[Xen-devel] [RFC PATCH 5/9] iommu/arm: Re-define iommu_use_hap_pt(d) as iommu_hap_pt_share

[Oleksandr Tyshchenko <olekstysh@xxxxxxxxx>]

From: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>

Not every integrated into ARM SoCs IOMMU can share page tables
with the CPU and as result the iommu_use_hap_pt(d) is not always true.
Reuse x86's iommu_hap_pt_share flag to indicate whether the IOMMU
page table is shared or not.

Now all IOMMU drivers on ARM are able to change this flag
according to their possibilities like x86-variants do.
Therefore set iommu_hap_pt_share flag for SMMU because it always shares
page table with the CPU.

Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
---
 xen/drivers/passthrough/arm/smmu.c | 3 +++
 xen/include/asm-arm/iommu.h        | 7 +++++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/xen/drivers/passthrough/arm/smmu.c 
b/xen/drivers/passthrough/arm/smmu.c
index 1082fcf..b2bb41f 100644
--- a/xen/drivers/passthrough/arm/smmu.c
+++ b/xen/drivers/passthrough/arm/smmu.c
@@ -2833,6 +2833,9 @@ static __init int arm_smmu_dt_init(struct dt_device_node 
*dev,
 
        platform_features &= smmu->features;
 
+       /* Always share P2M table between the CPU and the SMMU */
+       iommu_hap_pt_share = true;
+
        return 0;
 }
 
diff --git a/xen/include/asm-arm/iommu.h b/xen/include/asm-arm/iommu.h
index 57d9b1e..10a6f23 100644
--- a/xen/include/asm-arm/iommu.h
+++ b/xen/include/asm-arm/iommu.h
@@ -20,8 +20,11 @@ struct arch_iommu
     void *priv;
 };
 
-/* Always share P2M Table between the CPU and the IOMMU */
-#define iommu_use_hap_pt(d) (1)
+/*
+ * The ARM domain always has a P2M table, but not every integrated into
+ * ARM SoCs IOMMU can use it as page table.
+ */
+#define iommu_use_hap_pt(d) (iommu_hap_pt_share)
 
 const struct iommu_ops *iommu_get_ops(void);
 void __init iommu_set_ops(const struct iommu_ops *ops);
-- 
2.7.4


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