[Qemu-devel] [PATCH v1 2/3] target/s390x: Improve heuristic for ipte

[David Hildenbrand]

If only the page index is set, most likely we don't have a valid
virtual address. Let's do a full tlb flush for that case.

Signed-off-by: David Hildenbrand <address@hidden>
---
 target/s390x/mem_helper.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/target/s390x/mem_helper.c b/target/s390x/mem_helper.c
index 1de0494..bce7750 100644
--- a/target/s390x/mem_helper.c
+++ b/target/s390x/mem_helper.c
@@ -1559,13 +1559,23 @@ void HELPER(ipte)(CPUS390XState *env, uint64_t pto, 
uint64_t vaddr,
     /* XXX we exploit the fact that Linux passes the exact virtual
        address here - it's not obliged to! */
     if (s390_has_feat(S390_FEAT_LOCAL_TLB_CLEARING) && (m4 & 1)) {
-        tlb_flush_page(cs, page);
-        /* 31 bit hack */
-        tlb_flush_page(cs, page ^ 0x80000000);
+        if (vaddr & ~VADDR_PX) {
+            tlb_flush_page(cs, page);
+            /* 31 bit hack */
+            tlb_flush_page(cs, page ^ 0x80000000);
+        } else {
+            /* looks like we don't have a valid virtual address */
+            tlb_flush(cs);
+        }
     } else {
-        tlb_flush_page_all_cpus_synced(cs, page);
-        /* 31 bit hack */
-        tlb_flush_page_all_cpus_synced(cs, page ^ 0x80000000);
+        if (vaddr & ~VADDR_PX) {
+            tlb_flush_page_all_cpus_synced(cs, page);
+            /* 31 bit hack */
+            tlb_flush_page_all_cpus_synced(cs, page ^ 0x80000000);
+        } else {
+            /* looks like we don't have a valid virtual address */
+            tlb_flush_all_cpus_synced(cs);
+        }
     }
 }
 
-- 
2.9.4