target-ppc: Enable DABRX SPR and limit it to <=POWER7

This adds DABRX SPR.

As DABR(X) are present in POWER CPUs till POWER7 only and POWER8 does not
have them (as it implements more powerful facility instead), this limits
DABR/DABRX registration by POWER7 (inclusive).
Signed-off-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: NAlexander Graf <agraf@suse.de>

target-ppc/translate_init.c

@@ -7411,10 +7411,21 @@ static void gen_spr_book3s_altivec(CPUPPCState *env)
 
 static void gen_spr_book3s_dbg(CPUPPCState *env)
 {
+    /*
+     * TODO: different specs define different scopes for these,
+     * will have to address this:
+     * 970: super/write and super/read
+     * powerisa 2.03..2.04: hypv/write and super/read.
+     * powerisa 2.05 and newer: hypv/write and hypv/read.
+     */
     spr_register_kvm(env, SPR_DABR, "DABR",
                      SPR_NOACCESS, SPR_NOACCESS,
                      &spr_read_generic, &spr_write_generic,
                      KVM_REG_PPC_DABR, 0x00000000);
+    spr_register_kvm(env, SPR_DABRX, "DABRX",
+                     SPR_NOACCESS, SPR_NOACCESS,
+                     &spr_read_generic, &spr_write_generic,
+                     KVM_REG_PPC_DABRX, 0x00000000);
 }
 
 static void gen_spr_970_dbg(CPUPPCState *env)
@@ -7793,7 +7804,6 @@ static void init_proc_book3s_64(CPUPPCState *env, int version)
     gen_spr_book3s_altivec(env);
     gen_spr_book3s_pmu_sup(env);
     gen_spr_book3s_pmu_user(env);
-    gen_spr_book3s_dbg(env);
     gen_spr_book3s_common(env);
 
     switch (version) {
@@ -7837,6 +7847,9 @@ static void init_proc_book3s_64(CPUPPCState *env, int version)
         gen_spr_power8_pmu_user(env);
         gen_spr_power8_tm(env);
     }
+    if (version < BOOK3S_CPU_POWER8) {
+        gen_spr_book3s_dbg(env);
+    }
 #if !defined(CONFIG_USER_ONLY)
     switch (version) {
     case BOOK3S_CPU_970: