diff mbox series

[v21,06/20] s390x/cpu topology: interception of PTF instruction

Message ID 20230630091752.67190-7-pmorel@linux.ibm.com (mailing list archive)
State New, archived
Headers show
Series s390x: CPU Topology | expand

Commit Message

Pierre Morel June 30, 2023, 9:17 a.m. UTC 
When the host supports the CPU topology facility, the PTF
instruction with function code 2 is interpreted by the SIE,
provided that the userland hypervisor activates the interpretation
by using the KVM_CAP_S390_CPU_TOPOLOGY KVM extension.

The PTF instructions with function code 0 and 1 are intercepted
and must be emulated by the userland hypervisor.

During RESET all CPU of the configuration are placed in
horizontal polarity.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
---
 include/hw/s390x/s390-virtio-ccw.h |  6 ++++
 hw/s390x/cpu-topology.c            | 54 ++++++++++++++++++++++++++++++
 target/s390x/kvm/kvm.c             | 11 ++++++
 3 files changed, 71 insertions(+)

Comments

Thomas Huth July 4, 2023, 12:16 p.m. UTC | #1 
On 30/06/2023 11.17, Pierre Morel wrote:
> When the host supports the CPU topology facility, the PTF
> instruction with function code 2 is interpreted by the SIE,
> provided that the userland hypervisor activates the interpretation
> by using the KVM_CAP_S390_CPU_TOPOLOGY KVM extension.
> 
> The PTF instructions with function code 0 and 1 are intercepted
> and must be emulated by the userland hypervisor.
> 
> During RESET all CPU of the configuration are placed in
> horizontal polarity.
> 
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> Reviewed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
> ---
>   include/hw/s390x/s390-virtio-ccw.h |  6 ++++
>   hw/s390x/cpu-topology.c            | 54 ++++++++++++++++++++++++++++++
>   target/s390x/kvm/kvm.c             | 11 ++++++
>   3 files changed, 71 insertions(+)


Reviewed-by: Thomas Huth <thuth@redhat.com>
Pierre Morel July 12, 2023, 2:40 p.m. UTC | #2 
On 7/4/23 14:16, Thomas Huth wrote:
> On 30/06/2023 11.17, Pierre Morel wrote:
>> When the host supports the CPU topology facility, the PTF
>> instruction with function code 2 is interpreted by the SIE,
>> provided that the userland hypervisor activates the interpretation
>> by using the KVM_CAP_S390_CPU_TOPOLOGY KVM extension.
>>
>> The PTF instructions with function code 0 and 1 are intercepted
>> and must be emulated by the userland hypervisor.
>>
>> During RESET all CPU of the configuration are placed in
>> horizontal polarity.
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> Reviewed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
>> ---
>>   include/hw/s390x/s390-virtio-ccw.h |  6 ++++
>>   hw/s390x/cpu-topology.c            | 54 ++++++++++++++++++++++++++++++
>>   target/s390x/kvm/kvm.c             | 11 ++++++
>>   3 files changed, 71 insertions(+)
>
>
> Reviewed-by: Thomas Huth <thuth@redhat.com>
>

Thanks,

Pierre
diff mbox series

Patch

diff --git a/include/hw/s390x/s390-virtio-ccw.h b/include/hw/s390x/s390-virtio-ccw.h
index 9bba21a916..c1d46e78af 100644
--- a/include/hw/s390x/s390-virtio-ccw.h
+++ b/include/hw/s390x/s390-virtio-ccw.h
@@ -30,6 +30,12 @@  struct S390CcwMachineState {
     uint8_t loadparm[8];
 };
 
+#define S390_PTF_REASON_NONE (0x00 << 8)
+#define S390_PTF_REASON_DONE (0x01 << 8)
+#define S390_PTF_REASON_BUSY (0x02 << 8)
+#define S390_TOPO_FC_MASK 0xffUL
+void s390_handle_ptf(S390CPU *cpu, uint8_t r1, uintptr_t ra);
+
 struct S390CcwMachineClass {
     /*< private >*/
     MachineClass parent_class;
diff --git a/hw/s390x/cpu-topology.c b/hw/s390x/cpu-topology.c
index 764ff92573..8c1a82bd71 100644
--- a/hw/s390x/cpu-topology.c
+++ b/hw/s390x/cpu-topology.c
@@ -92,6 +92,59 @@  static void s390_topology_init(MachineState *ms)
                                             smp->books * smp->drawers);
 }
 
