On Wed, Oct 28, 2015 at 06:48:41PM +0100, Eric Auger wrote: > On 10/28/2015 06:37 PM, Alex Williamson wrote: > > Ok, so with hopefully correcting my understand of what this does, isn't > > this effectively the same: > > > > diff --git a/drivers/vfio/vfio_iommu_type1.c > > b/drivers/vfio/vfio_iommu_type1.c > > index 57d8c37..7db4f5a 100644 > > --- a/drivers/vfio/vfio_iommu_type1.c > > +++ b/drivers/vfio/vfio_iommu_type1.c > > @@ -403,13 +403,19 @@ static void vfio_remove_dma(struct vfio_iommu *iommu, > > stru > > static unsigned long vfio_pgsize_bitmap(struct vfio_iommu *iommu) > > { > > struct vfio_domain *domain; > > - unsigned long bitmap = PAGE_MASK; > > + unsigned long bitmap = ULONG_MAX; > > > > mutex_lock(&iommu->lock); > > list_for_each_entry(domain, &iommu->domain_list, next) > > bitmap &= domain->domain->ops->pgsize_bitmap; > > mutex_unlock(&iommu->lock); > > > > + /* Some comment about how the IOMMU API splits requests */ > > + if (bitmap & ~PAGE_MASK) { > > + bitmap &= PAGE_MASK; > > + bitmap |= PAGE_SIZE; > > + } > > + > > return bitmap; > > } > Yes, to me it is indeed the same > > > > This would also expose to the user that we're accepting PAGE_SIZE, which > > we weren't before, so it was not quite right to just let them do it > > anyway. I don't think we even need to get rid of the WARN_ONs, do we? > > Thanks, > > The end-user might be afraid of those latter. Personally I would get rid > of them but that's definitively up to you.
I think Alex's point is that the WARN_ON's won't trigger with this patch, because he clears those lower bits in the bitmap. Will -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html