[Qemu-devel] [PATCH v2 2/3] target/s390x: Improve heuristic for ipte

[David Hildenbrand <david@redhat.com>]

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 <david@redhat.com>
---
 target/s390x/mem_helper.c | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/target/s390x/mem_helper.c b/target/s390x/mem_helper.c
index 41e5a1d..1507175 100644
--- a/target/s390x/mem_helper.c
+++ b/target/s390x/mem_helper.c
@@ -1559,16 +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 (m4 & 1) {
-        tlb_flush_page(cs, page);
-    } else {
-        tlb_flush_page_all_cpus_synced(cs, page);
-    }
-
-    /* XXX 31-bit hack */
-    if (m4 & 1) {
-        tlb_flush_page(cs, page ^ 0x80000000);
+        if (vaddr & ~VADDR_PX) {
+            tlb_flush_page(cs, page);
+            /* XXX 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 ^ 0x80000000);
+        if (vaddr & ~VADDR_PX) {
+            tlb_flush_page_all_cpus_synced(cs, page);
+            /* XXX 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