[PATCH v9 0/7] PCI: Linux kernel SR-IOV support

[PATCH v9 0/7] PCI: Linux kernel SR-IOV support

[Yu Zhao]

Greetings,

Following patches are intended to support SR-IOV capability in the
Linux kernel. With these patches, people can turn a PCI device with
the capability into multiple ones from software perspective, which
will benefit KVM and achieve other purposes such as QoS, security,
and etc.

SR-IOV specification can be found at:
http://www.pcisig.com/members/downloads/specifications/iov/sr-iov1.0_11Sep07.pdf
(it requires membership.)

Devices that support SR-IOV are available from following vendors:
http://download.intel.com/design/network/ProdBrf/320025.pdf
http://www.myri.com/vlsi/Lanai_Z8ES_Datasheet.pdf
http://www.neterion.com/products/pdfs/X3100ProductBrief.pdf

Physical Function driver for Intel 82576 NIC (based on drivers/net/igb/)
will come soon.

Major changes from v8 to v9:
  1, put a might_sleep() into SR-IOV API which sleeps (Andi Kleen)
  2, block user config accesses before clearing VF Enable bit (Matthew Wilcox)

Yu Zhao (7):
  PCI: initialize and release SR-IOV capability
  PCI: restore saved SR-IOV state
  PCI: reserve bus range for SR-IOV device
  PCI: add SR-IOV API for Physical Function driver
  PCI: handle SR-IOV Virtual Function Migration
  PCI: document SR-IOV sysfs entries
  PCI: manual for SR-IOV user and driver developer

 Documentation/ABI/testing/sysfs-bus-pci |   27 ++
 Documentation/DocBook/kernel-api.tmpl   |    1 +
 Documentation/PCI/pci-iov-howto.txt     |   99 +++++
 drivers/pci/Kconfig                     |   13 +
 drivers/pci/Makefile                    |    3 +
 drivers/pci/iov.c                       |  707 +++++++++++++++++++++++++++++++
 drivers/pci/pci.c                       |    8 +
 drivers/pci/pci.h                       |   53 +++
 drivers/pci/probe.c                     |    7 +
 include/linux/pci.h                     |   28 ++
 include/linux/pci_regs.h                |   33 ++
 11 files changed, 979 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/PCI/pci-iov-howto.txt
 create mode 100644 drivers/pci/iov.c

[PATCH v9 1/7] PCI: initialize and release SR-IOV capability

[Yu Zhao]

Signed-off-by: Yu Zhao <yu.zhao@intel.com>
---
 drivers/pci/Kconfig      |   13 ++++
 drivers/pci/Makefile     |    3 +
 drivers/pci/iov.c        |  181 ++++++++++++++++++++++++++++++++++++++++++++++
 drivers/pci/pci.c        |    7 ++
 drivers/pci/pci.h        |   37 ++++++++++
 drivers/pci/probe.c      |    4 +
 include/linux/pci.h      |    8 ++
 include/linux/pci_regs.h |   33 +++++++++
 8 files changed, 286 insertions(+), 0 deletions(-)
 create mode 100644 drivers/pci/iov.c

diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 2a4501d..e8ea3e8 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -59,3 +59,16 @@ config HT_IRQ
 	   This allows native hypertransport devices to use interrupts.
 
 	   If unsure say Y.
+
+config PCI_IOV
+	bool "PCI IOV support"
+	depends on PCI
+	select PCI_MSI
+	default n
+	help
+	  PCI-SIG I/O Virtualization (IOV) Specifications support.
+	  Single Root IOV: allows the Physical Function driver to enable
+	  the hardware capability, so the Virtual Function is accessible
+	  via the PCI Configuration Space using its own Bus, Device and
+	  Function Numbers. Each Virtual Function also has the PCI Memory
+	  Space to map the device specific register set.
diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index 3d07ce2..ba99282 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -29,6 +29,9 @@ obj-$(CONFIG_DMAR) += dmar.o iova.o intel-iommu.o
 
 obj-$(CONFIG_INTR_REMAP) += dmar.o intr_remapping.o
 
+# PCI IOV support
+obj-$(CONFIG_PCI_IOV) += iov.o
+
 #
 # Some architectures use the generic PCI setup functions
 #
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
new file mode 100644
index 0000000..e6736d4
--- /dev/null
+++ b/drivers/pci/iov.c
@@ -0,0 +1,181 @@
+/*
+ * drivers/pci/iov.c
+ *
+ * Copyright (C) 2009 Intel Corporation, Yu Zhao <yu.zhao@intel.com>
+ *
+ * PCI Express I/O Virtualization (IOV) support.
+ *   Single Root IOV 1.0
+ */
+
+#include <linux/pci.h>
+#include <linux/mutex.h>
+#include <linux/string.h>
+#include <linux/delay.h>
+#include "pci.h"
+
+
+static int sriov_init(struct pci_dev *dev, int pos)
+{
+	int i;
+	int rc;
+	int nres;
+	u32 pgsz;
+	u16 ctrl, total, offset, stride;
+	struct pci_sriov *iov;
+	struct resource *res;
+	struct pci_dev *pdev;
+
+	if (dev->pcie_type != PCI_EXP_TYPE_RC_END &&
+	    dev->pcie_type != PCI_EXP_TYPE_ENDPOINT)
+		return -ENODEV;
+
+	pci_read_config_word(dev, pos + PCI_SRIOV_CTRL, &ctrl);
+	if (ctrl & PCI_SRIOV_CTRL_VFE) {
+		pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0);
+		ssleep(1);
+	}
+
+	pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
+	if (!total)
+		return 0;
+
+	list_for_each_entry(pdev, &dev->bus->devices, bus_list)
+		if (pdev->sriov)
+			break;
+	if (list_empty(&dev->bus->devices) || !pdev->sriov)
+		pdev = NULL;
+
+	ctrl = 0;
+	if (!pdev && pci_ari_enabled(dev->bus))
+		ctrl |= PCI_SRIOV_CTRL_ARI;
+
+	pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
+	pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, total);
+	pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset);
+	pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride);
+	if (!offset || (total > 1 && !stride))
+		return -EIO;
+
+	pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
+	i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
+	pgsz &= ~((1 << i) - 1);
+	if (!pgsz)
+		return -EIO;
+
+	pgsz &= ~(pgsz - 1);
+	pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
+
+	nres = 0;
+	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
+		res = dev->resource + PCI_SRIOV_RESOURCES + i;
+		i += __pci_read_base(dev, pci_bar_unknown, res,
+				     pos + PCI_SRIOV_BAR + i * 4);
+		if (!res->flags)
+			continue;
+		if (resource_size(res) & (PAGE_SIZE - 1)) {
+			rc = -EIO;
+			goto failed;
+		}
+		res->end = res->start + resource_size(res) * total - 1;
+		nres++;
+	}
+
+	iov = kzalloc(sizeof(*iov), GFP_KERNEL);
+	if (!iov) {
+		rc = -ENOMEM;
+		goto failed;
+	}
+
+	iov->pos = pos;
+	iov->nres = nres;
+	iov->ctrl = ctrl;
+	iov->total = total;
+	iov->offset = offset;
+	iov->stride = stride;
+	iov->pgsz = pgsz;
+	iov->self = dev;
+	pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
+	pci_read_config_byte(dev, pos + PCI_SRIOV_FUNC_LINK, &iov->link);
+
+	if (pdev)
+		iov->pdev = pci_dev_get(pdev);
+	else {
+		iov->pdev = dev;
+		mutex_init(&iov->lock);
+	}
+
+	dev->sriov = iov;
+
+	return 0;
+
+failed:
+	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
+		res = dev->resource + PCI_SRIOV_RESOURCES + i;
+		res->flags = 0;
+	}
+
+	return rc;
+}
+
+static void sriov_release(struct pci_dev *dev)
+{
+	if (dev == dev->sriov->pdev)
+		mutex_destroy(&dev->sriov->lock);
+	else
+		pci_dev_put(dev->sriov->pdev);
+
+	kfree(dev->sriov);
+	dev->sriov = NULL;
+}
+
+/**
+ * pci_iov_init - initialize the IOV capability
+ * @dev: the PCI device
+ *
+ * Returns 0 on success, or negative on failure.
+ */
+int pci_iov_init(struct pci_dev *dev)
+{
+	int pos;
+
+	if (!dev->is_pcie)
+		return -ENODEV;
+
+	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
+	if (pos)
+		return sriov_init(dev, pos);
+
+	return -ENODEV;
+}
+
+/**
+ * pci_iov_release - release resources used by the IOV capability
+ * @dev: the PCI device
+ */
+void pci_iov_release(struct pci_dev *dev)
+{
+	if (dev->sriov)
+		sriov_release(dev);
+}
+
+/**
+ * pci_iov_resource_bar - get position of the SR-IOV BAR
+ * @dev: the PCI device
+ * @resno: the resource number
+ * @type: the BAR type to be filled in
+ *
+ * Returns position of the BAR encapsulated in the SR-IOV capability.
+ */
+int pci_iov_resource_bar(struct pci_dev *dev, int resno,
+			 enum pci_bar_type *type)
+{
+	if (resno < PCI_SRIOV_RESOURCES || resno > PCI_SRIOV_RESOURCE_END)
+		return 0;
+
+	BUG_ON(!dev->sriov);
+
+	*type = pci_bar_unknown;
+
+	return dev->sriov->pos + PCI_SRIOV_BAR +
+		4 * (resno - PCI_SRIOV_RESOURCES);
+}
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e3efe6b..c4f14f3 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2341,12 +2341,19 @@ int pci_select_bars(struct pci_dev *dev, unsigned long flags)
  */
 int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type)
 {
+	int reg;
+
 	if (resno < PCI_ROM_RESOURCE) {
 		*type = pci_bar_unknown;
 		return PCI_BASE_ADDRESS_0 + 4 * resno;
 	} else if (resno == PCI_ROM_RESOURCE) {
 		*type = pci_bar_mem32;
 		return dev->rom_base_reg;
+	} else if (resno < PCI_BRIDGE_RESOURCES) {
+		/* device specific resource */
+		reg = pci_iov_resource_bar(dev, resno, type);
+		if (reg)
+			return reg;
 	}
 
