s390x: handle exceptions during s390_cpu_virt_mem_rw() correctly (TCG)

s390_cpu_virt_mem_rw() must always return, so callers can react on
an exception (e.g. see ioinst_handle_stcrw()).

However, for TCG we always have to exit the cpu loop (and restore the
cpu state before that) if we injected a program interrupt. So let's
introduce and use s390_cpu_virt_mem_handle_exc() in code that is not
purely KVM.

Directly pass the retaddr we already have available in these functions.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20171130162744.25442-8-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>

1 files changed, 17 insertions, 3 deletions

diff --git a/target/s390x/ioinst.c b/target/s390x/ioinst.c
index 25e0ad6f77..83c164a168 100644
--- a/target/s390x/ioinst.c
+++ b/target/s390x/ioinst.c
@@ -120,6 +120,7 @@ void ioinst_handle_msch(S390CPU *cpu, uint64_t reg1, uint32_t ipb, uintptr_t ra)
         return;
     }
     if (s390_cpu_virt_mem_read(cpu, addr, ar, &schib, sizeof(schib))) {
+        s390_cpu_virt_mem_handle_exc(cpu, ra);
         return;
     }
     if (ioinst_disassemble_sch_ident(reg1, &m, &cssid, &ssid, &schid) ||
@@ -176,6 +177,7 @@ void ioinst_handle_ssch(S390CPU *cpu, uint64_t reg1, uint32_t ipb, uintptr_t ra)
         return;
     }
     if (s390_cpu_virt_mem_read(cpu, addr, ar, &orig_orb, sizeof(orb))) {
+        s390_cpu_virt_mem_handle_exc(cpu, ra);
         return;
     }
     copy_orb_from_guest(&orb, &orig_orb);
@@ -212,9 +214,12 @@ void ioinst_handle_stcrw(S390CPU *cpu, uint32_t ipb, uintptr_t ra)
 
     if (s390_cpu_virt_mem_write(cpu, addr, ar, &crw, sizeof(crw)) == 0) {
         setcc(cpu, cc);
-    } else if (cc == 0) {
-        /* Write failed: requeue CRW since STCRW is a suppressing instruction */
-        css_undo_stcrw(&crw);
+    } else {
+        if (cc == 0) {
+            /* Write failed: requeue CRW since STCRW is suppressing */
+            css_undo_stcrw(&crw);
+        }
+        s390_cpu_virt_mem_handle_exc(cpu, ra);
     }
 }
 
@@ -243,6 +248,8 @@ void ioinst_handle_stsch(S390CPU *cpu, uint64_t reg1, uint32_t ipb,
          */
         if (!s390_cpu_virt_mem_check_write(cpu, addr, ar, sizeof(schib))) {
             s390_program_interrupt(env, PGM_OPERAND, 4, ra);
+        } else {
+            s390_cpu_virt_mem_handle_exc(cpu, ra);
         }
         return;
     }
@@ -268,11 +275,13 @@ void ioinst_handle_stsch(S390CPU *cpu, uint64_t reg1, uint32_t ipb,
     if (cc != 3) {
         if (s390_cpu_virt_mem_write(cpu, addr, ar, &schib,
                                     sizeof(schib)) != 0) {
+            s390_cpu_virt_mem_handle_exc(cpu, ra);
             return;
         }
     } else {
         /* Access exceptions have a higher priority than cc3 */
         if (s390_cpu_virt_mem_check_write(cpu, addr, ar, sizeof(schib)) != 0) {
+            s390_cpu_virt_mem_handle_exc(cpu, ra);
             return;
         }
     }
@@ -309,6 +318,7 @@ int ioinst_handle_tsch(S390CPU *cpu, uint64_t reg1, uint32_t ipb, uintptr_t ra)
     /* 0 - status pending, 1 - not status pending, 3 - not operational */
     if (cc != 3) {
         if (s390_cpu_virt_mem_write(cpu, addr, ar, &irb, irb_len) != 0) {
+            s390_cpu_virt_mem_handle_exc(cpu, ra);
             return -EFAULT;
         }
         css_do_tsch_update_subch(sch);
@@ -316,6 +326,7 @@ int ioinst_handle_tsch(S390CPU *cpu, uint64_t reg1, uint32_t ipb, uintptr_t ra)
         irb_len = sizeof(irb) - sizeof(irb.emw);
         /* Access exceptions have a higher priority than cc3 */
         if (s390_cpu_virt_mem_check_write(cpu, addr, ar, irb_len) != 0) {
+            s390_cpu_virt_mem_handle_exc(cpu, ra);
             return -EFAULT;
         }
     }
@@ -611,6 +622,7 @@ void ioinst_handle_chsc(S390CPU *cpu, uint32_t ipb, uintptr_t ra)
      * care of req->len here first.
      */
     if (s390_cpu_virt_mem_read(cpu, addr, reg, buf, sizeof(ChscReq))) {
+        s390_cpu_virt_mem_handle_exc(cpu, ra);
         return;
     }
     req = (ChscReq *)buf;
@@ -645,6 +657,8 @@ void ioinst_handle_chsc(S390CPU *cpu, uint32_t ipb, uintptr_t ra)
     if (!s390_cpu_virt_mem_write(cpu, addr + len, reg, res,
                                  be16_to_cpu(res->len))) {
         setcc(cpu, 0);    /* Command execution complete */
+    } else {
+        s390_cpu_virt_mem_handle_exc(cpu, ra);
     }
 }