Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-2.10-20170630' into staging

ppc patch queue 2017-06-30

  * More DRC cleanups, these now actually fix a few bugs
  * Properly implements the openpic timers (they now count and
    generate interrupts)
  * Fixes for XICS migration
  * Fixes for migration of POWER9 RPT guests
  * The last of the compatibility mode rework

# gpg: Signature made Fri 30 Jun 2017 10:52:25 BST
# gpg:                using RSA key 0x6C38CACA20D9B392
# gpg: Good signature from "David Gibson <david@gibson.dropbear.id.au>"
# gpg:                 aka "David Gibson (Red Hat) <dgibson@redhat.com>"
# gpg:                 aka "David Gibson (ozlabs.org) <dgibson@ozlabs.org>"
# gpg:                 aka "David Gibson (kernel.org) <dwg@kernel.org>"
# Primary key fingerprint: 75F4 6586 AE61 A66C C44E  87DC 6C38 CACA 20D9 B392

* remotes/dgibson/tags/ppc-for-2.10-20170630: (21 commits)
  spapr: Clean up DRC set_isolation_state() path
  spapr: Clean up DRC set_allocation_state path
  spapr: Make DRC reset force DRC into known state
  spapr: Split DRC release from DRC detach
  spapr: Eliminate DRC 'signalled' state variable
  spapr: Start hotplugged PCI devices in ISOLATED state
  target-ppc: Enable open-pic timers to count and generate interrupts
  hw/ppc/spapr.c: consecutive 'spapr->patb_entry = 0' statements
  spapr: prevent QEMU crash when CPU realization fails
  target/ppc: Proper cleanup when ppc_cpu_realizefn fails
  spapr: fix migration of ICPState objects from/to older QEMU
  xics: directly register ICPState objects to vmstate
  target/ppc: Fix return value in tcg radix mmu fault handler
  target/ppc/excp_helper: Take BQL before calling cpu_interrupt()
  spapr: Fix migration of Radix guests
  spapr: Add a "no HPT" encoding to HTAB migration stream
  ppc: Rework CPU compatibility testing across migration
  pseries: Reset CPU compatibility mode
  pseries: Move CPU compatibility property to machine
  qapi: add explicit null to string input and output visitors
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

18 files changed, 749 insertions, 308 deletions

diff --git a/hw/intc/openpic.c b/hw/intc/openpic.c
index 5595bb2e8c..9dd285b923 100644
--- a/hw/intc/openpic.c
+++ b/hw/intc/openpic.c
@@ -45,6 +45,7 @@
 #include "qemu/bitops.h"
 #include "qapi/qmp/qerror.h"
 #include "qemu/log.h"
+#include "qemu/timer.h"
 
 //#define DEBUG_OPENPIC
 
@@ -54,8 +55,10 @@ static const int debug_openpic = 1;
 static const int debug_openpic = 0;
 #endif
 
+static int get_current_cpu(void);
 #define DPRINTF(fmt, ...) do { \
         if (debug_openpic) { \
+            printf("Core%d: ", get_current_cpu()); \
             printf(fmt , ## __VA_ARGS__); \
         } \
     } while (0)
@@ -246,9 +249,31 @@ typedef struct IRQSource {
 #define IDR_EP      0x80000000  /* external pin */
 #define IDR_CI      0x40000000  /* critical interrupt */
 
+/* Convert between openpic clock ticks and nanosecs.  In the hardware the clock
+   frequency is driven by board inputs to the PIC which the PIC would then
+   divide by 4 or 8.  For now hard code to 25MZ.
+*/
+#define OPENPIC_TIMER_FREQ_MHZ 25
+#define OPENPIC_TIMER_NS_PER_TICK (1000 / OPENPIC_TIMER_FREQ_MHZ)
+static inline uint64_t ns_to_ticks(uint64_t ns)
+{
+    return ns    / OPENPIC_TIMER_NS_PER_TICK;
+}
+static inline uint64_t ticks_to_ns(uint64_t ticks)
+{
+    return ticks * OPENPIC_TIMER_NS_PER_TICK;
+}
+
 typedef struct OpenPICTimer {
     uint32_t tccr;  /* Global timer current count register */
     uint32_t tbcr;  /* Global timer base count register */
+    int                   n_IRQ;
+    bool                  qemu_timer_active; /* Is the qemu_timer is running? */
+    struct QEMUTimer     *qemu_timer;
+    struct OpenPICState  *opp;          /* Device timer is part of. */
+    /* The QEMU_CLOCK_VIRTUAL time (in ns) corresponding to the last
+       current_count written or read, only defined if qemu_timer_active. */
+    uint64_t              origin_time;
 } OpenPICTimer;
 
 typedef struct OpenPICMSI {
@@ -795,6 +820,65 @@ static uint64_t openpic_gbl_read(void *opaque, hwaddr addr, unsigned len)
     return retval;
 }
 
+static void openpic_tmr_set_tmr(OpenPICTimer *tmr, uint32_t val, bool enabled);
+
+static void qemu_timer_cb(void *opaque)
+{
+    OpenPICTimer *tmr = opaque;
+    OpenPICState *opp = tmr->opp;
+    uint32_t    n_IRQ = tmr->n_IRQ;
+    uint32_t val =   tmr->tbcr & ~TBCR_CI;
+    uint32_t tog = ((tmr->tccr & TCCR_TOG) ^ TCCR_TOG);  /* invert toggle. */
+
+    DPRINTF("%s n_IRQ=%d\n", __func__, n_IRQ);
+    /* Reload current count from base count and setup timer. */
+    tmr->tccr = val | tog;
+    openpic_tmr_set_tmr(tmr, val, /*enabled=*/true);
+    /* Raise the interrupt. */
+    opp->src[n_IRQ].destmask = read_IRQreg_idr(opp, n_IRQ);
+    openpic_set_irq(opp, n_IRQ, 1);
+    openpic_set_irq(opp, n_IRQ, 0);
+}
+
+/* If enabled is true, arranges for an interrupt to be raised val clocks into
+   the future, if enabled is false cancels the timer. */
+static void openpic_tmr_set_tmr(OpenPICTimer *tmr, uint32_t val, bool enabled)
+{
+    uint64_t ns = ticks_to_ns(val & ~TCCR_TOG);
+    /* A count of zero causes a timer to be set to expire immediately.  This
+       effectively stops the simulation since the timer is constantly expiring
+       which prevents guest code execution, so we don't honor that
+       configuration.  On real hardware, this situation would generate an
+       interrupt on every clock cycle if the interrupt was unmasked. */
+    if ((ns == 0) || !enabled) {
+        tmr->qemu_timer_active = false;
+        tmr->tccr = tmr->tccr & TCCR_TOG;
+        timer_del(tmr->qemu_timer); /* set timer to never expire. */
+    } else {
+        tmr->qemu_timer_active = true;
+        uint64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+        tmr->origin_time = now;
+        timer_mod(tmr->qemu_timer, now + ns);     /* set timer expiration. */
+    }
+}
+
+/* Returns the currrent tccr value, i.e., timer value (in clocks) with
+   appropriate TOG. */
+static uint64_t openpic_tmr_get_timer(OpenPICTimer *tmr)
+{
+    uint64_t retval;
+    if (!tmr->qemu_timer_active) {
+        retval = tmr->tccr;
+    } else {
+        uint64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+        uint64_t used = now - tmr->origin_time;  /* nsecs */
+        uint32_t used_ticks = (uint32_t)ns_to_ticks(used);
+        uint32_t count = (tmr->tccr & ~TCCR_TOG) - used_ticks;
+        retval = (uint32_t)((tmr->tccr & TCCR_TOG) | (count & ~TCCR_TOG));
+    }
+    return retval;
+}
+
 static void openpic_tmr_write(void *opaque, hwaddr addr, uint64_t val,
                               unsigned len)
 {
@@ -819,10 +903,15 @@ static void openpic_tmr_write(void *opaque, hwaddr addr, uint64_t val,
     case 0x00: /* TCCR */
         break;
     case 0x10: /* TBCR */
-        if ((opp->timers[idx].tccr & TCCR_TOG) != 0 &&
-            (val & TBCR_CI) == 0 &&
-            (opp->timers[idx].tbcr & TBCR_CI) != 0) {
-            opp->timers[idx].tccr &= ~TCCR_TOG;
+        /* Did the enable status change? */
+        if ((opp->timers[idx].tbcr & TBCR_CI) != (val & TBCR_CI)) {
+            /* Did "Count Inhibit" transition from 1 to 0? */
+            if ((val & TBCR_CI) == 0) {
+                opp->timers[idx].tccr = val & ~TCCR_TOG;
+            }
+            openpic_tmr_set_tmr(&opp->timers[idx],
+                                (val & ~TBCR_CI),
+                                /*enabled=*/((val & TBCR_CI) == 0));
         }
         opp->timers[idx].tbcr = val;
         break;
@@ -854,7 +943,7 @@ static uint64_t openpic_tmr_read(void *opaque, hwaddr addr, unsigned len)
     idx = (addr >> 6) & 0x3;
     switch (addr & 0x30) {
     case 0x00: /* TCCR */
-        retval = opp->timers[idx].tccr;
+        retval = openpic_tmr_get_timer(&opp->timers[idx]);
         break;
     case 0x10: /* TBCR */
         retval = opp->timers[idx].tbcr;
@@ -1136,7 +1225,10 @@ static uint32_t openpic_iack(OpenPICState *opp, IRQDest *dst, int cpu)
         IRQ_resetbit(&dst->raised, irq);
     }
 