 	dev_err(&dev->dev, "BAR: invalid resource #%d\n", resno);
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 26ddf78..d2dc6b7 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -195,4 +195,41 @@ static inline int pci_ari_enabled(struct pci_bus *bus)
 	return bus->self && bus->self->ari_enabled;
 }
 
+/* Single Root I/O Virtualization */
+struct pci_sriov {
+	int pos;		/* capability position */
+	int nres;		/* number of resources */
+	u32 cap;		/* SR-IOV Capabilities */
+	u16 ctrl;		/* SR-IOV Control */
+	u16 total;		/* total VFs associated with the PF */
+	u16 offset;		/* first VF Routing ID offset */
+	u16 stride;		/* following VF stride */
+	u32 pgsz;		/* page size for BAR alignment */
+	u8 link;		/* Function Dependency Link */
+	struct pci_dev *pdev;	/* lowest numbered PF */
+	struct pci_dev *self;	/* this PF */
+	struct mutex lock;	/* lock for VF bus */
+};
+
+#ifdef CONFIG_PCI_IOV
+extern int pci_iov_init(struct pci_dev *dev);
+extern void pci_iov_release(struct pci_dev *dev);
+extern int pci_iov_resource_bar(struct pci_dev *dev, int resno,
+				enum pci_bar_type *type);
+#else
+static inline int pci_iov_init(struct pci_dev *dev)
+{
+	return -ENODEV;
+}
+static inline void pci_iov_release(struct pci_dev *dev)
+
+{
+}
+static inline int pci_iov_resource_bar(struct pci_dev *dev, int resno,
+				       enum pci_bar_type *type)
+{
+	return 0;
+}
+#endif /* CONFIG_PCI_IOV */
+
 #endif /* DRIVERS_PCI_H */
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 55ec44a..03b6f29 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -785,6 +785,7 @@ static int pci_setup_device(struct pci_dev * dev)
 static void pci_release_capabilities(struct pci_dev *dev)
 {
 	pci_vpd_release(dev);
+	pci_iov_release(dev);
 }
 
 /**
@@ -972,6 +973,9 @@ static void pci_init_capabilities(struct pci_dev *dev)
 
 	/* Alternative Routing-ID Forwarding */
 	pci_enable_ari(dev);
+
+	/* Single Root I/O Virtualization */
+	pci_iov_init(dev);
 }
 
 void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 7bd624b..f4d740e 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -93,6 +93,12 @@ enum {
 	/* #6: expansion ROM resource */
 	PCI_ROM_RESOURCE,
 
+	/* device specific resources */
+#ifdef CONFIG_PCI_IOV
+	PCI_SRIOV_RESOURCES,
+	PCI_SRIOV_RESOURCE_END = PCI_SRIOV_RESOURCES + PCI_SRIOV_NUM_BARS - 1,
+#endif
+
 	/* resources assigned to buses behind the bridge */
 #define PCI_BRIDGE_RESOURCE_NUM 4
 
@@ -180,6 +186,7 @@ struct pci_cap_saved_state {
 
 struct pcie_link_state;
 struct pci_vpd;
+struct pci_sriov;
 
 /*
  * The pci_dev structure is used to describe PCI devices.
@@ -270,6 +277,7 @@ struct pci_dev {
 	struct list_head msi_list;
 #endif
 	struct pci_vpd *vpd;
+	struct pci_sriov *sriov;	/* SR-IOV capability related */
 };
 
 extern struct pci_dev *alloc_pci_dev(void);
diff --git a/include/linux/pci_regs.h b/include/linux/pci_regs.h
index 027815b..4ce5eb0 100644
--- a/include/linux/pci_regs.h
+++ b/include/linux/pci_regs.h
@@ -375,6 +375,7 @@
 #define  PCI_EXP_TYPE_UPSTREAM	0x5	/* Upstream Port */
 #define  PCI_EXP_TYPE_DOWNSTREAM 0x6	/* Downstream Port */
 #define  PCI_EXP_TYPE_PCI_BRIDGE 0x7	/* PCI/PCI-X Bridge */
+#define  PCI_EXP_TYPE_RC_END	0x9	/* Root Complex Integrated Endpoint */
 #define PCI_EXP_FLAGS_SLOT	0x0100	/* Slot implemented */
 #define PCI_EXP_FLAGS_IRQ	0x3e00	/* Interrupt message number */
 #define PCI_EXP_DEVCAP		4	/* Device capabilities */
@@ -498,6 +499,7 @@
 #define PCI_EXT_CAP_ID_DSN	3
 #define PCI_EXT_CAP_ID_PWR	4
 #define PCI_EXT_CAP_ID_ARI	14
+#define PCI_EXT_CAP_ID_SRIOV	16
 
 /* Advanced Error Reporting */
 #define PCI_ERR_UNCOR_STATUS	4	/* Uncorrectable Error Status */
@@ -615,4 +617,35 @@
 #define  PCI_ARI_CTRL_ACS	0x0002	/* ACS Function Groups Enable */
 #define  PCI_ARI_CTRL_FG(x)	(((x) >> 4) & 7) /* Function Group */
 
