[PATCH v4 12/16] powerpc/pseries/lpar: Enable VFIO
From: Alexey Kardashevskiy <hidden>
Date: 2014-07-30 09:31:50
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
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 <redacted> --- 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