p buf %p len %d\n",
+						trans, ts->rx, ts->tx, v, len);
+	if (len > ts->len)
+		len = ts->len;
+
+	if (len) {
+		memcpy_fromio(v, ts->rx, len);

net/9p/trans_pci.c new file +9 -0

+	init_waitqueue_head(&p9pci_trans->wait);
+	err = pci_enable_device(pdev);
+	if (err)
+		goto error;
+
+	p9pci_trans->pdev = pdev;
+	err = pci_request_regions(pdev, "9p");
+	if (err)
+		goto error;

net/9p/trans_pci.c new file +15 -0

+	pci_set_drvdata(pdev, p9pci_trans);
+	err = request_irq(pdev->irq, &p9pci_interrupt, 0, "p9pci", p9pci_trans);
+	if (err)
+		goto error;
+
+	p9pci_trans->irq = pdev->irq;
+	return 0;
+
+error:
+	P9_DPRINTK(P9_DEBUG_ERROR, "error %d\n", err);
+	if (p9pci_trans->irq >= 0) {
+		synchronize_irq(p9pci_trans->irq);
+		free_irq(p9pci_trans->irq, p9pci_trans);
+	}
+

Quoted 2 lines · Eric Van Hensbergen

This adds a shared memory transport for a synthetic 9p device for paravirtualized file system support under KVM/QEMU.

Nice driver. I'm hoping we can do a virtio driver using a similar concept.

net/9p/trans_pci.c line 44

Quoted 2 lines

net/9p/trans_pci.c new file +2 -0

+#define PCI_VENDOR_ID_9P     0x5002
+#define PCI_DEVICE_ID_9P     0x000D

Where do these numbers come from? Can we be sure they don't conflict with actual hardware?

net/9p/trans_pci.c line 57

Quoted 10 lines

net/9p/trans_pci.c new file +10 -0

+struct p9pci_trans {
+     struct pci_dev          *pdev;
+     void __iomem            *ioaddr;
+     void __iomem            *tx;
+     void __iomem            *rx;
+     int                     irq;
+     int                     pos;
+     int                     len;
+     wait_queue_head_t       wait;
+};

I would expect the data structure to contain an embedded struct p9_trans, which is how most drivers work nowadays.

Quoted 1 line

+static struct p9pci_trans *p9pci_trans; /* single channel for now */

As a result, it should be easier to get rid of this global. My feeling is that it really should not be here.

net/9p/trans_pci.c line 67

Quoted 3 lines

net/9p/trans_pci.c new file +3 -0

+static irqreturn_t p9pci_interrupt(int irq, void *dev)
+{
+     p9pci_trans = dev;

This can simply use a local variable.

Quoted 1 line

+ p9pci_trans->len = le32_to_cpu(readl(p9pci_trans->rx));

readl implies le32_to_cpu. Doing it twice on a PCI device is broken on big-endian hardware.

net/9p/trans_pci.c line 71

Quoted 3 lines

net/9p/trans_pci.c new file +3 -0

+     P9_DPRINTK(P9_DEBUG_TRANS, "%p len %d\n", p9pci_trans->pdev,
+                                                     p9pci_trans->len);
+     iowrite32(0, p9pci_trans->ioaddr + 4);

Also, you should not mix iowriteXX/ioreadXX and writeX/readX calls in one driver. Since you use pci_iomap, iowriteXX/ioreadXX are the correct functions.

Quoted 26 lines

net/9p/trans_pci.c new file +26 -0

+     wake_up_interruptible(&p9pci_trans->wait);
+     return IRQ_HANDLED;
+}
+
+static int p9pci_read(struct p9_trans *trans, void *v, int len)
+{
+     struct p9pci_trans *ts;
+
+     if (!trans || trans->status == Disconnected || !trans->priv)
+             return -EREMOTEIO;
+
+     ts = trans->priv;
+
+     P9_DPRINTK(P9_DEBUG_TRANS, "trans %p rx %p tx %p buf %p len %d\n",
+                                             trans, ts->rx, ts->tx, v, len);
+     if (len > ts->len)
+             len = ts->len;
+
+     if (len) {
+             memcpy_fromio(v, ts->rx, len);
+             ts->len = 0;
+             /* let the host knows the message is consumed */
+             writel(0, ts->rx);
+             iowrite32(0, p9pci_trans->ioaddr + 4);
+             P9_DPRINTK(P9_DEBUG_TRANS, "zero rxlen %d txlen %d\n",
+                                             readl(ts->rx), readl(ts->tx));

net/9p/trans_pci.c line 101

Quoted 4 lines

net/9p/trans_pci.c new file +4 -0

+     }
+
+     return len;
+}

I would expect memcpy_fromio and memcpy_toio to be relatively inefficient compared to virtual DMA, depending on the hypervisor. Do you have plans to change that, or did you have specific reasons to do the memcpy here?

net/9p/trans_pci.c line 118

Quoted 9 lines

net/9p/trans_pci.c new file +8 -0

+     P9_DPRINTK(P9_DEBUG_TRANS, "trans %p rx %p tx %p buf %p len %d\n",
+                                             trans, ts->rx, ts->tx, v, len);
+     P9_DPRINTK(P9_DEBUG_TRANS, "rxlen %d\n", readl(ts->rx));
+     if (readb(ts->tx) != 0)
+             return 0;
+
+     P9_DPRINTK(P9_DEBUG_TRANS, "tx addr %p io addr %p\n", ts->tx,
+                                                             ts->ioaddr);

All these P9_DPRINTK statements somewhat limit readability. I would suggest you kill them as soon as the driver is considered stable.

net/9p/trans_pci.c line 185

Quoted 8 lines

net/9p/trans_pci.c new file +8 -0

+static int __devinit p9pci_probe(struct pci_dev *pdev,
+             const struct pci_device_id *ent)
+{
+     int err;
+     u8 pci_rev;
+
+     if (p9pci_trans)
+             return -1;

probe should return -EBUSY or similar, not -1.

net/9p/trans_pci.c line 192

Quoted 6 lines

net/9p/trans_pci.c new file +6 -0

+     pci_read_config_byte(pdev, PCI_REVISION_ID, &pci_rev);
+
+     if (pdev->vendor == PCI_VENDOR_ID_9P &&
+         pdev->device == PCI_DEVICE_ID_9P)
+             printk(KERN_INFO "pci dev %s (id %04x:%04x rev %02x) is a 9P\n",
+                    pci_name(pdev), pdev->vendor, pdev->device, pci_rev);

You wouldn't be here for a different vendor/device code, so the check is bogus.

net/9p/trans_pci.c line 196

Quoted 3 lines

net/9p/trans_pci.c new file +3 -0

+     P9_DPRINTK(P9_DEBUG_TRANS, "%p\n", pdev);
+     p9pci_trans = kzalloc(sizeof(*p9pci_trans), GFP_KERNEL);
+     p9pci_trans->irq = -1;

Use NO_IRQ to signify an invalid irq.

