[PATCH v2 06/12] KVM: arm64: Use LPA2 page-tables for hyp stage1 if HW supports it

[Ryan Roberts]

Implement a simple policy whereby if the HW supports FEAT_LPA2 for the
page size we are using, always use LPA2-style page-tables for hyp stage
1, regardless of the IPA or PA size requirements. When in use we can now
support up to 52-bit IPA and PA sizes.

Signed-off-by: Ryan Roberts <ryan.roberts at arm.com>
---
 arch/arm64/kvm/arm.c         | 2 ++
 arch/arm64/kvm/hyp/pgtable.c | 3 ++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 3bd732eaf087..bef73c484162 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1548,6 +1548,8 @@ static void __init cpu_prepare_hyp_mode(int cpu, u32 hyp_va_bits)
 	tcr = (read_sysreg(tcr_el1) & TCR_EL2_MASK) | TCR_EL2_RES1;
 	tcr &= ~TCR_T0SZ_MASK;
 	tcr |= TCR_T0SZ(hyp_va_bits);
+	if (system_supports_lpa2())
+		tcr |= TCR_EL2_DS;
 	params->tcr_el2 = tcr;
 
 	params->pgd_pa = kvm_mmu_get_httbr();
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index 414a5dbf233d..bb481d6c7f2d 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -379,7 +379,8 @@ static int hyp_set_prot_attr(enum kvm_pgtable_prot prot, kvm_pte_t *ptep)
 	}
 
 	attr |= FIELD_PREP(KVM_PTE_LEAF_ATTR_LO_S1_AP, ap);
-	attr |= FIELD_PREP(KVM_PTE_LEAF_ATTR_LO_S1_SH, sh);
+	if (!system_supports_lpa2())
+		attr |= FIELD_PREP(KVM_PTE_LEAF_ATTR_LO_S1_SH, sh);
 	attr |= KVM_PTE_LEAF_ATTR_LO_S1_AF;
 	attr |= prot & KVM_PTE_LEAF_ATTR_HI_SW;
 	*ptep = attr;
-- 
2.25.1