4 files changed, 66 insertions, 1 deletions

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 06e295cdf1..137f5c9a33 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -46,6 +46,7 @@
 #include "migration/qemu-file-types.h"
 #include "migration/global_state.h"
 #include "migration/register.h"
+#include "migration/blocker.h"
 #include "mmu-hash64.h"
 #include "mmu-book3s-v3.h"
 #include "cpu-models.h"
@@ -1683,6 +1684,8 @@ static void spapr_machine_reset(MachineState *machine)
 
     /* Signal all vCPUs waiting on this condition */
     qemu_cond_broadcast(&spapr->mc_delivery_cond);
+
+    migrate_del_blocker(spapr->fwnmi_migration_blocker);
 }
 
 static void spapr_create_nvram(SpaprMachineState *spapr)
@@ -1965,6 +1968,42 @@ static const VMStateDescription vmstate_spapr_dtb = {
     },
 };
 
+static bool spapr_fwnmi_needed(void *opaque)
+{
+    SpaprMachineState *spapr = (SpaprMachineState *)opaque;
+
+    return spapr->guest_machine_check_addr != -1;
+}
+
+static int spapr_fwnmi_pre_save(void *opaque)
+{
+    SpaprMachineState *spapr = (SpaprMachineState *)opaque;
+
+    /*
+     * Check if machine check handling is in progress and print a
+     * warning message.
+     */
+    if (spapr->mc_status != -1) {
+        warn_report("A machine check is being handled during migration. The"
+                "handler may run and log hardware error on the destination");
+    }
+
+    return 0;
+}
+
+static const VMStateDescription vmstate_spapr_machine_check = {
+    .name = "spapr_machine_check",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = spapr_fwnmi_needed,
+    .pre_save = spapr_fwnmi_pre_save,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT64(guest_machine_check_addr, SpaprMachineState),
+        VMSTATE_INT32(mc_status, SpaprMachineState),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
 static const VMStateDescription vmstate_spapr = {
     .name = "spapr",
     .version_id = 3,
@@ -1999,6 +2038,7 @@ static const VMStateDescription vmstate_spapr = {
         &vmstate_spapr_cap_large_decr,
         &vmstate_spapr_cap_ccf_assist,
         &vmstate_spapr_cap_fwnmi,
+        &vmstate_spapr_machine_check,
         NULL
     }
 };
@@ -2814,6 +2854,13 @@ static void spapr_machine_init(MachineState *machine)
         spapr_create_lmb_dr_connectors(spapr);
     }
 
+    if (spapr_get_cap(spapr, SPAPR_CAP_FWNMI_MCE) == SPAPR_CAP_ON) {
+        /* Create the error string for live migration blocker */
+        error_setg(&spapr->fwnmi_migration_blocker,
+            "A machine check is being handled during migration. The handler"
+            "may run and log hardware error on the destination");
+    }
+
     /* Set up RTAS event infrastructure */
     spapr_events_init(spapr);
 
diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c
index 54eaf28a9e..884e455f02 100644
--- a/hw/ppc/spapr_events.c
+++ b/hw/ppc/spapr_events.c
@@ -43,6 +43,7 @@
 #include "qemu/main-loop.h"
 #include "hw/ppc/spapr_ovec.h"
 #include <libfdt.h>
+#include "migration/blocker.h"
 
 #define RTAS_LOG_VERSION_MASK                   0xff000000
 #define   RTAS_LOG_VERSION_6                    0x06000000
@@ -843,6 +844,8 @@ void spapr_mce_req_event(PowerPCCPU *cpu, bool recovered)
 {
     SpaprMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
     CPUState *cs = CPU(cpu);
+    int ret;
+    Error *local_err = NULL;
 
     if (spapr->guest_machine_check_addr == -1) {
         /*
@@ -872,8 +875,19 @@ void spapr_mce_req_event(PowerPCCPU *cpu, bool recovered)
             return;
         }
     }
-    spapr->mc_status = cpu->vcpu_id;
 
+    ret = migrate_add_blocker(spapr->fwnmi_migration_blocker, &local_err);
+    if (ret == -EBUSY) {
+        /*
+         * We don't want to abort so we let the migration to continue.
+         * In a rare case, the machine check handler will run on the target.
+         * Though this is not preferable, it is better than aborting
+         * the migration or killing the VM.
+         */
+        warn_report("Received a fwnmi while migration was in progress");
+    }
+
+    spapr->mc_status = cpu->vcpu_id;
     spapr_mce_dispatch_elog(cpu, recovered);
 }
 
diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
index 35d91260e6..883fe28465 100644
--- a/hw/ppc/spapr_rtas.c
+++ b/hw/ppc/spapr_rtas.c
@@ -50,6 +50,7 @@
 #include "hw/ppc/fdt.h"
 #include "target/ppc/mmu-hash64.h"
 #include "target/ppc/mmu-book3s-v3.h"
+#include "migration/blocker.h"
 
 static void rtas_display_character(PowerPCCPU *cpu, SpaprMachineState *spapr,
                                    uint32_t token, uint32_t nargs,
@@ -452,6 +453,7 @@ static void rtas_ibm_nmi_interlock(PowerPCCPU *cpu,
     spapr->mc_status = -1;
     qemu_cond_signal(&spapr->mc_delivery_cond);
     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
+    migrate_del_blocker(spapr->fwnmi_migration_blocker);
 }
 
 static struct rtas_call {
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index f6f82d88aa..a1fba95c82 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -218,6 +218,8 @@ struct SpaprMachineState {
 
     unsigned gpu_numa_id;
     SpaprTpmProxy *tpm_proxy;
+
+    Error *fwnmi_migration_blocker;
 };
 
 #define H_SUCCESS         0