Re: [PATCH v3] usertools: add check for IOMMU support in dpdk-devbind

[Bruce Richardson <bruce.richardson@intel.com>]

On Thu, Mar 31, 2022 at 03:37:40PM +0100, Burakov, Anatoly wrote:
> On 21-Mar-22 12:27 PM, Fidaullah Noonari wrote:
> > binding with vfio driver, when IOMMU is disabled, causes program to crash.
> > this patch adds a flag for noiommmu-mode. when this is set, if IOMMU is
> > disabled, it changes vfio into unsafe noiommu mode and prints warning
> > message.
> > 
> > Signed-off-by: Fidaullah Noonari <fidaullah.noonari@emumba.com>
> > ---
> 
> Hi,
> 
> > +def check_noiommu_mode():
> > +    """checks and enables the noiommu mode for vfio drivers"""
> > +    global noiommu_flag
> > +    filename = "/sys/module/vfio/parameters/enable_unsafe_noiommu_mode"
> > +
> > +    try:
> > +        with open(filename,"r") as f:
> > +            if f.read(1) == "1":
> > +                return
> > +    except OSError as err:
> > +        sys.exit("Error: failed to enable unsafe noiommu mode - Cannot open %s: %s"
> > +                % (filename, err))
> 
> Nitpick, but maybe use f-strings instead of old-school string interpolation?
> 

Do we still not need to support some distros that don't have Python earlier
than 3.6, where this support was added?