spapr, xics, xive: Move SpaprIrq::reset hook logic into activate/deactivate

It turns out that all the logic in the SpaprIrq::reset hooks (and some in
the SpaprIrq::post_load hooks) isn't really related to resetting the irq
backend (that's handled by the backends' own reset routines).  Rather its
about getting the backend ready to be the active interrupt controller or
stopping being the active interrupt controller - reset (and post_load) is
just the only time that changes at present.

To make this flow clearer, move the logic into the explicit backend
activate and deactivate hooks.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>

hw/intc/spapr_xive.c

@@ -640,6 +640,42 @@ static void spapr_xive_dt(SpaprInterruptController *intc, uint32_t nr_servers,
                      plat_res_int_priorities, sizeof(plat_res_int_priorities)));
 }
 
+static int spapr_xive_activate(SpaprInterruptController *intc, Error **errp)
+{
+    SpaprXive *xive = SPAPR_XIVE(intc);
+    CPUState *cs;
+
+    CPU_FOREACH(cs) {
+        PowerPCCPU *cpu = POWERPC_CPU(cs);
+
+        /* (TCG) Set the OS CAM line of the thread interrupt context. */
+        spapr_xive_set_tctx_os_cam(spapr_cpu_state(cpu)->tctx);
+    }
+
+    if (kvm_enabled()) {
+        int rc = spapr_irq_init_kvm(kvmppc_xive_connect, intc, errp);
+        if (rc < 0) {
+            return rc;
+        }
+    }
+
+    /* Activate the XIVE MMIOs */
+    spapr_xive_mmio_set_enabled(xive, true);
+
+    return 0;
+}
+
+static void spapr_xive_deactivate(SpaprInterruptController *intc)
+{
+    SpaprXive *xive = SPAPR_XIVE(intc);
+
+    spapr_xive_mmio_set_enabled(xive, false);
+
+    if (kvm_irqchip_in_kernel()) {
+        kvmppc_xive_disconnect(intc);
+    }
+}
+
 static void spapr_xive_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -658,6 +694,8 @@ static void spapr_xive_class_init(ObjectClass *klass, void *data)
     xrc->write_nvt = spapr_xive_write_nvt;
     xrc->get_tctx = spapr_xive_get_tctx;
 
+    sicc->activate = spapr_xive_activate;
+    sicc->deactivate = spapr_xive_deactivate;
     sicc->cpu_intc_create = spapr_xive_cpu_intc_create;
     sicc->claim_irq = spapr_xive_claim_irq;
     sicc->free_irq = spapr_xive_free_irq;

hw/intc/xics_spapr.c

@@ -395,6 +395,21 @@ static void xics_spapr_print_info(SpaprInterruptController *intc, Monitor *mon)
     ics_pic_print_info(ics, mon);
 }
 
+static int xics_spapr_activate(SpaprInterruptController *intc, Error **errp)
+{
+    if (kvm_enabled()) {
+        return spapr_irq_init_kvm(xics_kvm_connect, intc, errp);
+    }
+    return 0;
+}
+
+static void xics_spapr_deactivate(SpaprInterruptController *intc)
+{
+    if (kvm_irqchip_in_kernel()) {
+        xics_kvm_disconnect(intc);
+    }
+}
+
 static void ics_spapr_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -403,6 +418,8 @@ static void ics_spapr_class_init(ObjectClass *klass, void *data)
 
     device_class_set_parent_realize(dc, ics_spapr_realize,
                                     &isc->parent_realize);
+    sicc->activate = xics_spapr_activate;
+    sicc->deactivate = xics_spapr_deactivate;
     sicc->cpu_intc_create = xics_spapr_cpu_intc_create;
     sicc->claim_irq = xics_spapr_claim_irq;
     sicc->free_irq = xics_spapr_free_irq;

hw/ppc/spapr_irq.c

@@ -65,9 +65,9 @@ void spapr_irq_msi_free(SpaprMachineState *spapr, int irq, uint32_t num)
     bitmap_clear(spapr->irq_map, irq - SPAPR_IRQ_MSI, num);
 }
 
-static int spapr_irq_init_kvm(int (*fn)(SpaprInterruptController *, Error **),
-                              SpaprInterruptController *intc,
-                              Error **errp)
+int spapr_irq_init_kvm(int (*fn)(SpaprInterruptController *, Error **),
+                       SpaprInterruptController *intc,
+                       Error **errp)
 {
     MachineState *machine = MACHINE(qdev_get_machine());
     Error *local_err = NULL;
@@ -112,11 +112,6 @@ static int spapr_irq_post_load_xics(SpaprMachineState *spapr, int version_id)
     return 0;
 }
 
-static void spapr_irq_reset_xics(SpaprMachineState *spapr, Error **errp)
-{
-    spapr_irq_init_kvm(xics_kvm_connect, SPAPR_INTC(spapr->ics), errp);
-}
-
 SpaprIrq spapr_irq_xics = {
     .nr_xirqs    = SPAPR_NR_XIRQS,
     .nr_msis     = SPAPR_NR_MSIS,
@@ -124,7 +119,6 @@ SpaprIrq spapr_irq_xics = {
     .xive        = false,
 
