Messages in this thread Patch in this message | | | From | Niklas Schnelle <> | Date | Mon, 18 Sep 2023 13:51:44 +0200 | Subject | [PATCH v2 2/2] iommu/virtio: Add ops->flush_iotlb_all and enable deferred flush |
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Add ops->flush_iotlb_all operation to enable virtio-iommu for the dma-iommu deferred flush scheme. This results in a significant increase in performance in exchange for a window in which devices can still access previously IOMMU mapped memory when running with CONFIG_IOMMU_DEFAULT_DMA_LAZY. The previous strict behavior can be achieved with iommu.strict=1 on the kernel command line or CONFIG_IOMMU_DEFAULT_DMA_STRICT.
Link: https://lore.kernel.org/lkml/20230802123612.GA6142@myrica/ Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> --- drivers/iommu/virtio-iommu.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c index 3649586f0e5c..4dd330fbcbdd 100644 --- a/drivers/iommu/virtio-iommu.c +++ b/drivers/iommu/virtio-iommu.c @@ -926,6 +926,13 @@ static int viommu_iotlb_sync_map(struct iommu_domain *domain, return viommu_sync_req(vdomain->viommu); } +static void viommu_flush_iotlb_all(struct iommu_domain *domain) +{ + struct viommu_domain *vdomain = to_viommu_domain(domain); + + viommu_sync_req(vdomain->viommu); +} + static void viommu_get_resv_regions(struct device *dev, struct list_head *head) { struct iommu_resv_region *entry, *new_entry, *msi = NULL; @@ -1051,6 +1058,8 @@ static bool viommu_capable(struct device *dev, enum iommu_cap cap) switch (cap) { case IOMMU_CAP_CACHE_COHERENCY: return true; + case IOMMU_CAP_DEFERRED_FLUSH: + return true; default: return false; } @@ -1071,6 +1080,7 @@ static struct iommu_ops viommu_ops = { .map_pages = viommu_map_pages, .unmap_pages = viommu_unmap_pages, .iova_to_phys = viommu_iova_to_phys, + .flush_iotlb_all = viommu_flush_iotlb_all, .iotlb_sync = viommu_iotlb_sync, .iotlb_sync_map = viommu_iotlb_sync_map, .free = viommu_domain_free, -- 2.39.2
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