From 25986da4cfa1b20ca6e9f4e39a34e12d72435963 Mon Sep 17 00:00:00 2001

From: Ben Walker <benjamin.walker@intel.com>

Date: Mon, 18 Nov 2019 15:23:18 +0000

Subject: [PATCH 2/4] bus/pci: consider only usable devices for IOVA mode

When selecting the preferred IOVA mode of the pci bus, the current

heuristic ("are devices bound?", "are devices bound to UIO?", "are pmd

drivers supporting IOVA as VA?" etc..) should honor the device

white/blacklist so that an unwanted device does not impact the decision.

There is no reason to consider a device which has no driver available.

This applies to all OS, so implements this in common code then call a

OS specific callback.

On Linux side:

- the VFIO special considerations should be evaluated only if VFIO

  support is built,

- there is no strong requirement on using VA rather than PA if a driver

  supports VA, so defaulting to DC in such a case.

Signed-off-by: Ben Walker <benjamin.walker@intel.com>

Signed-off-by: David Marchand <david.marchand@redhat.com>

Reviewed-by: Anatoly Burakov <anatoly.burakov@intel.com>

(cherry picked from commit 703458e19c16135143b3f30089e1af66100c82dc)

Signed-off-by: David Marchand <david.marchand@redhat.com>

Conflicts:

        drivers/bus/pci/linux/pci.c

        drivers/bus/pci/pci_common.c

---

 drivers/bus/pci/bsd/pci.c    |   9 +-

 drivers/bus/pci/linux/pci.c  | 185 +++++++++--------------------------

 drivers/bus/pci/pci_common.c |  65 ++++++++++++

 drivers/bus/pci/private.h    |   8 ++

 4 files changed, 126 insertions(+), 141 deletions(-)

diff --git a/drivers/bus/pci/bsd/pci.c b/drivers/bus/pci/bsd/pci.c

index d09f8ee5a..0f23f12b9 100644

--- a/drivers/bus/pci/bsd/pci.c

+++ b/drivers/bus/pci/bsd/pci.c

@@ -377,11 +377,12 @@ rte_pci_scan(void)

 }

-/*

- * Get iommu class of PCI devices on the bus.

- */

 enum rte_iova_mode

-rte_pci_get_iommu_class(void)

+pci_device_iova_mode(const struct rte_pci_driver *pdrv __rte_unused,

+		     const struct rte_pci_device *pdev)

 {

 	/* Supports only RTE_KDRV_NIC_UIO */

+	if (pdev->kdrv != RTE_KDRV_NIC_UIO)

+		RTE_LOG(DEBUG, EAL, "Unsupported kernel driver? Defaulting to IOVA as 'PA'\n");

+

 	return RTE_IOVA_PA;

 }

diff --git a/drivers/bus/pci/linux/pci.c b/drivers/bus/pci/linux/pci.c

index 74794a3ba..7d73d9de5 100644

--- a/drivers/bus/pci/linux/pci.c

+++ b/drivers/bus/pci/linux/pci.c

@@ -498,91 +498,11 @@ rte_pci_scan(void)

 }

-/*

- * Is pci device bound to any kdrv

- */

-static inline int

-pci_one_device_is_bound(void)

-{

-	struct rte_pci_device *dev = NULL;

-	int ret = 0;

-

-	FOREACH_DEVICE_ON_PCIBUS(dev) {

-		if (dev->kdrv == RTE_KDRV_UNKNOWN ||

-		    dev->kdrv == RTE_KDRV_NONE) {

-			continue;

-		} else {

-			ret = 1;

-			break;

-		}

-	}

-	return ret;

-}

-

-/*

- * Any one of the device bound to uio

- */

-static inline int

-pci_one_device_bound_uio(void)

-{

-	struct rte_pci_device *dev = NULL;

-	struct rte_devargs *devargs;

-	int need_check;

-

-	FOREACH_DEVICE_ON_PCIBUS(dev) {

-		devargs = dev->device.devargs;

-

-		need_check = 0;

-		switch (rte_pci_bus.bus.conf.scan_mode) {

-		case RTE_BUS_SCAN_WHITELIST:

-			if (devargs && devargs->policy == RTE_DEV_WHITELISTED)

-				need_check = 1;

-			break;

-		case RTE_BUS_SCAN_UNDEFINED:

-		case RTE_BUS_SCAN_BLACKLIST:

-			if (devargs == NULL ||

-			    devargs->policy != RTE_DEV_BLACKLISTED)

-				need_check = 1;

-			break;

-		}

-

-		if (!need_check)

-			continue;

-

-		if (dev->kdrv == RTE_KDRV_IGB_UIO ||

-		   dev->kdrv == RTE_KDRV_UIO_GENERIC) {

-			return 1;

-		}

-	}

-	return 0;

-}

-

-/*

- * Any one of the device has iova as va

- */

-static inline int

-pci_one_device_has_iova_va(void)

-{

-	struct rte_pci_device *dev = NULL;

-	struct rte_pci_driver *drv = NULL;