Quoted 9 lines

net/9p/trans_pci.c new file +9 -0

+     init_waitqueue_head(&p9pci_trans->wait);
+     err = pci_enable_device(pdev);
+     if (err)
+             goto error;
+
+     p9pci_trans->pdev = pdev;
+     err = pci_request_regions(pdev, "9p");
+     if (err)
+             goto error;

net/9p/trans_pci.c line 215

Quoted 10 lines

net/9p/trans_pci.c new file +10 -0

+
+     p9pci_trans->ioaddr = pci_iomap(pdev, 0, 8);
+     if (!p9pci_trans->ioaddr) {
+             P9_DPRINTK(P9_DEBUG_ERROR, "Cannot remap MMIO, aborting\n");
+             err = -EIO;
+             goto error;
+     }
+
+     p9pci_trans->tx = pci_iomap(pdev, 1, 0x20000);
+     p9pci_trans->rx = pci_iomap(pdev, 2, 0x20000);

New code should use pcim_iomap, you don't need the unmapping code any more then.

Quoted 15 lines

net/9p/trans_pci.c new file +15 -0

+     pci_set_drvdata(pdev, p9pci_trans);
+     err = request_irq(pdev->irq, &p9pci_interrupt, 0, "p9pci", p9pci_trans);
+     if (err)
+             goto error;
+
+     p9pci_trans->irq = pdev->irq;
+     return 0;
+
+error:
+     P9_DPRINTK(P9_DEBUG_ERROR, "error %d\n", err);
+     if (p9pci_trans->irq >= 0) {
+             synchronize_irq(p9pci_trans->irq);
+             free_irq(p9pci_trans->irq, p9pci_trans);
+     }
+

net/9p/trans_pci.c line 240

Quoted 10 lines

net/9p/trans_pci.c new file +10 -0

+     if (p9pci_trans->pdev) {
+             pci_release_regions(pdev);
+             pci_iounmap(pdev, p9pci_trans->ioaddr);
+             pci_set_drvdata(pdev, NULL);
+             pci_disable_device(pdev);
+     }
+
+     kfree(p9pci_trans);
+     return -1;
+}

return err;

net/9p/trans_pci.c line 286

Quoted 6 lines

net/9p/trans_pci.c new file +6 -0

+static void __exit p9pci_cleanup_module(void)
+{
+     pci_unregister_driver(&p9pci_driver);
+     printk(KERN_ERR "Removal of 9p transports not implemented\n");
+     BUG();
+}

Not having a cleanup function at all is a much better way of preventing module unload.

Quoted 8 lines

Nice driver. I'm hoping we can do a virtio driver using a similar concept.

net/9p/trans_pci.c line 44

Quoted 2 lines

net/9p/trans_pci.c new file +2 -0

+#define PCI_VENDOR_ID_9P     0x5002
+#define PCI_DEVICE_ID_9P     0x000D

Where do these numbers come from? Can we be sure they don't conflict

with

Quoted 1 line

actual hardware?

I stole the VENDOR_ID from kvm's hypercall driver. There are no any guarantees that it doesn't conflict with actual hardware. As it was discussed before, there is still no ID assigned for the virtual devices.

Quoted 2 lines · Eric Van Hensbergen

This adds a shared memory transport for a synthetic 9p device for paravirtualized file system support under KVM/QEMU.

Nice driver. I'm hoping we can do a virtio driver using a similar concept.

Quoted 6 lines

Quoted 2 lines

This adds a shared memory transport for a synthetic 9p device for paravirtualized file system support under KVM/QEMU.

Nice driver. I'm hoping we can do a virtio driver using a similar concept.

Yes. I'm looking at the patches from Dor now, it should be pretty straight forward. The PCI is interesting in its own right for other (non-virtual) projects we've been playing with....

-eric

From: Latchesar Ionkov <lucho-OnYtXJJ0/[email protected]>

This adds a shared memory transport for a synthetic 9p device for paravirtualized file system support under KVM/QEMU.

Signed-off-by Latchesar Ionkov <lucho-OnYtXJJ0/[email protected]>

Signed-off-by Eric Van Hensbergen <[email protected]>

---
 Documentation/filesystems/9p.txt |    2 +
 net/9p/Kconfig                   |   10 ++-
 net/9p/Makefile                  |    4 +
 net/9p/trans_pci.c               |  295 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 310 insertions(+), 1 deletions(-)
 create mode 100644 net/9p/trans_pci.c

Documentation/filesystems/9p.txt +2 -0

index 1a5f50d..e1879bd 100644
@@ -46,6 +46,8 @@ OPTIONS
  			tcp  - specifying a normal TCP/IP connection
  			fd   - used passed file descriptors for connection
                                 (see rfdno and wfdno)
+			pci  - use a PCI pseudo device for 9p communication
+				over shared memory between a guest and host
 
   uname=name	user name to attempt mount as on the remote server.  The
   		server may override or ignore this value.  Certain user

net/9p/Kconfig +9 -1

index 09566ae..8517560 100644
@@ -16,13 +16,21 @@ menuconfig NET_9P
 config NET_9P_FD
 	depends on NET_9P
 	default y if NET_9P
-	tristate "9P File Descriptor Transports (Experimental)"
+	tristate "9p File Descriptor Transports (Experimental)"
 	help
 	  This builds support for file descriptor transports for 9p
 	  which includes support for TCP/IP, named pipes, or passed
 	  file descriptors.  TCP/IP is the default transport for 9p,
 	  so if you are going to use 9p, you'll likely want this.  
 
+config NET_9P_PCI
+	depends on NET_9P
+	tristate "9p PCI Shared Memory Transport (Experimental)"
+	help
+	  This builds support for a PCI psuedo-device currently available
+	  under KVM/QEMU which allows for 9p transactions over shared
+	  memory between the guest and the host.
+
 config NET_9P_DEBUG
 	bool "Debug information"
 	depends on NET_9P

net/9p/Makefile +4 -0

index 7b2a67a..26ce89d 100644
@@ -1,5 +1,6 @@
 obj-$(CONFIG_NET_9P) := 9pnet.o
 obj-$(CONFIG_NET_9P_FD) += 9pnet_fd.o
+obj-$(CONFIG_NET_9P_PCI) += 9pnet_pci.o
 
