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From: Alexey Kardashevskiy <aik@ozlabs.ru>
To: linuxppc-dev@lists.ozlabs.org
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>,
	Michael Anderson <andmike@linux.ibm.com>,
	Ram Pai <linuxram@us.ibm.com>,
	kvm-ppc@vger.kernel.org,
	Thiago Jung Bauermann <bauerman@linux.ibm.com>,
	David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH kernel v2 1/4] Revert "powerpc/pseries/iommu: Don't use dma_iommu_ops on secure guests"
Date: Mon, 16 Dec 2019 15:19:21 +1100
Message-ID: <20191216041924.42318-2-aik@ozlabs.ru> (raw)
In-Reply-To: <20191216041924.42318-1-aik@ozlabs.ru>

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(-)

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)
-- 
2.17.1


  reply index

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-16  4:19 [PATCH kernel v2 0/4] Enable IOMMU support for pseries Secure VMs Alexey Kardashevskiy
2019-12-16  4:19 ` Alexey Kardashevskiy [this message]
2019-12-16 22:58   ` [PATCH kernel v2 1/4] Revert "powerpc/pseries/iommu: Don't use dma_iommu_ops on secure guests" Thiago Jung Bauermann
2020-01-06 23:33   ` Michael Ellerman
2019-12-16  4:19 ` [PATCH kernel v2 2/4] powerpc/pseries: Allow not having ibm, hypertas-functions::hcall-multi-tce for DDW Alexey Kardashevskiy
2019-12-16 23:07   ` Thiago Jung Bauermann
2019-12-17  0:09     ` [PATCH kernel v2 2/4] powerpc/pseries: Allow not having ibm,hypertas-functions::hcall-multi-tce " Alexey Kardashevskiy
2019-12-17  2:06       ` [PATCH kernel v2 2/4] powerpc/pseries: Allow not having ibm, hypertas-functions::hcall-multi-tce " Thiago Jung Bauermann
2020-01-02 22:02   ` [PATCH kernel v2 2/4] powerpc/pseries: Allow not having ibm,hypertas-functions::hcall-multi-tce " Ram Pai
2019-12-16  4:19 ` [PATCH kernel v2 3/4] powerpc/pseries/iommu: Separate FW_FEATURE_MULTITCE to put/stuff features Alexey Kardashevskiy
2019-12-16 23:19   ` Thiago Jung Bauermann
2020-01-02 22:24   ` Ram Pai
2019-12-16  4:19 ` [PATCH kernel v2 4/4] powerpc/pseries/svm: Allow IOMMU to work in SVM Alexey Kardashevskiy
2019-12-16 23:23   ` Thiago Jung Bauermann
2020-01-02 22:21   ` Ram Pai
2020-01-03  0:08     ` David Gibson
2020-01-03  2:06       ` Ram Pai

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