[PATCH v1 6/9] s390x: kvm: topology: interception of PTF instruction

[Pierre Morel <pmorel@linux.ibm.com>]

Interception of the PTF instruction depending on the new
KVM_CAP_S390_CPU_TOPOLOGY KVM extension.

A global value is used to remember if a Topology change occured since
the last interception of a PTF instruction with function code 0.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
 hw/s390x/cpu-topology.c            | 19 +++++++++++
 include/hw/s390x/cpu-topology.h    |  8 +++++
 include/hw/s390x/s390-virtio-ccw.h |  1 +
 target/s390x/cpu.c                 |  4 +++
 target/s390x/cpu.h                 |  1 +
 target/s390x/kvm/kvm.c             | 52 ++++++++++++++++++++++++++++++
 6 files changed, 85 insertions(+)

diff --git a/hw/s390x/cpu-topology.c b/hw/s390x/cpu-topology.c
index 1224137f56..5e1cac9529 100644
--- a/hw/s390x/cpu-topology.c
+++ b/hw/s390x/cpu-topology.c
@@ -19,12 +19,25 @@
 #include "qemu/typedefs.h"
 #include "hw/s390x/s390-virtio-ccw.h"
 
+int s390_topology_changed(void)
+{
+    const MachineState *ms = MACHINE(qdev_get_machine());
+    S390CcwMachineState *s390ms = S390_CCW_MACHINE(ms);
+
+    if (s390ms->topology_changed) {
+        s390ms->topology_changed = 0;
+        return 1;
+    }
+    return 0;
+}
+
 static S390TopologyCores *s390_create_cores(S390TopologySocket *socket,
                                             int origin)
 {
     DeviceState *dev;
     S390TopologyCores *cores;
     const MachineState *ms = MACHINE(qdev_get_machine());
+    S390CcwMachineState *s390ms = S390_CCW_MACHINE(ms);
 
     if (socket->bus->num_children >= ms->smp.cores) {
         return NULL;
@@ -36,6 +49,7 @@ static S390TopologyCores *s390_create_cores(S390TopologySocket *socket,
     cores = S390_TOPOLOGY_CORES(dev);
     cores->origin = origin;
     socket->cnt += 1;
+    s390ms->topology_changed = 1;
 
     return cores;
 }
@@ -45,6 +59,7 @@ static S390TopologySocket *s390_create_socket(S390TopologyBook *book, int id)
     DeviceState *dev;
     S390TopologySocket *socket;
     const MachineState *ms = MACHINE(qdev_get_machine());
+    S390CcwMachineState *s390ms = S390_CCW_MACHINE(ms);
 
     if (book->bus->num_children >= ms->smp.sockets) {
         return NULL;
@@ -56,6 +71,7 @@ static S390TopologySocket *s390_create_socket(S390TopologyBook *book, int id)
     socket = S390_TOPOLOGY_SOCKET(dev);
     socket->socket_id = id;
     book->cnt++;
+    s390ms->topology_changed = 1;
 
     return socket;
 }
@@ -77,6 +93,7 @@ static S390TopologyBook *s390_create_book(S390TopologyDrawer *drawer, int id)
     book = S390_TOPOLOGY_BOOK(dev);
     book->book_id = id;
     drawer->cnt++;
+    s390ms->topology_changed = 1;
 
     return book;
 }
@@ -98,6 +115,7 @@ static S390TopologyDrawer *s390_create_drawer(S390TopologyNode *node, int id)
     drawer = S390_TOPOLOGY_DRAWER(dev);
     drawer->drawer_id = id;
     node->cnt++;
+    s390ms->topology_changed = 1;
 
     return drawer;
 }
@@ -210,6 +228,7 @@ void s390_topology_new_cpu(int core_id)
     bit = 63 - (core_id - origin);
     set_bit(bit, &cores->mask);
     cores->origin = origin;
+    s390ms->topology_changed = 1;
 }
 
 /*
diff --git a/include/hw/s390x/cpu-topology.h b/include/hw/s390x/cpu-topology.h
index 64424cb457..549a3e9a19 100644
--- a/include/hw/s390x/cpu-topology.h
+++ b/include/hw/s390x/cpu-topology.h
@@ -12,6 +12,7 @@
 
 #include "hw/qdev-core.h"
 #include "qom/object.h"
+#include "include/hw/sysbus.h"
 
 #define S390_TOPOLOGY_CPU_TYPE    0x03
 
@@ -88,4 +89,11 @@ S390TopologyNode *s390_get_topology(void);
 void s390_topology_setup(MachineState *ms);
 void s390_topology_new_cpu(int core_id);
 
