[PATCH v5 2/2] powerpc/pseries/iommu: Use dma_iommu_ops for Secure VM.

Ram Pai
2019-12-07T01:13:18Z

Commit edea902c1c1e ("powerpc/pseries/iommu: Don't use dma_iommu_ops on
secure guests")
disabled dma_iommu_ops path, for secure VMs. Disabling dma_iommu_ops
path for secure VMs, helped enable dma_direct path. This enabled
support for bounce-buffering through SWIOTLB. However it fails to
operate when IOMMU is enabled, since I/O pages are not TCE mapped.

Renable dma_iommu_ops path for pseries Secure VMs. It handles all
cases including, TCE mapping I/O pages, in the presence of a
IOMMU.

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
arch/powerpc/platforms/pseries/iommu.c | 11 +----------
1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 67b5009..4e27d66 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -36,7 +36,6 @@
#include <asm/udbg.h>
#include <asm/mmzone.h>
#include <asm/plpar_wrappers.h>
-#include <asm/svm.h>
#include <asm/ultravisor.h>

#include "pseries.h"
@@ -1346,15 +1345,7 @@ void iommu_init_early_pSeries(void)
of_reconfig_notifier_register(&iommu_reconfig_nb);
register_memory_notifier(&iommu_mem_nb);

- /*
- * Secure guest memory is inacessible to devices so regular DMA isn't
- * possible.
- *
- * In that case keep devices' dma_map_ops as NULL so that the generic
- * DMA code path will use SWIOTLB to bounce buffers for DMA.
- */
- if (!is_secure_guest())
- set_pci_dma_ops(&dma_iommu_ops);
+ set_pci_dma_ops(&dma_iommu_ops);
}

static int __init disable_multitce(char *str)
--
1.8.3.1