 9pnet-objs := \
 	mod.o \

@@ -14,3 +15,6 @@ obj-$(CONFIG_NET_9P_FD) += 9pnet_fd.o
 
 9pnet_fd-objs := \
 	trans_fd.o \
+
+9pnet_pci-objs := \
+	trans_pci.o \

net/9p/trans_pci.c new file +285 -0

new file mode 100644
index 0000000..36ddc5f
@@ -0,0 +1,295 @@
+/*
+ * net/9p/trans_pci.c
+ *
+ * 9P over PCI transport layer. For use with KVM/QEMU.
+ *
+ *  Copyright (C) 2007 by Latchesar Ionkov <lucho-OnYtXJJ0/[email protected]>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  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:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/compiler.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/completion.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <linux/irq.h>
+#include <linux/poll.h>
+#include <net/9p/9p.h>
+#include <net/9p/transport.h>
+
+#define P9PCI_DRIVER_NAME "9P PCI Device"
+#define P9PCI_DRIVER_VERSION "1"
+
+#define PCI_VENDOR_ID_9P	0x5002
+#define PCI_DEVICE_ID_9P	0x000D
+
+#define MAX_PCI_BUF		(4*1024) /* TODO: Get a number from lucho */
+
+struct p9pci_trans {
+	struct pci_dev		*pdev;
+	void __iomem		*ioaddr;
+	void __iomem		*tx;
+	void __iomem		*rx;
+	int			irq;
+	int			pos;
+	int			len;
+	wait_queue_head_t	wait;
+};
+static struct p9pci_trans *p9pci_trans; /* single channel for now */
+
+static struct pci_device_id p9pci_tbl[] = {
+	{PCI_VENDOR_ID_9P, PCI_DEVICE_ID_9P, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
+	{0,}
+};
+
+static irqreturn_t p9pci_interrupt(int irq, void *dev)
+{
+	p9pci_trans = dev;
+	p9pci_trans->len = le32_to_cpu(readl(p9pci_trans->rx));
+	P9_DPRINTK(P9_DEBUG_TRANS, "%p len %d\n", p9pci_trans->pdev,
+							p9pci_trans->len);
+	iowrite32(0, p9pci_trans->ioaddr + 4);
+	wake_up_interruptible(&p9pci_trans->wait);
+	return IRQ_HANDLED;
+}
+
+static int p9pci_read(struct p9_trans *trans, void *v, int len)
+{
+	struct p9pci_trans *ts;
+
+	if (!trans || trans->status == Disconnected || !trans->priv)
+		return -EREMOTEIO;
+
+	ts = trans->priv;
+
+	P9_DPRINTK(P9_DEBUG_TRANS, "trans %p rx %p tx %p buf %p len %d\n",
+						trans, ts->rx, ts->tx, v, len);
+	if (len > ts->len)
+		len = ts->len;
+
+	if (len) {
+		memcpy_fromio(v, ts->rx, len);
+		ts->len = 0;
+		/* let the host knows the message is consumed */
+		writel(0, ts->rx);
+		iowrite32(0, p9pci_trans->ioaddr + 4);
+		P9_DPRINTK(P9_DEBUG_TRANS, "zero rxlen %d txlen %d\n",
+						readl(ts->rx), readl(ts->tx));
+	}
+
+	return len;
+}
+
+static int p9pci_write(struct p9_trans *trans, void *v, int len)
+{
+	struct p9pci_trans *ts;
+
+	if (!trans || trans->status == Disconnected || !trans->priv)
+		return -EREMOTEIO;
+
+	ts = trans->priv;
+	P9_DPRINTK(P9_DEBUG_TRANS, "trans %p rx %p tx %p buf %p len %d\n",
+						trans, ts->rx, ts->tx, v, len);
+	P9_DPRINTK(P9_DEBUG_TRANS, "rxlen %d\n", readl(ts->rx));
+	if (readb(ts->tx) != 0)
+		return 0;
+
+	P9_DPRINTK(P9_DEBUG_TRANS, "tx addr %p io addr %p\n", ts->tx,
+								ts->ioaddr);
+	memcpy_toio(ts->tx, v, len);
+	iowrite32(len, ts->ioaddr);
+	return len;
+}
+
+static unsigned int
+p9pci_poll(struct p9_trans *trans, struct poll_table_struct *pt)
+{
+	int ret;
+	struct p9pci_trans *ts;
+
+	P9_DPRINTK(P9_DEBUG_TRANS, "trans %p\n", trans);
+	if (!trans || trans->status != Connected || !trans->priv)
+		return -EREMOTEIO;
+
+	ts = trans->priv;
+	poll_wait(NULL, &ts->wait, pt);
+	ret = 0;
+	if (!readl(ts->tx))
+		ret |= POLLOUT;
+	if (readl(ts->rx))
+		ret |= POLLIN;
+
+	P9_DPRINTK(P9_DEBUG_TRANS, "txlen %d rxlen %d\n", readl(ts->tx),
+								readl(ts->rx));
+	return ret;
+}
+
+/**
+ * p9_sock_close - shutdown socket
+ * @trans: private socket structure
+ *
+ */
+static void p9pci_close(struct p9_trans *trans)
+{
+	P9_DPRINTK(P9_DEBUG_TRANS, "trans %p\n", trans);
+}
+
+static struct p9_trans *p9pci_trans_create(const char *name, char *arg)
+{
+	struct p9_trans *trans;
+
+	P9_DPRINTK(P9_DEBUG_TRANS, "\n");
+	trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
+	if (!trans)
+		return ERR_PTR(-ENOMEM);
+
+	trans->status = Connected;
+	trans->write = p9pci_write;
+	trans->read = p9pci_read;
+	trans->close = p9pci_close;
+	trans->poll = p9pci_poll;
+	trans->priv = p9pci_trans;
+	writel(0, p9pci_trans->tx);
+	writel(0, p9pci_trans->rx);
+
+	return trans;
+}
+
+static int __devinit p9pci_probe(struct pci_dev *pdev,
+		const struct pci_device_id *ent)
+{
+	int err;
+	u8 pci_rev;
+
+	if (p9pci_trans)
+		return -1;
+
+	pci_read_config_byte(pdev, PCI_REVISION_ID, &pci_rev);
+
+	if (pdev->vendor == PCI_VENDOR_ID_9P &&
+	    pdev->device == PCI_DEVICE_ID_9P)
+		printk(KERN_INFO "pci dev %s (id %04x:%04x rev %02x) is a 9P\n",
+		       pci_name(pdev), pdev->vendor, pdev->device, pci_rev);
+
+	P9_DPRINTK(P9_DEBUG_TRANS, "%p\n", pdev);
+	p9pci_trans = kzalloc(sizeof(*p9pci_trans), GFP_KERNEL);
+	p9pci_trans->irq = -1;
+	init_waitqueue_head(&p9pci_trans->wait);
+	err = pci_enable_device(pdev);
+	if (err)
+		goto error;
+
+	p9pci_trans->pdev = pdev;
+	err = pci_request_regions(pdev, "9p");
+	if (err)
+		goto error;
+
+	p9pci_trans->ioaddr = pci_iomap(pdev, 0, 8);
+	if (!p9pci_trans->ioaddr) {
+		P9_DPRINTK(P9_DEBUG_ERROR, "Cannot remap MMIO, aborting\n");
+		err = -EIO;
+		goto error;
+	}
+
+	p9pci_trans->tx = pci_iomap(pdev, 1, 0x20000);
+	p9pci_trans->rx = pci_iomap(pdev, 2, 0x20000);
+	pci_set_drvdata(pdev, p9pci_trans);
+	err = request_irq(pdev->irq, &p9pci_interrupt, 0, "p9pci", p9pci_trans);
+	if (err)
+		goto error;
+
+	p9pci_trans->irq = pdev->irq;
+	return 0;
+
+error:
+	P9_DPRINTK(P9_DEBUG_ERROR, "error %d\n", err);
+	if (p9pci_trans->irq >= 0) {
+		synchronize_irq(p9pci_trans->irq);
+		free_irq(p9pci_trans->irq, p9pci_trans);
+	}
+
+	if (p9pci_trans->pdev) {
+		pci_release_regions(pdev);
+		pci_iounmap(pdev, p9pci_trans->ioaddr);
+		pci_set_drvdata(pdev, NULL);
+		pci_disable_device(pdev);
+	}
+
+	kfree(p9pci_trans);
+	return -1;
+}
+
+static void __devexit p9pci_remove(struct pci_dev *pdev)
+{
+	P9_DPRINTK(P9_DEBUG_TRANS, "%p\n", pdev);
+	p9pci_trans = pci_get_drvdata(pdev);
+	if (!p9pci_trans)
+		return;
+
+	if (p9pci_trans->irq) {
+		synchronize_irq(p9pci_trans->irq);
+		free_irq(p9pci_trans->irq, p9pci_trans);
+	}
+
+	pci_release_regions(pdev);
+	pci_iounmap(pdev, p9pci_trans->ioaddr);
+	pci_set_drvdata(pdev, NULL);
+	kfree(p9pci_trans);
+	pci_disable_device(pdev);
+}
+
+static struct pci_driver p9pci_driver = {
+	.name		= P9PCI_DRIVER_NAME,
+	.id_table	= p9pci_tbl,
+	.probe		= p9pci_probe,
+	.remove		= __devexit_p(p9pci_remove),
+};
+
+static struct p9_trans_module p9_pci_trans = {
+	.name = "pci",
+	.maxsize = MAX_PCI_BUF,
+	.def = 0,
+	.create = p9pci_trans_create,
+};
+
+static int __init p9pci_init_module(void)
+{
+	v9fs_register_trans(&p9_pci_trans);
+	return pci_register_driver(&p9pci_driver);
+}
+
+static void __exit p9pci_cleanup_module(void)
+{
+	pci_unregister_driver(&p9pci_driver);
+	printk(KERN_ERR "Removal of 9p transports not implemented\n");
+	BUG();