+/* Single Root I/O Virtualization */
+#define PCI_SRIOV_CAP		0x04	/* SR-IOV Capabilities */
+#define  PCI_SRIOV_CAP_VFM	0x01	/* VF Migration Capable */
+#define  PCI_SRIOV_CAP_INTR(x)	((x) >> 21) /* Interrupt Message Number */
+#define PCI_SRIOV_CTRL		0x08	/* SR-IOV Control */
+#define  PCI_SRIOV_CTRL_VFE	0x01	/* VF Enable */
+#define  PCI_SRIOV_CTRL_VFM	0x02	/* VF Migration Enable */
+#define  PCI_SRIOV_CTRL_INTR	0x04	/* VF Migration Interrupt Enable */
+#define  PCI_SRIOV_CTRL_MSE	0x08	/* VF Memory Space Enable */
+#define  PCI_SRIOV_CTRL_ARI	0x10	/* ARI Capable Hierarchy */
+#define PCI_SRIOV_STATUS	0x0a	/* SR-IOV Status */
+#define  PCI_SRIOV_STATUS_VFM	0x01	/* VF Migration Status */
+#define PCI_SRIOV_INITIAL_VF	0x0c	/* Initial VFs */
+#define PCI_SRIOV_TOTAL_VF	0x0e	/* Total VFs */
+#define PCI_SRIOV_NUM_VF	0x10	/* Number of VFs */
+#define PCI_SRIOV_FUNC_LINK	0x12	/* Function Dependency Link */
+#define PCI_SRIOV_VF_OFFSET	0x14	/* First VF Offset */
+#define PCI_SRIOV_VF_STRIDE	0x16	/* Following VF Stride */
+#define PCI_SRIOV_VF_DID	0x1a	/* VF Device ID */
+#define PCI_SRIOV_SUP_PGSIZE	0x1c	/* Supported Page Sizes */
+#define PCI_SRIOV_SYS_PGSIZE	0x20	/* System Page Size */
+#define PCI_SRIOV_BAR		0x24	/* VF BAR0 */
+#define  PCI_SRIOV_NUM_BARS	6	/* Number of VF BARs */
+#define PCI_SRIOV_VFM		0x3c	/* VF Migration State Array Offset*/
+#define  PCI_SRIOV_VFM_BIR(x)	((x) & 7)	/* State BIR */
+#define  PCI_SRIOV_VFM_OFFSET(x) ((x) & ~7)	/* State Offset */
+#define  PCI_SRIOV_VFM_UA	0x0	/* Inactive.Unavailable */
+#define  PCI_SRIOV_VFM_MI	0x1	/* Dormant.MigrateIn */
+#define  PCI_SRIOV_VFM_MO	0x2	/* Active.MigrateOut */
+#define  PCI_SRIOV_VFM_AV	0x3	/* Active.Available */
+
 #endif /* LINUX_PCI_REGS_H */
-- 
1.5.6.4

[PATCH v9 2/7] PCI: restore saved SR-IOV state

[Yu Zhao]

Signed-off-by: Yu Zhao <yu.zhao@intel.com>
---
 drivers/pci/iov.c |   25 +++++++++++++++++++++++++
 drivers/pci/pci.c |    1 +
 drivers/pci/pci.h |    4 ++++
 3 files changed, 30 insertions(+), 0 deletions(-)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index e6736d4..1cc879b 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -128,6 +128,21 @@ static void sriov_release(struct pci_dev *dev)
 	dev->sriov = NULL;
 }
 
+static void sriov_restore_state(struct pci_dev *dev)
+{
+	u16 ctrl;
+	struct pci_sriov *iov = dev->sriov;
+
+	pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &ctrl);
+	if (ctrl & PCI_SRIOV_CTRL_VFE)
+		return;
+
+	pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
+	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
+	if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
+		msleep(100);
+}
+
 /**
  * pci_iov_init - initialize the IOV capability
  * @dev: the PCI device
@@ -179,3 +194,13 @@ int pci_iov_resource_bar(struct pci_dev *dev, int resno,
 	return dev->sriov->pos + PCI_SRIOV_BAR +
 		4 * (resno - PCI_SRIOV_RESOURCES);
 }
+
+/**
+ * pci_restore_iov_state - restore the state of the IOV capability
+ * @dev: the PCI device
+ */
+void pci_restore_iov_state(struct pci_dev *dev)
+{
+	if (dev->sriov)
+		sriov_restore_state(dev);
+}
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index c4f14f3..f791dcf 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -773,6 +773,7 @@ pci_restore_state(struct pci_dev *dev)
 	}
 	pci_restore_pcix_state(dev);
 	pci_restore_msi_state(dev);
+	pci_restore_iov_state(dev);
 
 	return 0;
 }
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index d2dc6b7..9d76737 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -216,6 +216,7 @@ extern int pci_iov_init(struct pci_dev *dev);
 extern void pci_iov_release(struct pci_dev *dev);
 extern int pci_iov_resource_bar(struct pci_dev *dev, int resno,
 				enum pci_bar_type *type);
+extern void pci_restore_iov_state(struct pci_dev *dev);
 #else
 static inline int pci_iov_init(struct pci_dev *dev)
 {
@@ -230,6 +231,9 @@ static inline int pci_iov_resource_bar(struct pci_dev *dev, int resno,
 {
 	return 0;
 }
+static inline void pci_restore_iov_state(struct pci_dev *dev)
+{
+}
 #endif /* CONFIG_PCI_IOV */
 
 #endif /* DRIVERS_PCI_H */
-- 
1.5.6.4

[PATCH v9 3/7] PCI: reserve bus range for SR-IOV device

[Yu Zhao]

Signed-off-by: Yu Zhao <yu.zhao@intel.com>
---
 drivers/pci/iov.c   |   34 ++++++++++++++++++++++++++++++++++
 drivers/pci/pci.h   |    5 +++++
 drivers/pci/probe.c |    3 +++
 3 files changed, 42 insertions(+), 0 deletions(-)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 1cc879b..c89fcb1 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -14,6 +14,16 @@
 #include "pci.h"
 
 
+static inline void virtfn_bdf(struct pci_dev *dev, int id, u8 *busnr, u8 *devfn)
+{
+	u16 bdf;
+
+	bdf = (dev->bus->number << 8) + dev->devfn +
+	      dev->sriov->offset + dev->sriov->stride * id;
+	*busnr = bdf >> 8;
+	*devfn = bdf & 0xff;
+}
+
 static int sriov_init(struct pci_dev *dev, int pos)
 {
 	int i;
@@ -204,3 +214,27 @@ void pci_restore_iov_state(struct pci_dev *dev)
 	if (dev->sriov)
 		sriov_restore_state(dev);
 }
+
+/**
+ * pci_iov_bus_range - find bus range used by Virtual Function
+ * @bus: the PCI bus
+ *
+ * Returns max number of buses (exclude current one) used by Virtual
+ * Functions.
+ */
+int pci_iov_bus_range(struct pci_bus *bus)
+{
+	int max = 0;
+	u8 busnr, devfn;
+	struct pci_dev *dev;
+
+	list_for_each_entry(dev, &bus->devices, bus_list) {
+		if (!dev->sriov)
+			continue;
+		virtfn_bdf(dev, dev->sriov->total - 1, &busnr, &devfn);
+		if (busnr > max)
+			max = busnr;
+	}
+
+	return max ? max - bus->number : 0;
+}
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 9d76737..fdfc476 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -217,6 +217,7 @@ extern void pci_iov_release(struct pci_dev *dev);
 extern int pci_iov_resource_bar(struct pci_dev *dev, int resno,
 				enum pci_bar_type *type);
 extern void pci_restore_iov_state(struct pci_dev *dev);
+extern int pci_iov_bus_range(struct pci_bus *bus);
 #else
 static inline int pci_iov_init(struct pci_dev *dev)
 {
@@ -234,6 +235,10 @@ static inline int pci_iov_resource_bar(struct pci_dev *dev, int resno,
 static inline void pci_restore_iov_state(struct pci_dev *dev)
 {
 }
+static inline int pci_iov_bus_range(struct pci_bus *bus)
+{
+	return 0;
+}
 #endif /* CONFIG_PCI_IOV */
 
 #endif /* DRIVERS_PCI_H */
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 03b6f29..4c8abd0 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1078,6 +1078,9 @@ unsigned int __devinit pci_scan_child_bus(struct pci_bus *bus)
 	for (devfn = 0; devfn < 0x100; devfn += 8)
 		pci_scan_slot(bus, devfn);
 
+	/* Reserve buses for SR-IOV capability. */
+	max += pci_iov_bus_range(bus);
+
 	/*
 	 * After performing arch-dependent fixup of the bus, look behind
 	 * all PCI-to-PCI bridges on this bus.
-- 
1.5.6.4

[PATCH v9 4/7] PCI: add SR-IOV API for Physical Function driver

[Yu Zhao]

