[dpdk-dev] [PATCH v4 05/12] linuxapp/eal_pci: get iommu class

Hemant Agrawal hemant.agrawal at nxp.com
Tue Jul 18 12:55:21 CEST 2017


On 7/18/2017 11:29 AM, Santosh Shukla wrote:
> Get iommu class of PCI device on the bus and returns preferred iova
> mapping mode for that bus.
>
> Algorithm for iova scheme selection for PCI bus:
> 0. If no device bound then return with RTE_IOVA_DC mapping mode,
> else goto 1).
> 1. Look for device attached to vfio kdrv and has .drv_flag set
> to RTE_PCI_DRV_IOVA_AS_VA.
> 2. Look for any device attached to UIO class of driver.
> 3. Check for vfio-noiommu mode enabled.
>
> If 2) & 3) is false and 1) is true then select
> mapping scheme as RTE_IOVA_VA. Otherwise use default
> mapping scheme (RTE_IOVA_PA).
>
> Signed-off-by: Santosh Shukla <santosh.shukla at caviumnetworks.com>
> Signed-off-by: Jerin Jacob <jerin.jacob at caviumnetworks.com>
> ---
> v3 --> v4 :
> - Reworded WARNING message (suggested by Maxime)
> - Added pci_device_is_bound func to check for no device case
>   (suggested by Hemant).
> - Added ifdef vfio_present.
>
> v1 --> v2:
> - Removed Linux version check in vfio_noiommu func. Refer [1].
>   - Extending autodetction logic for _iommu_class.
>     Refer [2].
>
> [1] https://www.mail-archive.com/dev@dpdk.org/msg70108.html
> [2] https://www.mail-archive.com/dev@dpdk.org/msg70279.html
>
>  lib/librte_eal/linuxapp/eal/eal_pci.c           | 95 +++++++++++++++++++++++++
>  lib/librte_eal/linuxapp/eal/eal_vfio.c          | 19 +++++
>  lib/librte_eal/linuxapp/eal/eal_vfio.h          |  4 ++
>  lib/librte_eal/linuxapp/eal/rte_eal_version.map |  1 +
>  4 files changed, 119 insertions(+)
>
> diff --git a/lib/librte_eal/linuxapp/eal/eal_pci.c b/lib/librte_eal/linuxapp/eal/eal_pci.c
> index 7d9e1a99b..ecd946250 100644
> --- a/lib/librte_eal/linuxapp/eal/eal_pci.c
> +++ b/lib/librte_eal/linuxapp/eal/eal_pci.c
> @@ -45,6 +45,7 @@
>  #include "eal_filesystem.h"
>  #include "eal_private.h"
>  #include "eal_pci_init.h"
> +#include "eal_vfio.h"
>
>  /**
>   * @file
> @@ -488,6 +489,100 @@ rte_pci_scan(void)
>  	return -1;
>  }
>
> +/*
> + * Is pci device bound to any kdrv
> + */
> +static inline int
> +pci_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_device_bound_uio(void)
> +{
> +	struct rte_pci_device *dev = NULL;
> +
> +	FOREACH_DEVICE_ON_PCIBUS(dev) {
> +		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_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;
> +}
> +
> +/*
> + * Get iommu class of PCI devices on the bus.
> + */
> +enum rte_iova_mode
> +rte_pci_get_iommu_class(void)
> +{
> +	bool is_bound;
> +	bool is_vfio_noiommu_enabled = true;
> +	bool has_iova_va;
> +	bool is_bound_uio;
> +
> +	is_bound = pci_device_is_bound();
> +	if (!is_bound)
> +		return RTE_IOVA_DC;
> +
> +	has_iova_va = pci_device_has_iova_va();
> +	is_bound_uio = pci_device_bound_uio();
> +#ifdef VFIO_PRESENT
> +	is_vfio_noiommu_enabled = vfio_noiommu_is_enabled() == 1 ? 1 : 0;
> +#endif
> +
> +	if (has_iova_va && !is_bound_uio && !is_vfio_noiommu_enabled)
> +		return RTE_IOVA_VA;
> +
> +	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");
> +	}
> +
> +	return RTE_IOVA_PA;
> +}
> +
>  /* Read PCI config space. */
>  int rte_pci_read_config(const struct rte_pci_device *device,
>  		void *buf, size_t len, off_t offset)
> diff --git a/lib/librte_eal/linuxapp/eal/eal_vfio.c b/lib/librte_eal/linuxapp/eal/eal_vfio.c
> index 946df7e31..c8a97b7e7 100644
> --- a/lib/librte_eal/linuxapp/eal/eal_vfio.c
> +++ b/lib/librte_eal/linuxapp/eal/eal_vfio.c
> @@ -816,4 +816,23 @@ vfio_noiommu_dma_map(int __rte_unused vfio_container_fd)
>  	return 0;
>  }
>
> +int
> +vfio_noiommu_is_enabled(void)
> +{
> +	int fd, ret, cnt __rte_unused;
> +	char c;
> +
> +	ret = -1;
> +	fd = open(VFIO_NOIOMMU_MODE, O_RDONLY);
> +	if (fd < 0)
> +		return -1;
> +
> +	cnt = read(fd, &c, 1);
> +	if (c == 'Y')
> +		ret = 1;
> +
> +	close(fd);
> +	return ret;
> +}
> +
>  #endif
> diff --git a/lib/librte_eal/linuxapp/eal/eal_vfio.h b/lib/librte_eal/linuxapp/eal/eal_vfio.h
> index 5ff63e5d7..26ea8e119 100644
> --- a/lib/librte_eal/linuxapp/eal/eal_vfio.h
> +++ b/lib/librte_eal/linuxapp/eal/eal_vfio.h
> @@ -150,6 +150,8 @@ struct vfio_config {
>  #define VFIO_NOIOMMU_GROUP_FMT "/dev/vfio/noiommu-%u"
>  #define VFIO_GET_REGION_ADDR(x) ((uint64_t) x << 40ULL)
>  #define VFIO_GET_REGION_IDX(x) (x >> 40)
> +#define VFIO_NOIOMMU_MODE      \
> +	"/sys/module/vfio/parameters/enable_unsafe_noiommu_mode"
>
>  /* DMA mapping function prototype.
>   * Takes VFIO container fd as a parameter.
> @@ -210,6 +212,8 @@ int pci_vfio_is_enabled(void);
>
>  int vfio_mp_sync_setup(void);
>
> +int vfio_noiommu_is_enabled(void);
> +
>  #define SOCKET_REQ_CONTAINER 0x100
>  #define SOCKET_REQ_GROUP 0x200
>  #define SOCKET_CLR_GROUP 0x300
> diff --git a/lib/librte_eal/linuxapp/eal/rte_eal_version.map b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
> index a69bbb599..5dd40f948 100644
> --- a/lib/librte_eal/linuxapp/eal/rte_eal_version.map
> +++ b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
> @@ -206,6 +206,7 @@ DPDK_17.08 {
>  	rte_bus_find_by_device;
>  	rte_bus_find_by_name;
>  	rte_pci_match;
> +	rte_pci_get_iommu_class;
>
>  } DPDK_17.05;
>
>
Acked-by: Hemant Agrawal <hemant.agrawal at nxp.com>



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