I think that it would be nicer to implement the p9 transport on top of virtio instead of directly on top of PCI. I think your PCI transport would make a pretty nice start of a PCI virtio transport though.

Regards,

Anthony Liguori

Quoted 364 lines · Eric Van Hensbergen

From: Latchesar Ionkov <lucho-OnYtXJJ0/[email protected]>

This adds a shared memory transport for a synthetic 9p device for paravirtualized file system support under KVM/QEMU.

Signed-off-by Latchesar Ionkov <lucho-OnYtXJJ0/[email protected]>

Signed-off-by Eric Van Hensbergen <[email protected]>

---
 Documentation/filesystems/9p.txt |    2 +
 net/9p/Kconfig                   |   10 ++-
 net/9p/Makefile                  |    4 +
 net/9p/trans_pci.c               |  295 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 310 insertions(+), 1 deletions(-)
 create mode 100644 net/9p/trans_pci.c

Documentation/filesystems/9p.txt +2 -0

index 1a5f50d..e1879bd 100644
@@ -46,6 +46,8 @@ OPTIONS
                      tcp  - specifying a normal TCP/IP connection
                      fd   - used passed file descriptors for connection
                                 (see rfdno and wfdno)
+                     pci  - use a PCI pseudo device for 9p communication
+                             over shared memory between a guest and host
 
   uname=name user name to attempt mount as on the remote server.  The
              server may override or ignore this value.  Certain user

net/9p/Kconfig +9 -1

index 09566ae..8517560 100644
@@ -16,13 +16,21 @@ menuconfig NET_9P
 config NET_9P_FD
      depends on NET_9P
      default y if NET_9P
-     tristate "9P File Descriptor Transports (Experimental)"
+     tristate "9p File Descriptor Transports (Experimental)"
      help
        This builds support for file descriptor transports for 9p
        which includes support for TCP/IP, named pipes, or passed
        file descriptors.  TCP/IP is the default transport for 9p,
        so if you are going to use 9p, you'll likely want this.
 
+config NET_9P_PCI
+     depends on NET_9P
+     tristate "9p PCI Shared Memory Transport (Experimental)"
+     help
+       This builds support for a PCI psuedo-device currently available
+       under KVM/QEMU which allows for 9p transactions over shared
+       memory between the guest and the host.
+
 config NET_9P_DEBUG
      bool "Debug information"
      depends on NET_9P

net/9p/Makefile +4 -0

index 7b2a67a..26ce89d 100644
@@ -1,5 +1,6 @@
 obj-$(CONFIG_NET_9P) := 9pnet.o
 obj-$(CONFIG_NET_9P_FD) += 9pnet_fd.o
+obj-$(CONFIG_NET_9P_PCI) += 9pnet_pci.o
 