     .post_load   = spapr_irq_post_load_xics,
-    .reset       = spapr_irq_reset_xics,
 };
 
 /*
@@ -136,26 +130,6 @@ static int spapr_irq_post_load_xive(SpaprMachineState *spapr, int version_id)
     return spapr_xive_post_load(spapr->xive, version_id);
 }
 
-static void spapr_irq_reset_xive(SpaprMachineState *spapr, Error **errp)
-{
-    CPUState *cs;
-
-    CPU_FOREACH(cs) {
-        PowerPCCPU *cpu = POWERPC_CPU(cs);
-
-        /* (TCG) Set the OS CAM line of the thread interrupt context. */
-        spapr_xive_set_tctx_os_cam(spapr_cpu_state(cpu)->tctx);
-    }
-
-    if (spapr_irq_init_kvm(kvmppc_xive_connect,
-                           SPAPR_INTC(spapr->xive), errp) < 0) {
-        return;
-    }
-
-    /* Activate the XIVE MMIOs */
-    spapr_xive_mmio_set_enabled(spapr->xive, true);
-}
-
 SpaprIrq spapr_irq_xive = {
     .nr_xirqs    = SPAPR_NR_XIRQS,
     .nr_msis     = SPAPR_NR_MSIS,
@@ -163,7 +137,6 @@ SpaprIrq spapr_irq_xive = {
     .xive        = true,
 
     .post_load   = spapr_irq_post_load_xive,
-    .reset       = spapr_irq_reset_xive,
 };
 
 /*
@@ -187,37 +160,9 @@ static SpaprIrq *spapr_irq_current(SpaprMachineState *spapr)
 
 static int spapr_irq_post_load_dual(SpaprMachineState *spapr, int version_id)
 {
-    /*
-     * Force a reset of the XIVE backend after migration. The machine
-     * defaults to XICS at startup.
-     */
-    if (spapr_ovec_test(spapr->ov5_cas, OV5_XIVE_EXPLOIT)) {
-        if (kvm_irqchip_in_kernel()) {
-            xics_kvm_disconnect(SPAPR_INTC(spapr->ics));
-        }
-        spapr_irq_xive.reset(spapr, &error_fatal);
-    }
-
     return spapr_irq_current(spapr)->post_load(spapr, version_id);
 }
 
-static void spapr_irq_reset_dual(SpaprMachineState *spapr, Error **errp)
-{
-    /*
-     * Deactivate the XIVE MMIOs. The XIVE backend will reenable them
-     * if selected.
-     */
-    spapr_xive_mmio_set_enabled(spapr->xive, false);
-
-    /* Destroy all KVM devices */
-    if (kvm_irqchip_in_kernel()) {
-        xics_kvm_disconnect(SPAPR_INTC(spapr->ics));
-        kvmppc_xive_disconnect(SPAPR_INTC(spapr->xive));
-    }
-
-    spapr_irq_current(spapr)->reset(spapr, errp);
-}
-
 /*
  * Define values in sync with the XIVE and XICS backend
  */
@@ -228,7 +173,6 @@ SpaprIrq spapr_irq_dual = {
     .xive        = true,
 
     .post_load   = spapr_irq_post_load_dual,
-    .reset       = spapr_irq_reset_dual,
 };
 
 
@@ -512,10 +456,6 @@ void spapr_irq_reset(SpaprMachineState *spapr, Error **errp)
     assert(!spapr->irq_map || bitmap_empty(spapr->irq_map, spapr->irq_map_nr));
 
     spapr_irq_update_active_intc(spapr);
-
-    if (spapr->irq->reset) {
-        spapr->irq->reset(spapr, errp);
-    }
 }
 
 int spapr_irq_get_phandle(SpaprMachineState *spapr, void *fdt, Error **errp)
@@ -651,7 +591,6 @@ SpaprIrq spapr_irq_xics_legacy = {
     .xive        = false,
 
     .post_load   = spapr_irq_post_load_xics,
-    .reset       = spapr_irq_reset_xics,
 };
 
 static void spapr_irq_register_types(void)

include/hw/ppc/spapr_irq.h

@@ -84,7 +84,6 @@ typedef struct SpaprIrq {
     bool        xive;
 
     int (*post_load)(SpaprMachineState *spapr, int version_id);
-    void (*reset)(SpaprMachineState *spapr, Error **errp);
 } SpaprIrq;
 
 extern SpaprIrq spapr_irq_xics;
@@ -99,6 +98,9 @@ qemu_irq spapr_qirq(SpaprMachineState *spapr, int irq);
 int spapr_irq_post_load(SpaprMachineState *spapr, int version_id);
 void spapr_irq_reset(SpaprMachineState *spapr, Error **errp);
 int spapr_irq_get_phandle(SpaprMachineState *spapr, void *fdt, Error **errp);
+int spapr_irq_init_kvm(int (*fn)(SpaprInterruptController *, Error **),
+                       SpaprInterruptController *intc,
+                       Error **errp);
 
 /*
  * XICS legacy routines