Re: [dpdk-dev] [PATCH] pci/linux: use RTE_IOVA_VA whenever possible

[Thomas Monjalon <thomas@monjalon.net>]

Someone to review this patch please?


07/09/2018 16:53, Darek Stojaczyk:
> This allows DPDK to use RTE_IOVA_VA with VFIO/UIO-bound PCI
> devices present on the system, but not attached to any
> rte_pci_driver at the time of init.
> 
> So far we used RTE_IOVA_VA whenever there was at least one
> device attached to a driver with an RTE_PCI_DRV_IOVA_AS_VA flag,
> meaning that other drivers which didn't explicitly report such
> flag could have been forced to work in RTE_IOVA_VA as well.
> 
> This patch makes the RTE_PCI_DRV_IOVA_AS_VA explicitly a hint.
> If it's set, but RTE_IOVA_VA cannot be used, then EAL will print
> a proper warning.
> 
> Signed-off-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
> ---
>  drivers/bus/pci/linux/pci.c | 11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/bus/pci/linux/pci.c b/drivers/bus/pci/linux/pci.c
> index 04648ac93..961e24024 100644
> --- a/drivers/bus/pci/linux/pci.c
> +++ b/drivers/bus/pci/linux/pci.c
> @@ -534,7 +534,7 @@ pci_one_device_bound_uio(void)
>   * Any one of the device has iova as va
>   */
>  static inline int
> -pci_one_device_has_iova_va(void)
> +pci_one_device_want_iova_va(void)
>  {
>  	struct rte_pci_device *dev = NULL;
>  	struct rte_pci_driver *drv = NULL;
> @@ -635,7 +635,7 @@ rte_pci_get_iommu_class(void)
>  {
>  	bool is_bound;
>  	bool is_vfio_noiommu_enabled = true;
> -	bool has_iova_va;
> +	bool want_iova_va;
>  	bool is_bound_uio;
>  	bool iommu_no_va;
>  
> @@ -643,7 +643,7 @@ rte_pci_get_iommu_class(void)
>  	if (!is_bound)
>  		return RTE_IOVA_DC;
>  
> -	has_iova_va = pci_one_device_has_iova_va();
> +	want_iova_va = pci_one_device_want_iova_va();
>  	is_bound_uio = pci_one_device_bound_uio();
>  	iommu_no_va = !pci_devices_iommu_support_va();
>  #ifdef VFIO_PRESENT
> @@ -651,11 +651,10 @@ rte_pci_get_iommu_class(void)
>  					true : false;
>  #endif
>  
> -	if (has_iova_va && !is_bound_uio && !is_vfio_noiommu_enabled &&
> -			!iommu_no_va)
> +	if (!is_bound_uio && !is_vfio_noiommu_enabled && !iommu_no_va)
>  		return RTE_IOVA_VA;
>  
> -	if (has_iova_va) {
> +	if (want_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");
>