 9pnet-objs := \
      mod.o \

@@ -14,3 +15,6 @@ obj-$(CONFIG_NET_9P_FD) += 9pnet_fd.o
 
 9pnet_fd-objs := \
      trans_fd.o \
+
+9pnet_pci-objs := \
+     trans_pci.o \

net/9p/trans_pci.c new file +285 -0

new file mode 100644
index 0000000..36ddc5f
@@ -0,0 +1,295 @@
+/*
+ * net/9p/trans_pci.c
+ *
+ * 9P over PCI transport layer. For use with KVM/QEMU.
+ *
+ *  Copyright (C) 2007 by Latchesar Ionkov <lucho-OnYtXJJ0/[email protected]>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  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:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/compiler.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/completion.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <linux/irq.h>
+#include <linux/poll.h>
+#include <net/9p/9p.h>
+#include <net/9p/transport.h>
+
+#define P9PCI_DRIVER_NAME "9P PCI Device"
+#define P9PCI_DRIVER_VERSION "1"
+
+#define PCI_VENDOR_ID_9P     0x5002
+#define PCI_DEVICE_ID_9P     0x000D
+
+#define MAX_PCI_BUF          (4*1024) /* TODO: Get a number from lucho */
+
+struct p9pci_trans {
+     struct pci_dev          *pdev;
+     void __iomem            *ioaddr;
+     void __iomem            *tx;
+     void __iomem            *rx;
+     int                     irq;
+     int                     pos;
+     int                     len;
+     wait_queue_head_t       wait;
+};
+static struct p9pci_trans *p9pci_trans; /* single channel for now */
+
+static struct pci_device_id p9pci_tbl[] = {
+     {PCI_VENDOR_ID_9P, PCI_DEVICE_ID_9P, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
+     {0,}
+};
+
+static irqreturn_t p9pci_interrupt(int irq, void *dev)
+{
+     p9pci_trans = dev;
+     p9pci_trans->len = le32_to_cpu(readl(p9pci_trans->rx));
+     P9_DPRINTK(P9_DEBUG_TRANS, "%p len %d\n", p9pci_trans->pdev,
+                                                     p9pci_trans->len);
+     iowrite32(0, p9pci_trans->ioaddr + 4);
+     wake_up_interruptible(&p9pci_trans->wait);
+     return IRQ_HANDLED;
+}
+
+static int p9pci_read(struct p9_trans *trans, void *v, int len)
+{
+     struct p9pci_trans *ts;
+
+     if (!trans || trans->status == Disconnected || !trans->priv)
+             return -EREMOTEIO;
+
+     ts = trans->priv;
+
+     P9_DPRINTK(P9_DEBUG_TRANS, "trans %p rx %p tx %p buf %p len %d\n",
+                                             trans, ts->rx, ts->tx, v, len);
+     if (len > ts->len)
+             len = ts->len;
+
+     if (len) {
+             memcpy_fromio(v, ts->rx, len);
+             ts->len = 0;
+             /* let the host knows the message is consumed */
+             writel(0, ts->rx);
+             iowrite32(0, p9pci_trans->ioaddr + 4);
+             P9_DPRINTK(P9_DEBUG_TRANS, "zero rxlen %d txlen %d\n",
+                                             readl(ts->rx), readl(ts->tx));
+     }
+
+     return len;
+}
+
+static int p9pci_write(struct p9_trans *trans, void *v, int len)
+{
+     struct p9pci_trans *ts;
+
+     if (!trans || trans->status == Disconnected || !trans->priv)
+             return -EREMOTEIO;
+
+     ts = trans->priv;
+     P9_DPRINTK(P9_DEBUG_TRANS, "trans %p rx %p tx %p buf %p len %d\n",
+                                             trans, ts->rx, ts->tx, v, len);
+     P9_DPRINTK(P9_DEBUG_TRANS, "rxlen %d\n", readl(ts->rx));
+     if (readb(ts->tx) != 0)
+             return 0;
+
+     P9_DPRINTK(P9_DEBUG_TRANS, "tx addr %p io addr %p\n", ts->tx,
+                                                             ts->ioaddr);
+     memcpy_toio(ts->tx, v, len);
+     iowrite32(len, ts->ioaddr);
+     return len;
+}
+
+static unsigned int
+p9pci_poll(struct p9_trans *trans, struct poll_table_struct *pt)
+{
+     int ret;
+     struct p9pci_trans *ts;
+
+     P9_DPRINTK(P9_DEBUG_TRANS, "trans %p\n", trans);
+     if (!trans || trans->status != Connected || !trans->priv)
+             return -EREMOTEIO;
+
+     ts = trans->priv;
+     poll_wait(NULL, &ts->wait, pt);
+     ret = 0;
+     if (!readl(ts->tx))
+             ret |= POLLOUT;
+     if (readl(ts->rx))
+             ret |= POLLIN;
+
+     P9_DPRINTK(P9_DEBUG_TRANS, "txlen %d rxlen %d\n", readl(ts->tx),
+                                                             readl(ts->rx));
+     return ret;
+}
+
+/**
+ * p9_sock_close - shutdown socket
+ * @trans: private socket structure
+ *
+ */
+static void p9pci_close(struct p9_trans *trans)
+{
+     P9_DPRINTK(P9_DEBUG_TRANS, "trans %p\n", trans);
+}
+
+static struct p9_trans *p9pci_trans_create(const char *name, char *arg)
+{
+     struct p9_trans *trans;
+
+     P9_DPRINTK(P9_DEBUG_TRANS, "\n");
+     trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
+     if (!trans)
+             return ERR_PTR(-ENOMEM);
+
+     trans->status = Connected;
+     trans->write = p9pci_write;
+     trans->read = p9pci_read;
+     trans->close = p9pci_close;
+     trans->poll = p9pci_poll;
+     trans->priv = p9pci_trans;
+     writel(0, p9pci_trans->tx);
+     writel(0, p9pci_trans->rx);
+
+     return trans;
+}
+
+static int __devinit p9pci_probe(struct pci_dev *pdev,
+             const struct pci_device_id *ent)
+{
+     int err;
+     u8 pci_rev;
+
+     if (p9pci_trans)
+             return -1;
+
+     pci_read_config_byte(pdev, PCI_REVISION_ID, &pci_rev);
+
+     if (pdev->vendor == PCI_VENDOR_ID_9P &&
+         pdev->device == PCI_DEVICE_ID_9P)
+             printk(KERN_INFO "pci dev %s (id %04x:%04x rev %02x) is a 9P\n",
+                    pci_name(pdev), pdev->vendor, pdev->device, pci_rev);
+
+     P9_DPRINTK(P9_DEBUG_TRANS, "%p\n", pdev);
+     p9pci_trans = kzalloc(sizeof(*p9pci_trans), GFP_KERNEL);
+     p9pci_trans->irq = -1;
+     init_waitqueue_head(&p9pci_trans->wait);
+     err = pci_enable_device(pdev);
+     if (err)
+             goto error;
+
+     p9pci_trans->pdev = pdev;
+     err = pci_request_regions(pdev, "9p");
+     if (err)
+             goto error;
+
+     p9pci_trans->ioaddr = pci_iomap(pdev, 0, 8);
+     if (!p9pci_trans->ioaddr) {
+             P9_DPRINTK(P9_DEBUG_ERROR, "Cannot remap MMIO, aborting\n");
+             err = -EIO;
+             goto error;
+     }
+
+     p9pci_trans->tx = pci_iomap(pdev, 1, 0x20000);
+     p9pci_trans->rx = pci_iomap(pdev, 2, 0x20000);
+     pci_set_drvdata(pdev, p9pci_trans);
+     err = request_irq(pdev->irq, &p9pci_interrupt, 0, "p9pci", p9pci_trans);
+     if (err)
+             goto error;
+
+     p9pci_trans->irq = pdev->irq;
+     return 0;
+
+error:
+     P9_DPRINTK(P9_DEBUG_ERROR, "error %d\n", err);
+     if (p9pci_trans->irq >= 0) {
+             synchronize_irq(p9pci_trans->irq);
+             free_irq(p9pci_trans->irq, p9pci_trans);
+     }
+
+     if (p9pci_trans->pdev) {
+             pci_release_regions(pdev);
+             pci_iounmap(pdev, p9pci_trans->ioaddr);
+             pci_set_drvdata(pdev, NULL);
+             pci_disable_device(pdev);
+     }
+
+     kfree(p9pci_trans);
+     return -1;
+}
+
+static void __devexit p9pci_remove(struct pci_dev *pdev)
+{
+     P9_DPRINTK(P9_DEBUG_TRANS, "%p\n", pdev);
+     p9pci_trans = pci_get_drvdata(pdev);
+     if (!p9pci_trans)
+             return;
+
+     if (p9pci_trans->irq) {
+             synchronize_irq(p9pci_trans->irq);
+             free_irq(p9pci_trans->irq, p9pci_trans);
+     }
+
+     pci_release_regions(pdev);
+     pci_iounmap(pdev, p9pci_trans->ioaddr);
+     pci_set_drvdata(pdev, NULL);
+     kfree(p9pci_trans);
+     pci_disable_device(pdev);
+}
+
+static struct pci_driver p9pci_driver = {
+     .name           = P9PCI_DRIVER_NAME,
+     .id_table       = p9pci_tbl,
+     .probe          = p9pci_probe,
+     .remove         = __devexit_p(p9pci_remove),
+};
+
+static struct p9_trans_module p9_pci_trans = {
+     .name = "pci",
+     .maxsize = MAX_PCI_BUF,
+     .def = 0,
+     .create = p9pci_trans_create,
+};
+
+static int __init p9pci_init_module(void)
+{
+     v9fs_register_trans(&p9_pci_trans);
+     return pci_register_driver(&p9pci_driver);
+}
+
+static void __exit p9pci_cleanup_module(void)
+{
+     pci_unregister_driver(&p9pci_driver);
+     printk(KERN_ERR "Removal of 9p transports not implemented\n");
+     BUG();