+/*
+ * s390_handle_ptf:
+ *
+ * @register 1: contains the function code
+ *
+ * Function codes 0 (horizontal) and 1 (vertical) define the CPU
+ * polarization requested by the guest.
+ *
+ * Function code 2 is handling topology changes and is interpreted
+ * by the SIE.
+ */
+void s390_handle_ptf(S390CPU *cpu, uint8_t r1, uintptr_t ra)
+{
+    CpuS390Polarization polarization = S390_CPU_POLARIZATION_HORIZONTAL;
+    CPUS390XState *env = &cpu->env;
+    uint64_t reg = env->regs[r1];
+    int fc = reg & S390_TOPO_FC_MASK;
+
+    if (!s390_has_feat(S390_FEAT_CONFIGURATION_TOPOLOGY)) {
+        s390_program_interrupt(env, PGM_OPERATION, ra);
+        return;
+    }
+
+    if (env->psw.mask & PSW_MASK_PSTATE) {
+        s390_program_interrupt(env, PGM_PRIVILEGED, ra);
+        return;
+    }
+
+    if (reg & ~S390_TOPO_FC_MASK) {
+        s390_program_interrupt(env, PGM_SPECIFICATION, ra);
+        return;
+    }
+
+    switch (fc) {
+    case S390_CPU_POLARIZATION_VERTICAL:
+        polarization = S390_CPU_POLARIZATION_VERTICAL;
+        /* fallthrough */
+    case S390_CPU_POLARIZATION_HORIZONTAL:
+        if (s390_topology.polarization == polarization) {
+            env->regs[r1] |= S390_PTF_REASON_DONE;
+            setcc(cpu, 2);
+        } else {
+            s390_topology.polarization = polarization;
+            s390_cpu_topology_set_changed(true);
+            setcc(cpu, 0);
+        }
+        break;
+    default:
+        /* Note that fc == 2 is interpreted by the SIE */
+        s390_program_interrupt(env, PGM_SPECIFICATION, ra);
+    }
+}
+
 /**
  * s390_topology_reset:
  *
@@ -101,6 +154,7 @@  static void s390_topology_init(MachineState *ms)
 void s390_topology_reset(void)
 {
     s390_cpu_topology_set_changed(false);
+    s390_topology.polarization = S390_CPU_POLARIZATION_HORIZONTAL;
 }
 
 /**
diff --git a/target/s390x/kvm/kvm.c b/target/s390x/kvm/kvm.c
index bc953151ce..fb63be41b7 100644
--- a/target/s390x/kvm/kvm.c
+++ b/target/s390x/kvm/kvm.c
@@ -96,6 +96,7 @@ 
 
 #define PRIV_B9_EQBS                    0x9c
 #define PRIV_B9_CLP                     0xa0
+#define PRIV_B9_PTF                     0xa2
 #define PRIV_B9_PCISTG                  0xd0
 #define PRIV_B9_PCILG                   0xd2
 #define PRIV_B9_RPCIT                   0xd3
@@ -1464,6 +1465,13 @@  static int kvm_mpcifc_service_call(S390CPU *cpu, struct kvm_run *run)
     }
 }
 
+static void kvm_handle_ptf(S390CPU *cpu, struct kvm_run *run)
+{
+    uint8_t r1 = (run->s390_sieic.ipb >> 20) & 0x0f;
+
+    s390_handle_ptf(cpu, r1, RA_IGNORED);
+}
+
 static int handle_b9(S390CPU *cpu, struct kvm_run *run, uint8_t ipa1)
 {
     int r = 0;
@@ -1481,6 +1489,9 @@  static int handle_b9(S390CPU *cpu, struct kvm_run *run, uint8_t ipa1)
     case PRIV_B9_RPCIT:
         r = kvm_rpcit_service_call(cpu, run);
         break;
+    case PRIV_B9_PTF:
+        kvm_handle_ptf(cpu, run);
+        break;
     case PRIV_B9_EQBS:
         /* just inject exception */
         r = -1;