-    if ((irq >= opp->irq_ipi0) &&  (irq < (opp->irq_ipi0 + OPENPIC_MAX_IPI))) {
+    /* Timers and IPIs support multicast. */
+    if (((irq >= opp->irq_ipi0) && (irq < (opp->irq_ipi0 + OPENPIC_MAX_IPI))) ||
+        ((irq >= opp->irq_tim0) && (irq < (opp->irq_tim0 + OPENPIC_MAX_TMR)))) {
+        DPRINTF("irq is IPI or TMR\n");
         src->destmask &= ~(1 << cpu);
         if (src->destmask && !src->level) {
             /* trigger on CPUs that didn't know about it yet */
@@ -1341,6 +1433,10 @@ static void openpic_reset(DeviceState *d)
     for (i = 0; i < OPENPIC_MAX_TMR; i++) {
         opp->timers[i].tccr = 0;
         opp->timers[i].tbcr = TBCR_CI;
+        if (opp->timers[i].qemu_timer_active) {
+            timer_del(opp->timers[i].qemu_timer);  /* Inhibit timer */
+            opp->timers[i].qemu_timer_active = false;
+        }
     }
     /* Go out of RESET state */
     opp->gcr = 0;
@@ -1391,6 +1487,15 @@ static void fsl_common_init(OpenPICState *opp)
         opp->src[i].type = IRQ_TYPE_FSLSPECIAL;
         opp->src[i].level = false;
     }
+
+    for (i = 0; i < OPENPIC_MAX_TMR; i++) {
+        opp->timers[i].n_IRQ = opp->irq_tim0 + i;
+        opp->timers[i].qemu_timer_active = false;
+        opp->timers[i].qemu_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
+                                                 &qemu_timer_cb,
+                                                 &opp->timers[i]);
+        opp->timers[i].opp = opp;
+    }
 }
 
 static void map_list(OpenPICState *opp, const MemReg *list, int *count)
diff --git a/hw/intc/xics.c b/hw/intc/xics.c
index d4194d647b..a84ba51ad8 100644
--- a/hw/intc/xics.c
+++ b/hw/intc/xics.c
@@ -344,10 +344,14 @@ static void icp_realize(DeviceState *dev, Error **errp)
     }
 
     qemu_register_reset(icp_reset, dev);
+    vmstate_register(NULL, icp->cs->cpu_index, &vmstate_icp_server, icp);
 }
 
 static void icp_unrealize(DeviceState *dev, Error **errp)
 {
+    ICPState *icp = ICP(dev);
+
+    vmstate_unregister(NULL, &vmstate_icp_server, icp);
     qemu_unregister_reset(icp_reset, dev);
 }
 
@@ -355,7 +359,6 @@ static void icp_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
 
-    dc->vmsd = &vmstate_icp_server;
     dc->realize = icp_realize;
     dc->unrealize = icp_unrealize;
 }
diff --git a/hw/ppc/prep.c b/hw/ppc/prep.c
index d16646c95d..36d3dcd89a 100644
--- a/hw/ppc/prep.c
+++ b/hw/ppc/prep.c
@@ -36,7 +36,6 @@
 #include "hw/pci/pci_host.h"
 #include "hw/ppc/ppc.h"
 #include "hw/boards.h"
-#include "hw/audio/soundhw.h"
 #include "qemu/error-report.h"
 #include "qemu/log.h"
 #include "hw/ide.h"
@@ -782,9 +781,6 @@ static void ibm_40p_init(MachineState *machine)
     qbus_walk_children(BUS(isa_bus), prep_set_cmos_checksum, NULL, NULL, NULL,
                        &cmos_checksum);
 
-    /* initialize audio subsystem */
-    soundhw_init();
-
     /* add some more devices */
     if (defaults_enabled()) {
         isa_create_simple(isa_bus, "i8042");
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index ea44358e30..0ee9fac50b 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -127,9 +127,49 @@ error:
     return NULL;
 }
 
+static bool pre_2_10_vmstate_dummy_icp_needed(void *opaque)
+{
+    /* Dummy entries correspond to unused ICPState objects in older QEMUs,
+     * and newer QEMUs don't even have them. In both cases, we don't want
+     * to send anything on the wire.
+     */
+    return false;
+}
+
+static const VMStateDescription pre_2_10_vmstate_dummy_icp = {
+    .name = "icp/server",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = pre_2_10_vmstate_dummy_icp_needed,
+    .fields = (VMStateField[]) {
+        VMSTATE_UNUSED(4), /* uint32_t xirr */
+        VMSTATE_UNUSED(1), /* uint8_t pending_priority */
+        VMSTATE_UNUSED(1), /* uint8_t mfrr */
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+static void pre_2_10_vmstate_register_dummy_icp(int i)
+{
+    vmstate_register(NULL, i, &pre_2_10_vmstate_dummy_icp,
+                     (void *)(uintptr_t) i);
+}
+
+static void pre_2_10_vmstate_unregister_dummy_icp(int i)
+{
+    vmstate_unregister(NULL, &pre_2_10_vmstate_dummy_icp,
+                       (void *)(uintptr_t) i);
+}
+
+static inline int xics_max_server_number(void)
+{
+    return DIV_ROUND_UP(max_cpus * kvmppc_smt_threads(), smp_threads);
+}
+
 static void xics_system_init(MachineState *machine, int nr_irqs, Error **errp)
 {
     sPAPRMachineState *spapr = SPAPR_MACHINE(machine);
+    sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(machine);
 
     if (kvm_enabled()) {
         if (machine_kernel_irqchip_allowed(machine) &&
@@ -151,6 +191,17 @@ static void xics_system_init(MachineState *machine, int nr_irqs, Error **errp)
             return;
         }
     }
+
+    if (smc->pre_2_10_has_unused_icps) {
+        int i;
+
+        for (i = 0; i < xics_max_server_number(); i++) {
+            /* Dummy entries get deregistered when real ICPState objects
+             * are registered during CPU core hotplug.
+             */
+            pre_2_10_vmstate_register_dummy_icp(i);
+        }
+    }
 }
 
 static int spapr_fixup_cpu_smt_dt(void *fdt, int offset, PowerPCCPU *cpu,
@@ -979,7 +1030,6 @@ static void *spapr_build_fdt(sPAPRMachineState *spapr,
     void *fdt;
     sPAPRPHBState *phb;
     char *buf;
-    int smt = kvmppc_smt_threads();
 
     fdt = g_malloc0(FDT_MAX_SIZE);
     _FDT((fdt_create_empty_tree(fdt, FDT_MAX_SIZE)));
@@ -1019,7 +1069,7 @@ static void *spapr_build_fdt(sPAPRMachineState *spapr,
     _FDT(fdt_setprop_cell(fdt, 0, "#size-cells", 2));
 
     /* /interrupt controller */
-    spapr_dt_xics(DIV_ROUND_UP(max_cpus * smt, smp_threads), fdt, PHANDLE_XICP);
+    spapr_dt_xics(xics_max_server_number(), fdt, PHANDLE_XICP);
 
     ret = spapr_populate_memory(spapr, fdt);
     if (ret < 0) {
@@ -1326,7 +1376,6 @@ static void ppc_spapr_reset(void)
          * Set the GR bit in PATB so that we know there is no HPT. */
         spapr->patb_entry = PATBE1_GR;
     } else {
-        spapr->patb_entry = 0;
         spapr_setup_hpt_and_vrma(spapr);
     }
 
@@ -1346,6 +1395,8 @@ static void ppc_spapr_reset(void)
     if (!spapr->cas_reboot) {
         spapr_ovec_cleanup(spapr->ov5_cas);
         spapr->ov5_cas = spapr_ovec_new();
+
+        ppc_set_compat_all(spapr->max_compat_pvr, &error_fatal);
     }
 
     fdt = spapr_build_fdt(spapr, rtas_addr, spapr->rtas_size);
@@ -1443,6 +1494,18 @@ static int spapr_post_load(void *opaque, int version_id)
         err = spapr_rtc_import_offset(&spapr->rtc, spapr->rtc_offset);
     }
 
+    if (spapr->patb_entry) {
+        PowerPCCPU *cpu = POWERPC_CPU(first_cpu);
+        bool radix = !!(spapr->patb_entry & PATBE1_GR);
+        bool gtse = !!(cpu->env.spr[SPR_LPCR] & LPCR_GTSE);
+
+        err = kvmppc_configure_v3_mmu(cpu, radix, gtse, spapr->patb_entry);
+        if (err) {
+            error_report("Process table config unsupported by the host");
+            return -EINVAL;
+        }
+    }
+
     return err;
 }
 
@@ -1558,13 +1621,19 @@ static int htab_save_setup(QEMUFile *f, void *opaque)
     sPAPRMachineState *spapr = opaque;
 
     /* "Iteration" header */
-    qemu_put_be32(f, spapr->htab_shift);
+    if (!spapr->htab_shift) {
+        qemu_put_be32(f, -1);
+    } else {
+        qemu_put_be32(f, spapr->htab_shift);
+    }
 
     if (spapr->htab) {
         spapr->htab_save_index = 0;
         spapr->htab_first_pass = true;
     } else {
-        assert(kvm_enabled());
+        if (spapr->htab_shift) {
+            assert(kvm_enabled());
+        }
     }
 
 
@@ -1710,7 +1779,12 @@ static int htab_save_iterate(QEMUFile *f, void *opaque)
     int rc = 0;
 
     /* Iteration header */
-    qemu_put_be32(f, 0);
+    if (!spapr->htab_shift) {
+        qemu_put_be32(f, -1);
+        return 0;
+    } else {
+        qemu_put_be32(f, 0);
+    }
 
     if (!spapr->htab) {
         assert(kvm_enabled());
@@ -1744,7 +1818,12 @@ static int htab_save_complete(QEMUFile *f, void *opaque)
     int fd;
 
     /* Iteration header */
-    qemu_put_be32(f, 0);
+    if (!spapr->htab_shift) {
+        qemu_put_be32(f, -1);
+        return 0;
+    } else {
+        qemu_put_be32(f, 0);
+    }
 
     if (!spapr->htab) {
         int rc;
@@ -1788,6 +1867,11 @@ static int htab_load(QEMUFile *f, void *opaque, int version_id)
 
     section_hdr = qemu_get_be32(f);
 
