[Qemu-devel] [PULL 12/35] s390x/tcg: Introduce tcg_s390_vector_exception()

[Cornelia Huck <cohuck@redhat.com>]

From: David Hildenbrand <david@redhat.com>

Handling is similar to data exceptions, however we can always store the
VXC into the lowore and the FPC:

z14 PoP, 6-20, "Vector-Exception Code"
    When a vector-processing exception causes a pro-
    gram interruption, a vector-exception code (VXC) is
    stored at location 147, and zeros are stored at loca-
    tions 144-146. The VXC is also placed in the DXC
    field of the floating-point-control (FPC) register if bit
    45 of control register 0 is one. When bit 45 of control
    register 0 is zero and bit 46 of control register 0 is
    one, the DXC field of the FPC register and the con-
    tents of storage at location 147 are unpredictable.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 target/s390x/cpu.h         |  1 +
 target/s390x/excp_helper.c | 15 +++++++++++++++
 target/s390x/tcg_s390x.h   |  2 ++
 3 files changed, 18 insertions(+)

diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
index 317a1377e6ce..4fc08a2c88f6 100644
--- a/target/s390x/cpu.h
+++ b/target/s390x/cpu.h
@@ -215,6 +215,7 @@ extern const struct VMStateDescription vmstate_s390_cpu;
 #define PGM_SPECIAL_OP                  0x0013
 #define PGM_OPERAND                     0x0015
 #define PGM_TRACE_TABLE                 0x0016
+#define PGM_VECTOR_PROCESSING           0x001b
 #define PGM_SPACE_SWITCH                0x001c
 #define PGM_HFP_SQRT                    0x001d
 #define PGM_PC_TRANS_SPEC               0x001f
diff --git a/target/s390x/excp_helper.c b/target/s390x/excp_helper.c
index 85223d00c01f..f21bcf79ae18 100644
--- a/target/s390x/excp_helper.c
+++ b/target/s390x/excp_helper.c
@@ -62,6 +62,21 @@ void QEMU_NORETURN tcg_s390_data_exception(CPUS390XState *env, uint32_t dxc,
     tcg_s390_program_interrupt(env, PGM_DATA, ILEN_AUTO, ra);
 }
 
+void QEMU_NORETURN tcg_s390_vector_exception(CPUS390XState *env, uint32_t vxc,
+                                             uintptr_t ra)
+{
+    g_assert(vxc <= 0xff);
+#if !defined(CONFIG_USER_ONLY)
+    /* Always store the VXC into the lowcore, without AFP it is undefined */
+    stl_phys(CPU(s390_env_get_cpu(env))->as,
+             env->psa + offsetof(LowCore, data_exc_code), vxc);
+#endif
+
+    /* Always store the VXC into the FPC, without AFP it is undefined */
+    env->fpc = deposit32(env->fpc, 8, 8, vxc);
+    tcg_s390_program_interrupt(env, PGM_VECTOR_PROCESSING, ILEN_AUTO, ra);
+}
+
 void HELPER(data_exception)(CPUS390XState *env, uint32_t dxc)
 {
     tcg_s390_data_exception(env, dxc, GETPC());
diff --git a/target/s390x/tcg_s390x.h b/target/s390x/tcg_s390x.h
index ab2c4ba70327..2813f9d48e2e 100644
--- a/target/s390x/tcg_s390x.h
+++ b/target/s390x/tcg_s390x.h
@@ -18,5 +18,7 @@ void QEMU_NORETURN tcg_s390_program_interrupt(CPUS390XState *env, uint32_t code,
                                               int ilen, uintptr_t ra);
 void QEMU_NORETURN tcg_s390_data_exception(CPUS390XState *env, uint32_t dxc,
                                            uintptr_t ra);
+void QEMU_NORETURN tcg_s390_vector_exception(CPUS390XState *env, uint32_t vxc,
+                                             uintptr_t ra);
 
 #endif /* TCG_S390X_H */
-- 
2.20.1