From 3e5f043c493fa4765c5637bec66be2bd620bc53f Mon Sep 17 00:00:00 2001
From: Salil Mehta <salil.mehta@huawei.com>
Date: Sat, 9 May 2020 18:10:24 +0100
Subject: [PATCH] hw/arm: Changes required for reset and to support next boot

Updates the firmware config with the next boot cpus information and also
registers the reset callback to be called when guest reboots to reset the cpu.

Co-developed-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Co-developed-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
---
 hw/arm/boot.c         |  2 +-
 hw/arm/virt.c         | 18 +++++++++++++++---
 include/hw/arm/boot.h |  2 ++
 include/hw/arm/virt.h |  1 +
 4 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index d1671e1d42..345c7cfa19 100644
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -683,7 +683,7 @@ fail:
     return -1;
 }
 
-static void do_cpu_reset(void *opaque)
+void do_cpu_reset(void *opaque)
 {
     ARMCPU *cpu = opaque;
     CPUState *cs = CPU(cpu);
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 60cd560ab9..eedff8e525 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -46,6 +46,8 @@
 #include "sysemu/device_tree.h"
 #include "sysemu/numa.h"
 #include "sysemu/runstate.h"
+#include "sysemu/reset.h"
+#include "sysemu/sysemu.h"
 #include "sysemu/tpm.h"
 #include "sysemu/tcg.h"
 #include "sysemu/kvm.h"
@@ -1453,7 +1455,7 @@ static FWCfgState *create_fw_cfg(const VirtMachineState *vms, AddressSpace *as)
     char *nodename;
 
     fw_cfg = fw_cfg_init_mem_wide(base + 8, base, 8, base + 16, as);
-    fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, (uint16_t)ms->smp.cpus);
+    fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, vms->boot_cpus);
 
     nodename = g_strdup_printf("/fw-cfg@%" PRIx64, base);
     qemu_fdt_add_subnode(ms->fdt, nodename);
@@ -3276,7 +3278,13 @@ static void virt_cpu_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
         if (local_err) {
             goto fail;
         }
-        /* TODO: register cpu for reset & update F/W info for the next boot */
+        /* register this cpu for reset & update F/W info for the next boot */
+        qemu_register_reset(do_cpu_reset, ARM_CPU(cs));
+    }
+
+    vms->boot_cpus++;
+    if (vms->fw_cfg) {
+        fw_cfg_modify_i16(vms->fw_cfg, FW_CFG_NB_CPUS, vms->boot_cpus);
     }
 
     cs->disabled = false;
@@ -3351,7 +3359,11 @@ static void virt_cpu_unplug(HotplugHandler *hotplug_dev, DeviceState *dev,
     unwire_gic_cpu_irqs(vms, cs);
     virt_update_gic(vms, cs);
 
-    /* TODO: unregister cpu for reset & update F/W info for the next boot */
+    qemu_unregister_reset(do_cpu_reset, ARM_CPU(cs));
+    vms->boot_cpus--;
+    if (vms->fw_cfg) {
+        fw_cfg_modify_i16(vms->fw_cfg, FW_CFG_NB_CPUS, vms->boot_cpus);
+    }
 
     qobject_unref(dev->opts);
     dev->opts = NULL;
diff --git a/include/hw/arm/boot.h b/include/hw/arm/boot.h
index 80c492d742..f81326a1dc 100644
--- a/include/hw/arm/boot.h
+++ b/include/hw/arm/boot.h
@@ -178,6 +178,8 @@ AddressSpace *arm_boot_address_space(ARMCPU *cpu,
 int arm_load_dtb(hwaddr addr, const struct arm_boot_info *binfo,
                  hwaddr addr_limit, AddressSpace *as, MachineState *ms);
 
+void do_cpu_reset(void *opaque);
+
 /* Write a secure board setup routine with a dummy handler for SMCs */
 void arm_write_secure_board_setup_dummy_smc(ARMCPU *cpu,
                                             const struct arm_boot_info *info,
diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
index 069c9f2a09..ae0f5beb26 100644
--- a/include/hw/arm/virt.h
+++ b/include/hw/arm/virt.h
@@ -167,6 +167,7 @@ struct VirtMachineState {
     MemMapEntry *memmap;
     char *pciehb_nodename;
     const int *irqmap;
+    uint16_t boot_cpus;
     int fdt_size;
     uint32_t clock_phandle;
     uint32_t gic_phandle;
-- 
2.27.0