+    if (section_hdr == -1) {
+        spapr_free_hpt(spapr);
+        return 0;
+    }
+
     if (section_hdr) {
         Error *local_err = NULL;
 
@@ -2131,7 +2215,7 @@ static void ppc_spapr_init(MachineState *machine)
         machine->cpu_model = kvm_enabled() ? "host" : smc->tcg_default_cpu;
     }
 
-    ppc_cpu_parse_features(machine->cpu_model);
+    spapr_cpu_parse_features(spapr);
 
     spapr_init_cpus(spapr);
 
@@ -2503,6 +2587,10 @@ static void spapr_machine_initfn(Object *obj)
                                     " place of standard EPOW events when possible"
                                     " (required for memory hot-unplug support)",
                                     NULL);
+
+    ppc_compat_add_property(obj, "max-cpu-compat", &spapr->max_compat_pvr,
+                            "Maximum permitted CPU compatibility mode",
+                            &error_fatal);
 }
 
 static void spapr_machine_finalizefn(Object *obj)
@@ -2548,12 +2636,6 @@ static void spapr_add_lmbs(DeviceState *dev, uint64_t addr_start, uint64_t size,
 
         spapr_drc_attach(drc, dev, fdt, fdt_offset, !dev->hotplugged, errp);
         addr += SPAPR_MEMORY_BLOCK_SIZE;
-        if (!dev->hotplugged) {
-            sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
-            /* guests expect coldplugged LMBs to be pre-allocated */
-            drck->set_allocation_state(drc, SPAPR_DR_ALLOCATION_STATE_USABLE);
-            drck->set_isolation_state(drc, SPAPR_DR_ISOLATION_STATE_UNISOLATED);
-        }
     }
     /* send hotplug notification to the
      * guest only in case of hotplugged memory
@@ -2806,9 +2888,24 @@ static void spapr_core_unplug(HotplugHandler *hotplug_dev, DeviceState *dev,
                               Error **errp)
 {
     MachineState *ms = MACHINE(qdev_get_machine());
+    sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(ms);
     CPUCore *cc = CPU_CORE(dev);
     CPUArchId *core_slot = spapr_find_cpu_slot(ms, cc->core_id, NULL);
 
+    if (smc->pre_2_10_has_unused_icps) {
+        sPAPRCPUCore *sc = SPAPR_CPU_CORE(OBJECT(dev));
+        sPAPRCPUCoreClass *scc = SPAPR_CPU_CORE_GET_CLASS(OBJECT(cc));
+        const char *typename = object_class_get_name(scc->cpu_class);
+        size_t size = object_type_get_instance_size(typename);
+        int i;
+
+        for (i = 0; i < cc->nr_threads; i++) {
+            CPUState *cs = CPU(sc->threads + i * size);
+
+            pre_2_10_vmstate_register_dummy_icp(cs->cpu_index);
+        }
+    }
+
     assert(core_slot);
     core_slot->cpu = NULL;
     object_unparent(OBJECT(dev));
@@ -2860,6 +2957,7 @@ static void spapr_core_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
 {
     sPAPRMachineState *spapr = SPAPR_MACHINE(OBJECT(hotplug_dev));
     MachineClass *mc = MACHINE_GET_CLASS(spapr);
+    sPAPRMachineClass *smc = SPAPR_MACHINE_CLASS(mc);
     sPAPRCPUCore *core = SPAPR_CPU_CORE(OBJECT(dev));
     CPUCore *cc = CPU_CORE(dev);
     CPUState *cs = CPU(core->threads);
@@ -2905,17 +3003,23 @@ static void spapr_core_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
          * of hotplugged CPUs.
          */
         spapr_hotplug_req_add_by_index(drc);
-    } else {
-        /*
-         * Set the right DRC states for cold plugged CPU.
-         */
-        if (drc) {
-            sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
-            drck->set_allocation_state(drc, SPAPR_DR_ALLOCATION_STATE_USABLE);
-            drck->set_isolation_state(drc, SPAPR_DR_ISOLATION_STATE_UNISOLATED);
-        }
     }
     core_slot->cpu = OBJECT(dev);
+
+    if (smc->pre_2_10_has_unused_icps) {
+        sPAPRCPUCoreClass *scc = SPAPR_CPU_CORE_GET_CLASS(OBJECT(cc));
+        const char *typename = object_class_get_name(scc->cpu_class);
+        size_t size = object_type_get_instance_size(typename);
+        int i;
+
+        for (i = 0; i < cc->nr_threads; i++) {
+            sPAPRCPUCore *sc = SPAPR_CPU_CORE(dev);
+            void *obj = sc->threads + i * size;
+
+            cs = CPU(obj);
+            pre_2_10_vmstate_unregister_dummy_icp(cs->cpu_index);
+        }
+    }
 }
 
 static void spapr_core_pre_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
@@ -3356,7 +3460,12 @@ DEFINE_SPAPR_MACHINE(2_10, "2.10", true);
  * pseries-2.9
  */
 #define SPAPR_COMPAT_2_9                                               \
-    HW_COMPAT_2_9
+    HW_COMPAT_2_9                                                      \
+    {                                                                  \
+        .driver = TYPE_POWERPC_CPU,                                    \
+        .property = "pre-2.10-migration",                              \
+        .value    = "on",                                              \
+    },                                                                 \
 
 static void spapr_machine_2_9_instance_options(MachineState *machine)
 {
@@ -3365,9 +3474,12 @@ static void spapr_machine_2_9_instance_options(MachineState *machine)
 
 static void spapr_machine_2_9_class_options(MachineClass *mc)
 {
+    sPAPRMachineClass *smc = SPAPR_MACHINE_CLASS(mc);
+
     spapr_machine_2_10_class_options(mc);
     SET_MACHINE_COMPAT(mc, SPAPR_COMPAT_2_9);
     mc->numa_auto_assign_ram = numa_legacy_auto_assign_ram;
+    smc->pre_2_10_has_unused_icps = true;
 }
 
 DEFINE_SPAPR_MACHINE(2_9, "2.9", false);
diff --git a/hw/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c
index 9fb896b407..ea278ce2a7 100644
--- a/hw/ppc/spapr_cpu_core.c
+++ b/hw/ppc/spapr_cpu_core.c
@@ -20,6 +20,57 @@
 #include "sysemu/numa.h"
 #include "qemu/error-report.h"
 
+void spapr_cpu_parse_features(sPAPRMachineState *spapr)
+{
+    /*
+     * Backwards compatibility hack:
+     *
+     *   CPUs had a "compat=" property which didn't make sense for
+     *   anything except pseries.  It was replaced by "max-cpu-compat"
+     *   machine option.  This supports old command lines like
+     *       -cpu POWER8,compat=power7
+     *   By stripping the compat option and applying it to the machine
+     *   before passing it on to the cpu level parser.
+     */
+    gchar **inpieces;
+    int i, j;
+    gchar *compat_str = NULL;
+
+    inpieces = g_strsplit(MACHINE(spapr)->cpu_model, ",", 0);
+
+    /* inpieces[0] is the actual model string */
+    i = 1;
+    j = 1;
+    while (inpieces[i]) {
+        if (g_str_has_prefix(inpieces[i], "compat=")) {
+            /* in case of multiple compat= options */
+            g_free(compat_str);
+            compat_str = inpieces[i];
+        } else {
+            j++;
+        }
+
+        i++;
+        /* Excise compat options from list */
+        inpieces[j] = inpieces[i];
+    }
+
+    if (compat_str) {
+        char *val = compat_str + strlen("compat=");
+        gchar *newprops = g_strjoinv(",", inpieces);
+
+        object_property_set_str(OBJECT(spapr), val, "max-cpu-compat",
+                                &error_fatal);
+
+        ppc_cpu_parse_features(newprops);
+        g_free(newprops);
+    } else {
+        ppc_cpu_parse_features(MACHINE(spapr)->cpu_model);
+    }
+
+    g_strfreev(inpieces);
+}
+
 static void spapr_cpu_reset(void *opaque)
 {
     sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
@@ -67,16 +118,6 @@ static void spapr_cpu_init(sPAPRMachineState *spapr, PowerPCCPU *cpu,
     /* Enable PAPR mode in TCG or KVM */
     cpu_ppc_set_papr(cpu, PPC_VIRTUAL_HYPERVISOR(spapr));
 
-    if (cpu->max_compat) {
-        Error *local_err = NULL;
-
-        ppc_set_compat(cpu, cpu->max_compat, &local_err);
-        if (local_err) {
-            error_propagate(errp, local_err);
-            return;
-        }
-    }
-
     qemu_register_reset(spapr_cpu_reset, cpu);
     spapr_cpu_reset(cpu);
 }
@@ -137,7 +178,7 @@ static void spapr_cpu_core_realize_child(Object *child, Error **errp)
     sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
     CPUState *cs = CPU(child);
     PowerPCCPU *cpu = POWERPC_CPU(cs);
-    Object *obj = NULL;
+    Object *obj;
 
     object_property_set_bool(child, true, "realized", &local_err);
     if (local_err) {
@@ -157,13 +198,14 @@ static void spapr_cpu_core_realize_child(Object *child, Error **errp)
     object_property_add_const_link(obj, ICP_PROP_CPU, child, &error_abort);
     object_property_set_bool(obj, true, "realized", &local_err);
     if (local_err) {
-        goto error;
+        goto free_icp;
     }
 
     return;
 
-error:
+free_icp:
     object_unparent(obj);
+error:
     error_propagate(errp, local_err);
 }
 
diff --git a/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c
index 5cb75bbf34..bd40b84cfc 100644
--- a/hw/ppc/spapr_drc.c
+++ b/hw/ppc/spapr_drc.c
@@ -46,30 +46,64 @@ uint32_t spapr_drc_index(sPAPRDRConnector *drc)
         | (drc->id & DRC_INDEX_ID_MASK);
 }
 
