On Thu, May 15, 2025 at 11:47:15AM -0600, Alex Williamson wrote: > On Tue, 13 May 2025 13:48:10 +0300 > Leon Romanovsky <leon@xxxxxxxxxx> wrote: > > > Hi Alex, > > > > Please accept this pull request, which presents subset of new DMA-API > > patchset [1] specific for VFIO subsystem. > > > > It is based on Marek's dma-mapping-for-6.16-two-step-api branch, so merging > > now will allow us to reduce possible rebase errors in mlx5 vfio code and give > > enough time to start to work on second driver conversion. Such conversion will > > allow us to generalize the API for VFIO kernel drivers, in similiar way that > > was done for RDMA, HMM and block layers. > > Hi Leon, > > Pull requests are not my typical workflow. Are these mlx5-vfio-pci > changes intended to enter mainline through the vfio tree or your rdma > tree? VFIO changes will come through your tree. DMA patches are the same as in Marek's DMA tree and in our RDMA tree. I prepared PR to save from your hassle of merging dma/dma-mapping-for-6.16-two-step-api topic from Marek and collecting VFIO patches from ML. > Why do the commits not include a review/ack from Yishai? They have Jason's review tags and as far as I know Yishai, he trusts Jason's judgement. > > Typically I'd expect a patch series for the mlx5-vfio-pci changes that > I would apply, with Yishai's approval, to a shared branch containing the > commits Marek has already accepted. I'm not sure why we're preempting > that process here. Thanks, This is exactly what is in this PR: reviewed VFIO patches which were posted to the ML on top of Marek's shared branch. If you prefer, I can repost the VFIO patches. Thanks > > Alex > > > [1] [PATCH v10 00/24] Provide a new two step DMA mapping API > > https://lore.kernel.org/all/cover.1745831017.git.leon@xxxxxxxxxx/ > > > > ---------------------------------------------------------------- > > The following changes since commit 3ee7d9496342246f4353716f6bbf64c945ff6e2d: > > > > docs: core-api: document the IOVA-based API (2025-05-06 08:36:54 +0200) > > > > are available in the Git repository at: > > > > https://git.kernel.org/pub/scm/linux/kernel/git/leon/linux-rdma.git tags/vfio-dma-two-step > > > > for you to fetch changes up to 855c89a25e1756b7699b863afd4d6afcbd0de0d6: > > > > vfio/mlx5: Enable the DMA link API (2025-05-13 03:58:27 -0400) > > > > ---------------------------------------------------------------- > > Convert mlx5 VFIO PCI driver to new two step DMA API > > > > This PR is based on newly accepted DMA API, which allows us > > to avoid building scatter-gather lists just to batch mapping > > and unmapping of pages. > > > > VFIO PCI live migration code is building a very large "page list" > > for the device. Instead of allocating a scatter list entry per > > allocated page it can just allocate an array of 'struct page *', > > saving a large amount of memory. > > > > Signed-off-by: Leon Romanovsky <leon@xxxxxxxxxx> > > > > ---------------------------------------------------------------- > > Leon Romanovsky (3): > > vfio/mlx5: Explicitly use number of pages instead of allocated length > > vfio/mlx5: Rewrite create mkey flow to allow better code reuse > > vfio/mlx5: Enable the DMA link API > > > > drivers/vfio/pci/mlx5/cmd.c | 375 +++++++++++++++++++++---------------------- > > drivers/vfio/pci/mlx5/cmd.h | 35 ++-- > > drivers/vfio/pci/mlx5/main.c | 87 +++++----- > > 3 files changed, 239 insertions(+), 258 deletions(-) > > >
