My current view of the IO stack is the following: -------------- -------------- ------------ ---------- ---------- --------- |NET_PCI_BACK| |BLK_PCI_BACK| |9P_PCI_BACK| |NET_FRONT| |BLK_FRONT| |9P_FRONT| -------------- -------------- ------------ ---------- ---------- ---------
------------- --------------- ------------------- |KVM_PCI_BUS| |hypercall_ops| |shared_mem_virtio| ------------- --------------- ------------------- So the 9P implementation should add the front end logic and the p9_pci_backend that glues the shared_memory, pci_bus and hypercalls together. >That's also in our plans. There was no virtio support in KVM when I >started working in the transport. > >Thanks, > Lucho > >On 8/29/07, Anthony Liguori <[EMAIL PROTECTED]> wrote: >> 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 >> >> On Tue, 2007-08-28 at 13:52 -0500, Eric Van Hensbergen wrote: >> > From: Latchesar Ionkov <[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 <[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 >> > >> > diff --git a/Documentation/filesystems/9p.txt >b/Documentation/filesystems/9p.txt >> > index 1a5f50d..e1879bd 100644 >> > --- a/Documentation/filesystems/9p.txt >> > +++ b/Documentation/filesystems/9p.txt >> > @@ -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 >> > diff --git a/net/9p/Kconfig b/net/9p/Kconfig >> > index 09566ae..8517560 100644 >> > --- a/net/9p/Kconfig >> > +++ b/net/9p/Kconfig >> > @@ -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 >> > diff --git a/net/9p/Makefile b/net/9p/Makefile >> > index 7b2a67a..26ce89d 100644 >> > --- a/net/9p/Makefile >> > +++ b/net/9p/Makefile >> > @@ -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 \ >> > diff --git a/net/9p/trans_pci.c b/net/9p/trans_pci.c >> > new file mode 100644 >> > index 0000000..36ddc5f >> > --- /dev/null >> > +++ b/net/9p/trans_pci.c >> > @@ -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 <[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(); >> > +} >> > + >> > +module_init(p9pci_init_module); >> > +module_exit(p9pci_cleanup_module); >> > + >> > +MODULE_DEVICE_TABLE(pci, p9pci_tbl); >> > +MODULE_AUTHOR("Latchesar Ionkov <[EMAIL PROTECTED]>"); >> > +MODULE_DESCRIPTION(P9PCI_DRIVER_NAME); >> > +MODULE_LICENSE("GPL"); >> > +MODULE_VERSION(P9PCI_DRIVER_VERSION); >> >> >> ---------------------------------------------------------------------- >--- >> This SF.net email is sponsored by: Splunk Inc. >> Still grepping through log files to find problems? 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