net/9p/trans_pci.c line 295

Quoted 10 lines

net/9p/trans_pci.c new file +10 -0

+}
+
+module_init(p9pci_init_module);
+module_exit(p9pci_cleanup_module);
+
+MODULE_DEVICE_TABLE(pci, p9pci_tbl);
+MODULE_AUTHOR("Latchesar Ionkov <lucho-OnYtXJJ0/[email protected]>");
+MODULE_DESCRIPTION(P9PCI_DRIVER_NAME);
+MODULE_LICENSE("GPL");
+MODULE_VERSION(P9PCI_DRIVER_VERSION);

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That's also in our plans. There was no virtio support in KVM when I started working in the transport.

Thanks,
Lucho

Quoted 1 line · Anthony Liguori

I think that it would be nicer to implement the p9 transport on top

Quoted 20 lines

virtio instead of directly on top of PCI. I think your PCI transport would make a pretty nice start of a PCI virtio transport though.

Regards,

Anthony Liguori

Quoted 12 lines · Eric Van Hensbergen

From: Latchesar Ionkov <lucho-OnYtXJJ0/[email protected]>

This adds a shared memory transport for a synthetic 9p device for paravirtualized file system support under KVM/QEMU.

Signed-off-by Latchesar Ionkov <lucho-OnYtXJJ0/[email protected]>

Signed-off-by Eric Van Hensbergen <[email protected]>

---
 Documentation/filesystems/9p.txt |    2 +
 net/9p/Kconfig                   |   10 ++-
 net/9p/Makefile                  |    4 +
 net/9p/trans_pci.c               |  295

++++++++++++++++++++++++++++++++++++++

Quoted 4 lines

Review

Quoted 4 lines

 4 files changed, 310 insertions(+), 1 deletions(-)
 create mode 100644 net/9p/trans_pci.c

(quoted diff) +0 -0

b/Documentation/filesystems/9p.txt

Quoted 6 lines

Documentation/filesystems/9p.txt OPTIONS · line 47

Quoted 6 lines

index 1a5f50d..e1879bd 100644

Documentation/filesystems/9p.txt +0 -0

@@ -46,6 +46,8 @@ OPTIONS
                      tcp  - specifying a normal TCP/IP connection
                      fd   - used passed file descriptors for

connection

Quoted 2 lines

Documentation/filesystems/9p.txt OPTIONS · line 49

Quoted 2 lines

Documentation/filesystems/9p.txt +1 -0

                                 (see rfdno and wfdno)
+                     pci  - use a PCI pseudo device for 9p

communication

Quoted 1 line

Quoted 1 line

Documentation/filesystems/9p.txt +1 -0

+                             over shared memory between a guest

host

Quoted 2 lines

Documentation/filesystems/9p.txt OPTIONS · line 51

Quoted 2 lines

Documentation/filesystems/9p.txt +0 -0

   uname=name user name to attempt mount as on the remote server.

The

Quoted 1 line

Documentation/filesystems/9p.txt OPTIONS · line 52

Quoted 1 line

Documentation/filesystems/9p.txt +0 -0

              server may override or ignore this value.  Certain

user

Quoted 16 lines

Quoted 16 lines

net/9p/Kconfig +1 -1

index 09566ae..8517560 100644
@@ -16,13 +16,21 @@ menuconfig NET_9P
 config NET_9P_FD
      depends on NET_9P
      default y if NET_9P
-     tristate "9P File Descriptor Transports (Experimental)"
+     tristate "9p File Descriptor Transports (Experimental)"
      help
        This builds support for file descriptor transports for 9p
        which includes support for TCP/IP, named pipes, or passed
        file descriptors.  TCP/IP is the default transport for 9p,
        so if you are going to use 9p, you'll likely want this.
 

Quoted 5 lines

net/9p/Kconfig menuconfig NET_9P

Quoted 5 lines

net/9p/Kconfig +5 -0

+config NET_9P_PCI
+     depends on NET_9P
+     tristate "9p PCI Shared Memory Transport (Experimental)"
+     help
+       This builds support for a PCI psuedo-device currently

available

Quoted 31 lines

Quoted 31 lines

net/9p/Kconfig +3 -0

+       under KVM/QEMU which allows for 9p transactions over shared
+       memory between the guest and the host.
+
 config NET_9P_DEBUG
      bool "Debug information"
      depends on NET_9P

net/9p/Makefile +4 -0

index 7b2a67a..26ce89d 100644
@@ -1,5 +1,6 @@
 obj-$(CONFIG_NET_9P) := 9pnet.o
 obj-$(CONFIG_NET_9P_FD) += 9pnet_fd.o
+obj-$(CONFIG_NET_9P_PCI) += 9pnet_pci.o
 
 9pnet-objs := \
      mod.o \

@@ -14,3 +15,6 @@ obj-$(CONFIG_NET_9P_FD) += 9pnet_fd.o
 
 9pnet_fd-objs := \
      trans_fd.o \
+
+9pnet_pci-objs := \
+     trans_pci.o \

net/9p/trans_pci.c new file +1 -0

new file mode 100644
index 0000000..36ddc5f
@@ -0,0 +1,295 @@
+/*

Quoted 7 lines

net/9p/trans_pci.c

Quoted 7 lines

net/9p/trans_pci.c new file +7 -0

+ * net/9p/trans_pci.c
+ *
+ * 9P over PCI transport layer. For use with KVM/QEMU.
+ *
+ *  Copyright (C) 2007 by Latchesar Ionkov <lucho-OnYtXJJ0/[email protected]>
+ *
+ *  This program is free software; you can redistribute it and/or

modify

Quoted 4 lines

Quoted 4 lines

net/9p/trans_pci.c new file +4 -0

+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be

Quoted 5 lines

net/9p/trans_pci.c

Quoted 5 lines

net/9p/trans_pci.c new file +5 -0

+ *  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

Quoted 21 lines

Quoted 21 lines

net/9p/trans_pci.c new file +21 -0

+ *  along with this program; if not, write to:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/compiler.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/completion.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <linux/irq.h>
+#include <linux/poll.h>
+#include <net/9p/9p.h>
+#include <net/9p/transport.h>

