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Subject[PATCH 1/3] KVM: arm64: Check if 52-bits PA is enabled
Date
The 52-bits physical address is disabled until CONFIG_ARM64_PA_BITS_52
is chosen. This uses option for that check, to avoid the unconditional
check on PAGE_SHIFT in the hot path and thus save some CPU cycles.

Signed-off-by: Gavin Shan <gshan@redhat.com>
---
arch/arm64/kvm/hyp/pgtable.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index 0cdf6e461cbd..fd850353ee89 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -132,8 +132,9 @@ static u64 kvm_pte_to_phys(kvm_pte_t pte)
{
u64 pa = pte & KVM_PTE_ADDR_MASK;

- if (PAGE_SHIFT == 16)
- pa |= FIELD_GET(KVM_PTE_ADDR_51_48, pte) << 48;
+#ifdef CONFIG_ARM64_PA_BITS_52
+ pa |= FIELD_GET(KVM_PTE_ADDR_51_48, pte) << 48;
+#endif

return pa;
}
@@ -142,8 +143,9 @@ static kvm_pte_t kvm_phys_to_pte(u64 pa)
{
kvm_pte_t pte = pa & KVM_PTE_ADDR_MASK;

- if (PAGE_SHIFT == 16)
- pte |= FIELD_PREP(KVM_PTE_ADDR_51_48, pa >> 48);
+#ifdef CONFIG_ARM64_PA_BITS_52
+ pte |= FIELD_PREP(KVM_PTE_ADDR_51_48, pa >> 48);
+#endif

return pte;
}
--
2.23.0
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