Messages in this thread | | | From | Niklas Schnelle <> | Subject | [PATCH v2 0/2] iommu/virtio: Enable IOMMU_CAP_DERRED_FLUSH | Date | Mon, 18 Sep 2023 13:51:42 +0200 |
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Hi All,
Previously I used virtio-iommu as a non-s390x test vehicle[0] for the single queue flushing scheme introduced by my s390x DMA API conversion series[1]. For this I modified virtio-iommu to a) use .iotlb_sync_map and b) enable IOMMU_CAP_DEFERRED_FLUSH. It turned out that deferred flush and even just the introduction of ops->iotlb_sync_map yield performance uplift[2] even with per-CPU queues. So here is a small series of these two changes. This still applies on top of my series[1] because its first patch titled "iommu: Allow .iotlb_sync_map to fail and handle s390's -ENOMEM return" enable ops->iotlb_sync_map to return errors and virtio-iommu's sync can fail. This also makes sure there is no merge conflict with that series.
The code is also available on the b4/viommu-deferred-flush branch of my kernel.org git repository[3]
Thanks, Niklas
[0] https://lore.kernel.org/lkml/20230726111433.1105665-1-schnelle@linux.ibm.com/ [1] https://lore.kernel.org/lkml/20230825-dma_iommu-v12-0-4134455994a7@linux.ibm.com/ [2] https://lore.kernel.org/lkml/20230802123612.GA6142@myrica/ [3] https://git.kernel.org/pub/scm/linux/kernel/git/niks/linux.git/log/?h=b4/viommu-deferred-flush
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> --- Changes in v2: - Check for viommu == NULL in viommu_sync_req() instead of for 0 endpoints in ops (Jean-Philippe) - Added comment where viommu can be NULL (me) - Link to v1: https://lore.kernel.org/r/20230825-viommu-sync-map-v1-0-56bdcfaa29ec@linux.ibm.com
--- Niklas Schnelle (2): iommu/virtio: Make use of ops->iotlb_sync_map iommu/virtio: Add ops->flush_iotlb_all and enable deferred flush
drivers/iommu/virtio-iommu.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) --- base-commit: e165388f6d32dc8a49f49ef6e80584ad3def3d78 change-id: 20230825-viommu-sync-map-1bf0cc4fdc15
Best regards, -- Niklas Schnelle Linux on Z Development
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