+#define S390_PTF_REASON_NONE (0x00 << 8)
+#define S390_PTF_REASON_DONE (0x01 << 8)
+#define S390_PTF_REASON_BUSY (0x02 << 8)
+extern int s390_topology_changed(void);
+
+#define S390_TOPO_FC_MASK 0xffUL
+
 #endif
diff --git a/include/hw/s390x/s390-virtio-ccw.h b/include/hw/s390x/s390-virtio-ccw.h
index fb3c3a50ce..a091468c79 100644
--- a/include/hw/s390x/s390-virtio-ccw.h
+++ b/include/hw/s390x/s390-virtio-ccw.h
@@ -30,6 +30,7 @@ struct S390CcwMachineState {
     uint8_t loadparm[8];
     int drawers;
     int books;
+    int topology_changed;
 };
 
 struct S390CcwMachineClass {
diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
index 7b7b05f1d3..ac7b161190 100644
--- a/target/s390x/cpu.c
+++ b/target/s390x/cpu.c
@@ -35,6 +35,7 @@
 #include "fpu/softfloat-helpers.h"
 #include "disas/capstone.h"
 #include "sysemu/tcg.h"
+#include "hw/s390x/cpu-topology.h"
 
 #define CR0_RESET       0xE0UL
 #define CR14_RESET      0xC2000000UL;
@@ -154,6 +155,9 @@ static void s390_cpu_reset(CPUState *s, cpu_reset_type type)
 
         env->pfault_token = -1UL;
         env->bpbc = false;
+#if !defined(CONFIG_USER_ONLY)
+        s390_topology_changed();
+#endif
         break;
     default:
         g_assert_not_reached();
diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
index d573ba205e..4eacd06c59 100644
--- a/target/s390x/cpu.h
+++ b/target/s390x/cpu.h
@@ -901,4 +901,5 @@ typedef S390CPU ArchCPU;
 
 #include "exec/cpu-all.h"
 
+int s390_handle_ptf(S390CPU *cpu, uint8_t r1, uintptr_t ra);
 #endif
diff --git a/target/s390x/kvm/kvm.c b/target/s390x/kvm/kvm.c
index d78261c089..7c3594d793 100644
--- a/target/s390x/kvm/kvm.c
+++ b/target/s390x/kvm/kvm.c
@@ -98,6 +98,7 @@
 
 #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
@@ -1453,6 +1454,54 @@ static int kvm_mpcifc_service_call(S390CPU *cpu, struct kvm_run *run)
     }
 }
 
+int s390_handle_ptf(S390CPU *cpu, uint8_t r1, uintptr_t ra)
+{
+    CPUS390XState *env = &cpu->env;
+    uint64_t reg = env->regs[r1];
+    uint8_t fc = reg & S390_TOPO_FC_MASK;
+
+    if (!s390_has_feat(S390_FEAT_CONFIGURATION_TOPOLOGY)) {
+        s390_program_interrupt(env, PGM_OPERAND, ra);
+        return 0;
+    }
+
+    if (env->psw.mask & PSW_MASK_PSTATE) {
+        s390_program_interrupt(env, PGM_PRIVILEGED, ra);
+        return 0;
+    }
+
+    if (reg & ~S390_TOPO_FC_MASK) {
+        s390_program_interrupt(env, PGM_SPECIFICATION, ra);
+        return 0;
+    }
+
+    switch (fc) {
+    case 0:    /* Horizontal polarization is already set */
+        env->regs[r1] = S390_PTF_REASON_DONE;
+        return 2;
+    case 1:    /* Vertical polarization is not supported */
+        env->regs[r1] = S390_PTF_REASON_NONE;
+        return 2;
+    case 2:    /* Report if a topology change report is pending */
+        return s390_topology_changed();
+    default:
+        s390_program_interrupt(env, PGM_SPECIFICATION, ra);
+        break;
+    }
+
+    return 0;
+}
+
+static int kvm_handle_ptf(S390CPU *cpu, struct kvm_run *run)
+{
+    uint8_t r1 = (run->s390_sieic.ipb >> 20) & 0x0f;
+    uint8_t ret;
+
+    ret = s390_handle_ptf(cpu, r1, RA_IGNORED);
+    setcc(cpu, ret);
+    return 0;
+}
+
 static int handle_b9(S390CPU *cpu, struct kvm_run *run, uint8_t ipa1)
 {
     int r = 0;
@@ -1470,6 +1519,9 @@ 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:
+        r = kvm_handle_ptf(cpu, run);
+        break;
     case PRIV_B9_EQBS:
         /* just inject exception */
         r = -1;
-- 
2.25.1