s390x: enable runtime instrumentation

Introduce run-time-instrumentation support when running under kvm for
virtio-ccw 2.7 machine and make sure older machines can not enable it.

The new ri_allowed field in the s390MachineClass serves as an indicator
whether the feature can be used by the machine and should therefore be
activated if available.

riccb_needed() is used to check whether riccb is needed or not in live
migration.

Signed-off-by: Fan Zhang <zhangfan@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

3 files changed, 51 insertions, 0 deletions

diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h
index 07f76ad884..996b79023e 100644
--- a/target-s390x/cpu.h
+++ b/target-s390x/cpu.h
@@ -135,6 +135,8 @@ typedef struct CPUS390XState {
     uint64_t gbea;
     uint64_t pp;
 
+    uint8_t riccb[64];
+
     CPU_COMMON
 
     /* reset does memset(0) up to here */
@@ -1159,6 +1161,7 @@ void kvm_s390_reset_vcpu(S390CPU *cpu);
 int kvm_s390_set_mem_limit(KVMState *s, uint64_t new_limit, uint64_t *hw_limit);
 void kvm_s390_vcpu_interrupt_pre_save(S390CPU *cpu);
 int kvm_s390_vcpu_interrupt_post_load(S390CPU *cpu);
+int kvm_s390_get_ri(void);
 void kvm_s390_crypto_reset(void);
 #else
 static inline void kvm_s390_io_interrupt(uint16_t subchannel_id,
@@ -1209,6 +1212,10 @@ static inline int kvm_s390_vcpu_interrupt_post_load(S390CPU *cpu)
 {
     return 0;
 }
+static inline int kvm_s390_get_ri(void)
+{
+    return 0;
+}
 static inline void kvm_s390_crypto_reset(void)
 {
 }
@@ -1272,11 +1279,22 @@ static inline bool vregs_needed(void *opaque)
     }
     return 0;
 }
+static inline bool riccb_needed(void *opaque)
+{
+    if (kvm_enabled()) {
+        return kvm_s390_get_ri();
+    }
+    return 0;
+}
 #else
 static inline bool vregs_needed(void *opaque)
 {
     return 0;
 }
+static inline bool riccb_needed(void *opaque)
+{
+    return 0;
+}
 #endif
 
 /* machine check interruption code */
diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
index e1859cae04..55ae6d3304 100644
--- a/target-s390x/kvm.c
+++ b/target-s390x/kvm.c
@@ -46,6 +46,7 @@
 #include "hw/s390x/ipl.h"
 #include "hw/s390x/ebcdic.h"
 #include "exec/memattrs.h"
+#include "hw/s390x/s390-virtio-ccw.h"
 
 /* #define DEBUG_KVM */
 
@@ -135,6 +136,7 @@ static int cap_sync_regs;
 static int cap_async_pf;
 static int cap_mem_op;
 static int cap_s390_irq;
+static int cap_ri;
 
 static void *legacy_s390_alloc(size_t size, uint64_t *align);
 
@@ -270,6 +272,11 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
     kvm_vm_enable_cap(s, KVM_CAP_S390_USER_SIGP, 0);
     kvm_vm_enable_cap(s, KVM_CAP_S390_VECTOR_REGISTERS, 0);
     kvm_vm_enable_cap(s, KVM_CAP_S390_USER_STSI, 0);
+    if (ri_allowed()) {
+        if (kvm_vm_enable_cap(s, KVM_CAP_S390_RI, 0) == 0) {
+            cap_ri = 1;
+        }
+    }
 
     return 0;
 }
@@ -386,6 +393,11 @@ int kvm_arch_put_registers(CPUState *cs, int level)
         kvm_set_one_reg(cs, KVM_REG_S390_PP, &env->pp);
     }
 
+    if (can_sync_regs(cs, KVM_SYNC_RICCB)) {
+        memcpy(cs->kvm_run->s.regs.riccb, env->riccb, 64);
+        cs->kvm_run->kvm_dirty_regs |= KVM_SYNC_RICCB;
+    }
+
     /* pfault parameters */
     if (can_sync_regs(cs, KVM_SYNC_PFAULT)) {
         cs->kvm_run->s.regs.pft = env->pfault_token;
@@ -528,6 +540,10 @@ 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_RICCB)) {
+        memcpy(env->riccb, cs->kvm_run->s.regs.riccb, 64);
+    }
+
     /* pfault parameters */
     if (can_sync_regs(cs, KVM_SYNC_PFAULT)) {
         env->pfault_token = cs->kvm_run->s.regs.pft;
@@ -2136,6 +2152,11 @@ int kvm_s390_get_memslot_count(KVMState *s)
     return kvm_check_extension(s, KVM_CAP_NR_MEMSLOTS);
 }
 
+int kvm_s390_get_ri(void)
+{
+    return cap_ri;
+}
+
 int kvm_s390_set_cpu_state(S390CPU *cpu, uint8_t cpu_state)
 {
     struct kvm_mp_state mp_state = {};
diff --git a/target-s390x/machine.c b/target-s390x/machine.c
index 6b2609054b..a30b16fe3d 100644
--- a/target-s390x/machine.c
+++ b/target-s390x/machine.c
@@ -135,6 +135,17 @@ static const VMStateDescription vmstate_vregs = {
     }
 };
 
+const VMStateDescription vmstate_riccb = {
+    .name = "cpu/riccb",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = riccb_needed,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8_ARRAY(env.riccb, S390CPU, 64),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 const VMStateDescription vmstate_s390_cpu = {
     .name = "cpu",
     .post_load = cpu_post_load,
@@ -166,6 +177,7 @@ const VMStateDescription vmstate_s390_cpu = {
     .subsections = (const VMStateDescription*[]) {
         &vmstate_fpu,
         &vmstate_vregs,
+        &vmstate_riccb,
         NULL
     },
 };