Re: [RFC PATCH 10/11] vfio/iommu_type1: Optimize dirty bitmap population based on iommu HWDBM
From: Yi Sun <hidden>
Date: 2021-02-07 10:04:04
Also in:
kvm, kvmarm, linux-iommu, lkml
Hi, On 21-01-28 23:17:41, Keqian Zhu wrote: [...]
+static void vfio_dma_dirty_log_start(struct vfio_iommu *iommu,
+ struct vfio_dma *dma)
+{
+ struct vfio_domain *d;
+
+ list_for_each_entry(d, &iommu->domain_list, next) {
+ /* Go through all domain anyway even if we fail */
+ iommu_split_block(d->domain, dma->iova, dma->size);
+ }
+}This should be a switch to prepare for dirty log start. Per Intel Vtd spec, there is SLADE defined in Scalable-Mode PASID Table Entry. It enables Accessed/Dirty Flags in second-level paging entries. So, a generic iommu interface here is better. For Intel iommu, it enables SLADE. For ARM, it splits block.
+
+static void vfio_dma_dirty_log_stop(struct vfio_iommu *iommu,
+ struct vfio_dma *dma)
+{
+ struct vfio_domain *d;
+
+ list_for_each_entry(d, &iommu->domain_list, next) {
+ /* Go through all domain anyway even if we fail */
+ iommu_merge_page(d->domain, dma->iova, dma->size,
+ d->prot | dma->prot);
+ }
+}Same as above comment, a generic interface is required here.
quoted hunk ↗ jump to hunk
+ +static void vfio_iommu_dirty_log_switch(struct vfio_iommu *iommu, bool start) +{ + struct rb_node *n; + + /* Split and merge even if all iommu don't support HWDBM now */ + for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) { + struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node); + + if (!dma->iommu_mapped) + continue; + + /* Go through all dma range anyway even if we fail */ + if (start) + vfio_dma_dirty_log_start(iommu, dma); + else + vfio_dma_dirty_log_stop(iommu, dma); + } +} + static int vfio_iommu_type1_dirty_pages(struct vfio_iommu *iommu, unsigned long arg) {@@ -2812,8 +2900,10 @@ static int vfio_iommu_type1_dirty_pages(struct vfio_iommu *iommu, pgsize = 1 << __ffs(iommu->pgsize_bitmap); if (!iommu->dirty_page_tracking) { ret = vfio_dma_bitmap_alloc_all(iommu, pgsize); - if (!ret) + if (!ret) { iommu->dirty_page_tracking = true; + vfio_iommu_dirty_log_switch(iommu, true); + } } mutex_unlock(&iommu->lock); return ret;@@ -2822,6 +2912,7 @@ static int vfio_iommu_type1_dirty_pages(struct vfio_iommu *iommu, if (iommu->dirty_page_tracking) { iommu->dirty_page_tracking = false; vfio_dma_bitmap_free_all(iommu); + vfio_iommu_dirty_log_switch(iommu, false); } mutex_unlock(&iommu->lock); return 0;-- 2.19.1
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