The previous patch introduced iommu_table_ops::set_and_get() callback
which effectively disabled VFIO on pseries. This implements set_and_get()
for pseries/lpar so VFIO can work under pHyp again.
Since set_and_get() callback must return old TCE, it has to do H_GET_TCE
for every TCE being replaced, therefore VFIO's performance under pHyp
is expected to be slow.
Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
---
arch/powerpc/platforms/pseries/iommu.c | 25 +++++++++++++++++++++++--
1 file changed, 23 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/iommu.c
b/arch/powerpc/platforms/pseries/iommu.c
index 793f002..d3cded1 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -138,13 +138,14 @@ static void tce_freemulti_pSeriesLP(struct iommu_table*,
long, long);
static int tce_build_pSeriesLP(struct iommu_table *tbl, long tcenum,
long npages, unsigned long uaddr,
+ unsigned long *old_tces,
enum dma_data_direction direction,
struct dma_attrs *attrs)
{
u64 rc = 0;
u64 proto_tce, tce;
u64 rpn;
- int ret = 0;
+ int ret = 0, i = 0;
long tcenum_start = tcenum, npages_start = npages;
rpn = __pa(uaddr) >> TCE_SHIFT;
@@ -154,6 +155,9 @@ static int tce_build_pSeriesLP(struct iommu_table *tbl,
long tcenum,
while (npages--) {
tce = proto_tce | (rpn & TCE_RPN_MASK) << TCE_RPN_SHIFT;
+ if (old_tces)
+ plpar_tce_get((u64)tbl->it_index, (u64)tcenum << 12,
+ &old_tces[i++]);
rc = plpar_tce_put((u64)tbl->it_index, (u64)tcenum << 12, tce);
if (unlikely(rc == H_NOT_ENOUGH_RESOURCES)) {
@@ -179,8 +183,9 @@ static int tce_build_pSeriesLP(struct iommu_table *tbl,
long tcenum,
static DEFINE_PER_CPU(__be64 *, tce_page);
-static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
+static int tce_set_and_get_pSeriesLP(struct iommu_table *tbl, long tcenum,
long npages, unsigned long uaddr,
+ unsigned long *old_tces,
enum dma_data_direction direction,
struct dma_attrs *attrs)
{
@@ -195,6 +200,7 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table
*tbl, long tcenum,
if ((npages == 1) || !firmware_has_feature(FW_FEATURE_MULTITCE)) {
return tce_build_pSeriesLP(tbl, tcenum, npages, uaddr,
+ old_tces,
direction, attrs);
}
@@ -211,6 +217,7 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table
*tbl, long tcenum,
if (!tcep) {
local_irq_restore(flags);
return tce_build_pSeriesLP(tbl, tcenum, npages, uaddr,
+ old_tces,
direction, attrs);
}
__get_cpu_var(tce_page) = tcep;
@@ -232,6 +239,10 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table
*tbl, long tcenum,
for (l = 0; l < limit; l++) {
tcep[l] = cpu_to_be64(proto_tce | (rpn & TCE_RPN_MASK)
<< TCE_RPN_SHIFT);
rpn++;
+ if (old_tces)
+ plpar_tce_get((u64)tbl->it_index,
+ (u64)(tcenum + l) << 12,
+ &old_tces[tcenum + l]);
}
rc = plpar_tce_put_indirect((u64)tbl->it_index,
@@ -262,6 +273,15 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table
*tbl, long tcenum,
return ret;
}
+static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
+ long npages, unsigned long uaddr,
+ enum dma_data_direction direction,
+ struct dma_attrs *attrs)
+{
+ return tce_set_and_get_pSeriesLP(tbl, tcenum, npages, uaddr, NULL,
+ direction, attrs);
+}
+
static void tce_free_pSeriesLP(struct iommu_table *tbl, long tcenum, long
npages)
{
u64 rc;
@@ -637,6 +657,7 @@ static void pci_dma_bus_setup_pSeries(struct pci_bus *bus)
struct iommu_table_ops iommu_table_lpar_multi_ops = {
.set = tce_buildmulti_pSeriesLP,
+ .set_and_get = tce_set_and_get_pSeriesLP,
.clear = tce_freemulti_pSeriesLP,
.get = tce_get_pSeriesLP
};
--
2.0.0
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