Signed-off-by: Yu Zhao <yu.zhao@intel.com>
---
 drivers/pci/iov.c   |  348 +++++++++++++++++++++++++++++++++++++++++++++++++++
 drivers/pci/pci.h   |    3 +
 include/linux/pci.h |   14 ++
 3 files changed, 365 insertions(+), 0 deletions(-)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index c89fcb1..e4e2dac 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -13,6 +13,8 @@
 #include <linux/delay.h>
 #include "pci.h"
 
+#define VIRTFN_ID_LEN	8
+
 
 static inline void virtfn_bdf(struct pci_dev *dev, int id, u8 *busnr, u8 *devfn)
 {
@@ -24,6 +26,319 @@ static inline void virtfn_bdf(struct pci_dev *dev, int id, u8 *busnr, u8 *devfn)
 	*devfn = bdf & 0xff;
 }
 
+static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
+{
+	int rc;
+	struct pci_bus *child;
+
+	if (bus->number == busnr)
+		return bus;
+
+	child = pci_find_bus(pci_domain_nr(bus), busnr);
+	if (child)
+		return child;
+
+	child = pci_add_new_bus(bus, NULL, busnr);
+	if (!child)
+		return NULL;
+
+	child->subordinate = busnr;
+	child->dev.parent = bus->bridge;
+	rc = pci_bus_add_child(child);
+	if (rc) {
+		pci_remove_bus(child);
+		return NULL;
+	}
+
+	return child;
+}
+
+static void virtfn_remove_bus(struct pci_bus *bus, int busnr)
+{
+	struct pci_bus *child;
+
+	if (bus->number == busnr)
+		return;
+
+	child = pci_find_bus(pci_domain_nr(bus), busnr);
+	BUG_ON(!child);
+
+	if (list_empty(&child->devices))
+		pci_remove_bus(child);
+}
+
+static int virtfn_add(struct pci_dev *dev, int id, int reset)
+{
+	int i;
+	int rc;
+	u64 size;
+	u8 busnr, devfn;
+	char buf[VIRTFN_ID_LEN];
+	struct pci_dev *virtfn;
+	struct resource *res;
+	struct pci_sriov *iov = dev->sriov;
+
+	virtfn = alloc_pci_dev();
+	if (!virtfn)
+		return -ENOMEM;
+
+	virtfn_bdf(dev, id, &busnr, &devfn);
+	mutex_lock(&iov->pdev->sriov->lock);
+	virtfn->bus = virtfn_add_bus(dev->bus, busnr);
+	if (!virtfn->bus) {
+		kfree(virtfn);
+		mutex_unlock(&iov->pdev->sriov->lock);
+		return -ENOMEM;
+	}
+
+	virtfn->sysdata = dev->bus->sysdata;
+	virtfn->dev.parent = dev->dev.parent;
+	virtfn->dev.bus = dev->dev.bus;
+	virtfn->devfn = devfn;
+	virtfn->hdr_type = PCI_HEADER_TYPE_NORMAL;
+	virtfn->cfg_size = PCI_CFG_SPACE_EXP_SIZE;
+	virtfn->error_state = pci_channel_io_normal;
+	virtfn->current_state = PCI_UNKNOWN;
+	virtfn->is_pcie = 1;
+	virtfn->pcie_type = PCI_EXP_TYPE_ENDPOINT;
+	virtfn->dma_mask = 0xffffffff;
+	virtfn->vendor = dev->vendor;
+	virtfn->subsystem_vendor = dev->subsystem_vendor;
+	virtfn->class = dev->class;
+	pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device);
+	pci_read_config_byte(virtfn, PCI_REVISION_ID, &virtfn->revision);
+	pci_read_config_word(virtfn, PCI_SUBSYSTEM_ID,
+			     &virtfn->subsystem_device);
+
+	dev_set_name(&virtfn->dev, "%04x:%02x:%02x.%d",
+		     pci_domain_nr(virtfn->bus), busnr,
+		     PCI_SLOT(devfn), PCI_FUNC(devfn));
+
+	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
+		res = dev->resource + PCI_SRIOV_RESOURCES + i;
+		if (!res->parent)
+			continue;
+		virtfn->resource[i].name = pci_name(virtfn);
+		virtfn->resource[i].flags = res->flags;
+		size = resource_size(res);
+		do_div(size, iov->total);
+		virtfn->resource[i].start = res->start + size * id;
+		virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
+		rc = request_resource(res, &virtfn->resource[i]);
+		BUG_ON(rc);
+	}
+
+	if (reset)
+		pci_execute_reset_function(virtfn);
+
+	pci_device_add(virtfn, virtfn->bus);
+	mutex_unlock(&iov->pdev->sriov->lock);
+
+	virtfn->physfn = pci_dev_get(dev);
+
+	rc = pci_bus_add_device(virtfn);
+	if (rc)
+		goto failed1;
+	sprintf(buf, "%d", id);
+	rc = sysfs_create_link(&iov->dev.kobj, &virtfn->dev.kobj, buf);
+	if (rc)
+		goto failed1;
+	rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
+	if (rc)
+		goto failed2;
+
+	kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
+
+	return 0;
+
+failed2:
+	sysfs_remove_link(&iov->dev.kobj, buf);
+failed1:
+	pci_dev_put(dev);
+	mutex_lock(&iov->pdev->sriov->lock);
+	pci_remove_bus_device(virtfn);
+	virtfn_remove_bus(dev->bus, busnr);
+	mutex_unlock(&iov->pdev->sriov->lock);
+
+	return rc;
+}
+
+static void virtfn_remove(struct pci_dev *dev, int id, int reset)
+{
+	u8 busnr, devfn;
+	char buf[VIRTFN_ID_LEN];
+	struct pci_bus *bus;
+	struct pci_dev *virtfn;
+	struct pci_sriov *iov = dev->sriov;
+
+	virtfn_bdf(dev, id, &busnr, &devfn);
+	bus = pci_find_bus(pci_domain_nr(dev->bus), busnr);
+	if (!bus)
+		return;
+
+	virtfn = pci_get_slot(bus, devfn);
+	if (!virtfn)
+		return;
+
+	pci_dev_put(virtfn);
+
+	if (reset) {
+		device_release_driver(&virtfn->dev);
+		pci_execute_reset_function(virtfn);
+	}
+
+	sprintf(buf, "%d", id);
+	sysfs_remove_link(&iov->dev.kobj, buf);
+	sysfs_remove_link(&virtfn->dev.kobj, "physfn");
+
+	mutex_lock(&iov->pdev->sriov->lock);
+	pci_remove_bus_device(virtfn);
+	virtfn_remove_bus(dev->bus, busnr);
+	mutex_unlock(&iov->pdev->sriov->lock);
+
+	pci_dev_put(dev);
+}
+
+static void sriov_release_dev(struct device *dev)
+{
+	struct pci_sriov *iov = container_of(dev, struct pci_sriov, dev);
+
+	iov->nr_virtfn = 0;
+}
+
+static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
+{
+	int rc;
+	int i, j;
+	int nres;
+	u8 busnr, devfn;
+	u16 offset, stride, initial;
+	struct resource *res;
+	struct pci_dev *link;
+	struct pci_sriov *iov = dev->sriov;
+
+	if (!nr_virtfn)
+		return 0;
+
+	if (iov->nr_virtfn)
+		return -EINVAL;
+
+	pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
+	if (initial > iov->total ||
+	    (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total)))
+		return -EIO;
+
+	if (nr_virtfn < 0 || nr_virtfn > iov->total ||
+	    (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
+		return -EINVAL;
+
+	pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
+	pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &offset);
+	pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &stride);
+	if (!offset || (nr_virtfn > 1 && !stride))
+		return -EIO;
+
+	nres = 0;
+	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
+		res = dev->resource + PCI_SRIOV_RESOURCES + i;
+		if (!res->parent)
+			continue;
+		nres++;
+	}
+	if (nres != iov->nres) {
+		dev_err(&dev->dev, "no enough MMIO for SR-IOV\n");
+		return -ENOMEM;
+	}
+
+	iov->offset = offset;
+	iov->stride = stride;
+
+	virtfn_bdf(dev, nr_virtfn - 1, &busnr, &devfn);
+	if (busnr > dev->bus->subordinate) {
+		dev_err(&dev->dev, "no enough bus range for SR-IOV\n");
+		return -ENOMEM;
+	}
+
+	memset(&iov->dev, 0, sizeof(iov->dev));
+	strcpy(iov->dev.bus_id, "virtfn");
+	iov->dev.parent = &dev->dev;
+	iov->dev.release = sriov_release_dev;
+	rc = device_register(&iov->dev);
+	if (rc)
+		return rc;
+
+	if (iov->link != dev->devfn) {
+		rc = -ENODEV;
+		list_for_each_entry(link, &dev->bus->devices, bus_list) {
+			if (link->sriov && link->devfn == iov->link)
+				rc = sysfs_create_link(&iov->dev.kobj,
+						&link->dev.kobj, "dep_link");
+		}
+		if (rc)
+			goto failed1;
+	}
+
+	iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
+	pci_block_user_cfg_access(dev);
+	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
+	msleep(100);
+	pci_unblock_user_cfg_access(dev);
+
+	iov->initial = initial;
+	if (nr_virtfn < initial)
+		initial = nr_virtfn;
+
+	for (i = 0; i < initial; i++) {
+		rc = virtfn_add(dev, i, 0);
+		if (rc)
+			goto failed2;
+	}
+
+	kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
+	iov->nr_virtfn = nr_virtfn;
+
+	return 0;
+
+failed2:
+	for (j = 0; j < i; j++)
+		virtfn_remove(dev, j, 0);
+
+	iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
+	pci_block_user_cfg_access(dev);
+	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
+	ssleep(1);
+	pci_unblock_user_cfg_access(dev);
+
+	if (iov->link != dev->devfn)
+		sysfs_remove_link(&iov->dev.kobj, "dep_link");
+failed1:
+	device_unregister(&iov->dev);
+
+	return rc;
+}
+
+static void sriov_disable(struct pci_dev *dev)
+{
+	int i;
+	struct pci_sriov *iov = dev->sriov;
+
+	if (!iov->nr_virtfn)
+		return;
+
+	for (i = 0; i < iov->nr_virtfn; i++)
+		virtfn_remove(dev, i, 0);
+
+	iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
+	pci_block_user_cfg_access(dev);
+	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
+	ssleep(1);
+	pci_unblock_user_cfg_access(dev);
+
+	if (iov->link != dev->devfn)
+		sysfs_remove_link(&iov->dev.kobj, "dep_link");
+	device_unregister(&iov->dev);
+}
+
 static int sriov_init(struct pci_dev *dev, int pos)
 {
 	int i;
@@ -129,6 +444,8 @@ failed:
 
