Re: [RFC PATCH v4 5/5] s390: implementing CHSC SEI for AP config change

[Thomas Huth]

On 11/03/2025 16.16, Rorie Reyes wrote:
Handle interception of the CHSC SEI instruction for requests
indicating the guest's AP configuration has changed.
Signed-off-by: Rorie Reyes <rre...@linux.ibm.com>
Reviewed-by: Anthony Krowiak <akrow...@linux.ibm.com>
Tested-by: Anthony Krowiak <akrow...@linux.ibm.com>
---
  target/s390x/ioinst.c | 11 +++++++++--
  1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/target/s390x/ioinst.c b/target/s390x/ioinst.c
index a944f16c25..f061c6db14 100644
--- a/target/s390x/ioinst.c
+++ b/target/s390x/ioinst.c
@@ -17,6 +17,7 @@
  #include "trace.h"
  #include "hw/s390x/s390-pci-bus.h"
  #include "target/s390x/kvm/pv.h"
+#include "hw/s390x/ap-bridge.h"
  
  /* All I/O instructions but chsc use the s format */
  static uint64_t get_address_from_regs(CPUS390XState *env, uint32_t ipb,
@@ -573,13 +574,19 @@ out:
  
  static int chsc_sei_nt0_get_event(void *res)
  {
-    /* no events yet */
+    if (s390_has_feat(S390_FEAT_AP)) {
+        return ap_chsc_sei_nt0_get_event(res);
+    }
+
      return 1;
  }
  
  static int chsc_sei_nt0_have_event(void)
  {
-    /* no events yet */
+    if (s390_has_feat(S390_FEAT_AP)) {
+        return ap_chsc_sei_nt0_have_event();
+    }
+
      return 0;
  }

 Hi!

This unfortunately fails to link when configuring QEMU with the 
"--without-default-devices" configure switch:

/usr/bin/ld: libqemu-s390x-softmmu.a.p/target_s390x_ioinst.c.o: in function 
`ioinst_handle_chsc':
/tmp/qemu-mini/target/s390x/ioinst.c:587:(.text+0x1ce1): undefined reference 
to `ap_chsc_sei_nt0_have_event'
/usr/bin/ld: /tmp/qemu-mini/target/s390x/ioinst.c:578:(.text+0x1d1c): 
undefined reference to `ap_chsc_sei_nt0_get_event'
collect2: error: ld returned 1 exit status

I guess you have to rather use some callback mechanism, stubs or #ifdefs 
here instead.

 Thomas