-

-	FOREACH_DRIVER_ON_PCIBUS(drv) {

-		if (drv && drv->drv_flags & RTE_PCI_DRV_IOVA_AS_VA) {

-			FOREACH_DEVICE_ON_PCIBUS(dev) {

-				if (dev->kdrv == RTE_KDRV_VFIO &&

-				    rte_pci_match(drv, dev))

-					return 1;

-			}

-		}

-	}

-	return 0;

-}

-

 #if defined(RTE_ARCH_X86)

 static bool

-pci_one_device_iommu_support_va(struct rte_pci_device *dev)

+pci_one_device_iommu_support_va(const struct rte_pci_device *dev)

 {

 #define VTD_CAP_MGAW_SHIFT	16

 #define VTD_CAP_MGAW_MASK	(0x3fULL << VTD_CAP_MGAW_SHIFT)

-	struct rte_pci_addr *addr = &dev->addr;

+	const struct rte_pci_addr *addr = &dev->addr;

 	char filename[PATH_MAX];

 	FILE *fp;

@@ -628,5 +548,5 @@ pci_one_device_iommu_support_va(struct rte_pci_device *dev)

 #elif defined(RTE_ARCH_PPC_64)

 static bool

-pci_one_device_iommu_support_va(__rte_unused struct rte_pci_device *dev)

+pci_one_device_iommu_support_va(__rte_unused const struct rte_pci_device *dev)

 {

 	return false;

@@ -634,5 +554,5 @@ pci_one_device_iommu_support_va(__rte_unused struct rte_pci_device *dev)

 #else

 static bool

-pci_one_device_iommu_support_va(__rte_unused struct rte_pci_device *dev)

+pci_one_device_iommu_support_va(__rte_unused const struct rte_pci_device *dev)

 {

 	return true;

@@ -640,66 +560,57 @@ pci_one_device_iommu_support_va(__rte_unused struct rte_pci_device *dev)

 #endif

-/*

- * All devices IOMMUs support VA as IOVA

- */

-static bool

-pci_devices_iommu_support_va(void)

-{

-	struct rte_pci_device *dev = NULL;

-	struct rte_pci_driver *drv = NULL;

-

-	FOREACH_DRIVER_ON_PCIBUS(drv) {

-		FOREACH_DEVICE_ON_PCIBUS(dev) {

-			if (!rte_pci_match(drv, dev))

-				continue;

-			/*

-			 * just one PCI device needs to be checked out because

-			 * the IOMMU hardware is the same for all of them.

-			 */

-			return pci_one_device_iommu_support_va(dev);

-		}

-	}

-	return true;

-}

-

-/*

- * Get iommu class of PCI devices on the bus.

- */

 enum rte_iova_mode

-rte_pci_get_iommu_class(void)

+pci_device_iova_mode(const struct rte_pci_driver *pdrv,

+		     const struct rte_pci_device *pdev)

 {

-	bool is_bound;

-	bool is_vfio_noiommu_enabled = true;

-	bool has_iova_va;

-	bool is_bound_uio;

-	bool iommu_no_va;

+	enum rte_iova_mode iova_mode = RTE_IOVA_DC;

+	static int iommu_no_va = -1;

-	is_bound = pci_one_device_is_bound();

-	if (!is_bound)

-		return RTE_IOVA_DC;

-

-	has_iova_va = pci_one_device_has_iova_va();

-	is_bound_uio = pci_one_device_bound_uio();

-	iommu_no_va = !pci_devices_iommu_support_va();

+	switch (pdev->kdrv) {

+	case RTE_KDRV_VFIO: {

 #ifdef VFIO_PRESENT

-	is_vfio_noiommu_enabled = rte_vfio_noiommu_is_enabled() == true ?

-					true : false;

+		static int is_vfio_noiommu_enabled = -1;

+

+		if (is_vfio_noiommu_enabled == -1) {

+			if (rte_vfio_noiommu_is_enabled() == 1)

+				is_vfio_noiommu_enabled = 1;

+			else

+				is_vfio_noiommu_enabled = 0;

+		}

+		if ((pdrv->drv_flags & RTE_PCI_DRV_IOVA_AS_VA) == 0) {

+			iova_mode = RTE_IOVA_PA;

+		} else if (is_vfio_noiommu_enabled != 0) {

+			RTE_LOG(DEBUG, EAL, "Forcing to 'PA', vfio-noiommu mode configured\n");

+			iova_mode = RTE_IOVA_PA;

+		}

 #endif

+		break;

+	}

-	if (has_iova_va && !is_bound_uio && !is_vfio_noiommu_enabled &&

-			!iommu_no_va)

-		return RTE_IOVA_VA;

+	case RTE_KDRV_IGB_UIO:

+	case RTE_KDRV_UIO_GENERIC:

+		iova_mode = RTE_IOVA_PA;

+		break;

-	if (has_iova_va) {

-		RTE_LOG(WARNING, EAL, "Some devices want iova as va but pa will be used because.. ");