Quoted 8 lines

net/9p/trans_pci.c

Quoted 8 lines

net/9p/trans_pci.c new file +8 -0

+
+#define P9PCI_DRIVER_NAME "9P PCI Device"
+#define P9PCI_DRIVER_VERSION "1"
+
+#define PCI_VENDOR_ID_9P     0x5002
+#define PCI_DEVICE_ID_9P     0x000D
+
+#define MAX_PCI_BUF          (4*1024) /* TODO: Get a number from

lucho */

Quoted 4 lines

Quoted 4 lines

net/9p/trans_pci.c new file +4 -0

+
+struct p9pci_trans {
+     struct pci_dev          *pdev;
+     void __iomem            *ioaddr;

Quoted 8 lines

net/9p/trans_pci.c

Quoted 8 lines

net/9p/trans_pci.c new file +8 -0

+     void __iomem            *tx;
+     void __iomem            *rx;
+     int                     irq;
+     int                     pos;
+     int                     len;
+     wait_queue_head_t       wait;
+};
+static struct p9pci_trans *p9pci_trans; /* single channel for now

*/

Quoted 3 lines

net/9p/trans_pci.c

Quoted 3 lines

net/9p/trans_pci.c new file +3 -0

+
+static struct pci_device_id p9pci_tbl[] = {
+     {PCI_VENDOR_ID_9P, PCI_DEVICE_ID_9P, PCI_ANY_ID, PCI_ANY_ID,

0, 0, 0 },

Quoted 10 lines

net/9p/trans_pci.c

Quoted 9 lines

net/9p/trans_pci.c new file +9 -0

+     {0,}
+};
+
+static irqreturn_t p9pci_interrupt(int irq, void *dev)
+{
+     p9pci_trans = dev;
+     p9pci_trans->len = le32_to_cpu(readl(p9pci_trans->rx));
+     P9_DPRINTK(P9_DEBUG_TRANS, "%p len %d\n", p9pci_trans->pdev,
+                                                     p9pci_trans-

len);

Quoted 7 lines

Quoted 7 lines

net/9p/trans_pci.c new file +7 -0

+     iowrite32(0, p9pci_trans->ioaddr + 4);
+     wake_up_interruptible(&p9pci_trans->wait);
+     return IRQ_HANDLED;
+}
+
+static int p9pci_read(struct p9_trans *trans, void *v, int len)
+{

Quoted 8 lines

net/9p/trans_pci.c

Quoted 8 lines

net/9p/trans_pci.c new file +8 -0

+     struct p9pci_trans *ts;
+
+     if (!trans || trans->status == Disconnected || !trans->priv)
+             return -EREMOTEIO;
+
+     ts = trans->priv;
+
+     P9_DPRINTK(P9_DEBUG_TRANS, "trans %p rx %p tx %p buf %p len

%d\n",

Quoted 1 line

Quoted 1 line

net/9p/trans_pci.c new file +1 -0

+                                             trans, ts->rx,

v, len);

Quoted 10 lines

Quoted 10 lines

net/9p/trans_pci.c new file +10 -0

+     if (len > ts->len)
+             len = ts->len;
+
+     if (len) {
+             memcpy_fromio(v, ts->rx, len);
+             ts->len = 0;
+             /* let the host knows the message is consumed */
+             writel(0, ts->rx);
+             iowrite32(0, p9pci_trans->ioaddr + 4);
+             P9_DPRINTK(P9_DEBUG_TRANS, "zero rxlen %d txlen

Quoted 1 line

net/9p/trans_pci.c line 97

Quoted 1 line

net/9p/trans_pci.c new file +1 -0

+                                             readl(ts->rx),

readl(ts->tx));

Quoted 6 lines

Quoted 6 lines

net/9p/trans_pci.c new file +6 -0

+     }
+
+     return len;
+}
+
+static int p9pci_write(struct p9_trans *trans, void *v, int len)

Quoted 8 lines

net/9p/trans_pci.c

Quoted 8 lines

net/9p/trans_pci.c new file +8 -0

+{
+     struct p9pci_trans *ts;
+
+     if (!trans || trans->status == Disconnected || !trans->priv)
+             return -EREMOTEIO;
+
+     ts = trans->priv;
+     P9_DPRINTK(P9_DEBUG_TRANS, "trans %p rx %p tx %p buf %p len

%d\n",

Quoted 1 line

Quoted 1 line

net/9p/trans_pci.c new file +1 -0

+                                             trans, ts->rx,

v, len);

Quoted 24 lines

net/9p/trans_pci.c

Quoted 6 lines

net/9p/trans_pci.c new file +6 -0

+     P9_DPRINTK(P9_DEBUG_TRANS, "rxlen %d\n", readl(ts->rx));
+     if (readb(ts->tx) != 0)
+             return 0;
+
+     P9_DPRINTK(P9_DEBUG_TRANS, "tx addr %p io addr %p\n", ts->tx,
+                                                             ts-

ioaddr);

Quoted 17 lines

net/9p/trans_pci.c new file +17 -0

+     memcpy_toio(ts->tx, v, len);
+     iowrite32(len, ts->ioaddr);
+     return len;
+}
+
+static unsigned int
+p9pci_poll(struct p9_trans *trans, struct poll_table_struct *pt)
+{
+     int ret;
+     struct p9pci_trans *ts;
+
+     P9_DPRINTK(P9_DEBUG_TRANS, "trans %p\n", trans);
+     if (!trans || trans->status != Connected || !trans->priv)
+             return -EREMOTEIO;
+
+     ts = trans->priv;
+     poll_wait(NULL, &ts->wait, pt);

Quoted 9 lines

net/9p/trans_pci.c

Quoted 7 lines

net/9p/trans_pci.c new file +7 -0

+     ret = 0;
+     if (!readl(ts->tx))
+             ret |= POLLOUT;
+     if (readl(ts->rx))
+             ret |= POLLIN;
+
+     P9_DPRINTK(P9_DEBUG_TRANS, "txlen %d rxlen %d\n", readl(ts-

tx),

Quoted 1 line

net/9p/trans_pci.c new file +1 -0

+

readl(ts->rx));

Quoted 6 lines

Quoted 6 lines

net/9p/trans_pci.c new file +6 -0

+     return ret;
+}
+
+/**
+ * p9_sock_close - shutdown socket
+ * @trans: private socket structure

Quoted 8 lines

net/9p/trans_pci.c

Quoted 8 lines

net/9p/trans_pci.c new file +8 -0

+ *
+ */
+static void p9pci_close(struct p9_trans *trans)
+{
+     P9_DPRINTK(P9_DEBUG_TRANS, "trans %p\n", trans);
+}
+
+static struct p9_trans *p9pci_trans_create(const char *name, char

*arg)

Quoted 26 lines

Quoted 26 lines

net/9p/trans_pci.c new file +26 -0

+{
+     struct p9_trans *trans;
+
+     P9_DPRINTK(P9_DEBUG_TRANS, "\n");
+     trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
+     if (!trans)
+             return ERR_PTR(-ENOMEM);
+
+     trans->status = Connected;
+     trans->write = p9pci_write;
+     trans->read = p9pci_read;
+     trans->close = p9pci_close;
+     trans->poll = p9pci_poll;
+     trans->priv = p9pci_trans;
+     writel(0, p9pci_trans->tx);
+     writel(0, p9pci_trans->rx);
+
+     return trans;
+}
+
+static int __devinit p9pci_probe(struct pci_dev *pdev,
+             const struct pci_device_id *ent)
+{
+     int err;
+     u8 pci_rev;
+

