[Qemu-devel] [PATCH-for-4.2 v1 9/9] s390x/cpumodel: Add new TCG features to QEMU cpu model

[David Hildenbrand <david@redhat.com>]

We now implement a bunch of new facilities we can properly indicate.

ESOP-1/ESOP-2 handling is discussed in the PoP Chafter 3-15
("Suppression on Protection"). The "Basic suppression-on-protection (SOP)
facility" is a core part of z/Architecture without a facility
indication. ESOP-2 is indicated by ESOP-1 + Side-effect facility
("ESOP-2"). Besides ESOP-2, the side-effect facility is only relevant for
the guarded-storage facility (we don't implement).

S390_ESOP:
- We indicate DAT exeptions by setting bit 61 of the TEID (TEC) to 1 and
  bit 60 to zero. We don't trigger ALCP exceptions yet. Also, we set
  bit 0-51 and bit 62/63 to the right values.
S390_ACCESS_EXCEPTION_FS_INDICATION:
- The TEID (TEC) properly indicates in bit 52/53 on any access if it was
  a fetch or a store
S390_SIDE_EFFECT_ACCESS_ESOP2:
- We have no side-effect accesses (esp., we don't implement the
  guarded-storage faciliy), we correctly set bit 64 of the TEID (TEC) to
  0 (no side-effect).
- ESOP2: We properly set bit 56, 60, 61 in the TEID (TEC) to indicate the
  type of protection. We don't trigger KCP/ALCP exceptions yet.
S390_INSTRUCTION_EXEC_PROT:
- The MMU properly detects and indicates the exception on instruction fetches
- Protected TLB entries will never get PAGE_EXEC set.

There is no need to fake the abscence of any of the facilities - without
the facilities, some bits of the TEID (TEC) are simply unpredictable.

As IEP was added with z14 and we currently implement a z13, add it to
the MAX model instead.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 target/s390x/gen-features.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/target/s390x/gen-features.c b/target/s390x/gen-features.c
index 7e82f2f004..6e78d40d9a 100644
--- a/target/s390x/gen-features.c
+++ b/target/s390x/gen-features.c
@@ -704,12 +704,16 @@ static uint16_t qemu_V4_1[] = {
 };
 
 static uint16_t qemu_LATEST[] = {
+    S390_FEAT_ACCESS_EXCEPTION_FS_INDICATION,
+    S390_FEAT_SIDE_EFFECT_ACCESS_ESOP2,
+    S390_FEAT_ESOP,
 };
 
 /* add all new definitions before this point */
 static uint16_t qemu_MAX[] = {
     /* generates a dependency warning, leave it out for now */
     S390_FEAT_MSA_EXT_5,
+    S390_FEAT_INSTRUCTION_EXEC_PROT,
 };
 
 /****** END FEATURE DEFS ******/
-- 
2.21.0