[PATCH v4 05/28] s390x/diag: Introduce DIAG 320 for certificate store facility

[Zhuoying Cai <zycai@linux.ibm.com>]

DIAGNOSE 320 is introduced to support certificate store facility,
which includes operations such as query certificate storage
information and provide certificates in the certificate store.

Currently, only subcode 0 is supported with this patch, which is
used to query a bitmap of which subcodes are supported.

Signed-off-by: Zhuoying Cai <zycai@linux.ibm.com>
---
 include/hw/s390x/ipl/diag320.h | 17 ++++++++++++++
 target/s390x/diag.c            | 41 ++++++++++++++++++++++++++++++++++
 target/s390x/kvm/kvm.c         | 14 ++++++++++++
 target/s390x/s390x-internal.h  |  2 ++
 target/s390x/tcg/misc_helper.c |  7 ++++++
 5 files changed, 81 insertions(+)
 create mode 100644 include/hw/s390x/ipl/diag320.h

diff --git a/include/hw/s390x/ipl/diag320.h b/include/hw/s390x/ipl/diag320.h
new file mode 100644
index 0000000000..713570545d
--- /dev/null
+++ b/include/hw/s390x/ipl/diag320.h
@@ -0,0 +1,17 @@
+/*
+ * S/390 DIAGNOSE 320 definitions and structures
+ *
+ * Copyright 2025 IBM Corp.
+ * Author(s): Zhuoying Cai <zycai@linux.ibm.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef S390X_DIAG320_H
+#define S390X_DIAG320_H
+
+#define DIAG_320_SUBC_QUERY_ISM     0
+
+#define DIAG_320_RC_OK              0x0001
+
+#endif
diff --git a/target/s390x/diag.c b/target/s390x/diag.c
index cff9fbc4b0..d33c5daf38 100644
--- a/target/s390x/diag.c
+++ b/target/s390x/diag.c
@@ -18,6 +18,7 @@
 #include "hw/watchdog/wdt_diag288.h"
 #include "system/cpus.h"
 #include "hw/s390x/ipl.h"
+#include "hw/s390x/ipl/diag320.h"
 #include "hw/s390x/s390-virtio-ccw.h"
 #include "system/kvm.h"
 #include "kvm/kvm_s390x.h"
@@ -191,3 +192,43 @@ out:
         break;
     }
 }
+
+void handle_diag_320(CPUS390XState *env, uint64_t r1, uint64_t r3, uintptr_t ra)
+{
+    S390CPU *cpu = env_archcpu(env);
+    uint64_t subcode = env->regs[r3];
+    uint64_t addr = env->regs[r1];
+    int rc;
+
+    if (env->psw.mask & PSW_MASK_PSTATE) {
+        s390_program_interrupt(env, PGM_PRIVILEGED, ra);
+        return;
+    }
+
+    if (!s390_has_feat(S390_FEAT_DIAG_320)) {
+        s390_program_interrupt(env, PGM_SPECIFICATION, ra);
+        return;
+    }
+
+    if (r1 & 1) {
+        s390_program_interrupt(env, PGM_SPECIFICATION, ra);
+        return;
+    }
+
+    switch (subcode) {
+    case DIAG_320_SUBC_QUERY_ISM:
+        uint64_t ism =  0;
+
+        if (s390_cpu_virt_mem_write(cpu, addr, r1, &ism, sizeof(ism))) {
+            s390_cpu_virt_mem_handle_exc(cpu, ra);
+            return;
+        }
+
+        rc = DIAG_320_RC_OK;
+        break;
+    default:
+        s390_program_interrupt(env, PGM_SPECIFICATION, ra);
+        return;
+    }
+    env->regs[r1 + 1] = rc;
+}
diff --git a/target/s390x/kvm/kvm.c b/target/s390x/kvm/kvm.c
index 8f655a4b7f..d5b3694600 100644
--- a/target/s390x/kvm/kvm.c
+++ b/target/s390x/kvm/kvm.c
@@ -98,6 +98,7 @@
 #define DIAG_TIMEREVENT                 0x288
 #define DIAG_IPL                        0x308
 #define DIAG_SET_CONTROL_PROGRAM_CODES  0x318
+#define DIAG_CERT_STORE                 0x320
 #define DIAG_KVM_HYPERCALL              0x500
 #define DIAG_KVM_BREAKPOINT             0x501
 
@@ -1560,6 +1561,16 @@ static void handle_diag_318(S390CPU *cpu, struct kvm_run *run)
     }
 }
 
+static void kvm_handle_diag_320(S390CPU *cpu, struct kvm_run *run)
+{
+    uint64_t r1, r3;
+
+    r1 = (run->s390_sieic.ipa & 0x00f0) >> 4;
+    r3 = run->s390_sieic.ipa & 0x000f;
+
+    handle_diag_320(&cpu->env, r1, r3, RA_IGNORED);
+}
+
 #define DIAG_KVM_CODE_MASK 0x000000000000ffff
 
 static int handle_diag(S390CPU *cpu, struct kvm_run *run, uint32_t ipb)
@@ -1590,6 +1601,9 @@ static int handle_diag(S390CPU *cpu, struct kvm_run *run, uint32_t ipb)
     case DIAG_KVM_BREAKPOINT:
         r = handle_sw_breakpoint(cpu, run);
         break;
+    case DIAG_CERT_STORE:
+        kvm_handle_diag_320(cpu, run);
+        break;
     default:
         trace_kvm_insn_diag(func_code);
         kvm_s390_program_interrupt(cpu, PGM_SPECIFICATION);
diff --git a/target/s390x/s390x-internal.h b/target/s390x/s390x-internal.h
index a4ba6227ab..86a652f833 100644
--- a/target/s390x/s390x-internal.h
+++ b/target/s390x/s390x-internal.h
@@ -400,6 +400,8 @@ int mmu_translate_real(CPUS390XState *env, target_ulong raddr, int rw,
 int handle_diag_288(CPUS390XState *env, uint64_t r1, uint64_t r3);
 void handle_diag_308(CPUS390XState *env, uint64_t r1, uint64_t r3,
                      uintptr_t ra);
+void handle_diag_320(CPUS390XState *env, uint64_t r1, uint64_t r3,
+                     uintptr_t ra);
 
 
 /* translate.c */
diff --git a/target/s390x/tcg/misc_helper.c b/target/s390x/tcg/misc_helper.c
index f7101be574..412c34ed93 100644
--- a/target/s390x/tcg/misc_helper.c
+++ b/target/s390x/tcg/misc_helper.c
@@ -142,6 +142,13 @@ void HELPER(diag)(CPUS390XState *env, uint32_t r1, uint32_t r3, uint32_t num)
         /* time bomb (watchdog) */
         r = handle_diag_288(env, r1, r3);
         break;
+    case 0x320:
+        /* cert store */
+        bql_lock();
+        handle_diag_320(env, r1, r3, GETPC());
+        bql_unlock();
+        r = 0;
+        break;
     default:
         r = -1;
         break;
-- 
2.49.0