 static void sriov_release(struct pci_dev *dev)
 {
+	BUG_ON(dev->sriov->nr_virtfn);
+
 	if (dev == dev->sriov->pdev)
 		mutex_destroy(&dev->sriov->lock);
 	else
@@ -148,6 +465,7 @@ static void sriov_restore_state(struct pci_dev *dev)
 		return;
 
 	pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
+	pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, iov->nr_virtfn);
 	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 	if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
 		msleep(100);
@@ -238,3 +556,33 @@ int pci_iov_bus_range(struct pci_bus *bus)
 
 	return max ? max - bus->number : 0;
 }
+
+/**
+ * pci_enable_sriov - enable the SR-IOV capability
+ * @dev: the PCI device
+ *
+ * Returns 0 on success, or negative on failure.
+ */
+int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
+{
+	might_sleep();
+
+	if (!dev->sriov)
+		return -ENODEV;
+
+	return sriov_enable(dev, nr_virtfn);
+}
+EXPORT_SYMBOL_GPL(pci_enable_sriov);
+
+/**
+ * pci_disable_sriov - disable the SR-IOV capability
+ * @dev: the PCI device
+ */
+void pci_disable_sriov(struct pci_dev *dev)
+{
+	might_sleep();
+
+	if (dev->sriov)
+		sriov_disable(dev);
+}
+EXPORT_SYMBOL_GPL(pci_disable_sriov);
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index fdfc476..328a611 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -202,6 +202,8 @@ struct pci_sriov {
 	u32 cap;		/* SR-IOV Capabilities */
 	u16 ctrl;		/* SR-IOV Control */
 	u16 total;		/* total VFs associated with the PF */
+	u16 initial;		/* initial VFs associated with the PF */
+	u16 nr_virtfn;		/* number of VFs available */
 	u16 offset;		/* first VF Routing ID offset */
 	u16 stride;		/* following VF stride */
 	u32 pgsz;		/* page size for BAR alignment */
@@ -209,6 +211,7 @@ struct pci_sriov {
 	struct pci_dev *pdev;	/* lowest numbered PF */
 	struct pci_dev *self;	/* this PF */
 	struct mutex lock;	/* lock for VF bus */
+	struct device dev;
 };
 
 #ifdef CONFIG_PCI_IOV
diff --git a/include/linux/pci.h b/include/linux/pci.h
index f4d740e..3a24ff5 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -278,6 +278,7 @@ struct pci_dev {
 #endif
 	struct pci_vpd *vpd;
 	struct pci_sriov *sriov;	/* SR-IOV capability related */
+	struct pci_dev *physfn;	/* Physical Function the device belongs to */
 };
 
 extern struct pci_dev *alloc_pci_dev(void);
@@ -1202,5 +1203,18 @@ int pci_ext_cfg_avail(struct pci_dev *dev);
 
 void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar);
 
+#ifdef CONFIG_PCI_IOV
+extern int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn);
+extern void pci_disable_sriov(struct pci_dev *dev);
+#else
+static inline int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
+{
+	return -ENODEV;
+}
+static inline void pci_disable_sriov(struct pci_dev *dev)
+{
+}
+#endif
+
 #endif /* __KERNEL__ */
 #endif /* LINUX_PCI_H */
-- 
1.5.6.4

[PATCH v9 5/7] PCI: handle SR-IOV Virtual Function Migration

[Yu Zhao]

Signed-off-by: Yu Zhao <yu.zhao@intel.com>
---
 drivers/pci/iov.c   |  119 +++++++++++++++++++++++++++++++++++++++++++++++++++
 drivers/pci/pci.h   |    4 ++
 include/linux/pci.h |    6 +++
 3 files changed, 129 insertions(+), 0 deletions(-)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index e4e2dac..127f643 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -206,6 +206,97 @@ static void sriov_release_dev(struct device *dev)
 	iov->nr_virtfn = 0;
 }
 
+static int sriov_migration(struct pci_dev *dev)
+{
+	u16 status;
+	struct pci_sriov *iov = dev->sriov;
+
+	if (!iov->nr_virtfn)
+		return 0;
+
+	if (!(iov->cap & PCI_SRIOV_CAP_VFM))
+		return 0;
+
+	pci_read_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, &status);
+	if (!(status & PCI_SRIOV_STATUS_VFM))
+		return 0;
+
+	schedule_work(&iov->mtask);
+
+	return 1;
+}
+
+static void sriov_migration_task(struct work_struct *work)
+{
+	int i;
+	u8 state;
+	u16 status;
+	struct pci_sriov *iov = container_of(work, struct pci_sriov, mtask);
+
+	for (i = iov->initial; i < iov->nr_virtfn; i++) {
+		state = readb(iov->mstate + i);
+		if (state == PCI_SRIOV_VFM_MI) {
+			writeb(PCI_SRIOV_VFM_AV, iov->mstate + i);
+			state = readb(iov->mstate + i);
+			if (state == PCI_SRIOV_VFM_AV)
+				virtfn_add(iov->self, i, 1);
+		} else if (state == PCI_SRIOV_VFM_MO) {
+			virtfn_remove(iov->self, i, 1);
+			writeb(PCI_SRIOV_VFM_UA, iov->mstate + i);
+			state = readb(iov->mstate + i);
+			if (state == PCI_SRIOV_VFM_AV)
+				virtfn_add(iov->self, i, 0);
+		}
+	}
+
+	pci_read_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, &status);
+	status &= ~PCI_SRIOV_STATUS_VFM;
+	pci_write_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, status);
+}
+
+static int sriov_enable_migration(struct pci_dev *dev, int nr_virtfn)
+{
+	int bir;
+	u32 table;
+	resource_size_t pa;
+	struct pci_sriov *iov = dev->sriov;
+
+	if (nr_virtfn <= iov->initial)
+		return 0;
+
+	pci_read_config_dword(dev, iov->pos + PCI_SRIOV_VFM, &table);
+	bir = PCI_SRIOV_VFM_BIR(table);
+	if (bir > PCI_STD_RESOURCE_END)
+		return -EIO;
+
+	table = PCI_SRIOV_VFM_OFFSET(table);
+	if (table + nr_virtfn > pci_resource_len(dev, bir))
+		return -EIO;
+
+	pa = pci_resource_start(dev, bir) + table;
+	iov->mstate = ioremap(pa, nr_virtfn);
+	if (!iov->mstate)
+		return -ENOMEM;
+
+	INIT_WORK(&iov->mtask, sriov_migration_task);
+
+	iov->ctrl |= PCI_SRIOV_CTRL_VFM | PCI_SRIOV_CTRL_INTR;
+	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
+
+	return 0;
+}
+
+static void sriov_disable_migration(struct pci_dev *dev)
+{
+	struct pci_sriov *iov = dev->sriov;
+
+	iov->ctrl &= ~(PCI_SRIOV_CTRL_VFM | PCI_SRIOV_CTRL_INTR);
+	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
+
+	cancel_work_sync(&iov->mtask);
+	iounmap(iov->mstate);
+}
+
 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 {
 	int rc;
@@ -294,6 +385,12 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 			goto failed2;
 	}
 
