md/nvme: Enable PCI P2PDMA support for RAID0 and NVMe Multipath#834
Open
blktests-ci[bot] wants to merge 3 commits into
Open
md/nvme: Enable PCI P2PDMA support for RAID0 and NVMe Multipath#834blktests-ci[bot] wants to merge 3 commits into
blktests-ci[bot] wants to merge 3 commits into
Conversation
Author
|
Upstream branch: aa54b1d |
b1870f6 to
ca57796
Compare
…ting devices BLK_FEAT_NOWAIT and BLK_FEAT_POLL are cleared in blk_stack_limits() when an underlying device does not support them. Apply the same treatment to BLK_FEAT_PCI_P2PDMA: stacking drivers set it unconditionally and rely on the core to clear it whenever a non-supporting member device is stacked. Tested-by: Pranjal Shrivastava<praan@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com> Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
MD RAID does not propagate BLK_FEAT_PCI_P2PDMA from member devices to the RAID device, preventing peer-to-peer DMA through the RAID layer even when all underlying devices support it. Enable BLK_FEAT_PCI_P2PDMA unconditionally in raid0, raid1 and raid10 personalities during queue limits setup. blk_stack_limits() clears it automatically if any member device lacks support, consistent with how BLK_FEAT_NOWAIT and BLK_FEAT_POLL are handled in the block core. Parity RAID personalities (raid4/5/6) are excluded because they require CPU access to data pages for parity computation, which is incompatible with P2P mappings. Tested with RAID0/1/10 arrays containing multiple NVMe devices with P2PDMA support, confirming that peer-to-peer transfers work correctly through the RAID layer. Tested-by: Pranjal Shrivastava<praan@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Xiao Ni <xni@redhat.com> Signed-off-by: Kiran Kumar Modukuri <kmodukuri@nvidia.com> Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
NVMe multipath does not expose BLK_FEAT_PCI_P2PDMA on the head disk even when all underlying controllers support it. Set BLK_FEAT_PCI_P2PDMA unconditionally in nvme_mpath_alloc_disk() alongside the other features. nvme_update_ns_info_block() already calls queue_limits_stack_bdev() to stack each path's limits onto the head disk, which routes through blk_stack_limits(). The core now clears BLK_FEAT_PCI_P2PDMA automatically if any path (e.g., FC) does not support it, consistent with how BLK_FEAT_NOWAIT and BLK_FEAT_POLL are handled. Tested-by: Pranjal Shrivastava<praan@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com> Signed-off-by: Kiran Kumar Modukuri <kmodukuri@nvidia.com> Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Author
|
Upstream branch: 70eda68 |
513125d to
1948944
Compare
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Pull request for series with
subject: md/nvme: Enable PCI P2PDMA support for RAID0 and NVMe Multipath
version: 4
url: https://patchwork.kernel.org/project/linux-block/list/?series=1094418