[PATCH RFC 21/22] arm/cpuhp: Changes required for reset and to support next boot

[Salil Mehta]

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: Keqian Zhu <zhukeqi...@huawei.com>
Signed-off-by: Salil Mehta <salil.me...@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, 18 insertions(+), 5 deletions(-)

diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index fef4072db1..05f329c1e1 100644
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -675,7 +675,7 @@ 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 db7eca1b84..55101c0050 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -47,6 +47,7 @@
 #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/kvm.h"
@@ -1149,14 +1150,13 @@ static bool virt_firmware_init(VirtMachineState *vms,
 
 static FWCfgState *create_fw_cfg(const VirtMachineState *vms, AddressSpace *as)
 {
-    MachineState *ms = MACHINE(vms);
     hwaddr base = vms->memmap[VIRT_FW_CFG].base;
     hwaddr size = vms->memmap[VIRT_FW_CFG].size;
     FWCfgState *fw_cfg;
     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(vms->fdt, nodename);
@@ -2468,7 +2468,13 @@ static void virt_cpu_plug(HotplugHandler *hotplug_dev, 
DeviceState *dev,
         hhc->plug(HOTPLUG_HANDLER(vms->acpi_dev), dev, &local_err);
         if (local_err)
             goto fail;
-        /* TODO: register this 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;
@@ -2540,7 +2546,11 @@ static void virt_cpu_unplug(HotplugHandler *hotplug_dev, 
DeviceState *dev,
     unwire_gic_cpu_irqs(vms, cs);
     virt_update_gic(vms, cs);
 
-    /* TODO: unregister this 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);
+    }
 
     qemu_opts_del(dev->opts);
     dev->opts = NULL;
diff --git a/include/hw/arm/boot.h b/include/hw/arm/boot.h
index ce2b48b88b..aa156967af 100644
--- a/include/hw/arm/boot.h
+++ b/include/hw/arm/boot.h
@@ -163,6 +163,8 @@ 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 c287433219..df785ea6ba 100644
--- a/include/hw/arm/virt.h
+++ b/include/hw/arm/virt.h
@@ -147,6 +147,7 @@ typedef struct {
     const int *irqmap;
     int smp_cpus;
     int max_cpus;
+    uint16_t boot_cpus;
     void *fdt;
     int fdt_size;
     uint32_t clock_phandle;
-- 
2.17.1