-static uint32_t set_isolation_state(sPAPRDRConnector *drc,
-                                    sPAPRDRIsolationState state)
+static uint32_t drc_isolate_physical(sPAPRDRConnector *drc)
 {
-    trace_spapr_drc_set_isolation_state(spapr_drc_index(drc), state);
-
     /* if the guest is configuring a device attached to this DRC, we
      * should reset the configuration state at this point since it may
      * no longer be reliable (guest released device and needs to start
      * over, or unplug occurred so the FDT is no longer valid)
      */
-    if (state == SPAPR_DR_ISOLATION_STATE_ISOLATED) {
-        g_free(drc->ccs);
-        drc->ccs = NULL;
-    }
+    g_free(drc->ccs);
+    drc->ccs = NULL;
 
-    if (state == SPAPR_DR_ISOLATION_STATE_UNISOLATED) {
-        /* cannot unisolate a non-existent resource, and, or resources
-         * which are in an 'UNUSABLE' allocation state. (PAPR 2.7, 13.5.3.5)
-         */
-        if (!drc->dev ||
-            drc->allocation_state == SPAPR_DR_ALLOCATION_STATE_UNUSABLE) {
-            return RTAS_OUT_NO_SUCH_INDICATOR;
+    drc->isolation_state = SPAPR_DR_ISOLATION_STATE_ISOLATED;
+
+    /* if we're awaiting release, but still in an unconfigured state,
+     * it's likely the guest is still in the process of configuring
+     * the device and is transitioning the devices to an ISOLATED
+     * state as a part of that process. so we only complete the
+     * removal when this transition happens for a device in a
+     * configured state, as suggested by the state diagram from PAPR+
+     * 2.7, 13.4
+     */
+    if (drc->awaiting_release) {
+        uint32_t drc_index = spapr_drc_index(drc);
+        if (drc->configured) {
+            trace_spapr_drc_set_isolation_state_finalizing(drc_index);
+            spapr_drc_detach(drc, DEVICE(drc->dev), NULL);
+        } else {
+            trace_spapr_drc_set_isolation_state_deferring(drc_index);
         }
     }
+    drc->configured = false;
+
+    return RTAS_OUT_SUCCESS;
+}
+
+static uint32_t drc_unisolate_physical(sPAPRDRConnector *drc)
+{
+    /* cannot unisolate a non-existent resource, and, or resources
+     * which are in an 'UNUSABLE' allocation state. (PAPR 2.7,
+     * 13.5.3.5)
+     */
+    if (!drc->dev) {
+        return RTAS_OUT_NO_SUCH_INDICATOR;
+    }
+
+    drc->isolation_state = SPAPR_DR_ISOLATION_STATE_UNISOLATED;
+
+    return RTAS_OUT_SUCCESS;
+}
+
+static uint32_t drc_isolate_logical(sPAPRDRConnector *drc)
+{
+    /* if the guest is configuring a device attached to this DRC, we
+     * should reset the configuration state at this point since it may
+     * no longer be reliable (guest released device and needs to start
+     * over, or unplug occurred so the FDT is no longer valid)
+     */
+    g_free(drc->ccs);
+    drc->ccs = NULL;
 
     /*
      * Fail any requests to ISOLATE the LMB DRC if this LMB doesn't
@@ -81,66 +115,87 @@ static uint32_t set_isolation_state(sPAPRDRConnector *drc,
      * If the LMB being removed doesn't belong to a DIMM device that is
      * actually being unplugged, fail the isolation request here.
      */
-    if (spapr_drc_type(drc) == SPAPR_DR_CONNECTOR_TYPE_LMB) {
-        if ((state == SPAPR_DR_ISOLATION_STATE_ISOLATED) &&
-             !drc->awaiting_release) {
-            return RTAS_OUT_HW_ERROR;
-        }
+    if (spapr_drc_type(drc) == SPAPR_DR_CONNECTOR_TYPE_LMB
+        && !drc->awaiting_release) {
+        return RTAS_OUT_HW_ERROR;
     }
 
-    drc->isolation_state = state;
+    drc->isolation_state = SPAPR_DR_ISOLATION_STATE_ISOLATED;
 
-    if (drc->isolation_state == SPAPR_DR_ISOLATION_STATE_ISOLATED) {
-        /* if we're awaiting release, but still in an unconfigured state,
-         * it's likely the guest is still in the process of configuring
-         * the device and is transitioning the devices to an ISOLATED
-         * state as a part of that process. so we only complete the
-         * removal when this transition happens for a device in a
-         * configured state, as suggested by the state diagram from
-         * PAPR+ 2.7, 13.4
-         */
-        if (drc->awaiting_release) {
-            uint32_t drc_index = spapr_drc_index(drc);
-            if (drc->configured) {
-                trace_spapr_drc_set_isolation_state_finalizing(drc_index);
-                spapr_drc_detach(drc, DEVICE(drc->dev), NULL);
-            } else {
-                trace_spapr_drc_set_isolation_state_deferring(drc_index);
-            }
+    /* if we're awaiting release, but still in an unconfigured state,
+     * it's likely the guest is still in the process of configuring
+     * the device and is transitioning the devices to an ISOLATED
+     * state as a part of that process. so we only complete the
+     * removal when this transition happens for a device in a
+     * configured state, as suggested by the state diagram from PAPR+
+     * 2.7, 13.4
+     */
+    if (drc->awaiting_release) {
+        uint32_t drc_index = spapr_drc_index(drc);
+        if (drc->configured) {
+            trace_spapr_drc_set_isolation_state_finalizing(drc_index);
+            spapr_drc_detach(drc, DEVICE(drc->dev), NULL);
+        } else {
+            trace_spapr_drc_set_isolation_state_deferring(drc_index);
         }
-        drc->configured = false;
     }
+    drc->configured = false;
 
     return RTAS_OUT_SUCCESS;
 }
 
-static uint32_t set_allocation_state(sPAPRDRConnector *drc,
-                                     sPAPRDRAllocationState state)
+static uint32_t drc_unisolate_logical(sPAPRDRConnector *drc)
 {
-    trace_spapr_drc_set_allocation_state(spapr_drc_index(drc), state);
+    /* cannot unisolate a non-existent resource, and, or resources
+     * which are in an 'UNUSABLE' allocation state. (PAPR 2.7,
+     * 13.5.3.5)
+     */
+    if (!drc->dev ||
+        drc->allocation_state == SPAPR_DR_ALLOCATION_STATE_UNUSABLE) {
+        return RTAS_OUT_NO_SUCH_INDICATOR;
+    }
+
+    drc->isolation_state = SPAPR_DR_ISOLATION_STATE_UNISOLATED;
+
+    return RTAS_OUT_SUCCESS;
+}
 
-    if (state == SPAPR_DR_ALLOCATION_STATE_USABLE) {
-        /* if there's no resource/device associated with the DRC, there's
-         * no way for us to put it in an allocation state consistent with
-         * being 'USABLE'. PAPR 2.7, 13.5.3.4 documents that this should
-         * result in an RTAS return code of -3 / "no such indicator"
+static uint32_t drc_set_usable(sPAPRDRConnector *drc)
+{
+    /* if there's no resource/device associated with the DRC, there's
+     * no way for us to put it in an allocation state consistent with
+     * being 'USABLE'. PAPR 2.7, 13.5.3.4 documents that this should
+     * result in an RTAS return code of -3 / "no such indicator"
+     */
+    if (!drc->dev) {
+        return RTAS_OUT_NO_SUCH_INDICATOR;
+    }
+    if (drc->awaiting_release && drc->awaiting_allocation) {
+        /* kernel is acknowledging a previous hotplug event
+         * while we are already removing it.
+         * it's safe to ignore awaiting_allocation here since we know the
+         * situation is predicated on the guest either already having done
+         * so (boot-time hotplug), or never being able to acquire in the
+         * first place (hotplug followed by immediate unplug).
          */
-        if (!drc->dev) {
-            return RTAS_OUT_NO_SUCH_INDICATOR;
-        }
+        return RTAS_OUT_NO_SUCH_INDICATOR;
     }
 
-    if (spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PCI) {
-        drc->allocation_state = state;
-        if (drc->awaiting_release &&
-            drc->allocation_state == SPAPR_DR_ALLOCATION_STATE_UNUSABLE) {
-            uint32_t drc_index = spapr_drc_index(drc);
-            trace_spapr_drc_set_allocation_state_finalizing(drc_index);
-            spapr_drc_detach(drc, DEVICE(drc->dev), NULL);
-        } else if (drc->allocation_state == SPAPR_DR_ALLOCATION_STATE_USABLE) {
-            drc->awaiting_allocation = false;
-        }
+    drc->allocation_state = SPAPR_DR_ALLOCATION_STATE_USABLE;
+    drc->awaiting_allocation = false;
+
+    return RTAS_OUT_SUCCESS;
+}
+
+static uint32_t drc_set_unusable(sPAPRDRConnector *drc)
+{
+    drc->allocation_state = SPAPR_DR_ALLOCATION_STATE_UNUSABLE;
+    if (drc->awaiting_release) {
+        uint32_t drc_index = spapr_drc_index(drc);
+        trace_spapr_drc_set_allocation_state_finalizing(drc_index);
+        spapr_drc_detach(drc, DEVICE(drc->dev), NULL);
     }
+
     return RTAS_OUT_SUCCESS;
 }
 
@@ -172,12 +227,6 @@ static const char *spapr_drc_name(sPAPRDRConnector *drc)
     return g_strdup_printf("%s%d", drck->drc_name_prefix, drc->id);
 }
 
