[PATCH v4 10/12] KVM: arm64: Allow guests with >48-bit IPA size on FEAT_LPA2 systems

[Ryan Roberts]

With all the page-table infrastructure in place, we can finally increase
the maximum permisable IPA size to 52-bits on 4KB and 16KB page systems
that have FEAT_LPA2.

Signed-off-by: Ryan Roberts <ryan.roberts at arm.com>
---
 arch/arm64/kvm/reset.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index 7a65a35ee4ac..7816c64d4701 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -316,12 +316,11 @@ int __init kvm_set_ipa_limit(void)
 	parange = cpuid_feature_extract_unsigned_field(mmfr0,
 				ID_AA64MMFR0_EL1_PARANGE_SHIFT);
 	/*
-	 * IPA size beyond 48 bits could not be supported
-	 * on either 4K or 16K page size. Hence let's cap
-	 * it to 48 bits, in case it's reported as larger
-	 * on the system.
+	 * IPA size beyond 48 bits for 4K and 16K page size is only supported
+	 * when LPA2 is available. So if we have LPA2, enable it, else cap to 48
+	 * bits, in case it's reported as larger on the system.
 	 */
-	if (PAGE_SIZE != SZ_64K)
+	if (!system_supports_lpa2() && PAGE_SIZE != SZ_64K)
 		parange = min(parange, (unsigned int)ID_AA64MMFR0_EL1_PARANGE_48);
 
 	/*
-- 
2.25.1