On Thursday 30 August 2018 05:43 PM, Hemant wrote: > External Email > > Hi, > > On 8/30/2018 3:13 PM, Gaëtan Rivet wrote: >> Hi, >> >> On Thu, Aug 30, 2018 at 10:09:04AM +0100, Burakov, Anatoly wrote: >>> On 29-Aug-18 4:58 PM, eric zhang wrote: >>>> This patch adds a configuration option to force the IOVA mode to >>>> physical address (PA). There exists virtual devices that are not >>>> directly attached to the PCI bus, and therefore the auto detection >>>> of the IOVA mode based on probing the PCI bus and IOMMU configuration >>>> may not report the required addressing mode. Having the configuration >>>> option permits the mode to be explicitly configured in this scenario. >>>> >>>> Signed-off-by: eric zhang <eric.zh...@windriver.com> >>>> --- >>> Defining this at compile-time seems like an overkill. Wouldn't it be better >>> to just add an EAL command-line option to force IOVA mode to a particular >>> value? > That is a good suggestion. >>> -- >>> Thanks, >>> Anatoly >> What is the bus of these devices and why not implement get_iommu_class >> in it? > There are cases, where you are using dpdk libraries with external > libraries and you need to change the default behavior DPDK lib to use > physical address instead of virtual address. > Providing an option to user will help. > > More appropriate solution could be: * Either fix it at bus layer .. i.e.. get_iommu_class().. * Or introduce something like [1] --iova-mode=<pa/va> param.
Former is better solution than latter if autodetection is a key criteria. Thanks. [1] http://patchwork.dpdk.org/patch/25192/