-/* has the guest been notified of device attachment? */
-static void set_signalled(sPAPRDRConnector *drc)
-{
-    drc->signalled = true;
-}
-
 /*
  * dr-entity-sense sensor value
  * returned via get-sensor-state RTAS calls
@@ -304,33 +353,12 @@ void spapr_drc_attach(sPAPRDRConnector *drc, DeviceState *d, void *fdt,
     }
     g_assert(fdt || coldplug);
 
-    /* NOTE: setting initial isolation state to UNISOLATED means we can't
-     * detach unless guest has a userspace/kernel that moves this state
-     * back to ISOLATED in response to an unplug event, or this is done
-     * manually by the admin prior. if we force things while the guest
-     * may be accessing the device, we can easily crash the guest, so we
-     * we defer completion of removal in such cases to the reset() hook.
-     */
-    if (spapr_drc_type(drc) == SPAPR_DR_CONNECTOR_TYPE_PCI) {
-        drc->isolation_state = SPAPR_DR_ISOLATION_STATE_UNISOLATED;
-    }
     drc->dr_indicator = SPAPR_DR_INDICATOR_ACTIVE;
 
     drc->dev = d;
     drc->fdt = fdt;
     drc->fdt_start_offset = fdt_start_offset;
     drc->configured = coldplug;
-    /* 'logical' DR resources such as memory/cpus are in some cases treated
-     * as a pool of resources from which the guest is free to choose from
-     * based on only a count. for resources that can be assigned in this
-     * fashion, we must assume the resource is signalled immediately
-     * since a single hotplug request might make an arbitrary number of
-     * such attached resources available to the guest, as opposed to
-     * 'physical' DR resources such as PCI where each device/resource is
-     * signalled individually.
-     */
-    drc->signalled = (spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PCI)
-                     ? true : coldplug;
 
     if (spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PCI) {
         drc->awaiting_allocation = true;
@@ -342,49 +370,8 @@ void spapr_drc_attach(sPAPRDRConnector *drc, DeviceState *d, void *fdt,
                              NULL, 0, NULL);
 }
 
-void spapr_drc_detach(sPAPRDRConnector *drc, DeviceState *d, Error **errp)
+static void spapr_drc_release(sPAPRDRConnector *drc)
 {
-    trace_spapr_drc_detach(spapr_drc_index(drc));
-
-    /* if we've signalled device presence to the guest, or if the guest
-     * has gone ahead and configured the device (via manually-executed
-     * device add via drmgr in guest, namely), we need to wait
-     * for the guest to quiesce the device before completing detach.
-     * Otherwise, we can assume the guest hasn't seen it and complete the
-     * detach immediately. Note that there is a small race window
-     * just before, or during, configuration, which is this context
-     * refers mainly to fetching the device tree via RTAS.
-     * During this window the device access will be arbitrated by
-     * associated DRC, which will simply fail the RTAS calls as invalid.
-     * This is recoverable within guest and current implementations of
-     * drmgr should be able to cope.
-     */
-    if (!drc->signalled && !drc->configured) {
-        /* if the guest hasn't seen the device we can't rely on it to
-         * set it back to an isolated state via RTAS, so do it here manually
-         */
-        drc->isolation_state = SPAPR_DR_ISOLATION_STATE_ISOLATED;
-    }
-
-    if (drc->isolation_state != SPAPR_DR_ISOLATION_STATE_ISOLATED) {
-        trace_spapr_drc_awaiting_isolated(spapr_drc_index(drc));
-        drc->awaiting_release = true;
-        return;
-    }
-
-    if (spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PCI &&
-        drc->allocation_state != SPAPR_DR_ALLOCATION_STATE_UNUSABLE) {
-        trace_spapr_drc_awaiting_unusable(spapr_drc_index(drc));
-        drc->awaiting_release = true;
-        return;
-    }
-
-    if (drc->awaiting_allocation) {
-        drc->awaiting_release = true;
-        trace_spapr_drc_awaiting_allocation(spapr_drc_index(drc));
-        return;
-    }
-
     drc->dr_indicator = SPAPR_DR_INDICATOR_INACTIVE;
 
     /* Calling release callbacks based on spapr_drc_type(drc). */
@@ -412,6 +399,32 @@ void spapr_drc_detach(sPAPRDRConnector *drc, DeviceState *d, Error **errp)
     drc->dev = NULL;
 }
 
+void spapr_drc_detach(sPAPRDRConnector *drc, DeviceState *d, Error **errp)
+{
+    trace_spapr_drc_detach(spapr_drc_index(drc));
+
+    if (drc->isolation_state != SPAPR_DR_ISOLATION_STATE_ISOLATED) {
+        trace_spapr_drc_awaiting_isolated(spapr_drc_index(drc));
+        drc->awaiting_release = true;
+        return;
+    }
+
+    if (spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PCI &&
+        drc->allocation_state != SPAPR_DR_ALLOCATION_STATE_UNUSABLE) {
+        trace_spapr_drc_awaiting_unusable(spapr_drc_index(drc));
+        drc->awaiting_release = true;
+        return;
+    }
+
+    if (drc->awaiting_allocation) {
+        drc->awaiting_release = true;
+        trace_spapr_drc_awaiting_allocation(spapr_drc_index(drc));
+        return;
+    }
+
+    spapr_drc_release(drc);
+}
+
 static bool release_pending(sPAPRDRConnector *drc)
 {
     return drc->awaiting_release;
@@ -420,7 +433,6 @@ static bool release_pending(sPAPRDRConnector *drc)
 static void reset(DeviceState *d)
 {
     sPAPRDRConnector *drc = SPAPR_DR_CONNECTOR(d);
-    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
 
     trace_spapr_drc_reset(spapr_drc_index(drc));
 
@@ -428,32 +440,26 @@ static void reset(DeviceState *d)
     drc->ccs = NULL;
 
     /* immediately upon reset we can safely assume DRCs whose devices
-     * are pending removal can be safely removed, and that they will
-     * subsequently be left in an ISOLATED state. move the DRC to this
-     * state in these cases (which will in turn complete any pending
-     * device removals)
+     * are pending removal can be safely removed.
      */
     if (drc->awaiting_release) {
-        drck->set_isolation_state(drc, SPAPR_DR_ISOLATION_STATE_ISOLATED);
-        /* generally this should also finalize the removal, but if the device
-         * hasn't yet been configured we normally defer removal under the
-         * assumption that this transition is taking place as part of device
-         * configuration. so check if we're still waiting after this, and
-         * force removal if we are
-         */
-        if (drc->awaiting_release) {
-            spapr_drc_detach(drc, DEVICE(drc->dev), NULL);
-        }
-
-        /* non-PCI devices may be awaiting a transition to UNUSABLE */
-        if (spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PCI &&
-            drc->awaiting_release) {
-            drck->set_allocation_state(drc, SPAPR_DR_ALLOCATION_STATE_UNUSABLE);
-        }
+        spapr_drc_release(drc);
     }
 
-    if (drck->dr_entity_sense(drc) == SPAPR_DR_ENTITY_SENSE_PRESENT) {
-        drck->set_signalled(drc);
+    drc->awaiting_allocation = false;
+
+    if (drc->dev) {
+        /* A device present at reset is coldplugged */
+        drc->isolation_state = SPAPR_DR_ISOLATION_STATE_UNISOLATED;
+        if (spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PCI) {
+            drc->allocation_state = SPAPR_DR_ALLOCATION_STATE_USABLE;
+        }
+    } else {
+        /* Otherwise device is absent, but might be hotplugged */
+        drc->isolation_state = SPAPR_DR_ISOLATION_STATE_ISOLATED;
+        if (spapr_drc_type(drc) != SPAPR_DR_CONNECTOR_TYPE_PCI) {
+            drc->allocation_state = SPAPR_DR_ALLOCATION_STATE_UNUSABLE;
+        }
     }
 }
 
@@ -479,7 +485,7 @@ static bool spapr_drc_needed(void *opaque)
     case SPAPR_DR_CONNECTOR_TYPE_LMB:
         rc = !((drc->isolation_state == SPAPR_DR_ISOLATION_STATE_UNISOLATED) &&
                (drc->allocation_state == SPAPR_DR_ALLOCATION_STATE_USABLE) &&
-               drc->configured && drc->signalled && !drc->awaiting_release);
+               drc->configured && !drc->awaiting_release);
         break;
     case SPAPR_DR_CONNECTOR_TYPE_PHB:
     case SPAPR_DR_CONNECTOR_TYPE_VIO:
@@ -501,7 +507,6 @@ static const VMStateDescription vmstate_spapr_drc = {
         VMSTATE_BOOL(configured, sPAPRDRConnector),
         VMSTATE_BOOL(awaiting_release, sPAPRDRConnector),
         VMSTATE_BOOL(awaiting_allocation, sPAPRDRConnector),
-        VMSTATE_BOOL(signalled, sPAPRDRConnector),
         VMSTATE_END_OF_LIST()
     }
 };
@@ -596,10 +601,7 @@ static void spapr_dr_connector_class_init(ObjectClass *k, void *data)
     dk->reset = reset;
     dk->realize = realize;
     dk->unrealize = unrealize;
-    drck->set_isolation_state = set_isolation_state;
-    drck->set_allocation_state = set_allocation_state;
     drck->release_pending = release_pending;
-    drck->set_signalled = set_signalled;
     /*
      * Reason: it crashes FIXME find and document the real reason
      */
@@ -611,6 +613,8 @@ static void spapr_drc_physical_class_init(ObjectClass *k, void *data)
     sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_CLASS(k);
 
     drck->dr_entity_sense = physical_entity_sense;
+    drck->isolate = drc_isolate_physical;
+    drck->unisolate = drc_unisolate_physical;
 }
 
 static void spapr_drc_logical_class_init(ObjectClass *k, void *data)
@@ -618,6 +622,8 @@ static void spapr_drc_logical_class_init(ObjectClass *k, void *data)
     sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_CLASS(k);
 
     drck->dr_entity_sense = logical_entity_sense;
+    drck->isolate = drc_isolate_logical;
+    drck->unisolate = drc_unisolate_logical;
 }
 
 static void spapr_drc_cpu_class_init(ObjectClass *k, void *data)
@@ -858,24 +864,45 @@ static uint32_t rtas_set_isolation_state(uint32_t idx, uint32_t state)
     sPAPRDRConnectorClass *drck;
 
     if (!drc) {
-        return RTAS_OUT_PARAM_ERROR;
+        return RTAS_OUT_NO_SUCH_INDICATOR;
     }
 
