[PATCH v4 14/17] target/arm/kvm: Special case ID_AA64ISAR0_EL1 RES0 [24, 27] bits

[Eric Auger <eric.auger@redhat.com>]

RES0 [24, 27] bits seem to be reported as writable by the kernel.
This corresponds to former TME field that was turned to RES0 after
FEAT_TME removal from the architecture.

See kernel commit d65bf6e317e7b ("KVM: arm64: Remove all traces
of FEAT_TME") for additional info. However the kernel still exposes
it at writable. Until this gets fixed, Let's ignore those bits.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
---
 target/arm/kvm.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/target/arm/kvm.c b/target/arm/kvm.c
index f3aecef35c..18373b0936 100644
--- a/target/arm/kvm.c
+++ b/target/arm/kvm.c
@@ -430,10 +430,13 @@ decode_idreg_writemap(Object *obj, int index, uint64_t map, ARM64SysReg *reg)
         char *prop_name;
 
         if (!field) {
-            warn_report("%s bit %d of %s is writable but no named field "
-                        "in target/arm/cpu-sysreg-properties.c",
-                        __func__, i, reg->name);
-            warn_report("%s is target/arm/cpu-sysreg-properties.c up to date?", __func__);
+            if (strcmp(reg->name, "ID_AA64ISAR0_EL1") || i < 24 || i > 27) {
+                warn_report("%s bit %d of %s is writable but no named field "
+                            "in target/arm/cpu-sysreg-properties.c",
+                            __func__, i, reg->name);
+                warn_report("%s is target/arm/cpu-sysreg-properties.c up to date?",
+                            __func__);
+            }
             map =  map & ~BIT_ULL(i);
             i = ctz64(map);
             continue;
-- 
2.53.0