Quoted 8 lines

net/9p/trans_pci.c

Quoted 8 lines

net/9p/trans_pci.c new file +8 -0

+     if (p9pci_trans)
+             return -1;
+
+     pci_read_config_byte(pdev, PCI_REVISION_ID, &pci_rev);
+
+     if (pdev->vendor == PCI_VENDOR_ID_9P &&
+         pdev->device == PCI_DEVICE_ID_9P)
+             printk(KERN_INFO "pci dev %s (id %04x:%04x rev %02x)

is a 9P\n",

Quoted 1 line

net/9p/trans_pci.c line 192

Quoted 1 line

net/9p/trans_pci.c new file +1 -0

+                    pci_name(pdev), pdev->vendor, pdev->device,

pci_rev);

Quoted 9 lines

Quoted 9 lines

net/9p/trans_pci.c new file +9 -0

+
+     P9_DPRINTK(P9_DEBUG_TRANS, "%p\n", pdev);
+     p9pci_trans = kzalloc(sizeof(*p9pci_trans), GFP_KERNEL);
+     p9pci_trans->irq = -1;
+     init_waitqueue_head(&p9pci_trans->wait);
+     err = pci_enable_device(pdev);
+     if (err)
+             goto error;
+

Quoted 8 lines

net/9p/trans_pci.c

Quoted 8 lines

net/9p/trans_pci.c new file +8 -0

+     p9pci_trans->pdev = pdev;
+     err = pci_request_regions(pdev, "9p");
+     if (err)
+             goto error;
+
+     p9pci_trans->ioaddr = pci_iomap(pdev, 0, 8);
+     if (!p9pci_trans->ioaddr) {
+             P9_DPRINTK(P9_DEBUG_ERROR, "Cannot remap MMIO,

aborting\n");

Quoted 8 lines

net/9p/trans_pci.c

Quoted 8 lines

net/9p/trans_pci.c new file +8 -0

+             err = -EIO;
+             goto error;
+     }
+
+     p9pci_trans->tx = pci_iomap(pdev, 1, 0x20000);
+     p9pci_trans->rx = pci_iomap(pdev, 2, 0x20000);
+     pci_set_drvdata(pdev, p9pci_trans);
+     err = request_irq(pdev->irq, &p9pci_interrupt, 0, "p9pci",

p9pci_trans);

Quoted 59 lines

Quoted 59 lines

net/9p/trans_pci.c new file +59 -0

+     if (err)
+             goto error;
+
+     p9pci_trans->irq = pdev->irq;
+     return 0;
+
+error:
+     P9_DPRINTK(P9_DEBUG_ERROR, "error %d\n", err);
+     if (p9pci_trans->irq >= 0) {
+             synchronize_irq(p9pci_trans->irq);
+             free_irq(p9pci_trans->irq, p9pci_trans);
+     }
+
+     if (p9pci_trans->pdev) {
+             pci_release_regions(pdev);
+             pci_iounmap(pdev, p9pci_trans->ioaddr);
+             pci_set_drvdata(pdev, NULL);
+             pci_disable_device(pdev);
+     }
+
+     kfree(p9pci_trans);
+     return -1;
+}
+
+static void __devexit p9pci_remove(struct pci_dev *pdev)
+{
+     P9_DPRINTK(P9_DEBUG_TRANS, "%p\n", pdev);
+     p9pci_trans = pci_get_drvdata(pdev);
+     if (!p9pci_trans)
+             return;
+
+     if (p9pci_trans->irq) {
+             synchronize_irq(p9pci_trans->irq);
+             free_irq(p9pci_trans->irq, p9pci_trans);
+     }
+
+     pci_release_regions(pdev);
+     pci_iounmap(pdev, p9pci_trans->ioaddr);
+     pci_set_drvdata(pdev, NULL);
+     kfree(p9pci_trans);
+     pci_disable_device(pdev);
+}
+
+static struct pci_driver p9pci_driver = {
+     .name           = P9PCI_DRIVER_NAME,
+     .id_table       = p9pci_tbl,
+     .probe          = p9pci_probe,
+     .remove         = __devexit_p(p9pci_remove),
+};
+
+static struct p9_trans_module p9_pci_trans = {
+     .name = "pci",
+     .maxsize = MAX_PCI_BUF,
+     .def = 0,
+     .create = p9pci_trans_create,
+};
+
+static int __init p9pci_init_module(void)
+{

Quoted 8 lines

net/9p/trans_pci.c

Quoted 8 lines

net/9p/trans_pci.c new file +8 -0

+     v9fs_register_trans(&p9_pci_trans);
+     return pci_register_driver(&p9pci_driver);
+}
+
+static void __exit p9pci_cleanup_module(void)
+{
+     pci_unregister_driver(&p9pci_driver);
+     printk(KERN_ERR "Removal of 9p transports not

Quoted 6 lines

Quoted 6 lines

net/9p/trans_pci.c new file +6 -0

+     BUG();
+}
+
+module_init(p9pci_init_module);
+module_exit(p9pci_cleanup_module);
+

Quoted 8 lines

net/9p/trans_pci.c line 295

Quoted 5 lines

net/9p/trans_pci.c new file +5 -0

+MODULE_DEVICE_TABLE(pci, p9pci_tbl);
+MODULE_AUTHOR("Latchesar Ionkov <lucho-OnYtXJJ0/[email protected]>");
+MODULE_DESCRIPTION(P9PCI_DRIVER_NAME);
+MODULE_LICENSE("GPL");
+MODULE_VERSION(P9PCI_DRIVER_VERSION);

---

Quoted 3 lines

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Quoted 6 lines

Download your FREE copy of Splunk now >> http://get.splunk.com/
_______________________________________________
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https://lists.sourceforge.net/lists/listinfo/v9fs-developer

_______________________________________________
Lguest mailing list
[email protected]
https://ozlabs.org/mailman/listinfo/lguest

This patch set contains a set of virtualization transports for the 9p file system intended to provide a mechanism for guests to access a portion of the hosts name space without having to go through a virtualized network.

The lguest and kvm transports are functional, but we are still working out remaining bugs and need to spend some time focusing on performance issues. I wanted to send out this "preview" patch set to the community to solicit ideas on things we can do differently/better.

Quoted 4 lines · Eric Van Hensbergen

The lguest and kvm transports are functional, but we are still working out remaining bugs and need to spend some time focusing on performance issues. I wanted to send out this "preview" patch set to the community to solicit ideas on things we can do differently/better.

Patches look reasonable, but just a heads-up: lguest will be moving to
virtio, as will kvm. That means a single implementation for both (yay!), but it does complicate your life in the short term 8(

Dor has published a kvm virtio implementation, and we've already
discussed a couple of modifications. I expect that to be nailed in the next 2 weeks tho, and lguest will follow.