diff mbox series

[kernel,v2,1/4] Revert "powerpc/pseries/iommu: Don't use dma_iommu_ops on secure guests"

Message ID 20191216041924.42318-2-aik@ozlabs.ru (mailing list archive)
State Accepted
Commit d862b44133b7a1d7de25288e09eabf4df415e971
Headers show
Series Enable IOMMU support for pseries Secure VMs | expand

Checks

Context Check Description
snowpatch_ozlabs/apply_patch success Successfully applied on branch powerpc/merge (69b349a06f979f2c93a5d6902e57e3e19dcd0475)
snowpatch_ozlabs/checkpatch success total: 0 errors, 0 warnings, 0 checks, 23 lines checked

Commit Message

Alexey Kardashevskiy Dec. 16, 2019, 4:19 a.m. UTC 
From: Ram Pai <linuxram@us.ibm.com>

This reverts commit edea902c1c1efb855f77e041f9daf1abe7a9768a.

At the time the change allowed direct DMA ops for secure VMs; however
since then we switched on using SWIOTLB backed with IOMMU (direct mapping)
and to make this work, we need dma_iommu_ops which handles all cases
including TCE mapping I/O pages in the presence of an IOMMU.

Fixes: edea902c1c1e ("powerpc/pseries/iommu: Don't use dma_iommu_ops on secure guests")
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
[aik: added "revert" and "fixes:"]
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
Changes:
v2
* made it a revert patch, added "fixes:"
---
 arch/powerpc/platforms/pseries/iommu.c | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

Comments

Thiago Jung Bauermann Dec. 16, 2019, 10:58 p.m. UTC | #1 
Hello Alexey,

Alexey Kardashevskiy <aik@ozlabs.ru> writes:

> From: Ram Pai <linuxram@us.ibm.com>
>
> This reverts commit edea902c1c1efb855f77e041f9daf1abe7a9768a.
>
> At the time the change allowed direct DMA ops for secure VMs; however
> since then we switched on using SWIOTLB backed with IOMMU (direct mapping)
> and to make this work, we need dma_iommu_ops which handles all cases
> including TCE mapping I/O pages in the presence of an IOMMU.
>
> Fixes: edea902c1c1e ("powerpc/pseries/iommu: Don't use dma_iommu_ops on secure guests")
> Signed-off-by: Ram Pai <linuxram@us.ibm.com>
> [aik: added "revert" and "fixes:"]
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>

Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Tested-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Michael Ellerman Jan. 6, 2020, 11:33 p.m. UTC | #2 
On Mon, 2019-12-16 at 04:19:21 UTC, Alexey Kardashevskiy wrote:
> From: Ram Pai <linuxram@us.ibm.com>
> 
> This reverts commit edea902c1c1efb855f77e041f9daf1abe7a9768a.
> 
> At the time the change allowed direct DMA ops for secure VMs; however
> since then we switched on using SWIOTLB backed with IOMMU (direct mapping)
> and to make this work, we need dma_iommu_ops which handles all cases
> including TCE mapping I/O pages in the presence of an IOMMU.
> 
> Fixes: edea902c1c1e ("powerpc/pseries/iommu: Don't use dma_iommu_ops on secure guests")
> Signed-off-by: Ram Pai <linuxram@us.ibm.com>
> [aik: added "revert" and "fixes:"]
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>

Series applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/d862b44133b7a1d7de25288e09eabf4df415e971

cheers
diff mbox series

Patch

diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 6ba081dd61c9..df7db33ca93b 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 "pseries.h"
 
@@ -1320,15 +1319,7 @@  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)