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vfio/spapr_tce: Invalidate multiple TCEs at once

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Invalidating a TCE cache entry for each updated TCE is quite expensive.
This makes use of the new iommu_table_ops::xchg_no_kill()/tce_kill()
callbacks to bring down the time spent in mapping a huge guest DMA window.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190829085252.72370-4-aik@ozlabs.ru
This commit is contained in:
Alexey Kardashevskiy 2019-08-29 18:52:50 +10:00 committed by Michael Ellerman
parent 01b7d128b5
commit 650ab1e370
1 changed files with 12 additions and 6 deletions
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18
drivers/vfio/vfio_iommu_spapr_tce.c
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@ -435,7 +435,7 @@ static int tce_iommu_clear(struct tce_container *container,
unsigned long oldhpa;
long ret;
enum dma_data_direction direction;
unsigned long lastentry = entry + pages;
unsigned long lastentry = entry + pages, firstentry = entry;
for ( ; entry < lastentry; ++entry) {
if (tbl->it_indirect_levels && tbl->it_userspace) {
@ -460,7 +460,7 @@ static int tce_iommu_clear(struct tce_container *container,
direction = DMA_NONE;
oldhpa = 0;
ret = iommu_tce_xchg(container->mm, tbl, entry, &oldhpa,
ret = iommu_tce_xchg_no_kill(container->mm, tbl, entry, &oldhpa,
&direction);
if (ret)
continue;
@ -476,6 +476,8 @@ static int tce_iommu_clear(struct tce_container *container,
tce_iommu_unuse_page(container, oldhpa);
}
iommu_tce_kill(tbl, firstentry, pages);
return 0;
}
@ -518,8 +520,8 @@ static long tce_iommu_build(struct tce_container *container,
hpa |= offset;
dirtmp = direction;
ret = iommu_tce_xchg(container->mm, tbl, entry + i, &hpa,
&dirtmp);
ret = iommu_tce_xchg_no_kill(container->mm, tbl, entry + i,
&hpa, &dirtmp);
if (ret) {
tce_iommu_unuse_page(container, hpa);
pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n",
@ -536,6 +538,8 @@ static long tce_iommu_build(struct tce_container *container,
if (ret)
tce_iommu_clear(container, tbl, entry, i);
else
iommu_tce_kill(tbl, entry, pages);
return ret;
}
@ -572,8 +576,8 @@ static long tce_iommu_build_v2(struct tce_container *container,
if (mm_iommu_mapped_inc(mem))
break;
ret = iommu_tce_xchg(container->mm, tbl, entry + i, &hpa,
&dirtmp);
ret = iommu_tce_xchg_no_kill(container->mm, tbl, entry + i,
&hpa, &dirtmp);
if (ret) {
/* dirtmp cannot be DMA_NONE here */
tce_iommu_unuse_page_v2(container, tbl, entry + i);
@ -593,6 +597,8 @@ static long tce_iommu_build_v2(struct tce_container *container,
if (ret)
tce_iommu_clear(container, tbl, entry, i);
else
iommu_tce_kill(tbl, entry, pages);
return ret;
}