From 8fa5af7de07d9bc2535ea8fab087d509795e3579 Mon Sep 17 00:00:00 2001
From: Salil Mehta <salil.mehta@huawei.com>
Date: Sun, 6 Aug 2023 22:12:52 +0000
Subject: [PATCH] physmem,gdbstub: Common helping funcs/changes to *unrealize*
 vCPU

Supporting vCPU Hotplug for ARM arch also means introducing new functionality of
unrealizing the ARMCPU. This requires some new common functions.

Defining them as part of architecture independent change so that this code could
be reused by other interested parties.

Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
---
 gdbstub/gdbstub.c         |  6 ++++++
 include/exec/cpu-common.h |  8 ++++++++
 include/exec/gdbstub.h    |  1 +
 include/hw/core/cpu.h     |  1 +
 system/physmem.c          | 25 +++++++++++++++++++++++++
 5 files changed, 41 insertions(+)

diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c
index 46d752bbc2..f16006d2a8 100644
--- a/gdbstub/gdbstub.c
+++ b/gdbstub/gdbstub.c
@@ -582,6 +582,12 @@ void gdb_register_coprocessor(CPUState *cpu,
     }
 }
 
+void gdb_unregister_coprocessor_all(CPUState *cpu)
+{
+    g_array_free(cpu->gdb_regs, true);
+    cpu->gdb_regs = NULL;
+}
+
 static void gdb_process_breakpoint_remove_all(GDBProcess *p)
 {
     CPUState *cpu = gdb_get_first_cpu_in_process(p);
diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
index 41115d8919..2a3d4aa1c8 100644
--- a/include/exec/cpu-common.h
+++ b/include/exec/cpu-common.h
@@ -139,6 +139,14 @@ size_t qemu_ram_pagesize_largest(void);
  */
 void cpu_address_space_init(CPUState *cpu, int asidx,
                             const char *prefix, MemoryRegion *mr);
+/**
+ * cpu_address_space_destroy:
+ * @cpu: CPU for which address space needs to be destroyed
+ * @asidx: integer index of this address space
+ *
+ * Note that with KVM only one address space is supported.
+ */
+void cpu_address_space_destroy(CPUState *cpu, int asidx);
 
 void cpu_physical_memory_rw(hwaddr addr, void *buf,
                             hwaddr len, bool is_write);
diff --git a/include/exec/gdbstub.h b/include/exec/gdbstub.h
index d8a3c56fa2..d123b838c2 100644
--- a/include/exec/gdbstub.h
+++ b/include/exec/gdbstub.h
@@ -39,6 +39,7 @@ typedef int (*gdb_set_reg_cb)(CPUArchState *env, uint8_t *buf, int reg);
 void gdb_register_coprocessor(CPUState *cpu,
                               gdb_get_reg_cb get_reg, gdb_set_reg_cb set_reg,
                               int num_regs, const char *xml, int g_pos);
+void gdb_unregister_coprocessor_all(CPUState *cpu);
 
 /**
  * gdbserver_start: start the gdb server
diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index 0ca778eb75..6dbe163548 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -496,6 +496,7 @@ struct CPUState {
     QSIMPLEQ_HEAD(, qemu_work_item) work_list;
 
     CPUAddressSpace *cpu_ases;
+    int cpu_ases_ref_count;
     int num_ases;
     AddressSpace *as;
     MemoryRegion *memory;
diff --git a/system/physmem.c b/system/physmem.c
index 247c252e53..299174ad91 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -761,6 +761,7 @@ void cpu_address_space_init(CPUState *cpu, int asidx,
 
     if (!cpu->cpu_ases) {
         cpu->cpu_ases = g_new0(CPUAddressSpace, cpu->num_ases);
+        cpu->cpu_ases_ref_count = cpu->num_ases;
     }
 
     newas = &cpu->cpu_ases[asidx];
@@ -774,6 +775,30 @@ void cpu_address_space_init(CPUState *cpu, int asidx,
     }
 }
 
+void cpu_address_space_destroy(CPUState *cpu, int asidx)
+{
+    CPUAddressSpace *cpuas;
+
+    assert(asidx < cpu->num_ases);
+    assert(asidx == 0 || !kvm_enabled());
+    assert(cpu->cpu_ases);
+
+    cpuas = &cpu->cpu_ases[asidx];
+    if (tcg_enabled()) {
+        memory_listener_unregister(&cpuas->tcg_as_listener);
+    }
+
+    address_space_destroy(cpuas->as);
+    g_free_rcu(cpuas->as, rcu);
+
+    if (cpu->cpu_ases_ref_count == 1) {
+        g_free(cpu->cpu_ases);
+        cpu->cpu_ases = NULL;
+    }
+
+    cpu->cpu_ases_ref_count--;
+}
+
 AddressSpace *cpu_get_address_space(CPUState *cpu, int asidx)
 {
     /* Return the AddressSpace corresponding to the specified index */
-- 
2.27.0