[dpdk-dev] [PATCH v3 04/11] linuxapp/eal_pci: get iommu class

Maxime Coquelin maxime.coquelin at redhat.com
Tue Jul 11 11:23:19 CEST 2017



On 07/11/2017 08:16 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. Look for device attached to vfio kdrv and has .drv_flag set
> to RTE_PCI_DRV_NEED_IOVA_VA.
> 1. Look for any device attached to UIO class of driver.
> 2. Check for vfio-noiommu mode enabled.
> 
> If 1) & 2) is false and 0) is true then select
> mapping scheme as iova=va. Otherwise use default
> mapping scheme (iova_pa).
> 
> Signed-off-by: Santosh Shukla <santosh.shukla at caviumnetworks.com>
> Signed-off-by: Jerin Jacob <jerin.jacob at caviumnetworks.com>
> ---
> 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           | 66 +++++++++++++++++++++++++
>   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, 90 insertions(+)
> 
> diff --git a/lib/librte_eal/linuxapp/eal/eal_pci.c b/lib/librte_eal/linuxapp/eal/eal_pci.c
> index 7d9e1a99b..573caa000 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 +489,71 @@ rte_pci_scan(void)
>   	return -1;
>   }
>   
> +/*
> + * 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_NEED_IOVA_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_vfio_noiommu_enabled;
> +	bool has_iova_va;
> +	bool is_bound_uio;
> +
> +	has_iova_va = pci_device_has_iova_va();
> +	is_bound_uio = pci_device_bound_uio();
> +	is_vfio_noiommu_enabled = vfio_noiommu_is_enabled() == 1 ? 1 : 0;
> +
> +	if (has_iova_va && !is_bound_uio && !is_vfio_noiommu_enabled)
> +		return RTE_IOVA_VA;
> +
> +	if (has_iova_va) {
> +		if (is_vfio_noiommu_enabled)
> +			RTE_LOG(WARNING, EAL, "vfio-noiommu mode configured\n");
> +		if (is_bound_uio)
> +			RTE_LOG(WARNING, EAL, "Some device attached to UIO\n");

Maybe worth having more verbose warning for user not familiar with the
feature. Like stating that some devices want VA but PA will be used
because of vfio-noiommu or UIO.

Maxime


More information about the dev mailing list