On Tue, Oct 30, 2018 at 1:48 PM Burakov, Anatoly <anatoly.bura...@intel.com> wrote:
> On 30-Oct-18 12:02 PM, Alejandro Lucero wrote: > > > > > > On Sun, Oct 28, 2018 at 11:04 PM Thomas Monjalon <tho...@monjalon.net > > <mailto:tho...@monjalon.net>> wrote: > > > > 11/10/2018 12:08, Thomas Monjalon: > > > +Cc more maintainers in order to collect more reviews > > > > > > 04/10/2018 11:19, Burakov, Anatoly: > > > > On 03-Oct-18 9:53 PM, eric zhang wrote: > > > > > This patchset introduces an EAL command line option > "--iova-mode" > > > > > to give the user a facility to force IOVA mode to a special > > value. > > > > > > > > > > Auto detection of the IOVA mode, based on probing the bus and > > IOMMU > > > > > configuration, may not report the desired addressing mode > > when virtual > > > > > devices that are not directly attached to the bus are present. > > > > > The EAL command line option "--iova-mode" can be used to > > select either > > > > > physical addressing('pa') or virtual addressing('va'). > > > > > > > > Acked-by: Anatoly Burakov <anatoly.bura...@intel.com > > <mailto:anatoly.bura...@intel.com>> > > > > Rebased and applied, thanks > > > > > > > > Could not this lead to a problem if a device can not wok with the mode > set? > > For example, IOVA mode set to VA and IOMMU hw with less bits than those > > required for the virtual addresses? > > > > IMO any device should be attached to a bus, and a bus should have a > > function for setting IOVA mode and the --iova-mode option just allowed > > with supported IOVA modes within the bus. > > I don't think it should work that way. It should warn the user that an > incompatible IOVA mode was selected, but the user has specified an IOVA > mode for a reason - it probably implies he really means it, so let him :) > > Yes, that's true, but setting IOVA VA when a device has problems with it, it is a bad idea and it could lead to a system crash. My concern is not with the user knowing what he is doing but with the user that "uhmm, what is this for, let's try this option". > -- > Thanks, > Anatoly >