+	if (iov->cap & PCI_SRIOV_CAP_VFM) {
+		rc = sriov_enable_migration(dev, nr_virtfn);
+		if (rc)
+			goto failed2;
+	}
+
 	kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
 	iov->nr_virtfn = nr_virtfn;
 
@@ -325,6 +422,9 @@ static void sriov_disable(struct pci_dev *dev)
 	if (!iov->nr_virtfn)
 		return;
 
+	if (iov->cap & PCI_SRIOV_CAP_VFM)
+		sriov_disable_migration(dev);
+
 	for (i = 0; i < iov->nr_virtfn; i++)
 		virtfn_remove(dev, i, 0);
 
@@ -586,3 +686,22 @@ void pci_disable_sriov(struct pci_dev *dev)
 		sriov_disable(dev);
 }
 EXPORT_SYMBOL_GPL(pci_disable_sriov);
+
+/**
+ * pci_sriov_migration - notify SR-IOV core of Virtual Function Migration
+ * @dev: the PCI device
+ *
+ * Returns IRQ_HANDLED if the IRQ is handled, or IRQ_NONE if not.
+ *
+ * Physical Function driver is responsible to register IRQ handler using
+ * VF Migration Interrupt Message Number, and call this function when the
+ * interrupt is generated by the hardware.
+ */
+irqreturn_t pci_sriov_migration(struct pci_dev *dev)
+{
+	if (!dev->sriov)
+		return IRQ_NONE;
+
+	return sriov_migration(dev) ? IRQ_HANDLED : IRQ_NONE;
+}
+EXPORT_SYMBOL_GPL(pci_sriov_migration);
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 328a611..51bebb2 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -1,6 +1,8 @@
 #ifndef DRIVERS_PCI_H
 #define DRIVERS_PCI_H
 
+#include <linux/workqueue.h>
+
 #define PCI_CFG_SPACE_SIZE	256
 #define PCI_CFG_SPACE_EXP_SIZE	4096
 
@@ -211,6 +213,8 @@ struct pci_sriov {
 	struct pci_dev *pdev;	/* lowest numbered PF */
 	struct pci_dev *self;	/* this PF */
 	struct mutex lock;	/* lock for VF bus */
+	struct work_struct mtask; /* VF Migration task */
+	u8 __iomem *mstate;	/* VF Migration State Array */
 	struct device dev;
 };
 
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 3a24ff5..d16b913 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -52,6 +52,7 @@
 #include <asm/atomic.h>
 #include <linux/device.h>
 #include <linux/io.h>
+#include <linux/irqreturn.h>
 
 /* Include the ID list */
 #include <linux/pci_ids.h>
@@ -1206,6 +1207,7 @@ void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar);
 #ifdef CONFIG_PCI_IOV
 extern int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn);
 extern void pci_disable_sriov(struct pci_dev *dev);
+extern irqreturn_t pci_sriov_migration(struct pci_dev *dev);
 #else
 static inline int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 {
@@ -1214,6 +1216,10 @@ static inline int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 static inline void pci_disable_sriov(struct pci_dev *dev)
 {
 }
+static inline irqreturn_t pci_sriov_migration(struct pci_dev *dev)
+{
+	return IRQ_NONE;
+}
 #endif
 
 #endif /* __KERNEL__ */
-- 
1.5.6.4

[PATCH v9 6/7] PCI: document SR-IOV sysfs entries

[Yu Zhao]

Signed-off-by: Yu Zhao <yu.zhao@intel.com>
---
 Documentation/ABI/testing/sysfs-bus-pci |   27 +++++++++++++++++++++++++++
 1 files changed, 27 insertions(+), 0 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index ceddcff..84dc100 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -9,3 +9,30 @@ Description:
 		that some devices may have malformatted data.  If the
 		underlying VPD has a writable section then the
 		corresponding section of this file will be writable.
+
+What:		/sys/bus/pci/devices/.../virtfn/N
+Date:		February 2009
+Contact:	Yu Zhao <yu.zhao@intel.com>
+Description:
+		This symbol link appears when hardware supports SR-IOV
+		capability and Physical Function driver has enabled it.
+		The symbol link points to the PCI device sysfs entry of
+		Virtual Function whose index is N (0...MaxVFs-1).
+
+What:		/sys/bus/pci/devices/.../virtfn/dep_link
+Date:		February 2009
+Contact:	Yu Zhao <yu.zhao@intel.com>
+Description:
+		This symbol link appears when hardware supports SR-IOV
+		capability and Physical Function driver has enabled it,
+		and this device has vendor specific dependencies with
+		others. The symbol link points to the PCI device sysfs
+		entry of Physical Function this device depends on.
+
+What:		/sys/bus/pci/devices/.../physfn
+Date:		February 2009
+Contact:	Yu Zhao <yu.zhao@intel.com>
+Description:
+		This symbol link appears when a device is Virtual Function.
+		The symbol link points to the PCI device sysfs entry of
+		Physical Function this device associates with.
-- 
1.5.6.4

[PATCH v9 7/7] PCI: manual for SR-IOV user and driver developer

[Yu Zhao]

Signed-off-by: Yu Zhao <yu.zhao@intel.com>
---
 Documentation/DocBook/kernel-api.tmpl |    1 +
 Documentation/PCI/pci-iov-howto.txt   |   99 +++++++++++++++++++++++++++++++++
 2 files changed, 100 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/PCI/pci-iov-howto.txt

diff --git a/Documentation/DocBook/kernel-api.tmpl b/Documentation/DocBook/kernel-api.tmpl
index 5818ff7..506e611 100644
--- a/Documentation/DocBook/kernel-api.tmpl
+++ b/Documentation/DocBook/kernel-api.tmpl
@@ -251,6 +251,7 @@ X!Edrivers/pci/hotplug.c
 -->
 !Edrivers/pci/probe.c
 !Edrivers/pci/rom.c
+!Edrivers/pci/iov.c
      </sect1>
      <sect1><title>PCI Hotplug Support Library</title>
 !Edrivers/pci/hotplug/pci_hotplug_core.c
diff --git a/Documentation/PCI/pci-iov-howto.txt b/Documentation/PCI/pci-iov-howto.txt
new file mode 100644
index 0000000..fc73ef5
--- /dev/null
+++ b/Documentation/PCI/pci-iov-howto.txt
@@ -0,0 +1,99 @@
+		PCI Express I/O Virtualization Howto
+		Copyright (C) 2009 Intel Corporation
+		    Yu Zhao <yu.zhao@intel.com>
+
+
+1. Overview
+
+1.1 What is SR-IOV
+
+Single Root I/O Virtualization (SR-IOV) is a PCI Express Extended
+capability which makes one physical device appear as multiple virtual
+devices. The physical device is referred to as Physical Function (PF)
+while the virtual devices are referred to as Virtual Functions (VF).
+Allocation of the VF can be dynamically controlled by the PF via
+registers encapsulated in the capability. By default, this feature is
+not enabled and the PF behaves as traditional PCIe device. Once it's
+turned on, each VF's PCI configuration space can be accessed by its own
+Bus, Device and Function Number (Routing ID). And each VF also has PCI
+Memory Space, which is used to map its register set. VF device driver
+operates on the register set so it can be functional and appear as a
+real existing PCI device.
+
+2. User Guide
+
+2.1 How can I enable SR-IOV capability
+
+The device driver (PF driver) will control the enabling and disabling
+of the capability via API provided by SR-IOV core. If the hardware
+has SR-IOV capability, loading its PF driver would enable it and all
+VFs associated with the PF.
+
+2.2 How can I use the Virtual Functions
+
+The VF is treated as hot-plugged PCI devices in the kernel, so they
+should be able to work in the same way as real PCI devices. The VF
+requires device driver that is same as a normal PCI device's.
+
+3. Developer Guide
+
+3.1 SR-IOV API
+
+To enable SR-IOV capability:
+	int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn);
+	'nr_virtfn' is number of VFs to be enabled.
+
+To disable SR-IOV capability:
+	void pci_disable_sriov(struct pci_dev *dev);
+
+To notify SR-IOV core of Virtual Function Migration:
+	irqreturn_t pci_sriov_migration(struct pci_dev *dev);
+
+3.2 Usage example
+
+Following piece of code illustrates the usage of the SR-IOV API.
+
+static int __devinit dev_probe(struct pci_dev *dev, const struct pci_device_id *id)
+{
+	pci_enable_sriov(dev, NR_VIRTFN);
+
+	...
+
+	return 0;
+}
+
+static void __devexit dev_remove(struct pci_dev *dev)
+{
+	pci_disable_sriov(dev);
+
+	...
+}
+
+static int dev_suspend(struct pci_dev *dev, pm_message_t state)
+{
+	...
+
+	return 0;
+}
+
+static int dev_resume(struct pci_dev *dev)
+{
+	...
+
+	return 0;
+}
+
+static void dev_shutdown(struct pci_dev *dev)
+{
+	...
+}
+
+static struct pci_driver dev_driver = {
+	.name =		"SR-IOV Physical Function driver",
+	.id_table =	dev_id_table,
+	.probe =	dev_probe,
+	.remove =	__devexit_p(dev_remove),
+	.suspend =	dev_suspend,
+	.resume =	dev_resume,
+	.shutdown =	dev_shutdown,
+};
-- 
1.5.6.4

Re: [PATCH v9 6/7] PCI: document SR-IOV sysfs entries

[Yu Zhao]

Hi Greg,

The `struct device' is preferred over the `struct kobject' in all cases
that create subdirectory in sysfs, is this true?

I'd like to create a subdirectory under PCI device sysfs directory and
put some symbol links into that directory (only symbol links). Should I
use `device' or `kobject'? Currently I use `device' and get two extra
file/directory (uevent and power) which look like useless for my case
because this subdirectory doesn't reflect a real device.

I checked some code and found they use kobject_init_and_add(). Should
I use it instead, or keep using the `device'?

Please advise.

Regards,
Yu

On Mon, Feb 16, 2009 at 09:28:39PM +0800, Zhao, Yu wrote:
> Signed-off-by: Yu Zhao <yu.zhao@intel.com>
> ---
>  Documentation/ABI/testing/sysfs-bus-pci |   27 +++++++++++++++++++++++++++
>  1 files changed, 27 insertions(+), 0 deletions(-)
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
> index ceddcff..84dc100 100644
> --- a/Documentation/ABI/testing/sysfs-bus-pci
> +++ b/Documentation/ABI/testing/sysfs-bus-pci
> @@ -9,3 +9,30 @@ Description:
>  		that some devices may have malformatted data.  If the
>  		underlying VPD has a writable section then the
>  		corresponding section of this file will be writable.
> +
> +What:		/sys/bus/pci/devices/.../virtfn/N
> +Date:		February 2009
> +Contact:	Yu Zhao <yu.zhao@intel.com>
> +Description:
> +		This symbol link appears when hardware supports SR-IOV
> +		capability and Physical Function driver has enabled it.
> +		The symbol link points to the PCI device sysfs entry of
> +		Virtual Function whose index is N (0...MaxVFs-1).
> +
> +What:		/sys/bus/pci/devices/.../virtfn/dep_link
> +Date:		February 2009
> +Contact:	Yu Zhao <yu.zhao@intel.com>
> +Description:
> +		This symbol link appears when hardware supports SR-IOV
> +		capability and Physical Function driver has enabled it,
> +		and this device has vendor specific dependencies with
> +		others. The symbol link points to the PCI device sysfs
> +		entry of Physical Function this device depends on.
> +
> +What:		/sys/bus/pci/devices/.../physfn
> +Date:		February 2009
> +Contact:	Yu Zhao <yu.zhao@intel.com>
> +Description:
> +		This symbol link appears when a device is Virtual Function.
> +		The symbol link points to the PCI device sysfs entry of
> +		Physical Function this device associates with.
> -- 
> 1.5.6.4
> 

Re: [PATCH v9 6/7] PCI: document SR-IOV sysfs entries

[Yu Zhao]

On Tue, Feb 17, 2009 at 08:50:21PM +0800, Yu Zhao wrote:
> Hi Greg,
> 
> The `struct device' is preferred over the `struct kobject' in all cases
> that create subdirectory in sysfs, is this true?
> 
> I'd like to create a subdirectory under PCI device sysfs directory and
> put some symbol links into that directory (only symbol links). Should I
> use `device' or `kobject'? Currently I use `device' and get two extra
> file/directory (uevent and power) which look like useless for my case
> because this subdirectory doesn't reflect a real device.
> 
> I checked some code and found they use kobject_init_and_add(). Should

Oh, sorry. I meant to say kobject_create_and_add() here.

> I use it instead, or keep using the `device'?
> 
> Please advise.
> 
> Regards,
> Yu

Re: [PATCH v9 6/7] PCI: document SR-IOV sysfs entries

[Yu Zhao]

On Wed, Feb 18, 2009 at 11:49:10AM +0800, Greg KH wrote:
> On Tue, Feb 17, 2009 at 08:50:21PM +0800, Yu Zhao wrote:
> > Hi Greg,
> > 
> > The `struct device' is preferred over the `struct kobject' in all cases
> > that create subdirectory in sysfs, is this true?
> 
> If you have a parent directory being controlled by a struct device, yes.

Thanks! Do we need to document this somewhere?

> > I'd like to create a subdirectory under PCI device sysfs directory and
> > put some symbol links into that directory (only symbol links). Should I
> > use `device' or `kobject'? Currently I use `device' and get two extra
> > file/directory (uevent and power) which look like useless for my case
> > because this subdirectory doesn't reflect a real device.
> 
> Neither, just use an attribute group, no new struct device should be
> needed at all.

Yes, I was thinking using an attribute group, however, it looks like we
can't put symbol link into a group. Maybe I'm wrong, shed some light,
please?

Regards,
Yu

Re: [PATCH v9 6/7] PCI: document SR-IOV sysfs entries

[Yu Zhao]

On Wed, Feb 18, 2009 at 02:21:16PM +0800, Greg KH wrote:
> On Tue, Feb 17, 2009 at 10:43:03PM +0800, Yu Zhao wrote:
> > On Wed, Feb 18, 2009 at 11:49:10AM +0800, Greg KH wrote:
> > > On Tue, Feb 17, 2009 at 08:50:21PM +0800, Yu Zhao wrote:
> > > > I'd like to create a subdirectory under PCI device sysfs directory and
> > > > put some symbol links into that directory (only symbol links). Should I
> > > > use `device' or `kobject'? Currently I use `device' and get two extra
> > > > file/directory (uevent and power) which look like useless for my case
> > > > because this subdirectory doesn't reflect a real device.
> > > 
> > > Neither, just use an attribute group, no new struct device should be
> > > needed at all.
> > 
> > Yes, I was thinking using an attribute group, however, it looks like we
> > can't put symbol link into a group. Maybe I'm wrong, shed some light,
> > please?
> 
> Why would you want a symbolic link in an attribute group?