+    trace_spapr_drc_set_isolation_state(spapr_drc_index(drc), state);
+
     drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
-    return drck->set_isolation_state(drc, state);
+
+    switch (state) {
+    case SPAPR_DR_ISOLATION_STATE_ISOLATED:
+        return drck->isolate(drc);
+
+    case SPAPR_DR_ISOLATION_STATE_UNISOLATED:
+        return drck->unisolate(drc);
+
+    default:
+        return RTAS_OUT_PARAM_ERROR;
+    }
 }
 
 static uint32_t rtas_set_allocation_state(uint32_t idx, uint32_t state)
 {
     sPAPRDRConnector *drc = spapr_drc_by_index(idx);
-    sPAPRDRConnectorClass *drck;
 
-    if (!drc) {
-        return RTAS_OUT_PARAM_ERROR;
+    if (!drc || !object_dynamic_cast(OBJECT(drc), TYPE_SPAPR_DRC_LOGICAL)) {
+        return RTAS_OUT_NO_SUCH_INDICATOR;
     }
 
-    drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
-    return drck->set_allocation_state(drc, state);
+    trace_spapr_drc_set_allocation_state(spapr_drc_index(drc), state);
+
+    switch (state) {
+    case SPAPR_DR_ALLOCATION_STATE_USABLE:
+        return drc_set_usable(drc);
+
+    case SPAPR_DR_ALLOCATION_STATE_UNUSABLE:
+        return drc_set_unusable(drc);
+
+    default:
+        return RTAS_OUT_PARAM_ERROR;
+    }
 }
 
 static uint32_t rtas_set_dr_indicator(uint32_t idx, uint32_t state)
diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c
index 171aedc7e0..587a3dacb2 100644
--- a/hw/ppc/spapr_events.c
+++ b/hw/ppc/spapr_events.c
@@ -475,13 +475,6 @@ static void spapr_powerdown_req(Notifier *n, void *opaque)
                                                        RTAS_LOG_TYPE_EPOW)));
 }
 
-static void spapr_hotplug_set_signalled(uint32_t drc_index)
-{
-    sPAPRDRConnector *drc = spapr_drc_by_index(drc_index);
-    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
-    drck->set_signalled(drc);
-}
-
 static void spapr_hotplug_req_event(uint8_t hp_id, uint8_t hp_action,
                                     sPAPRDRConnectorType drc_type,
                                     union drc_identifier *drc_id)
@@ -528,9 +521,6 @@ static void spapr_hotplug_req_event(uint8_t hp_id, uint8_t hp_action,
     switch (drc_type) {
     case SPAPR_DR_CONNECTOR_TYPE_PCI:
         hp->hotplug_type = RTAS_LOG_V6_HP_TYPE_PCI;
-        if (hp->hotplug_action == RTAS_LOG_V6_HP_ACTION_ADD) {
-            spapr_hotplug_set_signalled(drc_id->index);
-        }
         break;
     case SPAPR_DR_CONNECTOR_TYPE_LMB:
         hp->hotplug_type = RTAS_LOG_V6_HP_TYPE_MEMORY;
diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
index aa1ffea9e5..8624ce8d5b 100644
--- a/hw/ppc/spapr_hcall.c
+++ b/hw/ppc/spapr_hcall.c
@@ -1045,11 +1045,11 @@ static target_ulong h_signal_sys_reset(PowerPCCPU *cpu,
     }
 }
 
-static uint32_t cas_check_pvr(PowerPCCPU *cpu, target_ulong *addr,
-                              Error **errp)
+static uint32_t cas_check_pvr(sPAPRMachineState *spapr, PowerPCCPU *cpu,
+                              target_ulong *addr, Error **errp)
 {
     bool explicit_match = false; /* Matched the CPU's real PVR */
-    uint32_t max_compat = cpu->max_compat;
+    uint32_t max_compat = spapr->max_compat_pvr;
     uint32_t best_compat = 0;
     int i;
 
@@ -1105,7 +1105,7 @@ static target_ulong h_client_architecture_support(PowerPCCPU *cpu,
     bool guest_radix;
     Error *local_err = NULL;
 
-    cas_pvr = cas_check_pvr(cpu, &addr, &local_err);
+    cas_pvr = cas_check_pvr(spapr, cpu, &addr, &local_err);
     if (local_err) {
         error_report_err(local_err);
         return H_HARDWARE;
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index f973b02845..a66bbac352 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -53,6 +53,7 @@ struct sPAPRMachineClass {
     bool dr_lmb_enabled;       /* enable dynamic-reconfig/hotplug of LMBs */
     bool use_ohci_by_default;  /* use USB-OHCI instead of XHCI */
     const char *tcg_default_cpu; /* which (TCG) CPU to simulate by default */
+    bool pre_2_10_has_unused_icps;
     void (*phb_placement)(sPAPRMachineState *spapr, uint32_t index,
                           uint64_t *buid, hwaddr *pio, 
                           hwaddr *mmio32, hwaddr *mmio64,
@@ -86,16 +87,19 @@ struct sPAPRMachineState {
     uint64_t rtc_offset; /* Now used only during incoming migration */
     struct PPCTimebase tb;
     bool has_graphics;
-    sPAPROptionVector *ov5;         /* QEMU-supported option vectors */
-    sPAPROptionVector *ov5_cas;     /* negotiated (via CAS) option vectors */
-    bool cas_reboot;
-    bool cas_legacy_guest_workaround;
 
     Notifier epow_notifier;
     QTAILQ_HEAD(, sPAPREventLogEntry) pending_events;
     bool use_hotplug_event_source;
     sPAPREventSource *event_sources;
 
+    /* ibm,client-architecture-support option negotiation */
+    bool cas_reboot;
+    bool cas_legacy_guest_workaround;
+    sPAPROptionVector *ov5;         /* QEMU-supported option vectors */
+    sPAPROptionVector *ov5_cas;     /* negotiated (via CAS) option vectors */
+    uint32_t max_compat_pvr;
+
     /* Migration state */
     int htab_save_index;
     bool htab_first_pass;
@@ -635,6 +639,7 @@ void spapr_hotplug_req_add_by_count_indexed(sPAPRDRConnectorType drc_type,
                                             uint32_t count, uint32_t index);
 void spapr_hotplug_req_remove_by_count_indexed(sPAPRDRConnectorType drc_type,
                                                uint32_t count, uint32_t index);
+void spapr_cpu_parse_features(sPAPRMachineState *spapr);
 void *spapr_populate_hotplug_cpu_dt(CPUState *cs, int *fdt_offset,
                                     sPAPRMachineState *spapr);
 
diff --git a/include/hw/ppc/spapr_drc.h b/include/hw/ppc/spapr_drc.h
index bc9f98851e..d9cacb368f 100644
--- a/include/hw/ppc/spapr_drc.h
+++ b/include/hw/ppc/spapr_drc.h
@@ -199,7 +199,6 @@ typedef struct sPAPRDRConnector {
     sPAPRConfigureConnectorState *ccs;
 
     bool awaiting_release;
-    bool signalled;
     bool awaiting_allocation;
 
     /* device pointer, via link property */
@@ -216,16 +215,11 @@ typedef struct sPAPRDRConnectorClass {
     const char *drc_name_prefix; /* used other places in device tree */
 
     sPAPRDREntitySense (*dr_entity_sense)(sPAPRDRConnector *drc);
-
-    /* accessors for guest-visible (generally via RTAS) DR state */
-    uint32_t (*set_isolation_state)(sPAPRDRConnector *drc,
-                                    sPAPRDRIsolationState state);
-    uint32_t (*set_allocation_state)(sPAPRDRConnector *drc,
-                                     sPAPRDRAllocationState state);
+    uint32_t (*isolate)(sPAPRDRConnector *drc);
+    uint32_t (*unisolate)(sPAPRDRConnector *drc);
 
     /* QEMU interfaces for managing hotplug operations */
     bool (*release_pending)(sPAPRDRConnector *drc);
-    void (*set_signalled)(sPAPRDRConnector *drc);
 } sPAPRDRConnectorClass;
 
 uint32_t spapr_drc_index(sPAPRDRConnector *drc);
diff --git a/qapi/string-input-visitor.c b/qapi/string-input-visitor.c
index c089491c24..63ae115b2a 100644
--- a/qapi/string-input-visitor.c
+++ b/qapi/string-input-visitor.c
@@ -326,6 +326,16 @@ static void parse_type_number(Visitor *v, const char *name, double *obj,
     *obj = val;
 }
 
+static void parse_type_null(Visitor *v, const char *name, Error **errp)
+{
+    StringInputVisitor *siv = to_siv(v);
+
+    if (!siv->string || siv->string[0]) {
+        error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
+                   "null");
+    }
+}
+
 static void string_input_free(Visitor *v)
 {
     StringInputVisitor *siv = to_siv(v);
@@ -349,6 +359,7 @@ Visitor *string_input_visitor_new(const char *str)
     v->visitor.type_bool = parse_type_bool;
     v->visitor.type_str = parse_type_str;
     v->visitor.type_number = parse_type_number;
+    v->visitor.type_null = parse_type_null;
     v->visitor.start_list = start_list;
     v->visitor.next_list = next_list;
     v->visitor.check_list = check_list;
diff --git a/qapi/string-output-visitor.c b/qapi/string-output-visitor.c
index 53c2175d81..af649e1d6e 100644
--- a/qapi/string-output-visitor.c
+++ b/qapi/string-output-visitor.c
@@ -256,6 +256,19 @@ static void print_type_number(Visitor *v, const char *name, double *obj,
     string_output_set(sov, g_strdup_printf("%f", *obj));
 }
 
