File 0256-s390x-kvm-Handle-bpb-feature.patch of Package qemu.12243

From aa1dbf8050a4a89ea30ff23a53181de92d367a20 Mon Sep 17 00:00:00 2001
From: Christian Borntraeger <borntraeger@de.ibm.com>
Date: Fri, 12 Jan 2018 17:34:47 +0100
Subject: [PATCH] s390x/kvm: Handle bpb feature

We need to handle the bpb control on reset and migration. Normally
stfle.82 is transparent (and the normal guest part works without
hypervisor activity). To prevent any issues we require full
host kernel support for this feature.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
(cherry picked from commit b073c87517d4d348c7bac0f0b35e8e83e6354d82)
[LY: BSC#1076814]
Signed-off-by: Liang Yan <lyan@suse.com>
---
 target-s390x/cpu.c | 1 +
 target-s390x/cpu.h | 1 +
 target-s390x/kvm.c | 9 +++++++++
 3 files changed, 11 insertions(+)

diff --git a/target-s390x/cpu.c b/target-s390x/cpu.c
index 4bfff341dc..3373d3cb5c 100644
--- a/target-s390x/cpu.c
+++ b/target-s390x/cpu.c
@@ -101,6 +101,7 @@ static void s390_cpu_reset(CPUState *s)
     CPUS390XState *env = &cpu->env;
 
     env->pfault_token = -1UL;
+    env->bpbc = false;
     scc->parent_reset(s);
     cpu->env.sigp_order = 0;
     s390_cpu_set_state(CPU_STATE_STOPPED, cpu);
diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h
index 6d97c089a4..8ce1c5bb7b 100644
--- a/target-s390x/cpu.h
+++ b/target-s390x/cpu.h
@@ -89,6 +89,7 @@ typedef struct CPUS390XState {
 
     uint32_t fpc;          /* floating-point control register */
     uint32_t cc_op;
+    bool bpbc;             /* branch prediction blocking */
 
     float_status fpu_status; /* passed to softfloat lib */
 
diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
index e1859cae04..8979944a1c 100644
--- a/target-s390x/kvm.c
+++ b/target-s390x/kvm.c
@@ -426,6 +426,11 @@ int kvm_arch_put_registers(CPUState *cs, int level)
         }
     }
 
+    if (can_sync_regs(cs, KVM_SYNC_BPBC)) {
+        cs->kvm_run->s.regs.bpbc = env->bpbc;
+        cs->kvm_run->kvm_dirty_regs |= KVM_SYNC_BPBC;
+    }
+
     /* Finally the prefix */
     if (can_sync_regs(cs, KVM_SYNC_PREFIX)) {
         cs->kvm_run->s.regs.prefix = env->psa;
@@ -528,6 +533,10 @@ int kvm_arch_get_registers(CPUState *cs)
         kvm_get_one_reg(cs, KVM_REG_S390_PP, &env->pp);
     }
 
+    if (can_sync_regs(cs, KVM_SYNC_BPBC)) {
+        env->bpbc = cs->kvm_run->s.regs.bpbc;
+    }
+
     /* pfault parameters */
     if (can_sync_regs(cs, KVM_SYNC_PFAULT)) {
         env->pfault_token = cs->kvm_run->s.regs.pft;