Sorry I didn't make myself clear. I'd like to create a subdirectory (its
parent is controlled by a `struct device') to only hold symbol links. Can
I use an `attribute group' of the parent `struct device' for this, or a
child `struct device', or a bare `struct kobject'?

Regards,
Yu

Re: [PATCH v9 6/7] PCI: document SR-IOV sysfs entries

[Yu Zhao]

On Wed, Feb 18, 2009 at 03:19:16PM +0800, Greg KH wrote:
> On Wed, Feb 18, 2009 at 01:01:35AM +0800, Yu Zhao wrote:
> > On Wed, Feb 18, 2009 at 02:21:16PM +0800, Greg KH wrote:
> > > On Tue, Feb 17, 2009 at 10:43:03PM +0800, Yu Zhao wrote:
> > > > On Wed, Feb 18, 2009 at 11:49:10AM +0800, Greg KH wrote:
> > > > > On Tue, Feb 17, 2009 at 08:50:21PM +0800, Yu Zhao wrote:
> > > > > > I'd like to create a subdirectory under PCI device sysfs directory and
> > > > > > put some symbol links into that directory (only symbol links). Should I
> > > > > > use `device' or `kobject'? Currently I use `device' and get two extra
> > > > > > file/directory (uevent and power) which look like useless for my case
> > > > > > because this subdirectory doesn't reflect a real device.
> > > > > 
> > > > > Neither, just use an attribute group, no new struct device should be
> > > > > needed at all.
> > > > 
> > > > Yes, I was thinking using an attribute group, however, it looks like we
> > > > can't put symbol link into a group. Maybe I'm wrong, shed some light,
> > > > please?
> > > 
> > > Why would you want a symbolic link in an attribute group?
> > 
> > Sorry I didn't make myself clear. I'd like to create a subdirectory (its
> > parent is controlled by a `struct device') to only hold symbol links.
> 
> Ick.  What would those links be to?  And what are they for?
> 
> > Can I use an `attribute group' of the parent `struct device' for this,
> > or a child `struct device', or a bare `struct kobject'?
> 
> You can't use an attribute group for symlinks.
> You should use a struct device, but be careful, you are going to be
> creating uevents that I don't think you really want to.

Thank you for the clarification.

> 
> Care to describe what you are trying to do first?

I'd like to link child PCI devices to their parent PCI device's
subdirectory.  These child PCI devices are PCI functions that are on
the same level as their parent in the PCI hierarchy, so current PCI code
won't create symbol links for them in their parent directory as what it
does for PCI bridge. For example, device 01:00.0 is the parent and 01:00.1
is the child, I'd like to put a symbol link into
/sys/bus/pci/device/0000:01:00.0/child/ which points to
/sys/bus/pci/device/0000:01:00.1.  This can let user space application
know the relationship between this two devices.

Regards,
Yu

Re: [PATCH v9 6/7] PCI: document SR-IOV sysfs entries

[Greg KH]

On Tue, Feb 17, 2009 at 08:50:21PM +0800, Yu Zhao wrote:
> Hi Greg,
> 
> The `struct device' is preferred over the `struct kobject' in all cases
> that create subdirectory in sysfs, is this true?

If you have a parent directory being controlled by a struct device, yes.

> I'd like to create a subdirectory under PCI device sysfs directory and
> put some symbol links into that directory (only symbol links). Should I
> use `device' or `kobject'? Currently I use `device' and get two extra
> file/directory (uevent and power) which look like useless for my case
> because this subdirectory doesn't reflect a real device.

Neither, just use an attribute group, no new struct device should be
needed at all.

thanks,

greg k-h

Re: [PATCH v9 6/7] PCI: document SR-IOV sysfs entries

[Greg KH]

On Tue, Feb 17, 2009 at 10:43:03PM +0800, Yu Zhao wrote:
> On Wed, Feb 18, 2009 at 11:49:10AM +0800, Greg KH wrote:
> > On Tue, Feb 17, 2009 at 08:50:21PM +0800, Yu Zhao wrote:
> > > Hi Greg,
> > > 
> > > The `struct device' is preferred over the `struct kobject' in all cases
> > > that create subdirectory in sysfs, is this true?
> > 
> > If you have a parent directory being controlled by a struct device, yes.
> 
> Thanks! Do we need to document this somewhere?

Probably, patches gladly accepted for documentation fixes/updates :)

> > > I'd like to create a subdirectory under PCI device sysfs directory and
> > > put some symbol links into that directory (only symbol links). Should I
> > > use `device' or `kobject'? Currently I use `device' and get two extra
> > > file/directory (uevent and power) which look like useless for my case
> > > because this subdirectory doesn't reflect a real device.
> > 
> > Neither, just use an attribute group, no new struct device should be
> > needed at all.
> 
> Yes, I was thinking using an attribute group, however, it looks like we
> can't put symbol link into a group. Maybe I'm wrong, shed some light,
> please?

Why would you want a symbolic link in an attribute group?

confused,

greg k-h

Re: [PATCH v9 6/7] PCI: document SR-IOV sysfs entries

[Greg KH]

On Wed, Feb 18, 2009 at 01:01:35AM +0800, Yu Zhao wrote:
> On Wed, Feb 18, 2009 at 02:21:16PM +0800, Greg KH wrote:
> > On Tue, Feb 17, 2009 at 10:43:03PM +0800, Yu Zhao wrote:
> > > On Wed, Feb 18, 2009 at 11:49:10AM +0800, Greg KH wrote:
> > > > On Tue, Feb 17, 2009 at 08:50:21PM +0800, Yu Zhao wrote:
> > > > > I'd like to create a subdirectory under PCI device sysfs directory and
> > > > > put some symbol links into that directory (only symbol links). Should I
> > > > > use `device' or `kobject'? Currently I use `device' and get two extra
> > > > > file/directory (uevent and power) which look like useless for my case
> > > > > because this subdirectory doesn't reflect a real device.
> > > > 
> > > > Neither, just use an attribute group, no new struct device should be
> > > > needed at all.
> > > 
> > > Yes, I was thinking using an attribute group, however, it looks like we
> > > can't put symbol link into a group. Maybe I'm wrong, shed some light,
> > > please?
> > 
> > Why would you want a symbolic link in an attribute group?
> 
> Sorry I didn't make myself clear. I'd like to create a subdirectory (its
> parent is controlled by a `struct device') to only hold symbol links.

Ick.  What would those links be to?  And what are they for?

> Can I use an `attribute group' of the parent `struct device' for this,
> or a child `struct device', or a bare `struct kobject'?

You can't use an attribute group for symlinks.
You should use a struct device, but be careful, you are going to be
creating uevents that I don't think you really want to.

Care to describe what you are trying to do first?

thanks,

greg k-h

Re: [PATCH v9 6/7] PCI: document SR-IOV sysfs entries

[Greg KH]

On Wed, Feb 18, 2009 at 03:21:55AM +0800, Yu Zhao wrote:
> > Care to describe what you are trying to do first?
> 
> I'd like to link child PCI devices to their parent PCI device's
> subdirectory.  These child PCI devices are PCI functions that are on
> the same level as their parent in the PCI hierarchy, so current PCI code
> won't create symbol links for them in their parent directory as what it
> does for PCI bridge. For example, device 01:00.0 is the parent and 01:00.1
> is the child, I'd like to put a symbol link into
> /sys/bus/pci/device/0000:01:00.0/child/ which points to
> /sys/bus/pci/device/0000:01:00.1.  This can let user space application
> know the relationship between this two devices.

If .1 is really the child of .0, then make it so in the sysfs tree in
the first place with the topology of the devices.  That way you don't
need any special "child" directory, as that would be different from all
other device types in the system.

thanks,

greg k-h