From 89628ec85c86fee920a518330759891dd0c01921 Mon Sep 17 00:00:00 2001

From: Thomas Huth <thuth@redhat.com>

Date: Tue, 23 Jan 2018 19:12:45 +0100

Subject: [PATCH 3/8] s390x/kvm: Handle bpb feature

RH-Author: Thomas Huth <thuth@redhat.com>

Message-id: <1516734766-12075-3-git-send-email-thuth@redhat.com>

Patchwork-id: 78701

O-Subject: [RHEL-7.5 qemu-kvm-ma PATCH 2/3] s390x/kvm: Handle bpb feature

Bugzilla: 1535606

RH-Acked-by: David Hildenbrand <david@redhat.com>

RH-Acked-by: Cornelia Huck <cohuck@redhat.com>

RH-Acked-by: Jens Freimann <jfreimann@redhat.com>

From: Christian Borntraeger <borntraeger@de.ibm.com>

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.

Cc: qemu-stable@nongnu.org

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

Message-Id: <20180118085628.40798-3-borntraeger@de.ibm.com>

Reviewed-by: Thomas Huth <thuth@redhat.com>

Reviewed-by: David Hildenbrand <david@redhat.com>

[CH: 'Branch Prediction Blocking' -> 'Branch prediction blocking']

Signed-off-by: Cornelia Huck <cohuck@redhat.com>

(cherry picked from commit b073c87517d4d348c7bac0f0b35e8e83e6354d82)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 target/s390x/cpu.c              |  1 +

 target/s390x/cpu.h              |  1 +

 target/s390x/cpu_features.c     |  1 +

 target/s390x/cpu_features_def.h |  1 +

 target/s390x/gen-features.c     |  1 +

 target/s390x/kvm.c              | 14 ++++++++++++++

 target/s390x/machine.c          | 17 +++++++++++++++++

 7 files changed, 36 insertions(+)

diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c

index 489bc25..8bd463c 100644

--- a/target/s390x/cpu.c

+++ b/target/s390x/cpu.c

@@ -78,6 +78,7 @@ 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 29fdd5d..ce1f933 100644

--- a/target/s390x/cpu.h

+++ b/target/s390x/cpu.h

@@ -96,6 +96,7 @@ 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/cpu_features.c b/target/s390x/cpu_features.c

index 1d3a036..d39efb0 100644

--- a/target/s390x/cpu_features.c

+++ b/target/s390x/cpu_features.c

@@ -89,6 +89,7 @@ static const S390FeatDef s390_features[] = {

     FEAT_INIT("msa4-base", S390_FEAT_TYPE_STFL, 77, "Message-security-assist-extension-4 facility (excluding subfunctions)"),

     FEAT_INIT("edat2", S390_FEAT_TYPE_STFL, 78, "Enhanced-DAT facility 2"),

     FEAT_INIT("dfppc", S390_FEAT_TYPE_STFL, 80, "Decimal-floating-point packed-conversion facility"),

+    FEAT_INIT("bpb", S390_FEAT_TYPE_STFL, 82, "Branch prediction blocking"),

     FEAT_INIT("vx", S390_FEAT_TYPE_STFL, 129, "Vector facility"),

     FEAT_INIT("iep", S390_FEAT_TYPE_STFL, 130, "Instruction-execution-protection facility"),

     FEAT_INIT("sea_esop2", S390_FEAT_TYPE_STFL, 131, "Side-effect-access facility and Enhanced-suppression-on-protection facility 2"),

diff --git a/target/s390x/cpu_features_def.h b/target/s390x/cpu_features_def.h

index 4b6d4e9..4487cfd 100644

--- a/target/s390x/cpu_features_def.h

+++ b/target/s390x/cpu_features_def.h

@@ -80,6 +80,7 @@ typedef enum {

     S390_FEAT_MSA_EXT_4,

     S390_FEAT_EDAT_2,

     S390_FEAT_DFP_PACKED_CONVERSION,

+    S390_FEAT_BPB,

     S390_FEAT_VECTOR,

     S390_FEAT_INSTRUCTION_EXEC_PROT,

     S390_FEAT_SIDE_EFFECT_ACCESS_ESOP2,

diff --git a/target/s390x/gen-features.c b/target/s390x/gen-features.c

index 68e6c31..13a6291 100644

--- a/target/s390x/gen-features.c

+++ b/target/s390x/gen-features.c

@@ -352,6 +352,7 @@ static uint16_t base_GEN14_GA1[] = {

  * support these features yet.

  */

 static uint16_t full_GEN7_GA1[] = {

+    S390_FEAT_BPB,

     S390_FEAT_SIE_F2,

     S390_FEAT_SIE_SKEY,

     S390_FEAT_SIE_GPERE,

diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c

index 3589e6e..871f441 100644

--- a/target/s390x/kvm.c

+++ b/target/s390x/kvm.c

@@ -488,6 +488,11 @@ int kvm_arch_put_registers(CPUState *cs, int level)

         cs->kvm_run->kvm_dirty_regs |= KVM_SYNC_GSCB;

     }

+    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;

@@ -598,6 +603,10 @@ int kvm_arch_get_registers(CPUState *cs)

         memcpy(env->gscb, cs->kvm_run->s.regs.gscb, 32);

     }

+    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;

@@ -2666,6 +2675,11 @@ void kvm_s390_get_host_cpu_model(S390CPUModel *model, Error **errp)

         clear_bit(S390_FEAT_CMM_NT, model->features);

     }

+    /* bpb needs kernel support for migration, VSIE and reset */

+    if (!kvm_check_extension(kvm_state, KVM_CAP_S390_BPB)) {

+        clear_bit(S390_FEAT_BPB, model->features);

+    }

+

     /* We emulate a zPCI bus and AEN, therefore we don't need HW support */

     set_bit(S390_FEAT_ZPCI, model->features);

     set_bit(S390_FEAT_ADAPTER_EVENT_NOTIFICATION, model->features);

diff --git a/target/s390x/machine.c b/target/s390x/machine.c

index 2dcadfd..f24088b 100644

--- a/target/s390x/machine.c

+++ b/target/s390x/machine.c

@@ -190,6 +190,22 @@ const VMStateDescription vmstate_gscb = {

         }

 };

+static bool bpbc_needed(void *opaque)

+{

+    return s390_has_feat(S390_FEAT_BPB);

+}

+

+const VMStateDescription vmstate_bpbc = {

+    .name = "cpu/bpbc",

+    .version_id = 1,

+    .minimum_version_id = 1,

+    .needed = bpbc_needed,

+    .fields = (VMStateField[]) {

+        VMSTATE_BOOL(env.bpbc, S390CPU),

+        VMSTATE_END_OF_LIST()

+    }

+};

+

 const VMStateDescription vmstate_s390_cpu = {

     .name = "cpu",

     .post_load = cpu_post_load,

@@ -224,6 +240,7 @@ const VMStateDescription vmstate_s390_cpu = {

         &vmstate_riccb,

         &vmstate_exval,

         &vmstate_gscb,

+        &vmstate_bpbc,

         NULL

     },

 };

-- 

1.8.3.1