+static void print_type_null(Visitor *v, const char *name, Error **errp)
+{
+    StringOutputVisitor *sov = to_sov(v);
+    char *out;
+
+    if (sov->human) {
+        out = g_strdup("<null>");
+    } else {
+        out = g_strdup("");
+    }
+    string_output_set(sov, out);
+}
+
 static void
 start_list(Visitor *v, const char *name, GenericList **list, size_t size,
            Error **errp)
@@ -341,6 +354,7 @@ Visitor *string_output_visitor_new(bool human, char **result)
     v->visitor.type_bool = print_type_bool;
     v->visitor.type_str = print_type_str;
     v->visitor.type_number = print_type_number;
+    v->visitor.type_null = print_type_null;
     v->visitor.start_list = start_list;
     v->visitor.next_list = next_list;
     v->visitor.end_list = end_list;
diff --git a/target/ppc/compat.c b/target/ppc/compat.c
index e8ec1e19e7..f1b67faa97 100644
--- a/target/ppc/compat.c
+++ b/target/ppc/compat.c
@@ -24,9 +24,11 @@
 #include "sysemu/cpus.h"
 #include "qemu/error-report.h"
 #include "qapi/error.h"
+#include "qapi/visitor.h"
 #include "cpu-models.h"
 
 typedef struct {
+    const char *name;
     uint32_t pvr;
     uint64_t pcr;
     uint64_t pcr_level;
@@ -38,6 +40,7 @@ static const CompatInfo compat_table[] = {
      * Ordered from oldest to newest - the code relies on this
      */
     { /* POWER6, ISA2.05 */
+        .name = "power6",
         .pvr = CPU_POWERPC_LOGICAL_2_05,
         .pcr = PCR_COMPAT_3_00 | PCR_COMPAT_2_07 | PCR_COMPAT_2_06 |
                PCR_COMPAT_2_05 | PCR_TM_DIS | PCR_VSX_DIS,
@@ -45,24 +48,28 @@ static const CompatInfo compat_table[] = {
         .max_threads = 2,
     },
     { /* POWER7, ISA2.06 */
+        .name = "power7",
         .pvr = CPU_POWERPC_LOGICAL_2_06,
         .pcr = PCR_COMPAT_3_00 | PCR_COMPAT_2_07 | PCR_COMPAT_2_06 | PCR_TM_DIS,
         .pcr_level = PCR_COMPAT_2_06,
         .max_threads = 4,
     },
     {
+        .name = "power7+",
         .pvr = CPU_POWERPC_LOGICAL_2_06_PLUS,
         .pcr = PCR_COMPAT_3_00 | PCR_COMPAT_2_07 | PCR_COMPAT_2_06 | PCR_TM_DIS,
         .pcr_level = PCR_COMPAT_2_06,
         .max_threads = 4,
     },
     { /* POWER8, ISA2.07 */
+        .name = "power8",
         .pvr = CPU_POWERPC_LOGICAL_2_07,
         .pcr = PCR_COMPAT_3_00 | PCR_COMPAT_2_07,
         .pcr_level = PCR_COMPAT_2_07,
         .max_threads = 8,
     },
     { /* POWER9, ISA3.00 */
+        .name = "power9",
         .pvr = CPU_POWERPC_LOGICAL_3_00,
         .pcr = PCR_COMPAT_3_00,
         .pcr_level = PCR_COMPAT_3_00,
@@ -189,3 +196,98 @@ int ppc_compat_max_threads(PowerPCCPU *cpu)
 
     return n_threads;
 }
+
+static void ppc_compat_prop_get(Object *obj, Visitor *v, const char *name,
+                                void *opaque, Error **errp)
+{
+    uint32_t compat_pvr = *((uint32_t *)opaque);
+    const char *value;
+
+    if (!compat_pvr) {
+        value = "";
+    } else {
+        const CompatInfo *compat = compat_by_pvr(compat_pvr);
+
+        g_assert(compat);
+
+        value = compat->name;
+    }
+
+    visit_type_str(v, name, (char **)&value, errp);
+}
+
+static void ppc_compat_prop_set(Object *obj, Visitor *v, const char *name,
+                                void *opaque, Error **errp)
+{
+    Error *local_err = NULL;
+    char *value;
+    uint32_t compat_pvr;
+
+    visit_type_str(v, name, &value, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    if (strcmp(value, "") == 0) {
+        compat_pvr = 0;
+    } else {
+        int i;
+        const CompatInfo *compat = NULL;
+
+        for (i = 0; i < ARRAY_SIZE(compat_table); i++) {
+            if (strcmp(value, compat_table[i].name) == 0) {
+                compat = &compat_table[i];
+                break;
+
+            }
+        }
+
+        if (!compat) {
+            error_setg(errp, "Invalid compatibility mode \"%s\"", value);
+            goto out;
+        }
+        compat_pvr = compat->pvr;
+    }
+
+    *((uint32_t *)opaque) = compat_pvr;
+
+out:
+    g_free(value);
+}
+
+void ppc_compat_add_property(Object *obj, const char *name,
+                             uint32_t *compat_pvr, const char *basedesc,
+                             Error **errp)
+{
+    Error *local_err = NULL;
+    gchar *namesv[ARRAY_SIZE(compat_table) + 1];
+    gchar *names, *desc;
+    int i;
+
+    object_property_add(obj, name, "string",
+                        ppc_compat_prop_get, ppc_compat_prop_set, NULL,
+                        compat_pvr, &local_err);
+    if (local_err) {
+        goto out;
+    }
+
+    for (i = 0; i < ARRAY_SIZE(compat_table); i++) {
+        /*
+         * Have to discard const here, because g_strjoinv() takes
+         * (gchar **), not (const gchar **) :(
+         */
+        namesv[i] = (gchar *)compat_table[i].name;
+    }
+    namesv[ARRAY_SIZE(compat_table)] = NULL;
+
+    names = g_strjoinv(", ", namesv);
+    desc = g_strdup_printf("%s. Valid values are %s.", basedesc, names);
+    object_property_set_description(obj, name, desc, &local_err);
+
+    g_free(names);
+    g_free(desc);
+
+out:
+    error_propagate(errp, local_err);
+}
diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
index d10808d9f4..6ee2a26a96 100644
--- a/target/ppc/cpu.h
+++ b/target/ppc/cpu.h
@@ -1189,7 +1189,6 @@ typedef struct PPCVirtualHypervisorClass PPCVirtualHypervisorClass;
  * PowerPCCPU:
  * @env: #CPUPPCState
  * @cpu_dt_id: CPU index used in the device tree. KVM uses this index too
- * @max_compat: Maximal supported logical PVR from the command line
  * @compat_pvr: Current logical PVR, zero if in "raw" mode
  *
  * A PowerPC CPU.
@@ -1201,7 +1200,6 @@ struct PowerPCCPU {
 
     CPUPPCState env;
     int cpu_dt_id;
-    uint32_t max_compat;
     uint32_t compat_pvr;
     PPCVirtualHypervisor *vhyp;
     Object *intc;
@@ -1213,6 +1211,7 @@ struct PowerPCCPU {
     uint64_t mig_insns_flags;
     uint64_t mig_insns_flags2;
     uint32_t mig_nb_BATs;
+    bool pre_2_10_migration;
 };
 
 static inline PowerPCCPU *ppc_env_get_cpu(CPUPPCState *env)
@@ -1375,6 +1374,9 @@ void ppc_set_compat(PowerPCCPU *cpu, uint32_t compat_pvr, Error **errp);
 void ppc_set_compat_all(uint32_t compat_pvr, Error **errp);
 #endif
 int ppc_compat_max_threads(PowerPCCPU *cpu);
+void ppc_compat_add_property(Object *obj, const char *name,
+                             uint32_t *compat_pvr, const char *basedesc,
+                             Error **errp);
 #endif /* defined(TARGET_PPC64) */
 
 #include "exec/cpu-all.h"
diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
index 9cb2123187..3a9f0861e7 100644
--- a/target/ppc/excp_helper.c
+++ b/target/ppc/excp_helper.c
@@ -17,6 +17,7 @@
  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  */
 #include "qemu/osdep.h"
+#include "qemu/main-loop.h"
 #include "cpu.h"
 #include "exec/helper-proto.h"
 #include "exec/exec-all.h"
@@ -1132,6 +1133,7 @@ void helper_msgsnd(target_ulong rb)
         return;
     }
 
+    qemu_mutex_lock_iothread();
     CPU_FOREACH(cs) {
         PowerPCCPU *cpu = POWERPC_CPU(cs);
         CPUPPCState *cenv = &cpu->env;
@@ -1141,5 +1143,6 @@ void helper_msgsnd(target_ulong rb)
             cpu_interrupt(cs, CPU_INTERRUPT_HARD);
         }
     }
+    qemu_mutex_unlock_iothread();
 }
 #endif
diff --git a/target/ppc/machine.c b/target/ppc/machine.c
index 445f489bd0..f578156dd4 100644
--- a/target/ppc/machine.c
+++ b/target/ppc/machine.c
@@ -8,6 +8,7 @@
 #include "helper_regs.h"
 #include "mmu-hash64.h"
 #include "migration/cpu.h"
+#include "qapi/error.h"
 
 static int cpu_load_old(QEMUFile *f, void *opaque, int version_id)
 {
@@ -195,6 +196,27 @@ static void cpu_pre_save(void *opaque)
     }
 }
 
