[PATCH 4/6] target/arm: Implement FEAT_LVA

[Richard Henderson]

This feature is relatively small, as it applies only to
64k pages and thus requires no additional changes to the
table descriptor walking algorithm, only a change to the
minimum TSZ (which is the inverse of the maximum virtual
address space size).

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/cpu-param.h | 2 +-
 target/arm/cpu.h       | 5 +++++
 target/arm/cpu64.c     | 1 +
 target/arm/helper.c    | 8 +++++++-
 4 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/target/arm/cpu-param.h b/target/arm/cpu-param.h
index 7f38d33b8e..5f9c288b1a 100644
--- a/target/arm/cpu-param.h
+++ b/target/arm/cpu-param.h
@@ -11,7 +11,7 @@
 #ifdef TARGET_AARCH64
 # define TARGET_LONG_BITS             64
 # define TARGET_PHYS_ADDR_SPACE_BITS  48
-# define TARGET_VIRT_ADDR_SPACE_BITS  48
+# define TARGET_VIRT_ADDR_SPACE_BITS  52
 #else
 # define TARGET_LONG_BITS             32
 # define TARGET_PHYS_ADDR_SPACE_BITS  40
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index e33f37b70a..3149000004 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -4288,6 +4288,11 @@ static inline bool isar_feature_aa64_ccidx(const 
ARMISARegisters *id)
     return FIELD_EX64(id->id_aa64mmfr2, ID_AA64MMFR2, CCIDX) != 0;
 }
 
+static inline bool isar_feature_aa64_lva(const ARMISARegisters *id)
+{
+    return FIELD_EX64(id->id_aa64mmfr2, ID_AA64MMFR2, VARANGE) != 0;
+}
+
 static inline bool isar_feature_aa64_tts2uxn(const ARMISARegisters *id)
 {
     return FIELD_EX64(id->id_aa64mmfr1, ID_AA64MMFR1, XNX) != 0;
diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index 15245a60a8..f44ee643ef 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -755,6 +755,7 @@ static void aarch64_max_initfn(Object *obj)
         t = FIELD_DP64(t, ID_AA64MMFR2, UAO, 1);
         t = FIELD_DP64(t, ID_AA64MMFR2, CNP, 1); /* TTCNP */
         t = FIELD_DP64(t, ID_AA64MMFR2, ST, 1); /* TTST */
+        t = FIELD_DP64(t, ID_AA64MMFR2, VARANGE, 1); /* FEAT_LPA */
         cpu->isar.id_aa64mmfr2 = t;
 
         t = cpu->isar.id_aa64zfr0;
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 568914bd42..6a59975028 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -11324,7 +11324,7 @@ static bool get_phys_addr_lpae(CPUARMState *env, 
uint64_t address,
 
     /* TODO: This code does not support shareability levels. */
     if (aarch64) {
-        int min_tsz = 16, max_tsz = 39;  /* TODO: ARMv8.2-LVA  */
+        int min_tsz = 16, max_tsz = 39;
         int parange;
 
         param = aa64_va_parameters(env, address, mmu_idx,
@@ -11334,6 +11334,12 @@ static bool get_phys_addr_lpae(CPUARMState *env, 
uint64_t address,
         if (cpu_isar_feature(aa64_st, env_archcpu(env))) {
             max_tsz = 48 - param.using64k;
         }
+        if (param.using64k) {
+            if (cpu_isar_feature(aa64_lva, env_archcpu(env))) {
+                min_tsz = 12;
+            }
+        }
+        /* TODO: FEAT_LPA2 */
 
         /*
          * If TxSZ is programmed to a value larger than the maximum,
-- 
2.25.1