3 files changed, 14 insertions, 1 deletions

diff --git a/hw/s390x/css.c b/hw/s390x/css.c
index 343c3520de..533357ad97 100644
--- a/hw/s390x/css.c
+++ b/hw/s390x/css.c
@@ -49,6 +49,7 @@ typedef struct IoAdapter {
 
 typedef struct ChannelSubSys {
     QTAILQ_HEAD(, CrwContainer) pending_crws;
+    bool sei_pending;
     bool do_crw_mchk;
     bool crws_lost;
     uint8_t max_cssid;
@@ -1359,7 +1360,15 @@ void css_generate_chp_crws(uint8_t cssid, uint8_t chpid)
 
 void css_generate_css_crws(uint8_t cssid)
 {
-    css_queue_crw(CRW_RSC_CSS, 0, 0, cssid);
+    if (!channel_subsys->sei_pending) {
+        css_queue_crw(CRW_RSC_CSS, 0, 0, cssid);
+    }
+    channel_subsys->sei_pending = true;
+}
+
+void css_clear_sei_pending(void)
+{
+    channel_subsys->sei_pending = false;
 }
 
 int css_enable_mcsse(void)
@@ -1509,6 +1518,7 @@ static void css_init(void)
 {
     channel_subsys = g_malloc0(sizeof(*channel_subsys));
     QTAILQ_INIT(&channel_subsys->pending_crws);
+    channel_subsys->sei_pending = false;
     channel_subsys->do_crw_mchk = true;
     channel_subsys->crws_lost = false;
     channel_subsys->chnmon_active = false;
@@ -1561,6 +1571,7 @@ void css_reset(void)
         QTAILQ_REMOVE(&channel_subsys->pending_crws, crw_cont, sibling);
         g_free(crw_cont);
     }
+    channel_subsys->sei_pending = false;
     channel_subsys->do_crw_mchk = true;
     channel_subsys->crws_lost = false;
 
diff --git a/hw/s390x/css.h b/hw/s390x/css.h
index a09bb1f87c..a47937dee5 100644
--- a/hw/s390x/css.h
+++ b/hw/s390x/css.h
@@ -103,6 +103,7 @@ void css_generate_sch_crws(uint8_t cssid, uint8_t ssid, uint16_t schid,
                            int hotplugged, int add);
 void css_generate_chp_crws(uint8_t cssid, uint8_t chpid);
 void css_generate_css_crws(uint8_t cssid);
+void css_clear_sei_pending(void);
 void css_adapter_interrupt(uint8_t isc);
 
 #define CSS_IO_ADAPTER_VIRTIO 1
diff --git a/target-s390x/ioinst.c b/target-s390x/ioinst.c
index 57c2d8b226..9a8de6d122 100644
--- a/target-s390x/ioinst.c
+++ b/target-s390x/ioinst.c
@@ -614,6 +614,7 @@ static void ioinst_handle_chsc_sei(ChscReq *req, ChscResp *res)
             (*res_flags) |= 0x80;
         } else {
             (*res_flags) &= ~0x80;
+            css_clear_sei_pending();
         }
     } else {
         res->code = cpu_to_be16(0x0005);