-		if (is_vfio_noiommu_enabled)

-			RTE_LOG(WARNING, EAL, "vfio-noiommu mode configured\n");

-		if (is_bound_uio)

-			RTE_LOG(WARNING, EAL, "few device bound to UIO\n");

-		if (iommu_no_va)

-			RTE_LOG(WARNING, EAL, "IOMMU does not support IOVA as VA\n");

+	default:

+		RTE_LOG(DEBUG, EAL, "Unsupported kernel driver? Defaulting to IOVA as 'PA'\n");

+		iova_mode = RTE_IOVA_PA;

+		break;

 	}

-	return RTE_IOVA_PA;

+	if (iova_mode != RTE_IOVA_PA) {

+		/*

+		 * We can check this only once, because the IOMMU hardware is

+		 * the same for all of them.

+		 */

+		if (iommu_no_va == -1)

+			iommu_no_va = pci_one_device_iommu_support_va(pdev)

+					? 0 : 1;

+		if (iommu_no_va != 0) {

+			RTE_LOG(DEBUG, EAL, "Forcing to 'PA', IOMMU does not support IOVA as 'VA'\n");

+			iova_mode = RTE_IOVA_PA;

+		}

+	}

+	return iova_mode;

 }

diff --git a/drivers/bus/pci/pci_common.c b/drivers/bus/pci/pci_common.c

index 6276e5d69..b8cc6d31a 100644

--- a/drivers/bus/pci/pci_common.c

+++ b/drivers/bus/pci/pci_common.c

@@ -529,4 +529,69 @@ pci_unplug(struct rte_device *dev)

 }

+static bool

+pci_ignore_device(const struct rte_pci_device *dev)

+{

+	struct rte_devargs *devargs = dev->device.devargs;

+

+	switch (rte_pci_bus.bus.conf.scan_mode) {

+	case RTE_BUS_SCAN_WHITELIST:

+		if (devargs && devargs->policy == RTE_DEV_WHITELISTED)

+			return false;

+		break;

+	case RTE_BUS_SCAN_UNDEFINED:

+	case RTE_BUS_SCAN_BLACKLIST:

+		if (devargs == NULL ||

+		    devargs->policy != RTE_DEV_BLACKLISTED)

+			return false;

+		break;

+	}

+	return true;

+}

+

+enum rte_iova_mode

+rte_pci_get_iommu_class(void)

+{

+	enum rte_iova_mode iova_mode = RTE_IOVA_DC;

+	const struct rte_pci_device *dev;

+	const struct rte_pci_driver *drv;

+	bool devices_want_va = false;

+	bool devices_want_pa = false;

+

+	FOREACH_DEVICE_ON_PCIBUS(dev) {

+		if (pci_ignore_device(dev))

+			continue;

+		if (dev->kdrv == RTE_KDRV_UNKNOWN ||

+		    dev->kdrv == RTE_KDRV_NONE)

+			continue;

+		FOREACH_DRIVER_ON_PCIBUS(drv) {

+			enum rte_iova_mode dev_iova_mode;

+

+			if (!rte_pci_match(drv, dev))

+				continue;

+

+			dev_iova_mode = pci_device_iova_mode(drv, dev);

+			RTE_LOG(DEBUG, EAL, "PCI driver %s for device "

+				PCI_PRI_FMT " wants IOVA as '%s'\n",

+				drv->driver.name,

+				dev->addr.domain, dev->addr.bus,

+				dev->addr.devid, dev->addr.function,

+				dev_iova_mode == RTE_IOVA_DC ? "DC" :

+				(dev_iova_mode == RTE_IOVA_PA ? "PA" : "VA"));

+			if (dev_iova_mode == RTE_IOVA_PA)

+				devices_want_pa = true;

+			else if (dev_iova_mode == RTE_IOVA_VA)

+				devices_want_va = true;

+		}

+	}

+	if (devices_want_pa) {

+		iova_mode = RTE_IOVA_PA;

+		if (devices_want_va)

+			RTE_LOG(WARNING, EAL, "Some devices want 'VA' but forcing 'PA' because other devices want it\n");

+	} else if (devices_want_va) {

+		iova_mode = RTE_IOVA_VA;

+	}

+	return iova_mode;

+}

+

 struct rte_pci_bus rte_pci_bus = {

 	.bus = {

diff --git a/drivers/bus/pci/private.h b/drivers/bus/pci/private.h

index 13c3324bb..8a5524052 100644

--- a/drivers/bus/pci/private.h

+++ b/drivers/bus/pci/private.h

@@ -173,4 +173,12 @@ rte_pci_match(const struct rte_pci_driver *pci_drv,

 	      const struct rte_pci_device *pci_dev);

+/**

+ * OS specific callback for rte_pci_get_iommu_class

+ *

+ */

+enum rte_iova_mode

+pci_device_iova_mode(const struct rte_pci_driver *pci_drv,

+		     const struct rte_pci_device *pci_dev);

+

 /**

  * Get iommu class of PCI devices on the bus.

-- 

2.21.0