[PATCH] arm,smmu: match start level of page table walk with P2M

[laurentiu.tudor@xxxxxxx]

From: Laurentiu Tudor <laurentiu.tudor@xxxxxxx>

Don't hardcode the lookup start level of the page table walk to 1
and instead match the one used in P2M. This should fix scenarios
involving SMMU where the start level is different than 1.

Signed-off-by: Laurentiu Tudor <laurentiu.tudor@xxxxxxx>
---
 xen/arch/arm/p2m.c                 | 2 +-
 xen/drivers/passthrough/arm/smmu.c | 2 +-
 xen/include/asm-arm/p2m.h          | 1 +
 3 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index ce59f2b503..0181b09dc0 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -18,7 +18,6 @@
 
 #ifdef CONFIG_ARM_64
 static unsigned int __read_mostly p2m_root_order;
-static unsigned int __read_mostly p2m_root_level;
 #define P2M_ROOT_ORDER    p2m_root_order
 #define P2M_ROOT_LEVEL p2m_root_level
 static unsigned int __read_mostly max_vmid = MAX_VMID_8_BIT;
@@ -39,6 +38,7 @@ static unsigned int __read_mostly max_vmid = MAX_VMID_8_BIT;
  * restricted by external entity (e.g. IOMMU).
  */
 unsigned int __read_mostly p2m_ipa_bits = 64;
+unsigned int __read_mostly p2m_root_level;
 
 /* Helpers to lookup the properties of each level */
 static const paddr_t level_masks[] =
diff --git a/xen/drivers/passthrough/arm/smmu.c 
b/xen/drivers/passthrough/arm/smmu.c
index 94662a8501..85709a136f 100644
--- a/xen/drivers/passthrough/arm/smmu.c
+++ b/xen/drivers/passthrough/arm/smmu.c
@@ -1152,7 +1152,7 @@ static void arm_smmu_init_context_bank(struct 
arm_smmu_domain *smmu_domain)
              (TTBCR_RGN_WBWA << TTBCR_IRGN0_SHIFT);
 
        if (!stage1)
-               reg |= (TTBCR_SL0_LVL_1 << TTBCR_SL0_SHIFT);
+               reg |= (2 - p2m_root_level) << TTBCR_SL0_SHIFT;
 
        writel_relaxed(reg, cb_base + ARM_SMMU_CB_TTBCR);
 
diff --git a/xen/include/asm-arm/p2m.h b/xen/include/asm-arm/p2m.h
index 5fdb6e8183..97b5eada2b 100644
--- a/xen/include/asm-arm/p2m.h
+++ b/xen/include/asm-arm/p2m.h
@@ -12,6 +12,7 @@
 
 /* Holds the bit size of IPAs in p2m tables.  */
 extern unsigned int p2m_ipa_bits;
+extern unsigned int p2m_root_level;
 
 struct domain;
 
-- 
2.17.1