+/*
+ * Determine if a given PVR is a "close enough" match to the CPU
+ * object.  For TCG and KVM PR it would probably be sufficient to
+ * require an exact PVR match.  However for KVM HV the user is
+ * restricted to a PVR exactly matching the host CPU.  The correct way
+ * to handle this is to put the guest into an architected
+ * compatibility mode.  However, to allow a more forgiving transition
+ * and migration from before this was widely done, we allow migration
+ * between sufficiently similar PVRs, as determined by the CPU class's
+ * pvr_match() hook.
+ */
+static bool pvr_match(PowerPCCPU *cpu, uint32_t pvr)
+{
+    PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
+
+    if (pvr == pcc->pvr) {
+        return true;
+    }
+    return pcc->pvr_match(pcc, pvr);
+}
+
 static int cpu_post_load(void *opaque, int version_id)
 {
     PowerPCCPU *cpu = opaque;
@@ -203,10 +225,31 @@ static int cpu_post_load(void *opaque, int version_id)
     target_ulong msr;
 
     /*
-     * We always ignore the source PVR. The user or management
-     * software has to take care of running QEMU in a compatible mode.
+     * If we're operating in compat mode, we should be ok as long as
+     * the destination supports the same compatiblity mode.
+     *
+     * Otherwise, however, we require that the destination has exactly
+     * the same CPU model as the source.
      */
-    env->spr[SPR_PVR] = env->spr_cb[SPR_PVR].default_value;
+
+#if defined(TARGET_PPC64)
+    if (cpu->compat_pvr) {
+        Error *local_err = NULL;
+
+        ppc_set_compat(cpu, cpu->compat_pvr, &local_err);
+        if (local_err) {
+            error_report_err(local_err);
+            error_free(local_err);
+            return -1;
+        }
+    } else
+#endif
+    {
+        if (!pvr_match(cpu, env->spr[SPR_PVR])) {
+            return -1;
+        }
+    }
+
     env->lr = env->spr[SPR_LR];
     env->ctr = env->spr[SPR_CTR];
     cpu_write_xer(env, env->spr[SPR_XER]);
@@ -560,6 +603,25 @@ static const VMStateDescription vmstate_tlbmas = {
     }
 };
 
+static bool compat_needed(void *opaque)
+{
+    PowerPCCPU *cpu = opaque;
+
+    assert(!(cpu->compat_pvr && !cpu->vhyp));
+    return !cpu->pre_2_10_migration && cpu->compat_pvr != 0;
+}
+
+static const VMStateDescription vmstate_compat = {
+    .name = "cpu/compat",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = compat_needed,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32(compat_pvr, PowerPCCPU),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 const VMStateDescription vmstate_ppc_cpu = {
     .name = "cpu",
     .version_id = 5,
@@ -613,6 +675,7 @@ const VMStateDescription vmstate_ppc_cpu = {
         &vmstate_tlb6xx,
         &vmstate_tlbemb,
         &vmstate_tlbmas,
+        &vmstate_compat,
         NULL
     }
 };
diff --git a/target/ppc/mmu-radix64.c b/target/ppc/mmu-radix64.c
index de18c0b69e..69fde65276 100644
--- a/target/ppc/mmu-radix64.c
+++ b/target/ppc/mmu-radix64.c
@@ -255,5 +255,5 @@ int ppc_radix64_handle_mmu_fault(PowerPCCPU *cpu, vaddr eaddr, int rwx,
 
     tlb_set_page(cs, eaddr & TARGET_PAGE_MASK, raddr & TARGET_PAGE_MASK,
                  prot, mmu_idx, 1UL << page_size);
-    return 1;
+    return 0;
 }
diff --git a/target/ppc/translate_init.c b/target/ppc/translate_init.c
index 56a0ab22cf..783bf98217 100644
--- a/target/ppc/translate_init.c
+++ b/target/ppc/translate_init.c
@@ -33,6 +33,7 @@
 #include "hw/qdev-properties.h"
 #include "hw/ppc/ppc.h"
 #include "mmu-book3s-v3.h"
+#include "sysemu/qtest.h"
 
 //#define PPC_DUMP_CPU
 //#define PPC_DEBUG_SPR
@@ -8413,73 +8414,38 @@ POWERPC_FAMILY(POWER5P)(ObjectClass *oc, void *data)
     pcc->l1_icache_size = 0x10000;
 }
 
-static void powerpc_get_compat(Object *obj, Visitor *v, const char *name,
-                               void *opaque, Error **errp)
-{
-    char *value = (char *)"";
-    Property *prop = opaque;
-    uint32_t *max_compat = qdev_get_prop_ptr(DEVICE(obj), prop);
-
-    switch (*max_compat) {
-    case CPU_POWERPC_LOGICAL_2_05:
-        value = (char *)"power6";
-        break;
-    case CPU_POWERPC_LOGICAL_2_06:
-        value = (char *)"power7";
-        break;
-    case CPU_POWERPC_LOGICAL_2_07:
-        value = (char *)"power8";
-        break;
-    case 0:
-        break;
-    default:
-        error_report("Internal error: compat is set to %x", *max_compat);
-        abort();
-        break;
-    }
-
-    visit_type_str(v, name, &value, errp);
-}
-
-static void powerpc_set_compat(Object *obj, Visitor *v, const char *name,
-                               void *opaque, Error **errp)
+/*
+ * The CPU used to have a "compat" property which set the
+ * compatibility mode PVR.  However, this was conceptually broken - it
+ * only makes sense on the pseries machine type (otherwise the guest
+ * owns the PCR and can control the compatibility mode itself).  It's
+ * been replaced with the 'max-cpu-compat' property on the pseries
+ * machine type.  For backwards compatibility, pseries specially
+ * parses the -cpu parameter and converts old compat= parameters into
+ * the appropriate machine parameters.  This stub implementation of
+ * the parameter catches any uses on explicitly created CPUs.
+ */
+static void getset_compat_deprecated(Object *obj, Visitor *v, const char *name,
+                                     void *opaque, Error **errp)
 {
-    Error *error = NULL;
-    char *value = NULL;
-    Property *prop = opaque;
-    uint32_t *max_compat = qdev_get_prop_ptr(DEVICE(obj), prop);
-
-    visit_type_str(v, name, &value, &error);
-    if (error) {
-        error_propagate(errp, error);
-        return;
+    if (!qtest_enabled()) {
+        error_report("CPU 'compat' property is deprecated and has no effect; "
+                     "use max-cpu-compat machine property instead");
     }
-
-    if (strcmp(value, "power6") == 0) {
-        *max_compat = CPU_POWERPC_LOGICAL_2_05;
-    } else if (strcmp(value, "power7") == 0) {
-        *max_compat = CPU_POWERPC_LOGICAL_2_06;
-    } else if (strcmp(value, "power8") == 0) {
-        *max_compat = CPU_POWERPC_LOGICAL_2_07;
-    } else {
-        error_setg(errp, "Invalid compatibility mode \"%s\"", value);
-    }
-
-    g_free(value);
+    visit_type_null(v, name, NULL);
 }
 
-static PropertyInfo powerpc_compat_propinfo = {
+static PropertyInfo ppc_compat_deprecated_propinfo = {
     .name = "str",
-    .description = "compatibility mode, power6/power7/power8",
-    .get = powerpc_get_compat,
-    .set = powerpc_set_compat,
+    .description = "compatibility mode (deprecated)",
+    .get = getset_compat_deprecated,
+    .set = getset_compat_deprecated,
 };
-
-#define DEFINE_PROP_POWERPC_COMPAT(_n, _s, _f) \
-    DEFINE_PROP(_n, _s, _f, powerpc_compat_propinfo, uint32_t)
-
 static Property powerpc_servercpu_properties[] = {
-    DEFINE_PROP_POWERPC_COMPAT("compat", PowerPCCPU, max_compat),
+    {
+        .name = "compat",
+        .info = &ppc_compat_deprecated_propinfo,
+    },
     DEFINE_PROP_END_OF_LIST(),
 };
 
@@ -9859,14 +9825,14 @@ static void ppc_cpu_realizefn(DeviceState *dev, Error **errp)
         error_append_hint(errp, "Adjust the number of cpus to %d "
                           "or try to raise the number of threads per core\n",
                           cpu->cpu_dt_id * smp_threads / max_smt);
-        return;
+        goto unrealize;
     }
 #endif
 
     if (tcg_enabled()) {
         if (ppc_fixup_cpu(cpu) != 0) {
             error_setg(errp, "Unable to emulate selected CPU with TCG");
-            return;
+            goto unrealize;
         }
     }
 
@@ -9875,14 +9841,14 @@ static void ppc_cpu_realizefn(DeviceState *dev, Error **errp)
         error_setg(errp, "CPU does not possess a BookE or 4xx MMU. "
                    "Please use qemu-system-ppc or qemu-system-ppc64 instead "
                    "or choose another CPU model.");
-        return;
+        goto unrealize;
     }
 #endif
 
     create_ppc_opcodes(cpu, &local_err);
     if (local_err != NULL) {
         error_propagate(errp, local_err);
-        return;
+        goto unrealize;
     }
     init_ppc_proc(cpu);
 
@@ -10067,6 +10033,10 @@ static void ppc_cpu_realizefn(DeviceState *dev, Error **errp)
         fflush(stdout);
     }
 #endif
+    return;
+
+unrealize:
+    cpu_exec_unrealizefn(cs);
 }
 
 static void ppc_cpu_unrealizefn(DeviceState *dev, Error **errp)
@@ -10640,6 +10610,8 @@ static gchar *ppc_gdb_arch_name(CPUState *cs)
 
 static Property ppc_cpu_properties[] = {
     DEFINE_PROP_BOOL("pre-2.8-migration", PowerPCCPU, pre_2_8_migration, false),
+    DEFINE_PROP_BOOL("pre-2.10-migration", PowerPCCPU, pre_2_10_migration,
+                     false),
     DEFINE_PROP_END_OF_LIST(),
 };