On Tue, 2016-06-09 at 06:27:31 UTC, Balbir Singh wrote: > When PCI Device pass-through is enabled via VFIO, KVM-PPC will > pin pages using get_user_pages_fast(). One of the downsides of > the pinning is that the page could be in CMA region. The CMA > region is used for other allocations like the hash page table. > Ideally we want the pinned pages to be from non CMA region. > > This patch (currently only for KVM PPC with VFIO) forcefully > migrates the pages out (huge pages are omitted for the moment). > There are more efficient ways of doing this, but that might > be elaborate and might impact a larger audience beyond just > the kvm ppc implementation. > > The magic is in new_iommu_non_cma_page() which allocates the > new page from a non CMA region. > > I've tested the patches lightly at my end. The full solution > requires migration of THP pages in the CMA region. That work > will be done incrementally on top of this. > > Signed-off-by: Balbir Singh <bsingharora@xxxxxxxxx> > Acked-by: Alexey Kardashevskiy <aik@xxxxxxxxx> Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/2e5bbb5461f138cac631fe21b4ad95 cheers -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
